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Sample records for nano-size solid additives

  1. Nano-sized Li4Ti5O12 anode material with excellent performance prepared by solid state reaction: The effect of precursor size and morphology

    International Nuclear Information System (INIS)

    Li, Xiangru; Hu, Hao; Huang, Sheng; Yu, Gaige; Gao, Lin; Liu, Haowen; Yu, Ying

    2013-01-01

    Graphical abstract: - Highlights: • Nano-sized Li 4 Ti 5 O 12 has been prepared through solid state reaction by using axiolitic TiO 2 as precursor. • The prepared nano-sized Li 4 Ti 5 O 12 anode material shows excellent electrochemical performance. • The utilization of precursor with special morphology and size is one of the useful ways to prepare more active electrode materials. - Abstract: Spinel nano-sized Li 4 Ti 5 O 12 anode material of secondary lithium-ion battery has been successfully prepared by solid state reaction using axiolitic TiO 2 assembled by 10–20 nm nanoparticles and Li 2 CO 3 as precursors. The synthesis condition, grain size effect and corresponding electrochemical performance of the special Li 4 Ti 5 O 12 have been studied in comparison with those of the normal Li 4 Ti 5 O 12 originated from commercial TiO 2 . We also propose the mechanism that using the nano-scaled TiO 2 with special structure and unexcess Li 2 CO 3 as precursors can synthesize pure phase nano-sized Li 4 Ti 5 O 12 at 800 °C through solid state reaction. The prepared nano-sized Li 4 Ti 5 O 12 anode material for Li-ion batteries shows excellent capacity performance with rate capacity of 174.2, 164.0, 157.4, 146.4 and 129.6 mA h g −1 at 0.5, 1, 2, 5 and 10 C, respectively, and capacity retention of 95.1% after 100 cycles at 1 C. In addition, the specific capacity fade for the cell with the different Li 4 Ti 5 O 12 active materials resulted from the increase of internal resistance after 100 cycles is compared

  2. In vitro toxicity test of nano-sized magnesium oxide synthesized via solid-phase transformation

    Science.gov (United States)

    Zheng, Jun; Zhou, Wei

    2018-04-01

    Nano-sized magnesium oxide (MgO) has been a promising potential material for biomedical pharmaceuticals. In the present investigation, MgO nanoparticles synthesized through in-situ solid-phase transformation based on the previous work (nano-Mg(OH)2 prepared by precipitation technique) using magnesium nitrate and sodium hydroxide. The phase structure and morphology of the MgO nanoparticles are characterized by X-ray powder diffraction (XRD), selected area electronic diffraction (SAED) and transmission electron microscopy (TEM) respectively. In vitro hemolysis tests are adopted to evaluate the toxicity of the synthesized nano-MgO. The results evident that nano-MgO with lower concentration is slightly hemolytic, and with concentration increasing nano-MgO exhibit dose-responsive hemolysis.

  3. Grain Refinement and Mechanical Properties of Cu-Cr-Zr Alloys with Different Nano-Sized TiCp Addition.

    Science.gov (United States)

    Zhang, Dongdong; Bai, Fang; Wang, Yong; Wang, Jinguo; Wang, Wenquan

    2017-08-08

    The TiC p /Cu master alloy was prepared via thermal explosion reaction. Afterwards, the nano-sized TiC p /Cu master alloy was dispersed by electromagnetic stirring casting into the melting Cu-Cr-Zr alloys to fabricate the nano-sized TiC p -reinforced Cu-Cr-Zr composites. Results show that nano-sized TiC p can effectively refine the grain size of Cu-Cr-Zr alloys. The morphologies of grain in Cu-Cr-Zr composites changed from dendritic grain to equiaxed crystal because of the addition and dispersion of nano-sized TiC p . The grain size decreased from 82 to 28 μm with the nano-sized TiC p content. Compared with Cu-Cr-Zr alloys, the ultimate compressive strength (σ UCS ) and yield strength (σ 0.2 ) of 4 wt% TiC p -reinforced Cu-Cr-Zr composites increased by 6.7% and 9.4%, respectively. The wear resistance of the nano-sized TiCp-reinforced Cu-Cr-Zr composites increased with the increasing nano-sized TiCp content. The wear loss of the nano-sized TiC p -reinforced Cu-Cr-Zr composites decreased with the increasing TiC p content under abrasive particles. The eletrical conductivity of Cu-Cr-Zr alloys, 2% and 4% nano-sized TiCp-reinforced Cu-Cr-Zr composites are 64.71% IACS, 56.77% IACS and 52.93% IACS, respectively.

  4. Core-shell architectures as nano-size transporters

    International Nuclear Information System (INIS)

    Adeli, M.; Zarnegar, Z.; Kabiri, R.; Salimi, F.; Dadkah, A.

    2006-01-01

    Core-shell architectures containing poly (ethylene imine) (PEI) as a core and poly (lactide) (PLA) as arms were prepared. PEI was used as macro initiator for ring opening polymerization of lactide. PEI-PLA core-shell architectures were able to encapsulate guest molecules. Size of the core-shell architectures was between 10- 100 nm, hence they can be considered as nano carriers to transport the guest molecules. Transport capacity of nano carriers depends on their nano-environments and type of self-assembly in solvent. In solid state nano carriers self-assemble as long structures with nano-size diameter or they form network structures. Aggregations type depends on the concentration of nano carriers in solution. Effect of the shell thickness and aggregation type on the release rate are also investigated

  5. Cu–Co–O nano-catalysts as a burn rate modifier for composite solid propellants

    Directory of Open Access Journals (Sweden)

    D. Chaitanya Kumar Rao

    2016-08-01

    Full Text Available Nano-catalysts containing copper–cobalt oxides (Cu–Co–O have been synthesized by the citric acid (CA complexing method. Copper (II nitrate and Cobalt (II nitrate were employed in different molar ratios as the starting reactants to prepare three types of nano-catalysts. Well crystalline nano-catalysts were produced after a period of 3 hours by the calcination of CA–Cu–Co–O precursors at 550 °C. The phase morphologies and crystal composition of synthesized nano-catalysts were examined using Scanning Electron Microscope (SEM, Energy Dispersive Spectroscopy (EDS and Fourier Transform Infrared Spectroscopy (FTIR methods. The particle size of nano-catalysts was observed in the range of 90 nm–200 nm. The prepared nano-catalysts were used to formulate propellant samples of various compositions which showed high reactivity toward the combustion of HTPB/AP-based composite solid propellants. The catalytic effects on the decomposition of propellant samples were found to be significant at higher temperatures. The combustion characteristics of composite solid propellants were significantly improved by the incorporation of nano-catalysts. Out of the three catalysts studied in the present work, CuCo-I was found to be the better catalyst in regard to thermal decomposition and burning nature of composite solid propellants. The improved performance of composite solid propellant can be attributed to the high crystallinity, low agglomeration and lowering the decomposition temperature of oxidizer by the addition of CuCo-I nano-catalyst.

  6. Finite size melting of spherical solid-liquid aluminium interfaces

    DEFF Research Database (Denmark)

    Chang, J.; Johnson, Erik; Sakai, T.

    2009-01-01

    We have investigated the melting of nano-sized cone shaped aluminium needles coated with amorphous carbon using transmission electron microscopy. The interface between solid and liquid aluminium was found to have spherical topology. For needles with fixed apex angle, the depressed melting tempera...... to the conclusion that the depressed melting temperature is not controlled solely by the inverse radius 1/R. Instead, we found a direct relation between the depressed melting temperature and the ratio between the solid-liquid interface area and the molten volume.......We have investigated the melting of nano-sized cone shaped aluminium needles coated with amorphous carbon using transmission electron microscopy. The interface between solid and liquid aluminium was found to have spherical topology. For needles with fixed apex angle, the depressed melting...

  7. Characterization on the coatings of Ni-base alloy with nano- and micron-size Sm2O3 addition prepared by laser deposition

    International Nuclear Information System (INIS)

    Zhang Shihong; Li Mingxi; Yoon, Jae Hong; Cho, Tong Yul

    2008-01-01

    The coating materials are the powder mixture of micron-size Ni-base alloy powders with both 1.5 wt.% micron-size and nano-size Sm 2 O 3 powders, which are prepared on Q235 steel plate by 2.0 kW CO 2 laser deposition. The results indicate that with rare earth oxide Sm 2 O 3 addition, the width of planar crystallization is smaller than that of the Ni-base alloy coatings. Micron- and nano-Sm 2 O 3 /Ni-base alloy coatings have similar microstructure showing the primary phase of γ-Ni dendrite and eutectic containing γ-Ni and Cr 23 C 6 phases. However, compared to micron-Sm 2 O 3 /Ni-base alloy, preferred orientation of γ-Ni dendrite of nano-Sm 2 O 3 /Ni-base alloy is weakened. Planar crystal of several-μm thickness is first grown and then dendrite growth is observed at 1.5% micron-Sm 2 O 3 /Ni-base alloy coating whereas equiaxed dendrite is grown at 1.5% nano-Sm 2 O 3 /Ni-base alloy coating. Hardness and wear resistance of the coating improves with decreasing Sm 2 O 3 size from micron to nano. The improvement on tribological property of nano-Sm 2 O 3 /Ni-base alloy over micron-Sm 2 O 3 /Ni-base alloy coatings can be attributed to the better resistance of equiaxed dendrite to adhesion interactions during the wear process. In 6 M HNO 3 solution, the corrosion resistance is greatly improved with nano-Sm 2 O 3 addition since the decrease of corrosion ratio along grain-boundary in nano-Sm 2 O 3 /Ni-base alloy coating contributes to harmonization of corrosion potential

  8. Nano-sized crystalline drug production by milling technology.

    Science.gov (United States)

    Moribe, Kunikazu; Ueda, Keisuke; Limwikrant, Waree; Higashi, Kenjirou; Yamamoto, Keiji

    2013-01-01

    Nano-formulation of poorly water-soluble drugs has been developed to enhance drug dissolution. In this review, we introduce nano-milling technology described in recently published papers. Factors affecting the size of drug crystals are compared based on the preparation methods and drug and excipient types. A top-down approach using the comminution process is a method conventionally used to prepare crystalline drug nanoparticles. Wet milling using media is well studied and several wet-milled drug formulations are now on the market. Several trials on drug nanosuspension preparation using different apparatuses, materials, and conditions have been reported. Wet milling using a high-pressure homogenizer is another alternative to preparing production-scale drug nanosuspensions. Dry milling is a simple method of preparing a solid-state drug nano-formulation. The effect of size on the dissolution of a drug from nanoparticles is an area of fundamental research, but it is sometimes incorrectly evaluated. Here, we discuss evaluation procedures and the associated problems. Lastly, the importance of quality control, process optimization, and physicochemical characterization are briefly discussed.

  9. Nano-sized cosmetic formulations or solid nanoparticles in sunscreens: a risk to human health?

    Science.gov (United States)

    Nohynek, Gerhard J; Dufour, Eric K

    2012-07-01

    Personal care products (PCP) often contain micron- or nano-sized formulation components, such as nanoemulsions or microscopic vesicles. A large number of studies suggest that such vesicles do not penetrate human skin beyond the superficial layers of the stratum corneum. Nano-sized PCP formulations may enhance or reduce skin absorption of ingredients, albeit at a limited scale. Modern sunscreens contain insoluble titanium dioxide (TiO₂) or zinc oxide (ZnO) nanoparticles (NP), which are efficient filters of UV light. A large number of studies suggest that insoluble NP do not penetrate into or through human skin. A number of in vivo toxicity tests, including in vivo intravenous studies, showed that TiO₂ and ZnO NP are non-toxic and have an excellent skin tolerance. Cytotoxicity, genotoxicity, photo-genotoxicity, general toxicity and carcinogenicity studies on TiO₂ and ZnO NP found no difference in the safety profile of micro- or nano-sized materials, all of which were found to be non-toxic. Although some published in vitro studies on insoluble nano- or micron-sized particles suggested cell uptake, oxidative cell damage or genotoxicity, these data are consistent with those from micron-sized particles and should be interpreted with caution. Data on insoluble NP, such as surgical implant-derived wear debris particles or intravenously administered magnetic resonance contrast agents suggest that toxicity of small particles is generally related to their chemistry rather than their particle size. Overall, the weight of scientific evidence suggests that insoluble NP used in sunscreens pose no or negligible risk to human health, but offer large health benefits, such as the protection of human skin against UV-induced skin ageing and cancer.

  10. Effect of a nano-sized TiC particle addition on the flow-assisted corrosion resistance of SA 106B carbon steel

    Science.gov (United States)

    Park, Jin-Ju; Park, Eun-Kwang; Lee, Gyoung-Ja; Rhee, Chang-Kyu; Lee, Min-Ku

    2017-09-01

    Carbon steel with dispersed nano-sized TiC ceramic particles was fabricated by the ex-situ introduction of the particles into the melt, with the flow-assisted corrosion (FAC) resistance then investigated in the presence and absence of TiC nanoparticles using a once-through type of FAC loop test. From the potentiodynamic polarization curves, the current density at any given anodic potential was decreased and the open-circuit potential was increased by the addition of TiC nanoparticles. In addition, when the nano-sized TiC particles were added, the FAC rate was 1.38 times lower than that of carbon steel without TiC nanoparticles, indicating an improvement of the FAC resistance due to the homogeneous distribution of the TiC reinforcing nanoparticles.

  11. A simple route for renewable nano-sized arjunolic and asiatic acids and self-assembly of arjuna-bromolactone

    Directory of Open Access Journals (Sweden)

    2008-07-01

    Full Text Available While separating two natural nano-sized triterpenic acids via bromolactonization, we serendipitously discovered that arjuna-bromolactone is an excellent gelator of various organic solvents. A simple and efficient method for the separation of two triterpenic acids and the gelation ability and solid state 1D-helical self-assembly of nano-sized arjuna-bromolactone are reported.

  12. Characterization on the coatings of Ni-base alloy with nano- and micron-size Sm{sub 2}O{sub 3} addition prepared by laser deposition

    Energy Technology Data Exchange (ETDEWEB)

    Zhang Shihong [School of Materials Science and Engineering, Anhui University of Technology, Maanshan City, Anhui Province 243002 (China); School of Nano and Advanced Materials Engineering, Changwon National University, 9, Sarim-Dong, Changwon, Gyeongnam 641-773 (Korea, Republic of)], E-mail: zsh10110903@hotmail.com; Li Mingxi [School of Materials Science and Engineering, Anhui University of Technology, Maanshan City, Anhui Province 243002 (China); Yoon, Jae Hong; Cho, Tong Yul [School of Nano and Advanced Materials Engineering, Changwon National University, 9, Sarim-Dong, Changwon, Gyeongnam 641-773 (Korea, Republic of)

    2008-12-01

    The coating materials are the powder mixture of micron-size Ni-base alloy powders with both 1.5 wt.% micron-size and nano-size Sm{sub 2}O{sub 3} powders, which are prepared on Q235 steel plate by 2.0 kW CO{sub 2} laser deposition. The results indicate that with rare earth oxide Sm{sub 2}O{sub 3} addition, the width of planar crystallization is smaller than that of the Ni-base alloy coatings. Micron- and nano-Sm{sub 2}O{sub 3}/Ni-base alloy coatings have similar microstructure showing the primary phase of {gamma}-Ni dendrite and eutectic containing {gamma}-Ni and Cr{sub 23}C{sub 6} phases. However, compared to micron-Sm{sub 2}O{sub 3}/Ni-base alloy, preferred orientation of {gamma}-Ni dendrite of nano-Sm{sub 2}O{sub 3}/Ni-base alloy is weakened. Planar crystal of several-{mu}m thickness is first grown and then dendrite growth is observed at 1.5% micron-Sm{sub 2}O{sub 3}/Ni-base alloy coating whereas equiaxed dendrite is grown at 1.5% nano-Sm{sub 2}O{sub 3}/Ni-base alloy coating. Hardness and wear resistance of the coating improves with decreasing Sm{sub 2}O{sub 3} size from micron to nano. The improvement on tribological property of nano-Sm{sub 2}O{sub 3}/Ni-base alloy over micron-Sm{sub 2}O{sub 3}/Ni-base alloy coatings can be attributed to the better resistance of equiaxed dendrite to adhesion interactions during the wear process. In 6 M HNO{sub 3} solution, the corrosion resistance is greatly improved with nano-Sm{sub 2}O{sub 3} addition since the decrease of corrosion ratio along grain-boundary in nano-Sm{sub 2}O{sub 3}/Ni-base alloy coating contributes to harmonization of corrosion potential.

  13. Nano-sized copper tungstate thin films as positive electrodes for rechargeable Li batteries

    International Nuclear Information System (INIS)

    Li Chilin; Fu Zhengwen

    2008-01-01

    Nano-sized CuWO 4 thin films have been fabricated by radio-frequency (R.F.) sputtering deposition, and are used as positive electrode with both LiClO 4 liquid electrolyte and LiPON solid electrolyte in rechargeable lithium batteries. An initial discharge capacity of 192 and 210 mAh/g is obtainable for CuWO 4 film electrode with and without coated LiPON in liquid electrolyte, respectively. An all-solid-state cell with Li/LiPON/CuWO 4 layers shows a high-volume rate capacity of 145 μAh/cm 2 μm in first discharge, and overcomes the unfavorable electrochemical degradation observed in liquid electrolyte system. A two-step reactive mechanism is investigated by both transmission electron microscopy and selected area electron diffraction techniques. Apart from the extrusion and injection of Cu 2+ /Cu 0 , additional capacity can be achieved by the reversible reactivity of (WO 4 ) 2- framework. The chemical diffusion coefficients of Li intercalation/deintercalation are estimated by cyclic voltammetry. Nano-CuWO 4 thin film is expected to be a promising positive electrode material for high-performance rechargeable thin-film lithium batteries

  14. [Effect of stability and dissolution of realgar nano-particles using solid dispersion technology].

    Science.gov (United States)

    Guo, Teng; Shi, Feng; Yang, Gang; Feng, Nian-Ping

    2013-09-01

    To improve the stability and dissolution of realgar nano-particles by solid dispersion. Using polyethylene glycol 6000 and poloxamer-188 as carriers, the solid dispersions were prepare by melting method. XRD, microscopic inspection were used to determine the status of realgar nano-particles in solid dispersions. The content and stability test of As(2)0(3) were determined by DDC-Ag method. Hydride generation atomic absorption spectrometry was used to determine the content of Arsenic and investigated the in vitro dissolution behavior of solid dispersions. The results of XRD and microscopic inspection showed that realgar nano-particles in solid dispersions were amorphous. The dissolution amount and rate of Arsenic from realgar nano-particles of all solid dispersions were increased significantly, the reunion of realgar nano-particles and content of As(2)0(3) were reduced for the formation of solid dispersions. The solid dispersion of realgar nano-particles with poloxamer-188 as carriers could obviously improve stability, dissolution and solubility.

  15. Gradiently Polymerized Solid Electrolyte Meets with Micro/Nano-Structured Cathode Array.

    Science.gov (United States)

    Dong, Wei; Zeng, Xian-Xiang; Zhang, Xu-Dong; Li, Jin-Yi; Shi, Ji-Lei; Xiao, Yao; Shi, Yang; Wen, Rui; Yin, Ya-Xia; Wang, Tai-Shan; Wang, Chun-Ru; Guo, Yu-Guo

    2018-05-02

    The poor contact between the solid-state electrolyte and cathode materials leads to high interfacial resistance, severely limiting the rate capability of solid Li metal batteries. Herein, an integrative battery design is introduced with a gradiently polymerized solid electrolyte (GPSE), a micro-channel current collector array and nano-sized cathode particles. In-situ formed GPSE encapsulates cathode nanoparticles in the micro-channel with ductile inclusions to lower interfacial impedance, and the stiff surface layer of GPSE toward anode suppresses Li dendrites growth. Li metal batteries based on GPSE and Li-free hydrogenated V2O5 (V2O5-H) cathode exhibit an outstanding high-rate response of up to 5 C (the capacity ratio of 5 C / 1 C is 90.3%) and an ultralow capacity fade rate of 0.07% per cycle over 300 cycles. Other Li-containing cathodes as LiFePO4 and LiNi0.5Mn0.3Co0.2O2 can also operate effectively at 5 C and 2 C rate, respectively. Such an ingenious design may provide new insights into other solid metal batteries through interfacial engineering manipulation at micro and nano level.

  16. Leaching of nano-ZnO in municipal solid waste

    Energy Technology Data Exchange (ETDEWEB)

    Sakallioglu, T.; Bakirdoven, M.; Temizel, I. [Institute of Environmental Sciences, Bogazici University, 34342 Istanbul (Turkey); Demirel, B., E-mail: burak.demirel@boun.edu.tr [Institute of Environmental Sciences, Bogazici University, 34342 Istanbul (Turkey); Copty, N.K.; Onay, T.T.; Uyguner Demirel, C.S. [Institute of Environmental Sciences, Bogazici University, 34342 Istanbul (Turkey); Karanfil, T. [Environmental Engineering and Earth Science, Clemson University, Clemson, SC 29634 (United States)

    2016-11-05

    Highlights: • Leaching potential of 3 different types of nano-ZnO in real fresh MSW was investigated. • Batch tests were conducted at different pH, ionic strength and ZnO concentrations. • Most of the added nano-ZnO mass was retained within the solid waste matrix. • The pH and IS conditions did not significantly influence the leaching behavior of ZnO. • A kinetic particle deposition/detachment model was developed to analyze ZnO behavior. - Abstract: Despite widespread use of engineered nanomaterials (ENMs) in commercial products and their potential disposal in landfills, the fate of ENMs in solid waste environments are still not well understood. In this study, the leaching behavior of nano ZnO -one of the most used ENMs- in fresh municipal solid waste (MSW) was investigated. Batch reactors containing municipal solid waste samples were spiked with three different types of nano ZnO having different surface stabilization. The leaching of ZnO was examined under acidic, basic and elevated ionic strength (IS) conditions. The results of the 3-day batch tests showed that the percent of the added nano-ZnO mass retained within the solid waste matrix ranged between 80% and 93% on average for the three types of nano-ZnO tested. The pH and IS conditions did not significantly influence the leaching behavior of ZnO. To further analyze the behavior of ZnO in the MSW matrix, a kinetic particle deposition/detachment model was developed. The model was able to reproduce the main trends of the batch experiments. Reaction rate constants for the batch tests ranged from 0.01 to 0.4 1/hr, reflecting the rapid deposition of nano-ZnO within the MSW matrix.

  17. Study on preparation and properties of molybdenum alloys reinforced by nano-sized ZrO2 particles

    International Nuclear Information System (INIS)

    Cui, Chaopeng; Gao, Yimin; Zhou, Yucheng; Wei, Shizhong; Zhang, Guoshang; Zhu, Xiangwei; Guo, Songliang

    2016-01-01

    The nano-sized ZrO 2 -reinforced Mo alloy was prepared by a hydrothermal method and a subsequent powder metallurgy process. During the hydrothermal process, the nano-sized ZrO 2 particles were added into the Mo powder via the hydrothermal synthesis. The grain size of Mo powder decreases obviously with the addition of ZrO 2 particles, and the fine-grain sintered structure is obtained correspondingly due to hereditation. In addition to a few of nano-sized ZrO 2 particles in grain boundaries or sub-boundaries, most are dispersed in grains. The tensile strength and yield strength have been increased by 32.33 and 53.76 %. (orig.)

  18. Modifications in Glass Ionomer Cements: Nano-Sized Fillers and Bioactive Nanoceramics

    Directory of Open Access Journals (Sweden)

    Shariq Najeeb

    2016-07-01

    Full Text Available Glass ionomer cements (GICs are being used for a wide range of applications in dentistry. In order to overcome the poor mechanical properties of glass ionomers, several modifications have been introduced to the conventional GICs. Nanotechnology involves the use of systems, modifications or materials the size of which is in the range of 1–100 nm. Nano-modification of conventional GICs and resin modified GICs (RMGICs can be achieved by incorporation of nano-sized fillers to RMGICs, reducing the size of the glass particles, and introducing nano-sized bioceramics to the glass powder. Studies suggest that the commercially available nano-filled RMGIC does not hold any significant advantage over conventional RMGICs as far as the mechanical and bonding properties are concerned. Conversely, incorporation of nano-sized apatite crystals not only increases the mechanical properties of conventional GICs, but also can enhance fluoride release and bioactivity. By increasing the crystallinity of the set matrix, apatites can make the set cement chemically more stable, insoluble, and improve the bond strength with tooth structure. Increased fluoride release can also reduce and arrest secondary caries. However, due to a lack of long-term clinical studies, the use of nano-modified glass ionomers is still limited in daily clinical dentistry. In addition to the in vitro and in vivo studies, more randomized clinical trials are required to justify the use of these promising materials. The aim of this paper is to review the modification performed in GIC-based materials to improve their physicochemical properties.

  19. The Nano-Sized In2O3 Powder Synthesis by Sol-Gel Method

    Institute of Scientific and Technical Information of China (English)

    潘庆谊; 程知萱; 等

    2002-01-01

    Wiwh InCl3·4H2O being used as raw materials,the precursor of nano-sized In2O3 powder was prepared by hydrolysis,peptization and gelation of InCl3·4H2O.After calcination,nano-sized In2O3 powder was obtained.The powder was characterized by thermogravimetric and differential thermal analysis(TG-DTA).X-ray diffractometry(XRD)and transmission electron microscopy(TEM),respectively,Calculation revealed that the mean crystablline size increased with increasing the calcination temperature,but crystal lattice distortion rate decreased with the increasing in the average crystalline size.This indicated that the smaller the particle size,the bigger the crystal lattice distortion,the worse the crystal growing.The activation energies for growth of nano-sized In2O3 were calculated to be 4.75kJ·mol-1 at the calcination temperature up tp 500℃ and 66.40kJ· mol-1 at the calcination temperature over 600℃.TEM photos revealed that the addition of the chemical additive(OP-10)greatly influenced the morphology and size of In2O3 particles.

  20. Finite Size Effects in Chemical Bonding: From Small Clusters to Solids

    DEFF Research Database (Denmark)

    Kleis, Jesper; Greeley, Jeffrey Philip; Romero, N. A.

    2011-01-01

    We address the fundamental question of which size a metallic nano-particle needs to have before its surface chemical properties can be considered to be those of a solid, rather than those of a large molecule. Calculations of adsorption energies for carbon monoxide and oxygen on a series of gold...

  1. Characteristics of Sodium Polyacrylate/Nano-Sized Carbon Hydrogel for Biomedical Patch.

    Science.gov (United States)

    Park, Jong-Kyu; Seo, Sun-Kyo; Cho, Seungkwan; Kim, Han-Sung; Lee, Chi-Hwan

    2018-03-01

    Conductive hydrogels were prepared for biomedical patch in order to improve the electrical conductivity. Sodium polyacrylate and nano-sized carbon were mixed and fabricated by aqueous solution gelation process in various contents of nano-sized carbon with 0.1, 0.5, 1.0 and 2.0 wt%. Sodium polyacrylate/nano-sized carbon conductive hydrogels were investigated by molecular structure, surface morphology and electrical conductivity. The conductivity of the hydrogel/nano-sized carbon conductive hydrogel proved to be 10% higher than conductive hydrogel without nano-sized carbon. However, it was founded that conductive hydrogels with nano-sized carbon content from 0.5 up to 2.0 wt% were remarkably decreased. This may be due to the non-uniform distribution of nano-sized carbon, resulting from agglomerates of nano-sized carbon. The developed hydrogel is intended for use in the medical and cosmetic fields that is applicable to supply micro-current from device to human body.

  2. Effects of micro-sized and nano-sized WO_3 on mass attenauation coefficients of concrete by using MCNPX code

    International Nuclear Information System (INIS)

    Tekin, H.O.; Singh, V.P.; Manici, T.

    2017-01-01

    In the present work the effect of tungsten oxide (WO_3) nanoparticles on mass attenauation coefficients of concrete has been investigated by using MCNPX (version 2.4.0). The validation of generated MCNPX simulation geometry has been provided by comparing the results with standard XCOM data for mass attenuation coefficients of concrete. A very good agreement between XCOM and MCNPX have been obtained. The validated geometry has been used for definition of nano-WO_3 and micro-WO_3 into concrete sample. The mass attenuation coefficients of pure concrete and WO_3 added concrete with micro-sized and nano-sized have been compared. It was observed that shielding properties of concrete doped with WO_3 increased. The results of mass attenauation coefficients also showed that the concrete doped with nano-WO_3 significanlty improve shielding properties than micro-WO_3. It can be concluded that addition of nano-sized particles can be considered as another mechanism to reduce radiation dose. - Highlights: • It was found that size of the WO_3 affected the mass attenuation coefficients of concrete in all photon energies.

  3. Study on preparation and properties of molybdenum alloys reinforced by nano-sized ZrO{sub 2} particles

    Energy Technology Data Exchange (ETDEWEB)

    Cui, Chaopeng; Gao, Yimin; Zhou, Yucheng [Xi' an Jiaotong University, State Key Laboratory for Mechanical Behavior of Materials, Xi' an, Shaanxi Province (China); Wei, Shizhong [Henan University of Science and Technology, School of Materials Science and Engineering, Luoyang (China); Henan University of Science and Technology, Engineering Research Center of Tribology and Materials Protection, Ministry of Education, Luoyang (China); Zhang, Guoshang; Zhu, Xiangwei; Guo, Songliang [Henan University of Science and Technology, School of Materials Science and Engineering, Luoyang (China)

    2016-03-15

    The nano-sized ZrO{sub 2}-reinforced Mo alloy was prepared by a hydrothermal method and a subsequent powder metallurgy process. During the hydrothermal process, the nano-sized ZrO{sub 2} particles were added into the Mo powder via the hydrothermal synthesis. The grain size of Mo powder decreases obviously with the addition of ZrO{sub 2} particles, and the fine-grain sintered structure is obtained correspondingly due to hereditation. In addition to a few of nano-sized ZrO{sub 2} particles in grain boundaries or sub-boundaries, most are dispersed in grains. The tensile strength and yield strength have been increased by 32.33 and 53.76 %. (orig.)

  4. Effects of nano TiN addition on the microstructure and mechanical properties of TiC based steel bonded carbides

    Institute of Scientific and Technical Information of China (English)

    WANG Zhi'an; DAI Haiyang; ZOU Yu

    2008-01-01

    TiC based steel bonded carbides with the addition of nano TiN were prepared by vicuum sintering techniques.The microstructure was investigated using scanning electron microscopy(SEM)and transmission electron microscopy (TEM),and the mechanical properties,such as bending strength,impact toughness,hardness,and density,were measured.The results indicate that the grain size becomes small and there is uniformity in the steel bonded carbide with nano addition;several smaller carbide particles are also found to be inlaid in the rim of the larger carbide grains and prevent the coalescence of TiC grains.The smaller and larger carbide grains joint firmly,and then the reduction of the average size of the grains leads to the increase in the mechanical properties of the steel bonded carbides with nano addition.But the mechanical properties do not increase monotonously with an increase in nano addition.When the nano TiN addition accounts for 6-8 wt.% of the amount of steel bonded carbides.the mechanical properties reach the maximum values and then decrease with further increase in nano TiN addition.

  5. Thermal conductivity enhancement and sedimentation reduction of magnetorheological fluids with nano-sized Cu and Al additives

    Science.gov (United States)

    Rahim, M. S. A.; Ismail, I.; Choi, S. B.; Azmi, W. H.; Aqida, S. N.

    2017-11-01

    This work presents enhanced material characteristics of smart magnetorheological (MR) fluids by utilizing nano-sized metal particles. Especially, enhancement of thermal conductivity and reduction of sedimentation rate of MR fluids those are crucial properties for applications of MR fluids are focussed. In order to achieve this goal, a series of MR fluid samples are prepared using carbonyl iron particles (CIP) and hydraulic oil, and adding nano-sized particles of copper (Cu), aluminium (Al), and fumed silica (SiO2). Subsequently, the thermal conductivity is measured by the thermal property analyser and the sedimentation of MR fluids is measured using glass tubes without any excitation for a long time. The measured thermal conductivity is then compared with theoretical models such as Maxwell model at various CIP concentrations. In addition, in order to show the effectiveness of MR fluids synthesized in this work, the thermal conductivity of MRF-132DG which is commercially available is measured and compared with those of the prepared samples. It is observed that the thermal conductivity of the samples is much better than MRF-132DG showing the 148% increment with 40 vol% of the magnetic particles. It is also observed that the sedimentation rate of the prepared MR fluid samples is less than that of MRF-132DG showing 9% reduction with 40 vol% of the magnetic particles. The mixture optimized sample with high conductivity and low sedimentation was also obtained. The magnetization of the sample recorded an enhancement of 70.5% when compared to MRF-132DG. Furthermore, the shear yield stress of the sample were also increased with and without the influence of magnetic field.

  6. Minimum ignition energy of nano and micro Ti powder in the presence of inert nano TiO₂ powder.

    Science.gov (United States)

    Chunmiao, Yuan; Amyotte, Paul R; Hossain, Md Nur; Li, Chang

    2014-06-15

    The inerting effect of nano-sized TiO2 powder on ignition sensitivity of nano and micro Ti powders was investigated with a Mike 3 apparatus. "A little is not good enough" is also suitable for micro Ti powders mixed with nano-sized solid inertants. MIE of the mixtures did not significantly increase until the TiO2 percentage exceeded 50%. Nano-sized TiO2 powders were ineffective as an inertant when mixed with nano Ti powders, especially at higher dust loadings. Even with 90% nano TiO2 powder, mixtures still showed high ignition sensitivity because the statistic energy was as low as 2.1 mJ. Layer fires induced by ignited but unburned metal particles may occur for micro Ti powders mixed with nano TiO2 powders following a low level dust explosion. Such layer fires could lead to a violent dust explosion after a second dispersion. Thus, additional attention is needed to prevent metallic layer fires even where electric spark potential is low. In the case of nano Ti powder, no layer fires were observed because of less flammable material involved in the mixtures investigated, and faster flame propagation in nanoparticle clouds. Copyright © 2014 Elsevier B.V. All rights reserved.

  7. Effect of organo clay addition on thermal properties of poly lactide/ polycaprolactone (PLA/ PCL) nano composites

    International Nuclear Information System (INIS)

    Siti Zulaiha Hairaldin; Wan Md Zin Wan Yunus; Norazoma Ibrahim

    2010-01-01

    In this study, melt blending technique was applied to prepare poly lactide/polycaprolactone (PLA/ PCL) nano composites with various blends. Montmorillonite (MMT) was used as an addition to the matrix. In this study, melt blending technique was applied to prepare poly lactide/polycaprolactone (PLA/ PCL) nano composites. Montmorillonite (MMT) was used as an addition to the matrix with various percentages. The other one is modified clay prepared by modifying the nature of montmorillonite with octadecylamine (ODA) to improve the characteristic of PLA/ PCL blends. X-ray diffraction (XRD) results indicated intercalation of the PLA/ PCL into silicate nano size interlayers galleries of the nano composites. The presence of modified clays in nano composite was confirmed by FTIR spectrum. TGA and DTG results show addition of MMT and modified clay ODA-MMT improved the thermal stability of the PLA/ PCL blends. (author)

  8. [Response surface method optimize of nano-silica solid dispersion technology assistant enzymatic hydrolysis preparation genistein].

    Science.gov (United States)

    Jin, Xin; Zhang, Zhen-Hai; Zhu, Jing; Sun, E; Yu, Dan-Hong; Chen, Xiao-Yun; Liu, Qi-Yuan; Ning, Qing; Jia, Xiao-Bin

    2012-04-01

    This article reports that nano-silica solid dispersion technology was used to raise genistein efficiency through increasing the enzymatic hydrolysis rate. Firstly, genistin-nano-silica solid dispersion was prepared by solvent method. And differential scanning calorimetry (DSC) and transmission electron microscopy (TEM) were used to verify the formation of solid dispersion, then enzymatic hydrolysis of solid dispersion was done by snailase to get genistein. With the conversion of genistein as criteria, single factor experiments were used to study the different factors affecting enzymatic hydrolysis of genistin and its solid dispersion. And then, response surface method was used to optimize of nano-silica solid dispersion technology assistant enzymatic hydrolysis. The optimum condition to get genistein through enzymatic hydrolysis of genistin-nano-silica solid dispersion was pH 7.1, temperature 52.2 degrees C, enzyme concentration 5.0 mg x mL(-1) and reaction time 7 h. Under this condition, the conversion of genistein was (93.47 +/- 2.40)%. Comparing with that without forming the genistin-nano-silica solid dispersion, the conversion increased 2.62 fold. At the same time, the product of hydrolysis was purified to get pure genistein. The method of enzymatic hydrolysis of genistin-nano-silica solid dispersion by snailase to obtain genistein is simple, efficiency and suitable for the modern scale production.

  9. Formulation and Testing of Paraffin-Based Solid Fuels Containing Energetic Additives for Hybrid Rockets

    Science.gov (United States)

    Larson, Daniel B.; Boyer, Eric; Wachs,Trevor; Kuo, Kenneth K.; Story, George

    2012-01-01

    Many approaches have been considered in an effort to improve the regression rate of solid fuels for hybrid rocket applications. One promising method is to use a fuel with a fast burning rate such as paraffin wax; however, additional performance increases to the fuel regression rate are necessary to make the fuel a viable candidate to replace current launch propulsion systems. The addition of energetic and/or nano-sized particles is one way to increase mass-burning rates of the solid fuels and increase the overall performance of the hybrid rocket motor.1,2 Several paraffin-based fuel grains with various energetic additives (e.g., lithium aluminum hydride (LiAlH4) have been cast in an attempt to improve regression rates. There are two major advantages to introducing LiAlH4 additive into the solid fuel matrix: 1) the increased characteristic velocity, 2) decreased dependency of Isp on oxidizer-to-fuel ratio. The testing and characterization of these solid-fuel grains have shown that continued work is necessary to eliminate unburned/unreacted fuel in downstream sections of the test apparatus.3 Changes to the fuel matrix include higher melting point wax and smaller energetic additive particles. The reduction in particle size through various methods can result in more homogeneous grain structure. The higher melting point wax can serve to reduce the melt-layer thickness, allowing the LiAlH4 particles to react closer to the burning surface, thus increasing the heat feedback rate and fuel regression rate. In addition to the formulation of LiAlH4 and paraffin wax solid-fuel grains, liquid additives of triethylaluminum and diisobutylaluminum hydride will be included in this study. Another promising fuel formulation consideration is to incorporate a small percentage of RDX as an additive to paraffin. A novel casting technique will be used by dissolving RDX in a solvent to crystallize the energetic additive. After dissolving the RDX in a solvent chosen for its compatibility

  10. Size effect of primary Y{sub 2}O{sub 3} additions on the characteristics of the nanostructured ferritic ODS alloys: Comparing as-milled and as-milled/annealed alloys using S/TEM

    Energy Technology Data Exchange (ETDEWEB)

    Saber, Mostafa, E-mail: msaber@ncsu.edu; Xu, Weizong; Li, Lulu; Zhu, Yuntian; Koch, Carl C.; Scattergood, Ronald O.

    2014-09-15

    The need for providing S/TEM evidence to clarify the mechanisms of nano-scale precipitate formation was the motivation of this investigation. In this study, an Fe–14Cr–0.4Ti alloy was ball-milled with different amounts of Y{sub 2}O{sub 3} content up to 10 wt.%, and then annealed at temperatures up to 1100 °C. Micron-size Y{sub 2}O{sub 3} particles were substituted for the nano-size counterpart to elucidate the mechanism of oxide precipitate formation. The S/TEM studies revealed that the microstructure of the alloy with 10 wt.% yttria contained amorphous undissolved Y{sub 2}O{sub 3} after ball milling, while a small part of the initial oxide particles were dissolved into the solid solution. Consequently, when the amount of yttria was reduced to 1 wt.%, the amorphous phase of the yttria vanished and the whole content of Y{sub 2}O{sub 3} was dissolved into the BCC solid solution. Defect analysis of precipitates on the annealed samples via S/TEM and micro-hardness studies revealed that the use of micron-size primary oxide particles can produce nano-size precipitates, stable up to temperatures as high as 1100 °C, and uniformly distributed throughout the microstructure. This study indicates that the use of high energy ball milling along with micron-size primary oxide particles can lead to nanostructured ferritic ODS alloys without the use of nano-size primary oxide additions.

  11. Building solids inside nano-space: from confined amorphous through confined solvate to confined 'metastable' polymorph.

    Science.gov (United States)

    Nartowski, K P; Tedder, J; Braun, D E; Fábián, L; Khimyak, Y Z

    2015-10-14

    The nanocrystallisation of complex molecules inside mesoporous hosts and control over the resulting structure is a significant challenge. To date the largest organic molecule crystallised inside the nano-pores is a known pharmaceutical intermediate - ROY (259.3 g mol(-1)). In this work we demonstrate smart manipulation of the phase of a larger confined pharmaceutical - indomethacin (IMC, 357.8 g mol(-1)), a substance with known conformational flexibility and complex polymorphic behaviour. We show the detailed structural analysis and the control of solid state transformations of encapsulated molecules inside the pores of mesoscopic cellular foam (MCF, pore size ca. 29 nm) and controlled pore glass (CPG, pore size ca. 55 nm). Starting from confined amorphous IMC we drive crystallisation into a confined methanol solvate, which upon vacuum drying leads to the stabilised rare form V of IMC inside the MCF host. In contrast to the pure form, encapsulated form V does not transform into a more stable polymorph upon heating. The size of the constraining pores and the drug concentration within the pores determine whether the amorphous state of the drug is stabilised or it recrystallises into confined nanocrystals. The work presents, in a critical manner, an application of complementary techniques (DSC, PXRD, solid-state NMR, N2 adsorption) to confirm unambiguously the phase transitions under confinement and offers a comprehensive strategy towards the formation and control of nano-crystalline encapsulated organic solids.

  12. Vapor-solid-solid growth mechanism driven by an epitaxial match between solid Au Zn alloy catalyst particle and Zn O nano wire at low temperature

    International Nuclear Information System (INIS)

    Campos, Leonardo C.; Tonezzer, Matteo; Ferlauto, Andre S.; Magalhaes-Paniago, Rogerio; Oliveira, Sergio; Ladeira, Luiz O.; Lacerda, Rodrigo G.

    2008-01-01

    Nowadays, the growth of nano materials, like nano wires and nano tubes, is one of the key research areas of nano technology. However, a full picture of the growth mechanism of these quasi-one dimensional systems still needs to be achieved if these materials are to be applied electronics, biology and medicinal fields. Nevertheless, in spite of considerable advances on the growth of numerous nano wires, a clear understanding of the growth mechanism is still controversial and highly discussed. The present work provides a comprehensive picture of the precise mechanism of Zn O vapor-solid-solid (VSS) nano wire growth at low temperatures and gives the fundamental reasons responsible. We demonstrate by using a combination of synchrotron XRD and high resolution TEM that the growth dynamics at low temperatures is not governed by the well-known vapor-liquid solid (VLS) mechanisms. A critical new insight on the driving factor of VSS growth is proposed in which the VSS process occurs by a solid diffusion mechanism that is driven by a preferential oxidation process of the Zn inside the alloy catalyst induced by an epitaxial match between the Zn O(10-10) plane and the γ-Au Zn(222) plane. We believe that these results are not only important for the understanding of Zn O nano wire growth but could also have significant impact on the understanding of growth mechanisms of other nano wire systems. (author)

  13. Presence of nano-sized silica during in vitro digestion of foods containing silica as a food additive

    NARCIS (Netherlands)

    Peters, R.; Kramer, E.; Oomen, A.G.; Herrera Rivera, Z.E.; Oegema, G.; Tromp, P.C.; Fokkink, R.; Rietveld, A.; Marvin, H.J.P.; Weigel, S.; Peijnenburg, A.A.C.M.; Bouwmeester, H.

    2012-01-01

    The presence, dissolution, agglomeration state, and release of materials in the nano-size range from food containing engineered nanoparticles during human digestion is a key question for the safety assessment of these materials. We used an in vitro model to mimic the human digestion. Food products

  14. Thermal Stress Behavior of Micro- and Nano-Size Aluminum Films

    International Nuclear Information System (INIS)

    Hanabusa, T.; Kusaka, K.; Nishida, M.

    2008-01-01

    In-situ observation of thermal stresses in thin films deposited on silicon substrate was made by X-ray and synchrotron radiation. Specimens prepared in this experiment were micro- and nano-size thin aluminum films with and without passivation film. The thickness of the film was 1 micrometer for micro-size films and 10, 20 and 50 nanometer for nano-size films. The stress measurement in micro-size films was made by X-ray radiation whereas the measurement of nano-size films was made by synchrotron radiation. Residual stress measurement revealed tensile stresses in all as-deposited films. Thermal stresses were measured in a series of heating- and cooling-stage. Thermal stress behavior of micro-size films revealed hysteresis loop during a heating and cooling process. The width of a hysteresis loop was larger in passivated film that unpassivated film. No hysteresis loops were observed in nano-size films with SiO 2 passivation. Strengthning mechanism in thin films was discussed on a passivation film and a film thickness

  15. Luminescence properties of YAG:Nd nano-sized ceramic powders ...

    Indian Academy of Sciences (India)

    Abstract. Nano-sized ceramic powders with weaker aggregation of Nd3+-doped yttrium aluminum garnet. (YAG:Nd3+) were synthesized via co-microemulsion and microwave heating. This method provides a limited small space in a micelle for the formation of nano-sized precursors. It also requires a very short heating time, ...

  16. Synthesising and comparing electrical properties of NTC thermistors prepared from nano powder and solid state reaction

    International Nuclear Information System (INIS)

    Azad, N.; Ghanbari Shohany, B.; Hosseini, S. M.; Kompany, A.

    2011-01-01

    In this research, NTC thermistors with composition of NiMn 2-x Co x O 4 (x = 0.4, 0.8, 1.2, 1.6) prepared by two methods: solid state reaction and sol-gel (gel-combustion). The average particle size was monitored and structure of the calcinated powders have been investigated using x-ray diffraction and tunneling electron microscopy techniques. The average particle size was estimated to be about 65 nm with the cubic and cubic + tetragonal phases for low and high cobalt concentrations, respectively. The grain size of samples verifies with scanning electron microscopy images. Upon increasing the cobalt fraction, the grain size of samples increases from about 2μm to a few μm in size. The electrical properties of these thermistors depend on the grain size. The grain size of samples made from sol-gel is smaller than from solid state reaction under the same condition. For longer sintering time of the samples prepared by gel-combustion method, the grain size was increased then the electrical parameters of nano powder improved and we obtain better results than the samples prepared from solid state reaction.

  17. Nano-sized Adsorbate Structure Formation in Anisotropic Multilayer System

    Science.gov (United States)

    Kharchenko, Vasyl O.; Kharchenko, Dmitrii O.; Yanovsky, Vladimir V.

    2017-05-01

    In this article, we study dynamics of adsorbate island formation in a model plasma-condensate system numerically. We derive the generalized reaction-diffusion model for adsorptive multilayer system by taking into account anisotropy in transfer of adatoms between neighbor layers induced by electric field. It will be found that with an increase in the electric field strength, a structural transformation from nano-holes inside adsorbate matrix toward separated nano-sized adsorbate islands on a substrate is realized. Dynamics of adsorbate island sizes and corresponding distributions are analyzed in detail. This study provides an insight into details of self-organization of adatoms into nano-sized adsorbate islands in anisotropic multilayer plasma-condensate systems.

  18. Solid oxide fuel cell cathode infiltrate particle size control and oxygen surface exchange resistance determination

    Science.gov (United States)

    Burye, Theodore E.

    Over the past decade, nano-sized Mixed Ionic Electronic Conducting (MIEC) -- micro-sized Ionic Conducting (IC) composite cathodes produced by the infiltration method have received much attention in the literature due to their low polarization resistance (RP) at intermediate (500-700°C) operating temperatures. Small infiltrated MIEC oxide nano-particle size and low intrinsic MIEC oxygen surface exchange resistance (Rs) have been two critical factors allowing these Nano-Micro-Composite Cathodes (NMCCs) to achieve high performance and/or low temperature operation. Unfortunately, previous studies have not found a reliable method to control or reduce infiltrated nano-particle size. In addition, controversy exists on the best MIEC infiltrate composition because: 1) Rs measurements on infiltrated MIEC particles are presently unavailable in the literature, and 2) bulk and thin film Rs measurements on nominally identical MIEC compositions often vary by up to 3 orders of magnitude. Here, two processing techniques, precursor nitrate solution desiccation and ceria oxide pre-infiltration, were developed to systematically produce a reduction in the average La0.6Sr0.4Co0.8Fe 0.2O3-delta (LSCF) infiltrated nano-particle size from 50 nm to 22 nm. This particle size reduction reduced the SOFC operating temperature, (defined as the temperature where RP=0.1 Ocm 2) from 650°C to 540°C. In addition, Rs values for infiltrated MIEC particles were determined for the first time through finite element modeling calculations on 3D Focused Ion Beam-Scanning Electron Microscope (FIB-SEM) reconstructions of electrochemically characterized infiltrated electrodes.

  19. The use of nano-sized eggshell powder for calcium fortification of cow?s and buffalo?s milk yogurts.

    Science.gov (United States)

    El-Shibiny, Safinaze; El-Gawad, Mona Abd El-Kader Mohamed Abd; Assem, Fayza Mohamed; El-Sayed, Samah Mosbah

    2018-01-01

    Calcium is an essential element for the growth, activity, and maintenance of the human body. Eggshells are a waste product which has received growing interest as a cheap and effective source of dietary calcium. Yogurt is a food which can be fortified with functional additives, including calcium. The aim of this study was to produce yogurt with a high calcium content by fortification with nano-sized eggshell powder (nano-ESP). Nano-sized ESP was prepared from pre-boiled and dried eggshell, using a ball mill. Yogurt was prepared from cow’s milk supplemented with 3% skimmed milk powder, and from buffalo’s milk fortified with 0.1, 0.2 and 0.3% and 0.1, 0.3 and 0.5% nano-ESP respectively. Electron microscopic transmission showed that the powder consisted of nano-sized crystalline struc- tures (~10 nm). Laser scattering showed that particles followed a normal distribution pattern with z-average of 590.5 nm, and had negative zeta-potential of –9.33 ±4.2 mV. Results regarding changes in yogurt composi- tion, acid development, calcium distribution, biochemical changes, textural parameters and sensory attributes have been presented and discussed. The addition of up to 0.3% nano-ESP made cow and buffalo high-calcium yogurts with an acceptable composition and quality. High-calcium yogurt may offer better health benefits, such as combating osteoporosis.

  20. Effect of nano Co reinforcements on the structure of the Sn-3.0Ag-0.5Cu solder in liquid and after reflow solid states

    Energy Technology Data Exchange (ETDEWEB)

    Yakymovych, Andriy, E-mail: yakymovych@univie.ac.at [Department of Inorganic Chemistry – Functional Materials, University of Vienna, Währinger Str. 42, 1090 Vienna (Austria); Department of Metal Physics, Ivan Franko National University of Lviv, Kyrylo i Mephodiy Str. 8, 79005 Lviv (Ukraine); Mudry, Stepan; Shtablavyi, Ihor [Department of Metal Physics, Ivan Franko National University of Lviv, Kyrylo i Mephodiy Str. 8, 79005 Lviv (Ukraine); Ipser, Herbert [Department of Inorganic Chemistry – Functional Materials, University of Vienna, Währinger Str. 42, 1090 Vienna (Austria)

    2016-09-15

    Sn-Ag-Cu (SAC) alloys are commonly recognized as lead-free solders employed in the electronics industry. However, some disadvantages in mechanical properties and their higher melting temperatures compared to Pb-Sn solders prompt new research relating to reinforcement of existing SAC solders. One of the ways to reinforce these solder materials is the formation of composites with nanoparticles as filler materials. Accordingly, this study presents structural features of nanocomposite (Sn-3.0Ag-0.5Cu){sub 100−x}(nanoCo){sub x} solders with up to 0.8 wt% nano Co. The effect of nano-sized Co particles was investigated by means of differential thermal analysis (DTA), X-ray diffraction (XRD) in both liquid and solid states, and scanning electron microscopy (SEM). The experimental data of DTA are compared with available literature data for bulk Sn-3.0Ag-0.5Cu alloy to check the capability of minor nano-inclusions to decrease the melting temperature of the SAC solder. The combination of structural data in liquid and solid states provides important information about the structural transformations of liquid Sn-3.0Ag-0.5Cu alloys caused by minor Co additions and the phase formation during crystallization. Furthermore, scanning electron microscopy has shown the mutual substitution of Co and Cu atoms in the Cu{sub 6}Sn{sub 5} and CoSn{sub 3} phases, respectively. - Highlights: • Differential thermal analysis of nanocomposite (Sn-3.0Ag-0.5Cu){sub 100−x}(nanoCo){sub x} alloys. • Structural transformations of liquid Sn-3.0Ag-0.5Cu solder by minor Co additions. • Structure data of the solid quaternary (Sn-3.0Ag-0.5Cu){sub 100−x}(Co){sub x} alloys. • Substitution of Co and Cu atoms in the Cu{sub 6}Sn{sub 5} and CoSn{sub 3} phases.

  1. The Effect of TiO₂ Doped Photocatalytic Nano-Additives on the Hydration and Microstructure of Portland and High Alumina Cements.

    Science.gov (United States)

    Pérez-Nicolás, María; Navarro-Blasco, Íñigo; Fernández, José M; Alvarez, José Ignacio

    2017-10-14

    Mortars with two different binders (Portland cement (PC) and high alumina cement (HAC)) were modified upon the bulk incorporation of nano-structured photocatalytic additives (bare TiO₂, and TiO₂ doped with either iron (Fe-TiO₂) or vanadium (V-TiO₂)). Plastic and hardened state properties of these mortars were assessed in order to study the influence of these nano-additives. Water demand was increased, slightly by bare TiO₂ and Fe-TiO₂, and strongly by V-TiO₂, in agreement with the reduction of the particle size and the tendency to agglomerate. Isothermal calorimetry showed that hydration of the cementitious matrices was accelerated due to additional nucleation sites offered by the nano-additives. TiO₂ and doped TiO₂ did not show pozzolanic reactivity in the binding systems. Changes in the pore size distribution, mainly the filler effect of the nano-additives, accounted for the increase in compressive strengths measured for HAC mortars. A complex microstructure was seen in calcium aluminate cement mortars, strongly dependent on the curing conditions. Fe-TiO₂ was found to be homogeneously distributed whereas the tendency of V-TiO₂ to agglomerate was evidenced by elemental distribution maps. Water absorption capacity was not affected by the nano-additive incorporation in HAC mortars, which is a favourable feature for the application of these mortars.

  2. Nano sized bismuth oxy chloride by metal organic chemical vapour deposition

    Energy Technology Data Exchange (ETDEWEB)

    Jagdale, Pravin, E-mail: pravin.jagdale@polito.it [Department of Applied Science and Technology (DISAT), Politecnico di Torino, 10129 (Italy); Castellino, Micaela [Center for Space Human Robotics, Istituto Italiano di Tecnologia, Corso Trento 21, 10129 Torino (Italy); Marrec, Françoise [Laboratory of Condensed Matter Physics, University of Picardie Jules Verne (UPJV), Amiens 80039 (France); Rodil, Sandra E. [Instituto de Investigaciones en Materiales, Universidad Nacional Autonoma de Mexicom (UNAM), Mexico D.F. 04510 (Mexico); Tagliaferro, Alberto [Department of Applied Science and Technology (DISAT), Politecnico di Torino, 10129 (Italy)

    2014-06-01

    Metal organic chemical vapour deposition (MOCVD) method was used to prepare thin films of bismuth based nano particles starting from bismuth salts. Nano sized bismuth oxy chloride (BiOCl) crystals were synthesized from solution containing bismuth chloride (BiCl{sub 3}) in acetone (CH{sub 3}-CO-CH{sub 3}). Self-assembly of nano sized BiOCl crystals were observed on the surface of silicon, fused silica, copper, carbon nanotubes and aluminium substrates. Various synthesis parameters and their significant impact onto the formation of self-assembled nano-crystalline BiOCl were investigated. BiOCl nano particles were characterized by X-ray diffraction, X-ray photoelectron spectroscopy, field emission scanning electron microscopy, energy-dispersive X-ray spectroscopy and Micro-Raman spectroscopy. These analyses confirm that bismuth nanometer-sized crystal structures showing a single tetragonal phase were indeed bismuth oxy chloride (BiOCl) square platelets 18–250 nm thick and a few micrometres wide.

  3. Studying the effect of nano lead compounds additives on the concrete shielding properties for γ-rays

    International Nuclear Information System (INIS)

    Hassan, H.E.; Badran, H.M.; Aydarous, A.; Sharshar, T.

    2015-01-01

    In the present work the effect of concrete incorporation with two types of nano-lead compounds on its γ-ray shielding characteristics is investigated. The concrete samples were prepared according to the local standards of building materials and doped by different percentages of PbO and PbTiO_3 nano powders which were prepared using co-precipitation and oxalate precursor techniques, respectively. In addition, commercial PbO_2 powder additive was used to check the effect of particle size on concrete attenuation properties. The phase composition and particle size of all the lead-oxide additives were confirmed by XRD and TEM imaging. The γ-rays attenuation coefficients were measured as a function of the additive percentage of lead compounds for γ-ray energies of 662, 1173 and 1332 keV using "1"3"7Cs and "6"0Co sources. The microstructure changes occurred in the concrete samples doped with Pb compounds additives were probed using the positron annihilation spectroscopy (PAS) and the results were compared with that for normal concrete. The obtained data revealed that the overall defect density of the investigated samples, as seen by the positrons, decreases with increasing the nano-PbO contents which is in agreement with the determined values of the samples apparent densities. It was found that the γ-ray attenuation coefficient of concrete doped by nano-PbO is improved. The results are explained in the view of the fine structure enhanced modification and its impact on the γ-ray interaction probability at different energies.

  4. Neurotoxicity of low-dose repeatedly intranasal instillation of nano- and submicron-sized ferric oxide particles in mice

    Energy Technology Data Exchange (ETDEWEB)

    Wang Bing; Feng Weiyue, E-mail: fengwy@mail.ihep.ac.cn; Zhu Motao; Wang Yun; Wang Meng [Chinese Academy of Sciences, Laboratory for Bio-Environmental Effects of Nanomaterials and Nanosafety and Key Laboratory of Nuclear Analytical Techniques, Institute of High Energy Physics (China); Gu Yiqun [Maternity Hospital of Haidian District (China); Ouyang Hong; Wang Huajian; Li Ming; Zhao Yuliang, E-mail: zhaoyuliang@mail.ihep.ac.cn; Chai Zhifang [Chinese Academy of Sciences, Laboratory for Bio-Environmental Effects of Nanomaterials and Nanosafety and Key Laboratory of Nuclear Analytical Techniques, Institute of High Energy Physics (China); Wang Haifang [Peking University, College of Chemistry and Molecular Engineering (China)

    2009-01-15

    Olfactory tract has been demonstrated to be an important portal for inhaled solid nanoparticle transportation into the central nervous system (CNS). We have previously demonstrated that intranasally instilled Fe{sub 2}O{sub 3} nanoparticles could transport into the CNS via olfactory pathway. In this study, we investigated the neurotoxicity and size effect of repeatedly low-dose (130 {mu}g) intranasal exposure of nano- and submicron-sized Fe{sub 2}O{sub 3} particles (21 nm and 280 nm) to mice. The biomarkers of oxidative stress, activity of nitric oxide synthases and release of monoamine neurotransmitter in the brain were studied. Our results showed that significant oxidative stress was induced by the two sizes of Fe{sub 2}O{sub 3} particles. The activities of GSH-Px, Cu,Zn-SOD, and cNOS significantly elevated and the total GSH and GSH/GSSG ratio significantly decreased in the olfactory bulb and hippocampus after the nano- and submicron-sized Fe{sub 2}O{sub 3} particle treatment (p < 0.05). The nano-sized Fe{sub 2}O{sub 3} generally induced greater alteration and more significant dose-effect response than the submicron-sized particle did. Some slight perturbation of monoamine neurotransmitters were found in the hippocampus after exposure to the two sizes of Fe{sub 2}O{sub 3} particle. The TEM image showed that some ultrastructural alterations in nerve cells, including neurodendron degeneration, membranous structure disruption and lysosome increase in the olfactory bulb, slight dilation in the rough endoplasmic reticulum and lysosome increase in the hippocampus were induced by the nano-sized Fe{sub 2}O{sub 3} treatment. In contrast, in the submicron-sized Fe{sub 2}O{sub 3} treated mice, slightly swollen mitochondria and some vacuoles were observed in the olfactory bulb and hippocampus, respectively. These results indicate that intranasal exposure of Fe{sub 2}O{sub 3} nanoparticles could induce more severe oxidative stress and nerve cell damage in the brain than the

  5. Structural stability of nano-sized clusters

    NARCIS (Netherlands)

    De Hosson, JTM; Palasantzas, G; Vystavel, T; Koch, S; Ovidko,; Pande, CS; Krishnamoorti, R; Lavernia, E; Skandan, G

    2004-01-01

    This contribution presents challenges to control the microstructure in nano-structured materials via a relatively new approach, i.e. using a so-called nanocluster source. An important aspect is that the cluster size distribution is monodisperse and that the kinetic energy of the clusters during

  6. Lennard–Jones interactions between nano-rod like particles at an arbitrary orientation and an infinite flat solid surface

    International Nuclear Information System (INIS)

    Hamady, Saleem; Hijazi, Abbas; Atwi, Ali

    2013-01-01

    An analytical expression for the Lennard–Jones interaction between nano-rods and an infinite flat solid surface is presented. Starting from the elementary Lennard–Jones interaction between two particles, and taking the shape of the nano-rod to be a filled cylinder of radius r and length L, the obtained expression was valid for arbitrary orientation of the nano-rod at variable elevation from the surface. By differentiating the potential with respect to the orientation and elevation we were able to extract the torque and force, respectively, exerted on the nano-rods when approaching a flat surface. The derivation is subjected to the assumption of additivity and approximated for some limiting case

  7. Improvement of the tool life of a micro-end mill using nano-sized SiC/Ni electroplating method.

    Science.gov (United States)

    Park, Shinyoung; Kim, Kwang-Su; Roh, Ji Young; Jang, Gyu-Beom; Ahn, Sung-Hoon; Lee, Caroline Sunyong

    2012-04-01

    High mechanical properties of a tungsten carbide micro-end-mill tool was achieved by extending its tool life by electroplating nano-sized SiC particles (electroplating method on the surface of the micro-end-mill tool was applied using SiC particles and Ni particles. Organic additives (saccharin and ammonium chloride) were added in a Watts bath to improve the nickel matrix density in the electroplating bath and to smooth the surface of the co-electroplating. The morphology of the coated nano-sized SiC particles and the composition were measured using Scanning Electron Microscope and Energy Dispersive Spectrometer. As the Ni/SiC co-electroplating layer was applied, the hardness and friction coefficient improved by 50%. Nano-sized SiC particles with 7 wt% were deposited on the surface of the micro-end mill while the Ni matrix was smoothed by adding organic additives. The tool life of the Ni/SiC co-electroplating coating on the micro-end mill was at least 25% longer than that of the existing micro-end mills without Ni/SiC co-electroplating. Thus, nano-sized SiC/Ni coating by electroplating significantly improves the mechanical properties of tungsten carbide micro-end mills.

  8. Effect of Alumina Addition to Zirconia Nano-composite on Low Temperature Degradation Process and Biaxial Strength

    Directory of Open Access Journals (Sweden)

    Moluk Aivazi

    2016-12-01

    Full Text Available Ceramic dental materials have been considered as alternatives to metals for dental implants application. In this respect, zirconia tetragonal stabilized with %3 yttrium, is of great importance among the ceramic materials for endosseous dental implant application. Because of its good mechanical properties and color similar to tooth. The aim and novelty of this study was to design and prepare Y-TZP nano-composite to reduce the degradation process at low temperature by alumina addition and maintaining submicron grain sized. Also, flexural strength of nano-composite samples was evaluated. Toward this purpose, alumina-Y-TZP nano-composites containing 0–30 vol% alumina (denoted as A-Y-TZP 0-30 were fabricated using α-alumina and Y-TZP nano-sized by sintering pressure less method. The synthesized samples were characterized using x-ray diffraction, field emission scanning electron microscopy equipped with energy dispersive x-ray spectroscopy techniques. Nano-composite samples with high density (≥96% and grain sized of ≤ 400 nm was obtained by sintering at 1270 °C for 170 min. After low temperature degradation test (LTD, A-Y-TZP20 and A-Y-TZP30 not showed monoclinic phase and the flexural strength in all of samples were higher than A-Y-TZP0. It was concluded that the grains were remained in submicron sized and A-Y-TZP20 and A-Y-TZP30 did not present biaxial strength reduction after LTD test.

  9. Fabrication and physical properties of permalloy nano-size wires

    International Nuclear Information System (INIS)

    Yu, C.; Lee, S.F.; Yao, Y.D.; Wong, M.S.; Huang, E.W.; Ma, Y.-R.; Tsai, J.L.; Chang, C.R.

    2003-01-01

    Nano-size NiFe wires with patterned shapes in half-ring-in-series, octagon-in-series, and zigzag-in-series configurations were fabricated. Their magnetoresistance was studied below room temperature and their magnetic domain images were investigated at room temperature by a magnetic force microscope. In general, we have experimentally demonstrated that the variation of the magnetoresistance of our patterned nano-size wires can be related to different domain configurations and explained by the domain switching effect. The number of magnetic domain walls in our patterned wires can be controlled by the shape anisotropy and the size of each section of patterns that form the wires

  10. X-ray diffraction microstructural analysis of bimodal size distribution MgO nano powder

    International Nuclear Information System (INIS)

    Suminar Pratapa; Budi Hartono

    2009-01-01

    Investigation on the characteristics of x-ray diffraction data for MgO powdered mixture of nano and sub-nano particles has been carried out to reveal the crystallite-size-related microstructural information. The MgO powders were prepared by co-precipitation method followed by heat treatment at 500 degree Celsius and 1200 degree Celsius for 1 hour, being the difference in the temperature was to obtain two powders with distinct crystallite size and size-distribution. The powders were then blended in air to give the presumably bimodal-size- distribution MgO nano powder. High-quality laboratory X-ray diffraction data for the powders were collected and then analysed using Rietveld-based MAUD software using the lognormal size distribution. Results show that the single-mode powders exhibit spherical crystallite size (R) of 20(1) nm and 160(1) nm for the 500 degree Celsius and 1200 degree Celsius data respectively with the nano metric powder displays narrower crystallite size distribution character, indicated by lognormal dispersion parameter of 0.21 as compared to 0.01 for the sub-nano metric powder. The mixture exhibits relatively more asymmetric peak broadening. Analysing the x-ray diffraction data for the latter specimen using single phase approach give unrealistic results. Introducing two phase models for the double-phase mixture to accommodate the bimodal-size-distribution characteristics give R = 100(6) and σ = 0.62 for the nano metric phase and R = 170(5) and σ= 0.12 for the σ sub-nano metric phase. (author)

  11. Characterization of Nano Sized Microstructures in Fe and Ni Base ODS Alloys Using Small Angle Neutron Scattering

    International Nuclear Information System (INIS)

    Han, Young-Soo; Jang, Jin-Sung; Mao, Xiaodong

    2015-01-01

    Ferritic ODS(Oxide-dispersion-strengthened) alloy is known as a primary candidate material of the cladding tubes of a sodium fast reactor (SFR) in the Generation IV research program. In ODS alloy, the major contribution to the enhanced high-temperature mechanical property comes from the existence of nano-sized oxide precipitates, which act as obstacles to the movement of dislocations. In addition for the extremely high temperature application(>950 .deg. C) of future nuclear system, Ni base ODS alloys are considered as candidate materials. Therefore the characterization of nano-sized microstructures is important for determining the mechanical properties of the material. Small angle neutron scattering (SANS) technique non-destructively probes structures in materials at the nano-meter length of scale (1 - 1000 nm) and has been a very powerful tool in a variety of scientific/engineering research areas. In this study, nano-sized microstructures were quantitatively analyzed by small angle neutron scattering. Quantitative microstructural information on nanosized oxide in ODS alloys was obtained from SANS data. The effects of the thermo mechanical treatment on the size and volume fraction of nano-sized oxides were analyzed. For 12Cr ODS alloy, the experimental A-ratio is two-times larger than the theoretical A-ratio., and this result is considered to be due to the imperfections included in YTaO 4 . For Ni base ODS alloy, the volume fraction of the mid-sized particles (- 30 nm) increases rapidly as hot extrusion temperature decreases

  12. Chemoselective Oxidation of Bio-Glycerol with Nano-Sized Metal Catalysts

    DEFF Research Database (Denmark)

    Li, Hu; Kotni, Ramakrishna; Zhang, Qiuyun

    2015-01-01

    to selectively oxidize glycerol and yield products with good selectivity is the use of nano-sized metal particles as heterogeneous catalysts. In this short review, recent developments in chemoselective oxidation of glycerol to specific products over nano-sized metal catalysts are described. Attention is drawn...... to various reaction parameters such as the type of the support, the size of the metal particles, and the acid/base properties of the reaction medium which were illustrated to largely influence the activity of the nanocatalyst and selectivity to the target product. - See more at: http...

  13. Solid nano-in-nanoparticles for potential delivery of siRNA.

    Science.gov (United States)

    Amsalem, Orit; Nassar, Taher; Benhamron, Sandrine; Lazarovici, Philip; Benita, Simon; Yavin, Eylon

    2017-07-10

    siRNA-based therapeutics possess great potential to treat a wide variety of genetic disorders. However, they suffer from low cellular uptake and short half-lives in blood circulation; issues that remain to be addressed. This work is, to the best of our knowledge, the first to report the production of solid nano-in-nanoparticles, termed double nano carriers (DNCs) by means of the innovative technology of nano spray drying. DNCs (with a median size of 580-770nm) were produced by spraying at low temperatures (50°C) to prevent damage to heat-sensitive biomacromolecules like siRNA. DNCs consisting of Poly (d,l-lactide-co-glycolide) used as a wall material, encapsulating 20% human serum albumin primary nanoparticles (PNPs) loaded with siRNA, were obtained as a dry nanoparticulate powder with smooth spherical surfaces and a unique inner morphology. Incubation of pegylated or non-pegylated DNCs under sink conditions at 37°C, elicited a controlled release profile of the siRNA for up to 12 or 24h, respectively, with a minimal burst effect. Prolonged incubation of pegylated DNCs loaded with active siRNA (anti EGFR) in an A549 epithelial cell culture monolayer did not induce any apparent cytotoxicity. A slow degradation of the internalized DNCs by the cells was also observed resulting in the progressive release of the siRNA for up to 6days, as corroborated by laser confocal microscopy. The structural integrity and silencing activity of the double encapsulated siRNA were fully preserved, as demonstrated by HPLC, gel electrophoresis, and potent RNAi activity of siRNA extracted from DNCs. These results demonstrate the potential use of DNCs as a nano drug delivery system for systemic administration and controlled release of siRNA and potentially other sensitive bioactive macromolecules. Copyright © 2016 Elsevier B.V. All rights reserved.

  14. Effect of Al2O3 nano-filler on properties of glass-based seals for solid oxide fuel cells.

    Science.gov (United States)

    Lee, Dong Bok; Choi, Myong-Jae; Park, Sung; Lee, Jae Chun

    2013-01-01

    This study compares the viscosity and strength of three glass-based seals prepared with or without nano or micron-sized alumina powder used as filler material. Measurements of the viscosity and bending strength of the glass-based seals showed that addition of the nano-sized alumina powder to the glass increased both the high-temperature viscosity and the strength of the sintered glass matrix. Strength tests and observations of the microstructure of the fracture surface of the seal samples confirmed the strengthening of the glass network structure. Conversion of non-bridging oxygen to bridging oxygen is presumed to occur upon the addition of alumina to the glass sample. The strengthening of the alumina-glass composite seal was attributed to the alumina nano-filler and prolonged heat treatment at elevated temperatures.

  15. Characterisation and Treatment of Nano-sized Particles, Colloids and Associated Polycyclic Aromatic Hydrocarbons in Stormwater

    DEFF Research Database (Denmark)

    Nielsen, Katrine

    such as pH, Total Suspended Solid(TSS), turbidity, and electrical conductivity.The five sites where stormwater was sampled from used two different methods of stormwater treatment: settling and filtration, and four different treatment techniques: detention ponds, stormwater pond, disc filter and combined...... sedimentation tanks. From all sites, inlet and outlet stormwater were collected,and pollutant concentrations were quantified as well as the removal efficiencies calculated. The colloidal and nano-sized particle-enhanced transportation of pollutants was also scrutinised in the stormwater.The μm-range PSD...

  16. The Effect of TiO2 Doped Photocatalytic Nano-Additives on the Hydration and Microstructure of Portland and High Alumina Cements

    Directory of Open Access Journals (Sweden)

    María Pérez-Nicolás

    2017-10-01

    Full Text Available Mortars with two different binders (Portland cement (PC and high alumina cement (HAC were modified upon the bulk incorporation of nano-structured photocatalytic additives (bare TiO2, and TiO2 doped with either iron (Fe-TiO2 or vanadium (V-TiO2. Plastic and hardened state properties of these mortars were assessed in order to study the influence of these nano-additives. Water demand was increased, slightly by bare TiO2 and Fe-TiO2, and strongly by V-TiO2, in agreement with the reduction of the particle size and the tendency to agglomerate. Isothermal calorimetry showed that hydration of the cementitious matrices was accelerated due to additional nucleation sites offered by the nano-additives. TiO2 and doped TiO2 did not show pozzolanic reactivity in the binding systems. Changes in the pore size distribution, mainly the filler effect of the nano-additives, accounted for the increase in compressive strengths measured for HAC mortars. A complex microstructure was seen in calcium aluminate cement mortars, strongly dependent on the curing conditions. Fe-TiO2 was found to be homogeneously distributed whereas the tendency of V-TiO2 to agglomerate was evidenced by elemental distribution maps. Water absorption capacity was not affected by the nano-additive incorporation in HAC mortars, which is a favourable feature for the application of these mortars.

  17. Effects of nano-silica (NS) additions on durability of SCC mixtures

    NARCIS (Netherlands)

    Quercia Bianchi, G.; Spiesz, P.R.; Brouwers, H.J.H.; Andrade, C; Gulikers, JJW; Polder, R

    2015-01-01

    In this study, three different types of nano-silica were applied in self-compacting concrete (SCC), one produced by the controlled dissolution of the olivine mineral and two having similar particle size distributions (PSD), but produced through two different processes: fumed powder nano-silica and

  18. Internal distribution of micro- / nano-sized inorganic particles and their cytocompatibility

    Energy Technology Data Exchange (ETDEWEB)

    Abe, Shigeaki; Iwadera, Nobuki; Esaki, Mitsue; Kida, Ikuhiro; Akasaka, Tsukasa; Uo, Motohiro; Yawaka, Yasutaka; Watari, Fumio [Graduate School of Dental Medicine, Hokkaido University, Sapporo 060-8586 (Japan); Mutoh, Mami [School of Dental Medicine, Hokkaido University, Sapporo 060-8586 (Japan); Morita, Manabu [Department of Oral Health, Okayama University Graduate School of Medicine, Dentisity and Pharmaceutical Science, Okayama 700-8525 (Japan); Haneda, Koichi [Department of Information Technology and Electronics, Senshu University of Ishinomaki, Ishinomaki 986-8580 (Japan); Yonezawa, Tetsu, E-mail: sabe@den.hokudai.ac.jp [Graduate School of Engineering, Hokkaido University, Sapporo 060-8628 (Japan)

    2011-10-29

    Nano-sized materials have received much attention lately, both in terms of their multiple applications and their biocompatibility. From both viewpoints, understanding the biodistribution of administered nano-materials is very important. In this study, we succeeded in visualizing the biodistribution of administered nano-materials using a scanning X-ray analytical microscope and magnetic resonance imaging method. Quantitative observation was carried out by inductively coupled plasma - atomic emission spectroscopy. We observed that the administered nano-particles accumulated in the liver, lung and spleen of mice. To estimate their cytocompatibility, the nano-particles were exposed to human liver cells. The results suggested that the micro-/ nano- particles have good cytocompatibility, except for copper oxide nano-particles.

  19. A facile method to prepare "green" nano-phosphors with a large Stokes-shift and solid-state enhanced photophysical properties based on surface-modified gold nanoclusters.

    Science.gov (United States)

    Cheng, C H; Huang, H Y; Talite, M J; Chou, W C; Yeh, J M; Yuan, C T

    2017-12-15

    Colloidal nano-materials, such as quantum dots (QDs) have been applied to light-conversion nano-phosphors due to their unique tunable emission. However, most of the QDs involve toxic elements and are synthesized in a hazardous solvent. In addition, conventional QD nano-phosphors with a small Stokes shift suffered from reabsorption losses and aggregation-induced quenching in the solid state. Here, we demonstrate a facile, matrix-free method to prepare eco-friendly nano-phosphors with a large Stokes shift based on aqueous thiolate-stabilized gold nanoclusters (GSH-AuNCs) with simple surface modifications. Our method is just to drop GSH-AuNCs solution on the aluminum foil and then surface-modified AuNCs (Al-GSH-AuNCs) can be spontaneously precipitated out of the aqueous solution. Compared with pristine GSH-AuNCs in solution, the Al-GSH-AuNCs exhibit enhanced solid-state PL quantum yields, lengthened PL lifetime, and spectral blue shift, which can be attributed to the aggregation-induced emission enhancement facilitated by surface modifications. Such surface-treatment induced aggregation of AuNCs can restrict the surface-ligand motion, leading to the enhancement of PL properties in the solid state. In addition, the Al-GSH-AuNCs nano-phosphors with a large Stokes shift can mitigate the aggregation-induced PL quenching and reabsorption losses, which would be potential candidates for "green" nano-phosphors. Copyright © 2017 Elsevier Inc. All rights reserved.

  20. Nano-sized surface modifications induced by the impact of slow highly charged ions - A first review

    International Nuclear Information System (INIS)

    Aumayr, F.; El-Said, A.S.; Meissl, W.

    2008-01-01

    Irradiation of crystalline solid targets with swift heavy ions can lead to the formation of latent tracks in the solid and the creation of (mostly-hillock type) nanostructures on the surface. Recently similar surface modifications with nanometer dimensions have been demonstrated for the impact of individual, very slow but highly charged ions on various surfaces. We will review the current state of this new field of research. In particular we will discuss the circumstances and conditions under which nano-sized features (hillocks or craters) on different surfaces due to impact of slow highly charged ions can be produced. The use of slow highly charged ions instead of swift heavy ions might be of considerable interest for some practical applications

  1. The role of stable interface in nano-sized FeNbO4 as anode electrode for lithium-ion batteries

    International Nuclear Information System (INIS)

    Wang, Ting; Shi, Shaojun; Kong, Fanjun; Yang, Gang; Qian, Bin; Yin, Fan

    2016-01-01

    Graphical abstract: After dozens of charge/discharge cycles, the electrode of Nano-FNO remains the homogeneous combination with active material and conductive carbon, but the microcrystals in Micro-FNO electrode are cracked to small particles. The pulverization of Micro-FNO not only blocks the transfer of Li + and electrons due to the separation of the active material and conductive carbon, but also results in the falling of active material from the current collector. Nano-FNO can remain the excellent capacity after dozens of cycles. - Abstract: Nano-sized FeNbO 4 (Nano-FNO) with an average diameter of 120 nm is facilely prepared by co-precipitation method. Bulk FeNbO 4 (Micro-FNO) as a comparison synthesized by conventional solid-state synthesis has an average grain size of 3–10 μm. In the high-resolution transmission electron microscopy (HRTEM) images, Nano-FNO reveals an ordered single crystal structure, but Mirco-FNO is composed of disordered crystallites with different crystal orientation. Nano-FNO as anode material delivers the initial capacity of 475 mAh g −1 which is much higher than Micro-FNO electrode of 250 mAh g −1 .After dozens of charge/discharge cycles, the electrode of Nano-FNO remains the homogeneous combination with active material and conductive carbon, but the microcrystals in Micro-FNO electrode are cracked to small particles. The pulverization of Micro-FNO not only blocks the transfer of Li + and electrons due to the separation between the active material and conductive carbon, but also results in the falling of active material from the current collector. Compared with the weakened electrochemical performances of Micro-FNO, Nano-FNO remains the excellent capacity after dozens of cycles. The charge transfer resistances of Nano-FNO and Micro-FNO after several cycles are further studied by fitting their electrochemical impedance spectra.

  2. Influence of Nano sized Silicon Oxide on the Luminescent Properties of Zn O Nanoparticles

    International Nuclear Information System (INIS)

    Shvalagin, V.; Grodziuk, G.; Kurmach, M.; Granchak, V.; Sarapulova, O.; Sherstiuk, V.

    2016-01-01

    For practical use of nano sized zinc oxide as the phosphor its luminescence quantum yields should be maximized. The aim of this work was to enhance luminescent properties of Zn O nanoparticles and obtain high-luminescent Zn O/SiO 2 composites using simpler approaches to colloidal synthesis. The luminescence intensity of zinc oxide nanoparticles was increased about 3 times by addition of silica nano crystals to the source solutions during the synthesis of Zn O nanoparticles. Then the quantum yield of luminescence of the obtained Zn O/SiO 2 composites is more than 30%. Such an impact of silica is suggested to be caused by the distribution of Zn O nano crystals on the surface of silica, which reduces the probability of separation of photo generated charges between the zinc oxide nanoparticles of different sizes, and as a consequence, there is a significant increase of the luminescence intensity of Zn O nanoparticles. This way of increasing nano-Zn O luminescence intensity facilitates its use in a variety of devices, including optical ultraviolet and visible screens, luminescent markers, antibacterial coatings, luminescent solar concentrators, luminescent inks for security printing, and food packaging with abilities of informing consumers about the quality and safety of the packaged product.

  3. Microstructures and Tensile Properties of Al–Cu Matrix Composites Reinforced with Nano-Sized SiCp Fabricated by Semisolid Stirring Process

    Directory of Open Access Journals (Sweden)

    Feng Qiu

    2017-02-01

    Full Text Available The nano-sized SiCp/Al–Cu composites were successfully fabricated by combining semisolid stirring with ball milling technology. Microstructures were examined by an olympus optical microscope (OM, field emission scanning electron microscope (FESEM and transmission electron microscope (TEM. Tensile properties were studied at room temperature. The results show that the α-Al dendrites of the composites were strongly refined, especially in the composite with 3 wt. % nano-sized SiCp, of which the morphology of the α-Al changes from 200 μm dendritic crystal to 90 μm much finer equiaxial grain. The strength and ductility of the composites are improved synchronously with the addition of nano-sized SiCp particles. The as-cast 3 wt. % nano-sized SiCp/Al–Cu composite displays the best tensile properties, i.e., the yield strength, ultimate tensile strength (UTS and fracture strain increase from 175 MPa, 310 MPa and 4.1% of the as-cast Al–Cu alloy to 220 MPa, 410 MPa and 6.3%, respectively. The significant improvement in the tensile properties of the composites is mainly due to the refinement of the α-Al dendrites, nano-sized SiCp strengthening, and good interface combination between the SiCp and Al–Cu alloys.

  4. Effect of Yttrium Addition on the Microstructure and Mechanical Properties of Cu-Rich Nano-phase Strengthened Ferritic Steel

    Science.gov (United States)

    Liu, Hongyu; He, Jibai; Luan, Guoqing; Ke, Mingpeng; Fang, Haoyan; Lu, Jianduo

    2018-03-01

    Due to the brittle problem of Cu-rich nano-phase strengthened ferritic steel (CNSFS) after air aging, the effect of Y addition in CNSFS was systemically investigated in the present work. The microstructure, tensile fracture morphology and oxide layer of the steels were surveyed by optical microscope and scanning electron microscope. Transmission electron microscope with the combination of energy-dispersive x-ray spectroscopy and selected area electron diffraction was used to analyze the morphology, size, number density, chemical compositions and crystal structure for nano-crystalline precipitates. Microstructural examinations of the nano-crystalline precipitates show that Cu-rich precipitates and Y compounds in the range of 2-10 and 50-100 nm, respectively, form in the Y-containing steel; meanwhile, the average size of nano-crystalline precipitates in Y-containing steel is larger, but the number density is lower, and the ferritic grains are refined. Furthermore, the tensile strength and ductility of Y-containing steel after air aging are improved, whereas the tensile strength is enhanced and the ductility decreased after vacuum aging. The drag effect of Y makes the oxide layer thinner and be compacted. Tensile properties of CNSFS after air aging are improved due to the refined grains, antioxidation and purification by the addition of Y.

  5. Sample-size resonance, ferromagnetic resonance and magneto-permittivity resonance in multiferroic nano-BiFeO3/paraffin composites at room temperature

    International Nuclear Information System (INIS)

    Wang, Lei; Li, Zhenyu; Jiang, Jia; An, Taiyu; Qin, Hongwei; Hu, Jifan

    2017-01-01

    In the present work, we demonstrate that ferromagnetic resonance and magneto-permittivity resonance can be observed in appropriate microwave frequencies at room temperature for multiferroic nano-BiFeO 3 /paraffin composite sample with an appropriate sample-thickness (such as 2 mm). Ferromagnetic resonance originates from the room-temperature weak ferromagnetism of nano-BiFeO 3 . The observed magneto-permittivity resonance in multiferroic nano-BiFeO 3 is connected with the dynamic magnetoelectric coupling through Dzyaloshinskii–Moriya (DM) magnetoelectric interaction or the combination of magnetostriction and piezoelectric effects. In addition, we experimentally observed the resonance of negative imaginary permeability for nano BiFeO 3 /paraffin toroidal samples with longer sample thicknesses D=3.7 and 4.9 mm. Such resonance of negative imaginary permeability belongs to sample-size resonance. - Highlights: • Nano-BiFeO 3 /paraffin composite shows a ferromagnetic resonance. • Nano-BiFeO 3 /paraffin composite shows a magneto-permittivity resonance. • Resonance of negative imaginary permeability in BiFeO 3 is a sample-size resonance. • Nano-BiFeO 3 /paraffin composite with large thickness shows a sample-size resonance.

  6. Effect of the shape of a nano-object on quantum-size states

    International Nuclear Information System (INIS)

    Dzyuba, Vladimir; Kulchin, Yurii; Milichko, Valentin

    2012-01-01

    In this paper, we propose an original functional method that makes it easy to determine the effect of any deviation in the shape of a nano-object from the well-studied shape (e.g., spherical) on the quantum characteristics of charge localized inside the nano-object. The maximum dimension of the object is determined by the magnitude of influence of quantum-size effects on quantum states of charge, and is limited by 100 nm. This method is ideologically similar to the perturbation theory, but the perturbation of the surface shape, rather than the potential, is used. Unlike the well-known variational methods of theoretical physics, this method is based on the assumption that the physical quantity is a functional of surface shape. Using the method developed, we present the quantum-size state of charges for two different complex shapes of nano-objects. The results from analyzing the quantum-size states of charge in the nano-objects with a deformed spherical shape indicated that the shape perturbations have a larger effect on the probability density of locating a particle inside the nano-object than on the surface energy spectrum and quantum density of the states.

  7. Effect of nano-TiO{sub 2} particles size on the corrosion resistance of alkyd coating

    Energy Technology Data Exchange (ETDEWEB)

    Deyab, M.A., E-mail: hamadadeiab@yahoo.com; Keera, S.T.

    2014-08-01

    The coating system containing various sizes (∼10, 50, 100, 150 nm) of nano-TiO{sub 2} were prepared and investigated for corrosion protection of carbon steel in 1.0 M H{sub 2}SO{sub 4} using polarization, EIS and transmission electron microscopy (TEM) techniques. It was found that nano-TiO{sub 2} particles improved the corrosion resistance of alkyd coatings. The corrosion resistance occurs via physical adhesion on the metal surface. O{sub 2} and H{sub 2}O permeability of coating decreased with decrease in the nano-TiO{sub 2} size. The inhibition efficiency was found to increase with decreasing the size of nano-TiO{sub 2} and with decreasing the temperature. - Highlights: • Nano-TiO{sub 2} coating were prepared and used for corrosion protection of C-steel. • Nano-TiO{sub 2} particles in coating are effective to improve the corrosion resistance. • Nano-TiO{sub 2} coating inhibit both anodic and cathodic reactions. • Corrosion inhibition efficiency increases with decrease in the size of nano-TiO{sub 2}. • O{sub 2} and H{sub 2}O permeability of coating decreased with decrease in the nano-TiO{sub 2} size.

  8. Nano-Ionic Solid State Resistive Memories (Re-RAM): A Review.

    Science.gov (United States)

    Sahoo, Satyajeet; Prabaharan, S R S

    2017-01-01

    Nano-ionic devices based on modest to fast ion conductors as active materials intrigued a revolution in the field of nano solid state resistive memories (the so-called Re-RAM) ever since HP labs unveiled the first solid state memristor device based on titanium dioxide (TiO2). This has brought impetus to the practical implementation of fourth missing element called “Memristor” correlating charge (q) and flux (φ) based on the conceptual thought by Chua in 1971 completing a missing gap between the passive electronic components (R, C and L). It depicts various functional features as memory element in terms of ionic charge transport in solid state by virtue of external electric flux variations. Consequently, a new avenue has been found by manipulating the ionic charge carriers creating a fast switching resistive random access memory (Re-RAM) or the so-called Memristors. The recent research has led to low power, faster switching speed, high endurance and high retention time devices that can be scaled down the order of few nanometers dimension and the 3D stacking is employed that significantly reduces the die area. This review is organized to provide the progress hitherto accomplished in the materials arena to make memristor devices with respect to current research attempts, different stack structures of ReRAM cells using various materials as well as the application of memristive system. Different synthesis approaches to make nano-ionic conducting metal oxides, the fabrication methods for ReRAM cells and its memory performance are reviewed comprehensively.

  9. Fabrication, Characterization, and Biological Activity of Avermectin Nano-delivery Systems with Different Particle Sizes

    Science.gov (United States)

    Wang, Anqi; Wang, Yan; Sun, Changjiao; Wang, Chunxin; Cui, Bo; Zhao, Xiang; Zeng, Zhanghua; Yao, Junwei; Yang, Dongsheng; Liu, Guoqiang; Cui, Haixin

    2018-01-01

    Nano-delivery systems for the active ingredients of pesticides can improve the utilization rates of pesticides and prolong their control effects. This is due to the nanocarrier envelope and controlled release function. However, particles containing active ingredients in controlled release pesticide formulations are generally large and have wide size distributions. There have been limited studies about the effect of particle size on the controlled release properties and biological activities of pesticide delivery systems. In the current study, avermectin (Av) nano-delivery systems were constructed with different particle sizes and their performances were evaluated. The Av release rate in the nano-delivery system could be effectively controlled by changing the particle size. The biological activity increased with decreasing particle size. These results suggest that Av nano-delivery systems can significantly improve the controllable release, photostability, and biological activity, which will improve efficiency and reduce pesticide residues.

  10. Synthesis of LaCoO{sub 3} nano-powders by aqueous gel-casting for intermediate temperature solid oxide fuel cells

    Energy Technology Data Exchange (ETDEWEB)

    Cheng, Chia Siang; Zhang, Lan; Jiang, San Ping [School of Mechanical and Aerospace Engineering, Nanyang Technological University (Singapore); Zhang, Yu.Jun [Key Lab for Liquid Structure and Heredity of Ministry of Education, School of Materials Science and Engineering, Shandong University, Jinan (China)

    2008-04-15

    LaCoO{sub 3} (LC) perovskite powders for intermediate temperature solid oxide fuel cells (IT-SOFCs) are synthesized by a simple and cost-effective aqueous gel-casting technique using metal nitrates as raw materials. Effect of the ratio of organic precursors (acrylamide (AM) monomer and N,N'-Methylenebisacrylamide (MBAM) crosslinker) to metal nitrates (lanthanum nitrate, cobalt nitrate) and the ratio of AM to MBAM on the particle size are investigated in detail. TEM results indicate that the particle size of LC nano-powders is in the range of 31-60 nm and decreases with increasing ratio of organic precursor to metal nitrates but is not affected by the ratio of AM to MBAM. Preliminary results show that the nano-structured electrode approach based on wet impregnation is effective to combine the high electrocatalytic activity of LC nano-powders and the structural stability of La{sub 0.72}Sr{sub 0.18}MnO{sub 3} {sub -} {sub {delta}} (LSM) electrodes for the development of IT-SOFC cathodes. (author)

  11. Laser clad Ni-base alloy added nano- and micron-size CeO 2 composites

    Science.gov (United States)

    Zhang, Shi Hong; Li, Ming Xi; Cho, Tong Yul; Yoon, Jae Hong; Lee, Chan Gyu; He, Yi Zhu

    2008-07-01

    Micron-size Ni-base alloy (NBA) powders are mixed with both 1.5 wt% (%) micron-CeO 2 (m-CeO 2) and also 1.0-3.0% nano-CeO 2 (n-CeO 2) powders. These mixtures are coated on low carbon steel (Q235) by 2.0 kW CO 2 laser cladding. The effects on microstructures, microhardness and wear resistance of the coating by the addition of m- and n-CeO 2 powders to NBA (m- and n-CeO 2/NBA) have been investigated. Addition to the primary phases of γ-Ni, Cr 23C 6 and Ni 3B of NBA coating, CeNi 3 shows up both in m- and n-CeO 2/NBA coatings and CeNi 5 appears only in n-CeO 2/NBA coating. Directional dendrite and coarse equiaxed dendrite are grown in m-CeO 2/NBA coating from interface to central zone, whereas multi-oriented dendrite and fine equiaxed dendrite growth by addition of n-CeO 2. The microhardness and wear resistance of coatings are greatly improved by CeO 2 powder addition, and compared to the addition of 1.0% and 3.0%, 1.5% n-CeO 2/NBA is the best. Hardness and wear resistance of the coating improves with decreasing CeO 2 size from micron to nano.

  12. Size dependence of adsorption kinetics of nano-MgO: a theoretical and experimental study

    International Nuclear Information System (INIS)

    Wang, Shuting; Wen, Yanzhen; Cui, Zixiang; Xue, Yongqiang

    2016-01-01

    Nanoparticles present tremendous differences in adsorption kinetics compared with corresponding bulk particles which have great influences on the applications of nanoparticles. A size-dependent adsorption kinetic theory was proposed, the relations between adsorption kinetic parameters, respectively, and particle size of nano-adsorbent were derived theoretically, and the influence mechanism of particle size on the adsorption kinetic parameters was discussed. In experiment, nanoscale magnesium oxide (nano-MgO) with different diameters between 11.5 and 41.4 nm with narrow size distribution and low agglomeration were prepared, and the kinetic parameters of adsorption of benzene on nano-MgO in aqueous solution were obtained. Then the influence regularities of the particle size on the adsorption kinetic parameters were obtained. The experimental results are consistent with the nano-adsorption kinetic theory. With particle size decreasing, the adsorption rate constant increases; the adsorption activation energy and the adsorption pre-exponential factor decrease. Furthermore, the logarithm of adsorption rate constant, the adsorption activation energy, and the logarithm of adsorption pre-exponential factor are linearly related to the reciprocal of particle diameter, respectively. The mechanism of particle size influence on the kinetic parameters is that the activation energy is influenced by the molar surface enthalpy of nano-adsorbent, the pre-exponential factor by the molar surface entropy, and the rate constant by both the molar surface enthalpy and the molar surface entropy

  13. Sample-size resonance, ferromagnetic resonance and magneto-permittivity resonance in multiferroic nano-BiFeO{sub 3}/paraffin composites at room temperature

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Lei; Li, Zhenyu; Jiang, Jia; An, Taiyu; Qin, Hongwei; Hu, Jifan, E-mail: hujf@sdu.edu.cn

    2017-01-01

    In the present work, we demonstrate that ferromagnetic resonance and magneto-permittivity resonance can be observed in appropriate microwave frequencies at room temperature for multiferroic nano-BiFeO{sub 3}/paraffin composite sample with an appropriate sample-thickness (such as 2 mm). Ferromagnetic resonance originates from the room-temperature weak ferromagnetism of nano-BiFeO{sub 3}. The observed magneto-permittivity resonance in multiferroic nano-BiFeO{sub 3} is connected with the dynamic magnetoelectric coupling through Dzyaloshinskii–Moriya (DM) magnetoelectric interaction or the combination of magnetostriction and piezoelectric effects. In addition, we experimentally observed the resonance of negative imaginary permeability for nano BiFeO{sub 3}/paraffin toroidal samples with longer sample thicknesses D=3.7 and 4.9 mm. Such resonance of negative imaginary permeability belongs to sample-size resonance. - Highlights: • Nano-BiFeO{sub 3}/paraffin composite shows a ferromagnetic resonance. • Nano-BiFeO{sub 3}/paraffin composite shows a magneto-permittivity resonance. • Resonance of negative imaginary permeability in BiFeO{sub 3} is a sample-size resonance. • Nano-BiFeO{sub 3}/paraffin composite with large thickness shows a sample-size resonance.

  14. NANO-SIZED PIGMENT APPLICATIONS IN İZNİK TILES

    Directory of Open Access Journals (Sweden)

    Esin GÜNAY

    2012-12-01

    Full Text Available Traditional İznik tiles are known as “unproducable” due to its high quartz content. İznik tiles contain four different layers as “body, engobe (slip, decors and glaze” and each one has some different starting materials. Recent studies have showed that the production techniques and the particle size of pigments are important parameters in development of colours. TUBITAK MRC and İznik Foundation carried out an experimental work to improve and understand the effects of nanotechnology application to İznik tiles. High quartz content was kept as it is and pigments were applied in decorationas nano-sized pigments.İznik tiles were produced and comparison was carried out between traditional and modern İznik tiles in colour and brightness. Characterization techniques were used in order to understand andcompare the results and also the effects of nano-sized pigments to İznik tiles.

  15. Nanometer, submicron and micron sized aluminum powder prepared by semi-solid mechanical stirring method with addition of ceramic particles

    International Nuclear Information System (INIS)

    Qin, X.H.; Jiang, D.L.; Dong, S.M.

    2004-01-01

    Composite powder, which is a mixture of Al/Al 2 O 3 composite particles and nanometer, submicron and micron sized aluminum powder, was prepared by semi-solid mechanical stirring method with addition of Al 2 O 3 ceramic particles. The ceramic particles have an average diameter of 80 μm and a volume fraction of 15% in the slurry. The methods used to measure the size distribution of particles greater than 50 μm and less than 50 μm were sieve analysis and photosedimentation, respectively. The surface morphology and transverse sections of the composite powder of different sizes were examined by scanning electron microscope (SEM), optical microscope and auger electron spectroscopy (AES). The results indicate that the composite powder prepared in present work have a wide size distribution ranging from less than 50-900 μm, and the aluminum particles and Al/Al 2 O 3 composite particles are separated and isolated. The particles greater than 200 μm and less than 50 μm are almost pure aluminum powder. The rate of conversion of ingot aluminum into particles less than 1 μm containing nanometer and submicron sizes is 1.777 wt.% in this work. The aluminum powder of different sizes has different shape and surface morphology, quasi-spherical in shape with rough surface for aluminum particles of micron scale, irregular in shape for aluminum particles of submicron scale, and quite close to a globular or an excellent globular in shape for aluminum particles of nanometer size. On the other hand, the surface of ceramic particle was coated by aluminum particles with maximum thickness less than 10 μm containing nanometer and submicron sizes as a single layer. It is suggested that the surface of ceramic particles can provide more nucleation sites for solidification of liquid aluminum and the nucleation of liquid aluminum can take place readily, grow and adhere on the surface of ceramic particles, although it is poorly wetted by the liquid aluminum and the semi-solid slurry can

  16. Synthesis and characterization of nano-sized CaCO3 in purified diet

    Science.gov (United States)

    Mulyaningsih, N. N.; Tresnasari, D. R.; Ramahwati, M. R.; Juwono, A. L.; Soejoko, D. S.; Astuti, D. A.

    2017-07-01

    The growth and development of animals depend strongly on the balanced nutrition in the diet. This research aims is to characterize the weight variations of nano-sized calcium carbonate (CaCO3) in purified diet that to be fed to animal model of rat. The nano-sized CaCO3 was prepared by milling the calcium carbonate particles for 20 hours at a rotation speed of 1000 rpm and resulting particle size in a range of 2-50 nm. Nano-sized CaCO3 added to purified diet to the four formulas that were identified as normal diet (N), deficiency calcium (DC), rich in calcium (RC), and poor calcium (PC) with containing in nano-sized CaCO3 much as 0.50 %, 0.00 %, 0.75 % and 0.25 % respectively. The nutritional content of the purified diet was proximate analyzed, it resulted as followed moisture, ash, fat, protein, crude fiber. The quantities of chemical element were analyzed by atomic absorption spectrometry (AAS), it resulted iron, magnesium, potassium and calcium. The results showed that N diet (Ca: 16,914.29 ppm) were suggested for healthy rats and RC diet (Ca: 33,696.13 ppm) for conditioned osteoporosis rats. The crystalline phases of the samples that were examined by X-ray diffraction showed that crystalline phase increased with the increasing concentration of CaCO3.

  17. Antitumor Effect of Selenium and Modified Pectin Nano Particles and Gamma Radiation on Ehrilch Solid Tumor in Female Mice

    International Nuclear Information System (INIS)

    Mansour, S. Z.; Anis, L.M.; EI- Batal, A.I.

    2010-01-01

    Selenium nano particle (Nano- Se) is a novel Se species with novel biological activities with low toxicity. The aim of the present work was to evaluate the antitumor activity of a novel Nano- Se compound with or without gamma irradiation of female mice. Selenium size- controlled Nano-Se was prepared by a simple method by adding modified pectin to the selenious acid and ascorbic acid. The antitumor activity of Selenium and Modified Pectin Nano Particles (Se-Mp- NPs) were evaluated against Ehrilch ascites carcinoma (In vitro) and Ehrilch solid tumor model (In vivo). The antioxidant states of the novel compound were assessed measuring parameters in blood and tumor tissue of female mice. Malonaldehydoyl (MDA) end product of lipid peroxidation was evaluated in plasma and tumor tissue. Glutathione -S- transferase (GST) and cytochrome P450 (Cyto P450) were determined in tumor tissue homogenate. Tumor necrosis factor alpha (TNF- a) concentration and interleukin 10 (IL- 10) concentrations was evaluated in plasma of female mice. The effect of tumor inoculation and different treatments on liver enzymes (ALT and AST) and kidney Function (urea and creatinine) were detected in the plasma of animals. Apoptosis was shown and estimated in tumor tissue of animals histopathological of tumor in different groups of mice were examined. Ehrilch solid tumor induced a significant increase in MDA content, GSH-Px and GST activities level and in the amount of metabolites of CYP 450. Moreover, a significant decrease was observed in GSH content, SOD activity level in the tumor tissue, INF- a concentration, IL- 10 concentration in the plasma. Also, a significant alteration in kidney and liver functions was occurred as compared to control group. The results showed a significant antitumor activity of selenium and Modified Pectin Nano Particles (Se-Mp- NPs) at the concentration 2.25 μg / ml was 70%

  18. Scalable shape- and size-controlled synthesis of metal nano-alloys

    KAUST Repository

    Bakr, Osman M.

    2016-01-21

    Embodiments of the present disclosure provide for a continuous-flow reactor, methods of making metal nano-alloys, and metal nano-alloys. An embodiment of the continuous-flow reactor includes a first tubular component having a tubular inlet and a tubular outlet, and a heated tube-in-tube gas reactor fluidly connected to the first tubular component, wherein the heated tube-in-tube gas reactor comprises an inner tube having a gas permeable surface and an outer tube. An embodiment of the method of producing metal nano-alloys, includes contacting a reducible metal precursor and a reducing fluid in a continuous-flow reactor to form a mixed solution; and flowing the mixed solution through the continuous-flow reactor for a residence time to form the metal nano-alloys. An embodiment of the composition includes a plurality of metal nano-alloys having a monodisperse size distribution and a uniform shape distribution.

  19. Laser induced morphology change of silver colloids: formation of nano-size wires

    International Nuclear Information System (INIS)

    Tsuji, Takeshi; Watanabe, Norihisa; Tsuji, Masaharu

    2003-01-01

    We have performed laser irradiation at 355 nm onto spherical silver colloids in pure water, which were prepared by laser ablation of silver plate in pure water. In addition to size-reduced particles due to fragmentation, we have found that nano-size wire structures were formed in solution for the first time. The width of the wires was in the 10-100 nm range, and the length of long wires was more than 1 μm. Electron diffraction patterns revealed that these wires were composed of pure silver. It was suggested that the wires were formed via fusion of particles photo-thermally melted by laser irradiation

  20. Effects of γ-irradiation and ageing on surface and catalytic properties of nano-sized Cu O/Mg O system

    International Nuclear Information System (INIS)

    El-Molla, S. A.; Ismail, S. A.; Ibrahim, M. M.

    2011-01-01

    0.2 Cu O/Mg O system prepared by impregnation method was calcined at 350 and 450 C. The effects of γ-rays (0.2-1.6 MGy) on its structure, surface and catalytic properties were investigated by using XRD, N 2 -adsorption at -196 C and catalytic conversion of isopropanol at 150-275 C using a flow technique. The results revealed that the investigated solids consisted of nano-sized Mg O as a major phase besides Cu O and trace amount of Cu 2 O. γ-Irradiation of the solids investigated exerted measurable changes in their surface and catalytic properties dependent on the calcination temperature and dose of irradiation. The catalysts investigated acted as active dehydrogenation solids. The five years-ageing of different solids showed limited changes of their surface and catalytic properties indicating a good catalytic stability of the irradiated prepared solids. (Author)

  1. Effects of {gamma}-irradiation and ageing on surface and catalytic properties of nano-sized Cu O/Mg O system

    Energy Technology Data Exchange (ETDEWEB)

    El-Molla, S. A. [Ain Shams University, Faculty of Education, Chemistry Deparment, Roxy, Heliopolis, 11757 Cairo (Egypt); Ismail, S. A.; Ibrahim, M. M., E-mail: saharelmolla@yahoo.com [National Center for Radiation Research and Technology, Nasr City, P.O. Box 29, 11731 Cairo (Egypt)

    2011-07-01

    0.2 Cu O/Mg O system prepared by impregnation method was calcined at 350 and 450 C. The effects of {gamma}-rays (0.2-1.6 MGy) on its structure, surface and catalytic properties were investigated by using XRD, N{sub 2}-adsorption at -196 C and catalytic conversion of isopropanol at 150-275 C using a flow technique. The results revealed that the investigated solids consisted of nano-sized Mg O as a major phase besides Cu O and trace amount of Cu{sub 2}O. {gamma}-Irradiation of the solids investigated exerted measurable changes in their surface and catalytic properties dependent on the calcination temperature and dose of irradiation. The catalysts investigated acted as active dehydrogenation solids. The five years-ageing of different solids showed limited changes of their surface and catalytic properties indicating a good catalytic stability of the irradiated prepared solids. (Author)

  2. Nano sized clay detected on chalk particle surfaces

    DEFF Research Database (Denmark)

    Skovbjerg, Lone; Hassenkam, Tue; Makovicky, Emil

    2012-01-01

    that in calcite saturated water, both the polar and the nonpolar functional groups adhere to the nano sized clay particles but not to calcite. This is fundamentally important information for the development of conceptual and chemical models to explain wettability alterations in chalk reservoirs...

  3. Electroporation - a biophysical method for transferring nano-sized systems and drugs in vitro and in vivo

    International Nuclear Information System (INIS)

    Nikolova, B.; Atanasova, S.; Pehlivanova, V.; Jelev, J.; Tsoneva, Y.; Bakalova, R.; Peycheva, E.

    2017-01-01

    The aim of this study was to investigate the electrostatic internalisation of quinatum dots (QDs) and QDs containing nano-hydrogels in the Colon 26 cell line and their effect on cell viability as well as their passive and electrically mediated delivery in solid murine tumor models. Materials and methods: Colon 26 cancer cell line was used for in vitro experiments, survival was followed by a MTS test, and images were obtained by confocal microscopy. For in vivo experiments, mouse models with implanted Colon 26 cells were used. All in vivo measurements are carried out ~ 9-10 days after the inoculation, when the tumor size is ~ 100 mm 3 . Results: Electroporation facilitates the delivery of nanoparticles - both in vivo and in vitro. We demonstrate that increasing the applied tension leads to increased nanoparticle penetration into the cells without significantly reducing cell survival. The penetration of nano-hydrogels into tumor tissue is visualized by fluorescence imaging and MRI. The highest intensity of the tumor signal was recorded 30 minutes after the combined treatment (electroporation and QDs loaded nano-hydrogels), even 48 hours post electroporation. The data show a more efficient penetration and long retention of nanoparticles in the tumor after electroporation, due to the increased permeability of the cell membranes and local cleavage of the blood vessels. Conclusion: The internalization and retention of nano-hydrogels is a promising tool both in future strategies for the treatment of cancer and nano medicine. [bg

  4. Controlling morphology and crystallite size of Cu(In0.7Ga0.3)Se2 nano-crystals synthesized using a heating-up method

    International Nuclear Information System (INIS)

    Hsu, Wei-Hsiang; Hsiang, Hsing-I; Chia, Chih-Ta; Yen, Fu-Su

    2013-01-01

    CuIn 0.7 Ga 0.3 Se 2 (CIGS) nano-crystals were successfully synthesized via a heating-up process. The non-coordinating solvent (1-octadecene) and selenium/cations ratio effects on the crystalline phase and crystallite size of CIGS nano-crystallites were investigated. It was observed that the CIGS nano-crystallite morphology changed from sheet into spherical shape as the amount of 1-octadecene addition was increased. CIGS nano-crystals were obtained in 9–20 nm sizes as the selenium/cations ratio increased. These results suggest that the monomer reactivity in the solution can be adjusted by changing the solvent type and selenium/cations ratio, hence affecting the crystallite size and distribution. - Graphical abstract: CuIn 0.7 Ga 0.3 Se 2 (CIGS) nano-crystals were successfully synthesized via a heating-up process in this study. The super-saturation in the solution can be adjusted by changing the OLA/ODE ratio and selenium/cation ratio.

  5. Energy-effective Grinding of Inorganic Solids Using Organic Additives.

    Science.gov (United States)

    Mishra, Ratan K; Weibel, Martin; Müller, Thomas; Heinz, Hendrik; Flatt, Robert J

    2017-08-09

    We present our research findings related to new formulations of the organic additives (grinding aids) needed for the efficient grinding of inorganic solids. Even though the size reduction phenomena of the inorganic solid particles in a ball mill is purely a physical process, the addition of grinding aids in milling media introduces a complex physicochemical process. In addition to further gain in productivity, the organic additive helps to reduce the energy needed for grinding, which in the case of cement clinker has major environmental implications worldwide. This is primarily due to the tremendous amounts of cement produced and almost 30% of the associated electrical energy is consumed for grinding. In this paper, we examine the question of how to optimize these grinding aids linking molecular insight into their working mechanisms, and also how to design chemical additives of improved performance for industrial comminution.

  6. On airborne nano/micro-sized wear particles released from low-metallic automotive brakes

    International Nuclear Information System (INIS)

    Kukutschova, Jana; Moravec, Pavel; Tomasek, Vladimir; Matejka, Vlastimil; Smolik, Jiri; Schwarz, Jaroslav; Seidlerova, Jana; Safarova, Klara; Filip, Peter

    2011-01-01

    The paper addresses the wear particles released from commercially available 'low-metallic' automotive brake pads subjected to brake dynamometer tests. Particle size distribution was measured in situ and the generated particles were collected. The collected fractions and the original bulk material were analyzed using several chemical and microscopic techniques. The experiments demonstrated that airborne wear particles with sizes between 10 nm and 20 μm were released into the air. The numbers of nanoparticles (<100 nm) were by three orders of magnitude larger when compared to the microparticles. A significant release of nanoparticles was measured when the average temperature of the rotor reached 300 deg. C, the combustion initiation temperature of organics present in brakes. In contrast to particle size distribution data, the microscopic analysis revealed the presence of nanoparticles, mostly in the form of agglomerates, in all captured fractions. The majority of elements present in the bulk material were also detected in the ultra-fine fraction of the wear particles. - Research highlights: → Wear of low-metallic friction composite produces airborne nano-sized particles. → Nano-sized particles contain carbon black and metallic compounds. → Carbon black nano-sized particles are related to resin degradation. → Number of nanoparticles higher by three orders of magnitude than microparticles. - Braking of automobiles may contribute to nano-particulate air pollution caused by friction processes associated with wear of low-metallic brake pads.

  7. Optical Detection and Sizing of Single Nano-Particles Using Continuous Wetting Films

    Science.gov (United States)

    Hennequin, Yves; McLeod, Euan; Mudanyali, Onur; Migliozzi, Daniel; Ozcan, Aydogan; Dinten, Jean-Marc

    2013-01-01

    The physical interaction between nano-scale objects and liquid interfaces can create unique optical properties, enhancing the signatures of the objects with sub-wavelength features. Here we show that the evaporation on a wetting substrate of a polymer solution containing sub-micrometer or nano-scale particles creates liquid micro-lenses that arise from the local deformations of the continuous wetting film. These micro-lenses have properties similar to axicon lenses that are known to create beams with a long depth of focus. This enhanced depth of focus allows detection of single nanoparticles using a low magnification microscope objective lens, achieving a relatively wide field-of-view, while also lifting the constraints on precise focusing onto the object plane. Hence, by creating these liquid axicon lenses through spatial deformations of a continuous thin wetting film, we transfer the challenge of imaging individual nano-particles to detecting the light focused by these lenses. As a proof of concept, we demonstrate the detection and sizing of single nano-particles (100 and 200 nm), CpGV granuloviruses as well as Staphylococcus epidermidis bacteria over a wide field of view of e.g., 5.10×3.75 mm2 using a ×5 objective lens with a numerical aperture of 0.15. In addition to conventional lens-based microscopy, this continuous wetting film based approach is also applicable to lensfree computational on-chip imaging, which can be used to detect single nano-particles over a large field-of-view of e.g., >20-30 mm2. These results could be especially useful for high-throughput field-analysis of nano-scale objects using compact and cost-effective microscope designs. PMID:23889001

  8. Ductility and work hardening in nano-sized metallic glasses

    Energy Technology Data Exchange (ETDEWEB)

    Chen, D. Z., E-mail: dzchen@caltech.edu [Division of Engineering and Applied Sciences, California Institute of Technology, Pasadena, California 91125 (United States); Gu, X. W. [Department of Chemistry and Chemical Engineering, California Institute of Technology, Pasadena, California 91125 (United States); An, Q.; Goddard, W. A. [Materials and Process Simulation Center, California Institute of Technology, Pasadena, California 91125 (United States); Greer, J. R. [Division of Engineering and Applied Sciences, California Institute of Technology, Pasadena, California 91125 (United States); The Kavli Nanoscience Institute, California Institute of Technology, Pasadena, California 91125 (United States)

    2015-02-09

    In-situ nano-tensile experiments on 70 nm-diameter free-standing electroplated NiP metallic glass nanostructures reveal tensile true strains of ∼18%, an amount comparable to compositionally identical 100 nm-diameter focused ion beam samples and ∼3 times greater than 100 nm-diameter electroplated samples. Simultaneous in-situ observations and stress-strain data during post-elastic deformation reveal necking and work hardening, features uncharacteristic for metallic glasses. The evolution of free volume within molecular dynamics-simulated samples suggests a free surface-mediated relaxation mechanism in nano-sized metallic glasses.

  9. Microwave sintering of nano size powder β-TCP bioceramics

    Directory of Open Access Journals (Sweden)

    Mirhadi B.

    2014-01-01

    Full Text Available A nano sized beta tricalcium phosphate (β-TCP powder was conventional sintered (CS and microwave sintered (MW, in order to obtain dense β-TCP ceramics. In this work the effect of microwave sintering conditions on the microstructure, phase composition and mechanical properties of materials based on tricalcium phosphate (TCP was investigated by SEM (scanning electron microscopyand XRD(X-ray diffraction and then compared with conventional sintered samples. Nano-size β-TCP powders with average grain size of 80 nm were prepared by the wet chemical precipitation method with calcium nitrate and diammonium hydrogen phosphate as calcium and phosphorus precursors, respectively. The precipitation process employed was also found to be suitable for the production of submicrometre β-TCP powder in situ. The β-TCP samples microwave (MW sintered for 15 min at 1100°C, with average grain size of 3μm, showed better densification, higher density and certainly higher hardness than samples conventionally sintered for 2 h at the same temperature. By comparing sintered and MW sintered β-TCP samples, it was concluded that MW sintered β-TCP samples have superior mechanical properties.

  10. Effect of nano-additives on microstructure, mechanical properties and wear behaviour of Fe–Cr–B hardfacing alloy

    International Nuclear Information System (INIS)

    Gou, Junfeng; Lu, Pengpeng; Wang, You; Liu, Saiyue; Zou, Zhiwei

    2016-01-01

    Graphical abstract: Wear rate of the hardfacing layers with different nano-additives content and the counterpart GCr15 steel balls under conditions: normal load = 15 N, rotating speed = 400 rpm, total sliding time = 20 min. - Highlights: • Nano-additives remarkably improved the microstructure of hardfacing layers. • The hardness of hardfacing layers increased linearly with the increase of nano-additives. • The wear rate of the hardfacing layer with 0.65 wt.% nano-additives decreased about 88% than that of the hardfacing layer without nano-additives. • According to observation of wear tracks of hardfacing layers, the main wear mechanism was adhesion wear. - Abstract: Fe–Cr–B hardfacing alloys with different nano-additives content were investigated. The effects of nano-additives on the microstructures of hardfacing alloy were studied by using optical microscope, scanning electron microscope, X-ray diffractometer. The hardness and the fracture toughness of hardfacing alloys were measured, respectively. The sliding wear tests were carried out using a ball-on-disc tribometer. The experimental results showed that primary carbide of hardfacing alloys was refined and its distribution became uniform with content of nano-additives increased. The hardfacing alloys are composed of Cr_7C_3, Fe_7C_3, α-Fe and Fe_2B according to the results of X-ray diffraction. The hardness of hardfacing alloys increased linearly with the increase of nano-additives. The hardness of the hardfacing alloy with 1.5 wt.% nano-additives increased 54.8% than that of the hardfacing alloy without nano-additives and reached to 1011HV. The K_I_C of the hardfacing alloy with 0.65 wt.% nano-additives was 15.4 MPam"1"/"2, which reached a maximum. The value increased 57.1% than that of the hardfacing alloy without nano-additives. The wear rates of the hardfacing layer with 0.65 wt.% and 1.0 wt.% nano-additives decreased about 88% than that of the hardfacing layer without nano-additives. The main

  11. Spatially confined synthesis of SiOx nano-rod with size-controlled Si quantum dots in nano-porous anodic aluminum oxide membrane.

    Science.gov (United States)

    Pai, Yi-Hao; Lin, Gong-Ru

    2011-01-17

    By depositing Si-rich SiOx nano-rod in nano-porous anodic aluminum oxide (AAO) membrane using PECVD, the spatially confined synthesis of Si quantum-dots (Si-QDs) with ultra-bright photoluminescence spectra are demonstrated after low-temperature annealing. Spatially confined SiOx nano-rod in nano-porous AAO membrane greatly increases the density of nucleated positions for Si-QD precursors, which essentially impedes the route of thermally diffused Si atoms and confines the degree of atomic self-aggregation. The diffusion controlled growth mechanism is employed to determine the activation energy of 6.284 kJ mole(-1) and diffusion length of 2.84 nm for SiO1.5 nano-rod in nano-porous AAO membrane. HRTEM results verify that the reduced geometric dimension of the SiOx host matrix effectively constrain the buried Si-QD size at even lower annealing temperature. The spatially confined synthesis of Si-QD essentially contributes the intense PL with its spectral linewidth shrinking from 210 to 140 nm and its peak intensity enhancing by two orders of magnitude, corresponding to the reduction on both the average Si-QD size and its standard deviation from 2.6 to 2.0 nm and from 25% to 12.5%, respectively. The red-shifted PL wavelength of the Si-QD reveals an inverse exponential trend with increasing temperature of annealing, which is in good agree with the Si-QD size simulation via the atomic diffusion theory.

  12. Nano-sized polystyrene affects feeding, behavior and physiology of brine shrimp Artemia franciscana larvae.

    Science.gov (United States)

    Bergami, Elisa; Bocci, Elena; Vannuccini, Maria Luisa; Monopoli, Marco; Salvati, Anna; Dawson, Kenneth A; Corsi, Ilaria

    2016-01-01

    Nano-sized polymers as polystyrene (PS) constitute one of the main challenges for marine ecosystems, since they can distribute along the whole water column affecting planktonic species and consequently disrupting the energy flow of marine ecosystems. Nowadays very little knowledge is available on the impact of nano-sized plastics on marine organisms. Therefore, the present study aims to evaluate the effects of 40nm anionic carboxylated (PS-COOH) and 50nm cationic amino (PS-NH2) polystyrene nanoparticles (PS NPs) on brine shrimp Artemia franciscana larvae. No signs of mortality were observed at 48h of exposure for both PS NPs at naplius stage but several sub-lethal effects were evident. PS-COOH (5-100μg/ml) resulted massively sequestered inside the gut lumen of larvae (48h) probably limiting food intake. Some of them were lately excreted as fecal pellets but not a full release was observed. Likewise, PS-NH2 (5-100µg/ml) accumulated in larvae (48h) but also adsorbed at the surface of sensorial antennules and appendages probably hampering larvae motility. In addition, larvae exposed to PS-NH2 undergo multiple molting events during 48h of exposure compared to controls. The activation of a defense mechanism based on a physiological process able to release toxic cationic NPs (PS-NH2) from the body can be hypothesized. The general observed accumulation of PS NPs within the gut during the 48h of exposure indicates a continuous bioavailability of nano-sized PS for planktonic species as well as a potential transfer along the trophic web. Therefore, nano-sized PS might be able to impair food uptake (feeding), behavior (motility) and physiology (multiple molting) of brine shrimp larvae with consequences not only at organism and population level but on the overall ecosystem based on the key role of zooplankton on marine food webs. Copyright © 2015 Elsevier Inc. All rights reserved.

  13. Size dependent compressibility of nano-ceria: Minimum near 33 nm

    International Nuclear Information System (INIS)

    Rodenbough, Philip P.; Song, Junhua; Chan, Siu-Wai; Walker, David; Clark, Simon M.; Kalkan, Bora

    2015-01-01

    We report the crystallite-size-dependency of the compressibility of nanoceria under hydrostatic pressure for a wide variety of crystallite diameters and comment on the size-based trends indicating an extremum near 33 nm. Uniform nano-crystals of ceria were synthesized by basic precipitation from cerium (III) nitrate. Size-control was achieved by adjusting mixing time and, for larger particles, a subsequent annealing temperature. The nano-crystals were characterized by transmission electron microscopy and standard ambient x-ray diffraction (XRD). Compressibility, or its reciprocal, bulk modulus, was measured with high-pressure XRD at LBL-ALS, using helium, neon, or argon as the pressure-transmitting medium for all samples. As crystallite size decreased below 100 nm, the bulk modulus first increased, and then decreased, achieving a maximum near a crystallite diameter of 33 nm. We review earlier work and examine several possible explanations for the peaking of bulk modulus at an intermediate crystallite size

  14. Size dependent compressibility of nano-ceria: Minimum near 33 nm

    Energy Technology Data Exchange (ETDEWEB)

    Rodenbough, Philip P. [Department of Applied Physics and Applied Mathematics, Materials Science and Engineering Program, Columbia University, New York, New York 10027 (United States); Chemistry Department, Columbia University, New York, New York 10027 (United States); Song, Junhua; Chan, Siu-Wai, E-mail: sc174@columbia.edu [Department of Applied Physics and Applied Mathematics, Materials Science and Engineering Program, Columbia University, New York, New York 10027 (United States); Walker, David [Department of Earth and Environmental Sciences, Lamont-Doherty Earth Observatory, Columbia University, Palisades, New York 10964 (United States); Clark, Simon M. [ARC Center of Excellence for Core to Crust Fluid Systems and Department of Earth and Planetary Sciences, Macquarie University, Sydney, New South Wales 2019, Australia and The Bragg Institute, Australian Nuclear Science and Technology Organisation, Kirrawee DC, New South Wales 2232 (Australia); Kalkan, Bora [Department of Physics Engineering, Hacettepe University, 06800 Beytepe, Ankara (Turkey)

    2015-04-20

    We report the crystallite-size-dependency of the compressibility of nanoceria under hydrostatic pressure for a wide variety of crystallite diameters and comment on the size-based trends indicating an extremum near 33 nm. Uniform nano-crystals of ceria were synthesized by basic precipitation from cerium (III) nitrate. Size-control was achieved by adjusting mixing time and, for larger particles, a subsequent annealing temperature. The nano-crystals were characterized by transmission electron microscopy and standard ambient x-ray diffraction (XRD). Compressibility, or its reciprocal, bulk modulus, was measured with high-pressure XRD at LBL-ALS, using helium, neon, or argon as the pressure-transmitting medium for all samples. As crystallite size decreased below 100 nm, the bulk modulus first increased, and then decreased, achieving a maximum near a crystallite diameter of 33 nm. We review earlier work and examine several possible explanations for the peaking of bulk modulus at an intermediate crystallite size.

  15. A submerged ceramic membrane reactor for the p-nitrophenol hydrogenation over nano-sized nickel catalysts.

    Science.gov (United States)

    Chen, R Z; Sun, H L; Xing, W H; Jin, W Q; Xu, N P

    2009-02-01

    The catalytic hydrogenation of p-nitrophenol to p-aminophenol over nano-sized nickel catalysts was carried out in a submerged ceramic membrane reactor. It has been demonstrated that the submerged ceramic membrane reactor is more suitable for the p-nitrophenol hydrogenation over nano-sized nickel catalysts compared with the side-stream ceramic membrane reactor, and the membrane module configuration has a great influence on the reaction rate of p-nitrophenol hydrogenation and the membrane treating capacity. The deactivation of nano-sized nickel is mainly caused by the adsorption of impurity on the surface of nickel and the increase of oxidation degree of nickel.

  16. Localization of solid micro and nano-inclusions in heterophase bioplastic blends

    Science.gov (United States)

    Dil, Ebrahim Jalali

    Blending poly(lactic acid), PLA, with other high impact bioplastics has been introduced as an effective method for improving the toughness of PLA; however, this strategy considerably reduces the modulus and mechanical strength of PLA. The addition of solid particles is a well-known method for tuning the stiffness/toughness balance in toughened polymer matrices. Notwithstanding the significance of controlling the localization of solid inclusions in polymer blends, the literature is lacking a detailed analysis of the migration mechanisms and the effects of thermodynamic and kinetic parameters on the localization of solid particles in polymer blends. In this dissertation, the localization and migration of spherical micro- and nano-silica particles in two bioplastic blends of PLA/low density polyethylene (LDPE) and PLA/poly(butylene adipateco-terephthalate), PBAT, were studied. In the first part of this work, a detailed study on the miscibility and morphology development in the PLA/PBAT blend was carried out. The interfacial tension between PLA and PBAT was determined to be 0.6 +/- 0.15 mN/m by fitting Palierne's model on the rheological data. The miscibility of PLA/PBAT was then examined by studying the shift in the glass transition temperature (Tg) of the polymer phases at different blend compositions. The obtained results indicate a limited one-way partial miscibility of PBAT molecules in the PLA-rich phase. This partial miscibility depends significantly on the molecular weight of PBAT, which underlines its entropic nature. The morphology analysis of the blend samples revealed that the dispersed phase in PLA/PBAT blends exists in the form of fibers, even at low compositions of 1 vol.% of the dispersed phase. Finally, the co-continuity region in PLA/PBAT blends was determined using a rheological approach and it was shown that PLA/PBAT has a wide symmetric co-continuous region located between 30-40 and 60-70 vol.% of PBAT. In the second part of this project, the

  17. Does size matter? Study of performance of pseudo-ELISAs based on molecularly imprinted polymer nanoparticles prepared for analytes of different sizes.

    Science.gov (United States)

    Cáceres, C; Canfarotta, F; Chianella, I; Pereira, E; Moczko, E; Esen, C; Guerreiro, A; Piletska, E; Whitcombe, M J; Piletsky, S A

    2016-02-21

    The aim of this work is to evaluate whether the size of the analyte used as template for the synthesis of molecularly imprinted polymer nanoparticles (nanoMIPs) can affect their performance in pseudo-enzyme linked immunosorbent assays (pseudo-ELISAs). Successful demonstration of a nanoMIPs-based pseudo-ELISA for vancomycin (1449.3 g mol(-1)) was demonstrated earlier. In the present investigation, the following analytes were selected: horseradish peroxidase (HRP, 44 kDa), cytochrome C (Cyt C, 12 kDa) biotin (244.31 g mol(-1)) and melamine (126.12 g mol(-1)). NanoMIPs with a similar composition for all analytes were synthesised by persulfate-initiated polymerisation in water. In addition, core-shell nanoMIPs coated with polyethylene glycol (PEG) and imprinted for melamine were produced in organics and tested. The polymerisation of the nanoparticles was done using a solid-phase approach with the correspondent template immobilised on glass beads. The performance of the nanoMIPs used as replacement for antibodies in direct pseudo-ELISA (for the enzymes) and competitive pseudo-ELISA for the smaller analytes was investigated. For the competitive mode we rely on competition for the binding to the nanoparticles between free analyte and corresponding analyte-HRP conjugate. The results revealed that the best performances were obtained for nanoMIPs synthesised in aqueous media for the larger analytes. In addition, this approach was successful for biotin but completely failed for the smallest template melamine. This problem was solved using nanoMIP prepared by UV polymerisation in an organic media with a PEG shell. This study demonstrates that the preparation of nanoMIP by solid-phase approach can produce material with high affinity and potential to replace antibodies in ELISA tests for both large and small analytes. This makes this technology versatile and applicable to practically any target analyte and diagnostic field.

  18. Modification of unsaturated polyester resins using nano-size core ...

    African Journals Online (AJOL)

    Modification of unsaturated polyester resins using nano-size core-shell particles. MO Munyati, PA Lovell. Abstract. No Abstract Available Journal of Science and Technology Special Edition 2004: 24-31. Full Text: EMAIL FULL TEXT EMAIL FULL TEXT · DOWNLOAD FULL TEXT DOWNLOAD FULL TEXT.

  19. Preparation and tribological properties of surface-modified nano-Y{sub 2}O{sub 3} as additive in liquid paraffin

    Energy Technology Data Exchange (ETDEWEB)

    Yu Lin, E-mail: gych@gdut.edu.cn [School of Chemical Engineering and Light Industry, Guangdong University of Technology, Guangzhou 510006 (China); Zhang Lin; Ye Fei; Sun Ming; Cheng Xiaoling; Diao Guiqiang [School of Chemical Engineering and Light Industry, Guangdong University of Technology, Guangzhou 510006 (China)

    2012-12-15

    Highlights: Black-Right-Pointing-Pointer Nano-Y{sub 2}O{sub 3} was for the first time used as lubricant additive in liquid paraffin. Black-Right-Pointing-Pointer The nano-Y{sub 2}O{sub 3} modified by a coupling-grafting method shows good dispersibility in liquid paraffin. Black-Right-Pointing-Pointer The surface-modified nano-Y{sub 2}O{sub 3} considerably improves the tribological performances of liquid paraffin. - Abstract: Surface-modified nano-Y{sub 2}O{sub 3} was prepared by a coupling-grafting method with vinyl methylerichlorosilane and methyl methacrylate as the coupling agent and grafting agent, respectively. The prepared samples were characterized by X-ray diffraction (XRD), Fourier transform infrared spectra (FT-IR), transmission electron micrograph (TEM) and thermal gravimetric analysis (TGA). The tribological properties of the surface-modified nano-Y{sub 2}O{sub 3} as additive in liquid paraffin were evaluated with a four-ball tester. The results show that the nano-Y{sub 2}O{sub 3} keeps its original crystalline structure after surface modification, and the modified nano-Y{sub 2}O{sub 3} forms a core-shell structure with an average particle size of 24.5 nm. The maximum non-seizure load (P{sub B} value) and sintered load (P{sub D} value) increase by 25% and 26.9%, respectively, when compared with those of liquid paraffin, and the wear scar diameter (WSD) also decrease by 21% when 0.10% surface-modified nano-Y{sub 2}O{sub 3} was added. The protective inorganic-organic film formed by nano-Y{sub 2}O{sub 3} and organic modifiers plays an important role in the improved tribological properties of liquid paraffin.

  20. Effects of amorphous nano-silica additions on mechanical and durability performance of SCC mixtures

    NARCIS (Netherlands)

    Quercia Bianchi, G.; Spiesz, P.R.; Hüsken, G.; Brouwers, H.J.H.; Justnes, H.; Jacobsen, S.

    2012-01-01

    In the recent years the application of nanotechnology in building materials has increased exponentially. One of the most referred and used nano-materials is amorphous silica with particles size in the nano-range, even though its application and effect in concrete has not been fully understood yet.

  1. Controlling morphology and crystallite size of Cu(In{sub 0.7}Ga{sub 0.3})Se{sub 2} nano-crystals synthesized using a heating-up method

    Energy Technology Data Exchange (ETDEWEB)

    Hsu, Wei-Hsiang [Department of Resources Engineering, Particulate Materials Research Center, National Cheng Kung University, Tainan, 70101 Taiwan (China); Hsiang, Hsing-I, E-mail: hsingi@mail.ncku.edu.tw [Department of Resources Engineering, Particulate Materials Research Center, National Cheng Kung University, Tainan, 70101 Taiwan (China); Chia, Chih-Ta [Department of Physics, National Taiwan Normal University, Taipei, 116 Taiwan (China); Yen, Fu-Su [Department of Resources Engineering, Particulate Materials Research Center, National Cheng Kung University, Tainan, 70101 Taiwan (China)

    2013-12-15

    CuIn{sub 0.7}Ga{sub 0.3}Se{sub 2}(CIGS) nano-crystals were successfully synthesized via a heating-up process. The non-coordinating solvent (1-octadecene) and selenium/cations ratio effects on the crystalline phase and crystallite size of CIGS nano-crystallites were investigated. It was observed that the CIGS nano-crystallite morphology changed from sheet into spherical shape as the amount of 1-octadecene addition was increased. CIGS nano-crystals were obtained in 9–20 nm sizes as the selenium/cations ratio increased. These results suggest that the monomer reactivity in the solution can be adjusted by changing the solvent type and selenium/cations ratio, hence affecting the crystallite size and distribution. - Graphical abstract: CuIn{sub 0.7}Ga{sub 0.3}Se{sub 2}(CIGS) nano-crystals were successfully synthesized via a heating-up process in this study. The super-saturation in the solution can be adjusted by changing the OLA/ODE ratio and selenium/cation ratio.

  2. Oxide nano-rod array structure via a simple metallurgical process

    International Nuclear Information System (INIS)

    Nanko, M; Do, D T M

    2011-01-01

    A simple method for fabricating oxide nano-rod array structure via metallurgical process is reported. Some dilute alloys such as Ni(Al) solid solution shows internal oxidation with rod-like oxide precipices during high-temperature oxidation with low oxygen partial pressure. By removing a metal part in internal oxidation zone, oxide nano-rod array structure can be developed on the surface of metallic components. In this report, Al 2 O 3 or NiAl 2 O 4 nano-rod array structures were prepared by using Ni(Al) solid solution. Effects of Cr addition into Ni(Al) solid solution on internal oxidation were also reported. Pack cementation process for aluminizing of Ni surface was applied to prepare nano-rod array components with desired shape. Near-net shape Ni components with oxide nano-rod array structure on their surface can be prepared by using the pack cementation process and internal oxidation,

  3. Coupling DNA nano-breadboards to solid state conductors

    International Nuclear Information System (INIS)

    Wang, Liqian; Morales, Piero; Dalmastri, Claudia; Rapone, Bruno; Gothelf, Kurt; Krissanaprasit, Abhichart; Rettere, Scott

    2015-01-01

    DNA is not only a most extraordinary information storage medium: the programmable pairing of DNA single strands into precisely engineered, connecting double helices make it an extremely appealing material for assemblage of nanoscale architectures. This is the basis of DNA nanotechnology, and designing almost any structure made of DNA at the nanometer scale, decorating it with a variety of functional molecules, and accomplishing it by virtually inexpensive self-assembly, is already a reality in many research laboratories in the world. But can we extend the range of applications of this technology by coupling DNA grafted molecular electronic nano circuitry to solid state devices, and interface molecular smart functions to our senses? This challenging research is addressed by a collaborative research among ENEA, the Universities of Roma 'Tor Vergata' and 'Aarhus', and the CNMS of the Oak Ridge National Laboratory. The first results obtained by our consortium pave the way to the technological ability to interface and use completely self-assembled, DNA-based electronic nano-breadboards, endowed with ultra-high-density functional organic components [it

  4. Nano ZnO/amine composites antimicrobial additives to acrylic paints

    Directory of Open Access Journals (Sweden)

    H.B. Kamal

    2015-12-01

    Full Text Available Nano ZnO has been widely used as an antimicrobial agent not only for food packaging purposes but also in many coating processes. The present work is meant to enhance such functions through the preparation of sustainable and safe conduct of nano ZnO composites with amine derivatives that are characterized by their antimicrobial and anti-fouling functional activities. The results obtained revealed a more comprehensive approach to the antimicrobial function based on the reported active oxide species role. The oxide/amine composites and the acrylic emulsion paint were characterized chemically and structurally through FT-IR, TGA and TEM supported by biological assessment of each ZnO/amine composite action. Results of the study concluded that equilibrium between the nano ZnO particles size, their dispersion form, and amine ability to stabilize the actively produced oxygen species responsible for the antimicrobial function, should all be accounted for when persistence of antimicrobial agent efficiency is regarded.

  5. Synthesis and characterization of nano-crystalline Ce1-xGd xO2-x/2 (x = 0-0.30) solid solutions

    DEFF Research Database (Denmark)

    Jadhav, L. D.; Chourashiya, M. G.; Jamale, A. P.

    2010-01-01

    glycine-nitrate process (GNP) has been presented. Evolution of structural and morphological properties of nano-powders as a function of heat treatment has also been studied. The prepared samples were characterized using TG-DTA, FT-IR, Raman spectroscopy, XRD, SEM, etc. In addition, the effect of Gd......In recent years, doped ceria is an established and promising candidate as solid electrolyte for intermediate temperature solid oxide fuel cell (IT-SOFC). In this investigation, synthesis and characterizations of nano-crystalline Gd doped ceria, (Ce1-xGdxO2-x/2, where x = 0-0.3), prepared using...... of sintered samples was observed to hinder with an increase in Gd content....

  6. Polyol mediated nano size zinc oxide and nanocomposites with poly(methyl methacrylate

    Directory of Open Access Journals (Sweden)

    2011-07-01

    Full Text Available Organophilic nano ZnO particles have been synthesized in various diols (ethylene glycol – EG, 1,2 propane diol – PD, 1,4 butane diol – BD and tetra(ethylene glycol – TEG in the presence of p-toluenesulfonic acid, p-TsOH, as an end capping agent. The addition of p-TsOH reduces the ZnO particle size and increases its crystallite size. With increasing diol main chain length the ZnO particle size increases (EG (32 nm < PD (33 nm < BD (72 nm < TEG (86 nm. Using the assynthesized and unmodified ZnO nanocomposites with poly(methyl methacrylate, PMMA, matrix have been prepared by the in-situ bulk polymerization of methyl methacrylate, MMA. The addition of surface modifiers is avoided which is an advantage for the application since they can influence other properties of the material. ZnO particles, especially those with smaller particle sizes (EG – 32 nm, PD – 33 nm showed enhanced effect on the thermal stability of PMMA, ultraviolet, UV, absorption and transparency for visible light. Transparent materials with high UV absorption and with enhanced resistance to sunlight were obtained by optimizing the nanocomposite preparation procedure using ZnO particles of about 30 nm size in concentrations between 0.05 and 0.1 wt%. The reported nanocomposite preparation procedure is compatible with the industrial process of PMMA sheet production.

  7. Preparation of nano-sized α-Al2O3 from oil shale ash

    International Nuclear Information System (INIS)

    An, Baichao; Wang, Wenying; Ji, Guijuan; Gan, Shucai; Gao, Guimei; Xu, Jijing; Li, Guanghuan

    2010-01-01

    Oil shale ash (OSA), the residue of oil shale semi-coke roasting, was used as a raw material to synthesize nano-sized α-Al 2 O 3 . Ultrasonic oscillation pretreatment followed by azeotropic distillation was employed for reducing the particle size of α-Al 2 O 3 . The structural characterization at molecular and nanometer scales was performed using X-ray diffraction (XRD), transmission electron microscopy (TEM), respectively. The interaction between alumina and n-butanol was characterized by Fourier transform infrared spectroscopy (FT-IR). The results revealed that the crystalline phase of alumina nanoparticles was regular and the well dispersed alumina nanoparticles had a diameter of 50-80 nm. In addition, the significant factors including injection rate of carbon oxide (CO 2 ), ultrasonic oscillations, azeotropic distillation and surfactant were investigated with respect to their effects on the size of the alumina particles.

  8. Nano-scale Materials and Nano-technology Processes in Environmental Protection

    International Nuclear Information System (INIS)

    Vissokov, Gh; Tzvetkoff, T.

    2003-01-01

    A number of environmental and energy technologies have benefited substantially from nano-scale technology: reduced waste and improved energy efficiency; environmentally friendly composite structures; waste remediation; energy conversion. In this report examples of current achievements and paradigm shifts are presented: from discovery to application; a nano structured materials; nanoparticles in the environment (plasma chemical preparation); nano-porous polymers and their applications in water purification; photo catalytic fluid purification; hierarchical self-assembled nano-structures for adsorption of heavy metals, etc. Several themes should be considered priorities in developing nano-scale processes related to environmental management: 1. To develop understanding and control of relevant processes, including protein precipitation and crystallisation, desorption of pollutants, stability of colloidal dispersion, micelle aggregation, microbe mobility, formation and mobility of nanoparticles, and tissue-nanoparticle interaction. Emphasis should be given to processes at phase boundaries (solid-liquid, solid-gas, liquid-gas) that involve mineral and organic soil components, aerosols, biomolecules (cells, microbes), bio tissues, derived components such as bio films and membranes, and anthropogenic additions (e.g. trace and heavy metals); 2. To carry out interdisciplinary research that initiates Noel approaches and adopts new methods for characterising surfaces and modelling complex systems to problems at interfaces and other nano-structures in the natural environment, including those involving biological or living systems. New technological advances such as optical traps, laser tweezers, and synchrotrons are extending examination of molecular and nano-scale processes to the single-molecule or single-cell level; 3. To integrate understanding of the roles of molecular and nano-scale phenomena and behaviour at the meso- and/or macro-scale over a period of time

  9. Synthesis of nano-sized amorphous boron powders through active dilution self-propagating high-temperature synthesis method

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Jilin [The State Key Laboratory of Advanced Technology for Materials Synthesis and Processing, Wuhan University of Technology, Wuhan 430070 (China); Gu, Yunle [School of Material Science and Engineering, Wuhan Institute of Technology, Wuhan 430073 (China); Li, Zili [The State Key Laboratory of Advanced Technology for Materials Synthesis and Processing, Wuhan University of Technology, Wuhan 430070 (China); Wang, Weimin, E-mail: wangwm@hotmail.com [The State Key Laboratory of Advanced Technology for Materials Synthesis and Processing, Wuhan University of Technology, Wuhan 430070 (China); Fu, Zhengyi [The State Key Laboratory of Advanced Technology for Materials Synthesis and Processing, Wuhan University of Technology, Wuhan 430070 (China)

    2013-06-01

    Graphical abstract: Nano-sized amorphous boron powders were synthesized by active dilution self-propagating high-temperature synthesis (SHS) method. The effects of endothermic reaction rate, the possible chemical reaction mechanism and active dilution model for synthesis of the product were also discussed. Highlights: ► Nano-sized amorphous boron powders were synthesized by active dilution self-propagating high-temperature synthesis method. ► The morphology, particle size and purity of the samples could be effectively controlled via changing the endothermic rate. ► The diluter KBH{sub 4} played an important role in active dilution synthesis of amorphous nano-sized boron powders. ► The active dilution method could be further popularized and become a common approach to prepare various inorganic materials. - Abstract: Nano-sized amorphous boron powders were synthesized by active dilution self-propagating high-temperature synthesis (SHS) method at temperatures ranging from 700 °C to 850 °C in a SHS furnace using Mg, B{sub 2}O{sub 3} and KBH{sub 4} as raw materials. Samples were characterized by X-ray powder diffraction (XRD), Laser particle size analyzer, Fourier transform infrared spectra (FTIR), X-ray energy dispersive spectroscopy (EDX), scanning electron microscopy (SEM), transmission electron microscopy (TEM) and high-resolution transmission TEM (HRTEM). The boron powders demonstrated an average particle size of 50 nm with a purity of 95.64 wt.%. The diluter KBH{sub 4} played an important role in the active dilution synthesis of amorphous nano-sized boron powders. The effects of endothermic reaction rate, the possible chemical reaction mechanism and active dilution model for synthesis of the product were also discussed.

  10. Synthesis of nano-sized amorphous boron powders through active dilution self-propagating high-temperature synthesis method

    International Nuclear Information System (INIS)

    Wang, Jilin; Gu, Yunle; Li, Zili; Wang, Weimin; Fu, Zhengyi

    2013-01-01

    Graphical abstract: Nano-sized amorphous boron powders were synthesized by active dilution self-propagating high-temperature synthesis (SHS) method. The effects of endothermic reaction rate, the possible chemical reaction mechanism and active dilution model for synthesis of the product were also discussed. Highlights: ► Nano-sized amorphous boron powders were synthesized by active dilution self-propagating high-temperature synthesis method. ► The morphology, particle size and purity of the samples could be effectively controlled via changing the endothermic rate. ► The diluter KBH 4 played an important role in active dilution synthesis of amorphous nano-sized boron powders. ► The active dilution method could be further popularized and become a common approach to prepare various inorganic materials. - Abstract: Nano-sized amorphous boron powders were synthesized by active dilution self-propagating high-temperature synthesis (SHS) method at temperatures ranging from 700 °C to 850 °C in a SHS furnace using Mg, B 2 O 3 and KBH 4 as raw materials. Samples were characterized by X-ray powder diffraction (XRD), Laser particle size analyzer, Fourier transform infrared spectra (FTIR), X-ray energy dispersive spectroscopy (EDX), scanning electron microscopy (SEM), transmission electron microscopy (TEM) and high-resolution transmission TEM (HRTEM). The boron powders demonstrated an average particle size of 50 nm with a purity of 95.64 wt.%. The diluter KBH 4 played an important role in the active dilution synthesis of amorphous nano-sized boron powders. The effects of endothermic reaction rate, the possible chemical reaction mechanism and active dilution model for synthesis of the product were also discussed

  11. Application of nano- and micro-sized particles of cattle manure on soybean growth

    Directory of Open Access Journals (Sweden)

    Hesam Aryanpour

    2017-10-01

    Full Text Available Background: Cattle manure (CM is the most common organic fertilizer used by farmers. However, its usually slow decomposition leads to the use of chemical fertilizers. Therefore, experiments on nano- and micro-sized particles of CM were conducted to evaluate the possibility of accelerating its decomposition in soil. Methods: The effects of a sole application of CM in different sizes (nano-, micro-, and natural-sized particles in two ranges (5 and 20 Mg ha-1 and the combined application of CM and chemical fertilizers on the plant growth characteristics of soybean (cv. JS 335 were studied at Gorgan University. Nano- and micro-sized particles of CM were produced using a ball mill, and their half-life in soil was measured. Soil properties were measured before planting. Grain yield, 1000 grain weight, number of pods per plant, biological yield, plant height, and nutrient contents in plant shoot material were measured. Results: The results showed that the use of nano-sized particles of CM (nCM caused a significant increase in yield and yield components. Increasing the amount of crushing resulted in an increased rate of CM mineralization and in proper nitration before the formation of nodes in the roots. A significantly higher yield was obtained with nCM than with chemical fertilizer, and due to the nCM particles’ half-life in soil, the plants were allowed to absorb nutrients for a longer time period. Conclusion: The nCM has two major advantages over chemical fertilizers in that it does not release nutrients as quickly as chemical fertilizers and the loss of nutrients from soil is low.

  12. A Novel Approach of Using Ground CNTs as the Carbon Source to Fabricate Uniformly Distributed Nano-Sized TiCx/2009Al Composites.

    Science.gov (United States)

    Wang, Lei; Qiu, Feng; Ouyang, Licheng; Wang, Huiyuan; Zha, Min; Shu, Shili; Zhao, Qinglong; Jiang, Qichuan

    2015-12-17

    Nano-sized TiC x /2009Al composites (with 5, 7, and 9 vol% TiC x ) were fabricated via the combustion synthesis of the 2009Al-Ti-CNTs system combined with vacuum hot pressing followed by hot extrusion. In the present study, CNTs were used as the carbon source to synthesize nano-sized TiC x particles. An attempt was made to correlate the effect of ground CNTs by milling and the distribution of synthesized nano-sized TiC x particles in 2009Al as well as the tensile properties of nano-sized TiC x /2009Al composites. Microstructure analysis showed that when ground CNTs were used, the synthesized nano-sized TiC x particles dispersed more uniformly in the 2009Al matrix. Moreover, when 2 h-milled CNTs were used, the 5, 7, and 9 vol% nano-sized TiC x /2009Al composites had the highest tensile properties, especially, the 9 vol% nano-sized TiC x /2009Al composites. The results offered a new approach to improve the distribution of in situ nano-sized TiC x particles and tensile properties of composites.

  13. Complete Chiral Resolution Using Additive-Induced Crystal Size Bifurcation During Grinding

    NARCIS (Netherlands)

    Noorduin, Wim L.; Asdonk, Pim van der; Meekes, Hugo; Enckevort, Willem J.P. van; Kaptein, Bernard; Leeman, Michel; Kellogg, Richard M.; Vlieg, Elias

    2009-01-01

    Grinding them down: By using a tailor-made additive, even in the absence of racemization in solution, abrasive grinding can yield an enantiopure solid state. This novel chiral resolution technique is based on an asymmetric bifurcation in the crystal size distribution as a result of stereoselective

  14. Characterisation of micro-sized and nano-sized tungsten oxide-epoxy composites for radiation shielding of diagnostic X-rays

    Energy Technology Data Exchange (ETDEWEB)

    Noor Azman, N.Z. [Department of Imaging and Applied Physics, Curtin University, GPO Box U1987, Perth, WA 6845 Australia (Australia); School of Physics, Universiti Sains Malaysia, 11800 Penang (Malaysia); Siddiqui, S.A. [Department of Imaging and Applied Physics, Curtin University, GPO Box U1987, Perth, WA 6845 Australia (Australia); Low, I.M., E-mail: j.low@curtin.edu.au [Department of Imaging and Applied Physics, Curtin University, GPO Box U1987, Perth, WA 6845 Australia (Australia)

    2013-12-01

    Characteristics of X-ray transmissions were investigated for epoxy composites filled with 2–10 vol% WO{sub 3} loadings using synchrotron X-ray absorption spectroscopy (XAS) at 10–40 keV. The results obtained were used to determine the equivalent X-ray energies for the operating X-ray tube voltages of mammography and radiology machines. The results confirmed the superior attenuation ability of nano-sized WO{sub 3}-epoxy composites in the energy range of 10–25 keV when compared to their micro-sized counterparts. However, at higher synchrotron radiation energies (i.e., 30–40 keV), the X-ray transmission characteristics were similar with no apparent size effect for both nano-sized and micro-sized WO{sub 3}-epoxy composites. The equivalent X-ray energies for the operating X-ray tube voltages of the mammography unit (25–49 kV) were in the range of 15–25 keV. Similarly, for a radiology unit operating at 40–60 kV, the equivalent energy range was 25–40 keV, and for operating voltages greater than 60 kV (i.e., 70–100 kV), the equivalent energy was in excess of 40 keV. The mechanical properties of epoxy composites increased initially with an increase in the filler loading but a further increase in the WO{sub 3} loading resulted in deterioration of flexural strength, modulus and hardness. - Highlights: • Nano-sized WO{sub 3}-epoxy composites have superior x-ray shielding capability. • No size effect in x-ray attenuation was observed at 30–40 keV. • An optimum filler loading for improving the mechanical properties of WO{sub 3}-epoxy composites.

  15. A comparison of nano bentonite and some nano chemical additives to improve drilling fluid using local clay and commercial bentonites

    Directory of Open Access Journals (Sweden)

    Nada S. Al-Zubaidi

    2017-09-01

    In the second part, a commercial bentonite was used and mixed with nano commercial bentonite and nano chemical materials (MgO, TiO2, and graphene at 0.005, 0.01, 0.05, 0.1, 0.2 and 0.4 wt% concentrations. The results showed that nano commercial bentonite gives the same filtration behavior of graphene, whereas, the plastic viscosity, yield point and apparent viscosity were the same when using nano commercial bentonite, TiO2 and graphene. The best results were obtained with MgO addition, whereby the filter loss decreased to 35% with a higher value of yield point.

  16. Enhancement in ionic conductivity on solid polymer electrolytes containing large conducting species

    Energy Technology Data Exchange (ETDEWEB)

    Praveen, D. [Department of Physics, Amrita Viswha Vidyapeetham, Bangalore, India, E-mail: d-praveen@blr.amrita.edu (India); Damle, Ramakrishna [Department of Physics, Bangalore University, Bangalore, India. E-mail: ramkrishnadamle@bub.ernet.in (India)

    2016-05-23

    Solid Polymer Electrolytes (SPEs) lack better conducting properties at ambient temperatures. Various methods to enhance their ionic conductivity like irradiation with swift heavy ions, γ-rays, swift electrons and quenching at low temperature etc., have been explored in the literature. Among these, one of the oldest methods is incorporation of different conducting species into the polymer matrix and/or addition of nano-sized inert particles into SPEs. Various new salts like LiBr, Mg(ClO{sub 4}){sub 2}, NH{sub 4}I etc., have already been tried in the past with some success. Also various nanoparticles like Al{sub 2}O{sub 3}, TiO{sub 2} etc., have been tried in the past. In this article, we have investigated an SPE containing Rubidium as a conducting species. Rubidium has a larger ionic size compared to lithium and sodium ions which have been investigated in the recent past. In the present article, we have investigated the conductivity of large sized conducting species and shown the enhancement in the ionic conductivity by addition of nano-sized inert particles.

  17. Enhancement in ionic conductivity on solid polymer electrolytes containing large conducting species

    International Nuclear Information System (INIS)

    Praveen, D.; Damle, Ramakrishna

    2016-01-01

    Solid Polymer Electrolytes (SPEs) lack better conducting properties at ambient temperatures. Various methods to enhance their ionic conductivity like irradiation with swift heavy ions, γ-rays, swift electrons and quenching at low temperature etc., have been explored in the literature. Among these, one of the oldest methods is incorporation of different conducting species into the polymer matrix and/or addition of nano-sized inert particles into SPEs. Various new salts like LiBr, Mg(ClO_4)_2, NH_4I etc., have already been tried in the past with some success. Also various nanoparticles like Al_2O_3, TiO_2 etc., have been tried in the past. In this article, we have investigated an SPE containing Rubidium as a conducting species. Rubidium has a larger ionic size compared to lithium and sodium ions which have been investigated in the recent past. In the present article, we have investigated the conductivity of large sized conducting species and shown the enhancement in the ionic conductivity by addition of nano-sized inert particles.

  18. Size characterisation of noble-metal nano-crystals formed in sapphire by ion irradiation and subsequent thermal annealing

    Energy Technology Data Exchange (ETDEWEB)

    Mota-Santiago, Pablo-Ernesto [Instituto de Fisica, Universidad Nacional Autonoma de Mexico A.P. 20-364 01000 Mexico D.F. (Mexico); Crespo-Sosa, Alejandro, E-mail: crespo@fisica.unam.mx [Instituto de Fisica, Universidad Nacional Autonoma de Mexico A.P. 20-364 01000 Mexico D.F. (Mexico); Jimenez-Hernandez, Jose-Luis; Silva-Pereyra, Hector-Gabriel; Reyes-Esqueda, Jorge-Alejandro; Oliver, Alicia [Instituto de Fisica, Universidad Nacional Autonoma de Mexico A.P. 20-364 01000 Mexico D.F. (Mexico)

    2012-10-15

    Highlights: Black-Right-Pointing-Pointer Systematic study on the formation of Ag and Au nano-particles in Al{sub 2}O{sub 3}. Black-Right-Pointing-Pointer Annealing in a reducing atmosphere, below the metal melting point is more suitable. Black-Right-Pointing-Pointer Au nano-particles grow up to 15 nm and Ag nano-particles up to 45 nm in radius. Black-Right-Pointing-Pointer Ostwald ripening is the mechanism responsible for the formation of large nanoparticles. Black-Right-Pointing-Pointer Optical properties of metallic nano-particles in Al{sub 2}O{sub 3} can be related to their size. - Abstract: Metallic nano-particles embedded in transparent dielectrics are very important for new technological applications because of their unique optical properties. These properties depend strongly on the size and shape of the nano-particles. In order to achieve the synthesis of metallic nano-particles it has been used the technique of ion implantation. This is a very common technique because it allows the control of the depth and concentration of the metallic ions inside the sample, limited mostly by straggling, without introducing other contaminant agents. The purpose of this work was to measure the size of the nano-particles grown under different conditions in Sapphire and its size evolution during the growth process. To achieve this goal, {alpha}-Al{sub 2}O{sub 3} single crystals were implanted with Ag or Au ions at room temperature with different fluences (from 2 Multiplication-Sign 10{sup 16} ions/cm{sup 2} to 8 Multiplication-Sign 10{sup 16} ions/cm{sup 2}). Afterwards, the samples were annealed at different temperatures (from 600 Degree-Sign C to 1100 Degree-Sign C) in oxidising, reducing, Ar or N{sub 2} atmospheres. We measured the ion depth profile by Rutherford Backscattering Spectroscopy (RBS) and the nano-crystals size distribution by using two methods, the surface plasmon resonance in the optical extinction spectrum and the Transmission Electron Microscopy (TEM).

  19. Tribological study on rapeseed oil with nano-additives in close contact sliding situation

    Science.gov (United States)

    Gupta, Rajeev Nayan; Harsha, A. P.; Singh, Sagar

    2018-02-01

    The present work deals with the tribological evaluation of three types of nano-additives, i.e., copper oxide (CuO; ≈ 151.2 nm), cerium oxide (CeO2; ≈ 80 nm) and polytetrafluoroethylene (PTFE; ≈ 90.4 nm) with rapeseed oil under steel-steel sliding contacts. The nano-additives concentrations in the base oil were 0.1, 0.25 and 0.5% w/v for the lubricant formulation. Further, the rapeseed oil was also epoxidized by a chemical method and the tribological behavior was compared with the base oil (unmodified oil) at similar nano-additives concentrations. The ASTM standards were followed for the study of wear preventive and extreme-pressure analysis of nanolubricants, and it was carried out using four-ball tester. In the antiwear test, CeO2 and PTFE nano-additives have shown the significant reduction in the wear scar diameter at the concentration of 0.1% w/v. In the extreme-pressure test, 0.5% w/v concentration was optimum for oxide nanoparticles; however, PTFE nanoparticles did not show positive effect with both the base oils. Different characterization techniques were employed to confirm the oil modification and for the study of the worn surfaces.

  20. Characteristic of Water Pervaporation Using Hydrophilic Composite Membrane Containing Functional Nano Sized NaA zeolites

    International Nuclear Information System (INIS)

    Oh, Duckkyu; Lee, Yongtaek

    2013-01-01

    The NaA zeolite particles were dispersed in a poly(vinyl alcohol) (PVA) matrix to prepare a composite membrane. The nano sized zeolite particles of NaA were synthesized in the laboratory and the mean size was approximately 60 nm. Pervaporation characteristics such as a permeation flux and a separation factor were investigated using the membrane as a function of the feed concentration from 0.01 to 0.05 mole fraction and the weight % of NaA particles between 0 wt% and 5 wt% in the membrane. Also, the micro sized particles of 5 mm were dispersed in the membrane for a comparison purpose. When the ethanol concentration in the feed solution was 0.01 mole fraction, the flux of water significantly increased from 600 g/m 2 /hr to 2000 g/m 2 /hr as the content of the nano NaA particles in the membrane increased from 0 wt% to 5 wt%, while the NaA particles improved the separation factor from 1.5 to 7.9. When the flux of water through the membrane containing nano sized particles was roughly 15% increased compared to the micro sized particles, whereas the separation factor of water was found to be approximately 5% increased. It can be said that the role of the nano sized NaA particles is quite important since both the flux and the separation factor are strongly affected

  1. Micro Nano Replication Processes and Applications

    CERN Document Server

    Kang, Shinill

    2012-01-01

    This book is an introduction to the fundamentals and processes for micro and nano molding for plastic components. In addition to the basics, the book covers applications details and examples. The book helps both students and professionals to understand and work with the growing tools of molding and uses for micro and nano-sized plastic parts.Provides a comprehensive presentation on fundamentals and practices of manufacturing for micro / nano sized plastics partsCovers a relatively new but fast-growing field that is impacting any industry using plastic parts in their products (electronics, tele

  2. Nano size crystals of goethite, α-FeOOH: Synthesis and thermal transformation

    International Nuclear Information System (INIS)

    Christensen, Axel Norlund; Jensen, Torben R.; Bahl, Christian R.H.; DiMasi, Elaine

    2007-01-01

    An aqueous suspension of amorphous iron(III) hydroxide was kept at room temperature (298 K) for 23 years. During this period of time the pH of the liquid phase changed from 4.3 to 2.85, and nano size crystals of goethite, α-FeOOH crystallised from the amorphous iron(III) hydroxide. Transmission electron microscopy (TEM) investigations, Moessbauer spectra, and powder X-ray diffraction using Co Kα radiation showed that the only iron containing crystalline phase present in the recovered product was α-FeOOH. The size of these nano particles range from 10 to 100 nm measured by TEM. The thermal decomposition of α-FeOOH was investigated by time-resolved in situ synchrotron radiation powder X-ray diffraction and the data showed that the sample of α-FeOOH transformed to α-Fe 2 O 3 in the temperature range 444-584 K. A quantitative phase analysis shows the increase in scattered X-ray intensity from α-Fe 2 O 3 to follow the decrease of intensity from α-FeOOH in agreement with the topotactic phase transition. - Graphical abstract: Nano size crystals of goethite, α-FeOOH formed from amorphous iron(III) hydroxide after 23 years, and transforms faster to α-Fe 2 O 3 upon heating

  3. Friction-induced nano-structural evolution of graphene as a lubrication additive

    Science.gov (United States)

    Zhao, Jun; Mao, Junyuan; Li, Yingru; He, Yongyong; Luo, Jianbin

    2018-03-01

    Graphene has attracted enormous attention in the field of lubrication based on its excellent physical and chemical properties. Although many studies have obtained thermally or chemically- exfoliated graphene and investigated their wide and important application, few studies have reported their physical nano-structural evolution under friction. In this study, we investigated the lubrication properties of graphene additives with different layer numbers and interlayer spacing by exfoliating. The additives with a higher degrees of exfoliation changed to ordering under friction, and had better lubrication properties, while that with a lower degrees exhibited obvious structural defects and high friction. Therefore, the original degrees of exfoliation plays a key role in the structural evolution of graphene and superior lubrication can be achieved through the physical nano-structure changing to ordering, even graphitization. Furthermore, the ordered tribofilm on the frictional interfaces was parallel to the sliding direction, meaning the highly exfoliated graphene indeed reaching slippage between its layers, which wasn't experimentally discovered in previous studies. This work provides a new understanding of the relationship between friction-induced nano-structural evolution and lubrication properties of graphene as a lubrication additive, and has great potential for the structural design of graphene as a lubrication additive.

  4. Microstructure, mechanical response and fractography of AZ91E/Al2O3 (p nano composite fabricated by semi solid stir casting method

    Directory of Open Access Journals (Sweden)

    Sameer Kumar D.

    2017-03-01

    Full Text Available The present study confers to the fabrication and its characterization of magnesium alloy (AZ91E based nano composites with nano Al2O3 particulate reinforcements. A novel Semi Solid stir casting technique was adopted for the fabrication of the composite. An average particle size of 50 nm was used as reinforcement to disperse in matrix. The effects of change in weight fraction of reinforcements on the distribution of particles, particle–matrix interfacial reactions, physical as well as mechanical properties were reported. The SEM and EDS analysis has shown the uniform distribution of particles in the composite along with the presence of elements. The mechanical properties of reinforced and unreinforced composite were evaluated and presented. Fractography of tensile specimens was also discussed.

  5. Elaboration and Characterization of Nano-Sized AlxMoyOz/Al Thermites

    National Research Council Canada - National Science Library

    Comet, M; Spitzer, D

    2006-01-01

    ...) has been developed at the Institut franco-allemand de recherches de Saint Louis (ISL). This process consists of a new sol-gel method nano-sized mixed AlxMoyOz phases whose structure is correlated to the chemical composition...

  6. An understanding of anomalous capacity of nano-sized CoO anode materials for advanced Li-ion battery

    Energy Technology Data Exchange (ETDEWEB)

    Chen, C.H.; Venkateswarlu, M.; Cheng, M.Y.; Ragavendran, K.; Hwang, B.J. [Nano-Electrochemistry Lab., Department of Chemical Engineering, National Taiwan University of Science and Technology, 43 Keelung Rd., Sec. 4, Taipei 106 (China); Weng, J.H. [Department of Chemical and Materials Engineering, Tunghai University, Taichung 407 (China); Santhanam, R. [Solid State and Surface Sciences Lab., Department of Physics, Southern University, Baton Rouge, LA-70808 (United States); Lee, J.F.; Chen, J.M.; Liu, D.G. [National Synchrotron Radiation Research Center (NSRRC), Hsinchu (China)

    2010-03-15

    Nanostructured transition metal oxides are of great interest as a new generation of anode materials for high energy density lithium-ion batteries. In this work, research has been focused on the nano-sized (grain size {proportional_to}7 nm) CoO anode material and this material delivers charge capacity of 900 mAh g{sup -1} that exceeds the theoretical value of 715 mAh g{sup -1}. Possible reason for this unaccounted and unexplained anomalous capacity of the nano-sized CoO material has been suggested by thermogravimetric analysis. A mechanism for this interesting behavior has been systematically evaluated by using X-ray absorption spectroscopy. The anomalous capacity is proposed to be associated with the formation of oxygen-rich CoO material. The results obtained from the nano-sized CoO material have been compared with relatively larger-sized material (grain size {proportional_to}32 nm). (author)

  7. Nano-sized metabolic precursors for heterogeneous tumor-targeting strategy using bioorthogonal click chemistry in vivo.

    Science.gov (United States)

    Lee, Sangmin; Jung, Seulhee; Koo, Heebeom; Na, Jin Hee; Yoon, Hong Yeol; Shim, Man Kyu; Park, Jooho; Kim, Jong-Ho; Lee, Seulki; Pomper, Martin G; Kwon, Ick Chan; Ahn, Cheol-Hee; Kim, Kwangmeyung

    2017-12-01

    Herein, we developed nano-sized metabolic precursors (Nano-MPs) for new tumor-targeting strategy to overcome the intrinsic limitations of biological ligands such as the limited number of biological receptors and the heterogeneity in tumor tissues. We conjugated the azide group-containing metabolic precursors, triacetylated N-azidoacetyl-d-mannosamine to generation 4 poly(amidoamine) dendrimer backbone. The nano-sized dendrimer of Nano-MPs could generate azide groups on the surface of tumor cells homogeneously regardless of cell types via metabolic glycoengineering. Importantly, these exogenously generated 'artificial chemical receptors' containing azide groups could be used for bioorthogonal click chemistry, regardless of phenotypes of different tumor cells. Furthermore, in tumor-bearing mice models, Nano-MPs could be mainly localized at the target tumor tissues by the enhanced permeation and retention (EPR) effect, and they successfully generated azide groups on tumor cells in vivo after an intravenous injection. Finally, we showed that these azide groups on tumor tissues could be used as 'artificial chemical receptors' that were conjugated to bioorthogonal chemical group-containing liposomes via in vivo click chemistry in heterogeneous tumor-bearing mice. Therefore, overall results demonstrated that our nano-sized metabolic precursors could be extensively applied to new alternative tumor-targeting technique for molecular imaging and drug delivery system, regardless of the phenotype of heterogeneous tumor cells. Copyright © 2017 Elsevier Ltd. All rights reserved.

  8. Experimental demonstration of line-width modulation in plasmonic lithography using a solid immersion lens-based active nano-gap control

    International Nuclear Information System (INIS)

    Lee, Won-Sup; Kim, Taeseob; Choi, Guk-Jong; Lim, Geon; Joe, Hang-Eun; Gang, Myeong-Gu; Min, Byung-Kwon; Park, No-Cheol; Moon, Hyungbae; Kim, Do-Hyung; Park, Young-Pil

    2015-01-01

    Plasmonic lithography has been used in nanofabrication because of its utility beyond the diffraction limit. The resolution of plasmonic lithography depends on the nano-gap between the nanoaperture and the photoresist surface—changing the gap distance can modulate the line-width of the pattern. In this letter, we demonstrate solid-immersion lens based active non-contact plasmonic lithography, applying a range of gap conditions to modulate the line-width of the pattern. Using a solid-immersion lens-based near-field control system, the nano-gap between the exit surface of the nanoaperture and the media can be actively modulated and maintained to within a few nanometers. The line-widths of the recorded patterns using 15- and 5-nm gaps were 47 and 19.5 nm, respectively, which matched closely the calculated full-width at half-maximum. From these results, we conclude that changing the nano-gap within a solid-immersion lens-based plasmonic head results in varying line-width patterns

  9. Effect of TiC nano-particles on the mechanical properties of an Al-5Cu alloy after various heat treatments

    Science.gov (United States)

    Zhang, Qingquan; Zhang, Wei; Tian, Weisi; Zhao, Qinglong

    2017-12-01

    In this paper, the effects of TiC nano-particles on the mechanical properties of Al-5Cu alloy were investigated. Adding TiC nano-particles can effectively refine grain size and secondary dendritic arm. The ultimate tensile strength, yield strength and elongation of the Al-5Cu alloy in each of the three states (i.e. as-cast, solid-solution state and T6 state) were also improved by adding TiC nano-particles. Moreover, the elastic-plastic plane-strain fracture toughness (K J) and work of fracture ( wof) of Al-5Cu containing TiC were significantly higher than those of Al-5Cu without TiC after aging for 10 h. The addition of TiC nano-particles also led to finer and denser ‧ precipitates.

  10. Development of nano-sized α-Al2O3:C films for application in digital radiology

    International Nuclear Information System (INIS)

    Silva, Edna C.

    2011-01-01

    Ceramic materials are widely used as sensors for ionizing radiation. In nuclear applications, the alpha-alumina doped with carbon (α-Al 2 O 3 :C) is the most widely ceramic used because of its excellent optically stimulated luminescence (OSL) and thermoluminescent (TL) properties applied to detection of ionizing radiation. Another application of OSL and TL materials are in Digital Radiography, with ceramic/polymeric film composites. Recently, Computed Radiography (CR) devices based on OSL materials are replacing the old conventional film radiography. In this study we investigate the thermoluminescence of nano-sized α-Al 2 O 3 samples doped with different percentages of carbon, sintered in reducing atmospheres at temperatures ranging from 1300 to 1750 deg C. The results indicate that the nano-sized α-Al 2 O 3 :C materials have a luminescent response that could be due to both OSL and RPL properties, but without application to radiation dosimetry. Moreover, the results indicate that micro-sized α-Al 2 O 3 :C, doped with 0.5% carbon, and nano-sized ones doped with 2% of carbon, present thermoluminescent signal around 30 to 100 times the TL output signal of commercial TLD-100, the most used TL dosimeter in the world. The results indicate that these ceramic nano-particles have great potential for use in Digital Radiography based on thermoluminescent film imaging, being able to provide image resolutions much higher than the micro-sized α-Al 2 O 3 :C, in view of their improved resolution provided by nano-particulates. (author)

  11. Effect of nano-oxide particle size on radiation resistance of iron–chromium alloys

    Energy Technology Data Exchange (ETDEWEB)

    Xu, Weizong; Li, Lulu [Department of Materials Science and Engineering, North Carolina State University, Raleigh, NC 27695 (United States); Valdez, James A. [Materials Science and Technology Division, Los Alamos National Laboratory, Los Alamos, NM 87545 (United States); Saber, Mostafa [Department of Mechanical and Materials Engineering, Portland State University, Portland, OR 97201 (United States); Zhu, Yuntian, E-mail: ytzhu@ncsu.edu [Department of Materials Science and Engineering, North Carolina State University, Raleigh, NC 27695 (United States); Koch, Carl C.; Scattergood, Ronald O. [Department of Materials Science and Engineering, North Carolina State University, Raleigh, NC 27695 (United States)

    2016-02-15

    Radiation resistance of Fe–14Cr alloys under 200 keV He irradiation at 500 °C was systematically investigated with varying sizes of nano oxide Zr, Hf and Cr particles. It is found that these nano oxide particles acted as effective sites for He bubble formation. By statistically analyzing 700–1500 He bubbles at the depth of about 150–700 nm from a series of HRTEM images for each sample, we established the variation of average He bubble size, He bubble density, and swelling percentage along the depth, and found them to be consistent with the He concentration profile calculated from the SIRM program. Oxide particles with sizes less than 3.5–4 nm are found most effective for enhancing radiation resistance in the studied alloy systems.

  12. On the Size Dependence of Molar and Specific Properties of Independent Nano-phases and Those in Contact with Other Phases

    Science.gov (United States)

    Kaptay, George

    2018-05-01

    Nano-materials are materials with at least one nano-phase. A nano-phase is a phase with at least one of its dimensions below 100 nm. It is shown here that nano-phases have at least 1% of their atoms along their surface layer. The ratio of surface atoms is proportional to the specific surface area of the phase, defined as the ratio of its surface area to its volume. Each specific/molar property has its bulk value and its surface value for the given phase, being always different, as the energetic states of the atoms in the bulk and in the surface layer of a phase are different. The average specific/molar property of a nano-phase is modeled here as a linear combination of the bulk and surface values of the same property, scaled with the ratio of the surface atoms. That makes the performance of all nano-phases proportional to their specific surface area. As the characteristic size of the nano-phase is inversely proportional to its specific surface area, all specific/molar properties of nano-phases are inversely proportional to the characteristic size of the phase. This is applied to the size dependence of the molar Gibbs energy of the nano-phase, which appears to be in agreement with the thermodynamics of Gibbs. This agreement proves the general validity of the present model on the size dependence of the specific/molar properties of independent nano-phases. It is shown that the properties of nano-phases are different for independent nano-phases (surrounded only by their equilibrium vapor phase) and for nano-phases in multi-phase situations, such as a liquid nano-droplet in the sessile drop configuration.

  13. Superior high creep resistance of in situ nano-sized TiCx/Al-Cu-Mg composite.

    Science.gov (United States)

    Wang, Lei; Qiu, Feng; Zhao, Qinglong; Zha, Min; Jiang, Qichuan

    2017-07-03

    The tensile creep behavior of Al-Cu-Mg alloy and its composite containing in situ nano-sized TiC x were explored at temperatures of 493 K, 533 K and 573 K with the applied stresses in the range of 40 to 100 MPa. The composite reinforced by nano-sized TiC x particles exhibited excellent creep resistance ability, which was about 4-15 times higher than those of the unreinforced matrix alloy. The stress exponent of 5 was noticed for both Al-Cu-Mg alloy and its composite, which suggested that their creep behavior was related to dislocation climb mechanism. During deformation at elevated temperatures, the enhanced creep resistance of the composite was mainly attributed to two aspects: (a) Orowan strengthening and grain boundary (GB) strengthening induced by nano-sized TiC x particles, (b) θ' and S' precipitates strengthening.

  14. Surface energy effect on free vibration of nano-sized piezoelectric double-shell structures

    Science.gov (United States)

    Fang, Xue-Qian; Zhu, Chang-Song; Liu, Jin-Xi; Liu, Xiang-Lin

    2018-01-01

    Combining Goldenveizer-Novozhilov shell theory, thin plate theory and electro-elastic surface theory, the size-dependent vibration of nano-sized piezoelectric double-shell structures under simply supported boundary condition is presented, and the surface energy effect on the natural frequencies is discussed. The displacement components of the cylindrical nano-shells and annular nano-plates are expanded as the superposition of standard Fourier series based on Hamilton's principle. The total stresses with consideration of surface energy effect are derived, and the total energy function is obtained by using Rayleigh-Ritz energy method. The free vibration equation is solved, and the natural frequency is analyzed. In numerical examples, it is found that the surface elastic constant, piezoelectric constant and surface residual stress show different effects on the natural frequencies. The effect of surface piezoelectric constant is the maximum. The effect of dimensions of the double-shell under different surface material properties is also examined.

  15. Effect of high content nano-thoria addition on the properties of tungsten electrode

    International Nuclear Information System (INIS)

    Wang Fazhan; Zhuge Fei; Zhang Hui; Ding Bingjun

    2003-01-01

    By hot swaging, the nano-composite W-4.5%ThO 2 cathode was fabricated. A comparative investigation has been made on the operation characteristics for a conventional W-2%ThO 2 cathode, a conventional W-4%ThO 2 cathode and a nano-composite W-4.5%ThO 2 cathode. The results showed that the arc starting and arc voltage-current characteristic of the nano-composite W-4.5%ThO 2 electrode was the best among the three cathodes. These operating characteristics depended on the content and the size of thoria. The anti-erosion ability of the nano-composite W-4.5%ThO 2 cathode was slightly better than that of conventional W-4%ThO 2 cathode, but was obviously improved as compared to W-2%ThO 2 cathode, indicating that the content of thoria governs the resistance to arc erosion of the electrodes

  16. High Performance Nano-Ceria Electrodes for Solid Oxide Cells

    DEFF Research Database (Denmark)

    Graves, Christopher R.; Martinez Aguilera, Lev; Sudireddy, Bhaskar Reddy

    2016-01-01

    forming the active surfaces on a porous backbone with embedded electronic current collector material, yielding one of the highest performances reported for an electrode that operates either on fuel or oxidant. The second is a nano-Ce0.9Gd0.1O2-δ thin film prepared by spin-coating, which provides......In solid oxide electrochemical cells, the conventional Ni-based fuel-electrodes provide high electrocatalytic activity but they are often a major source of long-term performance degradation due to carbon deposition, poisoning of reaction sites, Ni mobility, etc. Doped-ceria is a promising mixed...

  17. Comparative study of nano-sized particles CoFe{sub 2}O{sub 4} effects on superconducting properties of Y-123 and Y-358

    Energy Technology Data Exchange (ETDEWEB)

    Slimani, Y.; Hannachi, E.; Ben Salem, M.K.; Hamrita, A. [Laboratory of Physics of Materials-Structures and Properties, Department of Physics, Faculty of Sciences of Bizerte, University of Carthage, 7021 Zarzouna (Tunisia); Varilci, A. [Faculty of Arts and Sciences, Department of Physics, Abant Izzet Baysal University, 14280 Bolu (Turkey); Dachraoui, W. [CINaM-CNRS, Luminy Campus, 13288 Marseille (France); Ben Salem, M., E-mail: salemwiem2005@yahoo.fr [Laboratory of Physics of Materials-Structures and Properties, Department of Physics, Faculty of Sciences of Bizerte, University of Carthage, 7021 Zarzouna (Tunisia); Ben Azzouz, F. [Laboratory of Physics of Materials-Structures and Properties, Department of Physics, Faculty of Sciences of Bizerte, University of Carthage, 7021 Zarzouna (Tunisia); College of Sciences-Girls, Department of Physics, University of Dammam (Saudi Arabia)

    2014-10-01

    The effects of nano-sized CoFe{sub 2}O{sub 4} particles (10 nm) addition on the structural and the normal state resistivity of YBa{sub 2}Cu{sub 3}O{sub 7} (noted Y-123) and Y{sub 3}Ba{sub 5}Cu{sub 8}O{sub 18} (noted Y-358) polycrystalline were systematically studied. Samples were synthesized in oxygen atmosphere using a standard solid state reaction technique by adding CoFe{sub 2}O{sub 4} up to 2 wt%. Phases, microstructure and superconductivity have been systematically investigated using X-ray diffraction (XRD), scanning electron microscopy (SEM) and electrical measurements ρ(T). XRD results reveal that the lattice parameters change for both Y-123 and Y-358 phases. SEM observations reveal that the grain size is reduced with increasing the content of CoFe{sub 2}O{sub 4}. The measurements for the resistivity dependence of temperature show that the depression in superconducting temperature is more pronounced for CoFe{sub 2}O{sub 4} addition in Y-358 compound than in Y-123 one. These results may be attributed to the existence of much more disorder due to a greater number of Cu sites to be substituted by Fe and Co in Y-358 compared to Y-123.

  18. In vitro study of nano-sized zinc doped bioactive glass

    Energy Technology Data Exchange (ETDEWEB)

    Goh, Yi-Fan; Alshemary, Ammar Z.; Akram, Muhammad [Department of Chemistry, Faculty of Science, Universiti Teknologi Malaysia, 81310 UTM skudai, Johor Darul Ta' zim (Malaysia); Abdul Kadir, Mohammed Rafiq [Medical Implant Technology Group, Faculty of Biomedical Engineering and Health Science, Universiti Teknologi Malaysia, 81310 UTMJohor Bahru (Malaysia); Hussain, Rafaqat, E-mail: rafaqat@kimia.fs.utm.my [IbnuSina Institute for Fundamental Science Studies, Universiti Teknologi Malaysia, 81310 UTM Johor Bahru, Johor DarulTa' zim (Malaysia)

    2013-01-15

    Surface reactivity in physiological fluid has been linked to bioactivity of a material. Past research has shown that bioactive glass containing zinc has the potential in bone regeneration field due to its enhanced bioactivity. However, results from literature are always contradictory. Therefore, in this study, surface reactivity of bioactive glass containing zinc was evaluated through the study of morphology and composition of apatite layer formed after immersion in simulated body fluid (SBF). Nano-sized bioactive glass with 5 and 10 mol% zinc were synthesized through quick alkali sol-gel method. The synthesized Zn-bioglass was characterized using field emission scanning electron microscope (FESEM), energy dispersive X-ray spectrometer (EDX), X-ray diffractometer (XRD) and Fourier transform infrared spectrometer (FTIR). Samples after SBF immersion were characterized using scanning electron microscope (SEM) and EDX. Morphological study through SEM showed the formation of spherical apatite particles with Ca/P ratio closer to 1.67 on the surface of 5 mol% Zn-bioglass. Whereas, the 10 mol% Zn-bioglass samples induced the formation of flake-like structure of calcite in addition to the spherical apatite particles with much higher Ca/P ratio. Our results suggest that the higher Zn content increases the bioactivity through the formation of bone-bonding calcite as well as the spherical apatite particles. -- Highlights: Black-Right-Pointing-Pointer Nano-sized bioactive glasses were synthesized through quick alkali sol-gel method. Black-Right-Pointing-Pointer 5 and 10 mol% Zn-bioglass induced the formation of spherical particles in SBF test. Black-Right-Pointing-Pointer 10 mol% Zn-bioglass also induced the formation of flake-like structure. Black-Right-Pointing-Pointer The flake-like structure is calcium carbonate; spherical particles are apatite. Black-Right-Pointing-Pointer High Zn contents negatively influence the chemical composition of the apatite layer.

  19. Novel polyoxometalate silica nano-sized spheres: efficient catalysts for olefin oxidation and the deep desulfurization process.

    Science.gov (United States)

    Nogueira, Lucie S; Ribeiro, Susana; Granadeiro, Carlos M; Pereira, Eulália; Feio, Gabriel; Cunha-Silva, Luís; Balula, Salete S

    2014-07-07

    A novel method to prepare silica nano-sized particles incorporating polyoxometalates was developed leading to a new efficient heterogeneous oxidative catalyst. Zinc-substituted polyoxotungstate [PW11Zn(H2O)O39](5-) (PW11Zn) was encapsulated into silica nanoparticles using a cross-linked organic-inorganic core, performed through successive spontaneous reactions in water. The potassium salt of PW11Zn and the composite formed, PW11Zn-APTES@SiO2, were characterized by a myriad of solid-state methods such as FT-IR, FT-Raman, (31)P and (13)C CP/MAS solid-state NMR, elemental analysis and SEM-EDS, confirming the integrity of the PW11Zn structure immobilized in the silica nanoparticles. The new composite has shown to be a versatile catalyst for the oxidation of olefins and also to catalyze the desulfurization of a model oil using H2O2 as the oxidant and acetonitrile as the solvent. The novel composite material was capable of being recycled without significant loss of activity and maintaining its structural stability for consecutive desulfurization and olefin oxidative cycles.

  20. Nano-sized Fe2O3/Fe3O4 facilitate anaerobic transformation of hexavalent chromium in soil-water systems.

    Science.gov (United States)

    Zhang, Yaxian; Li, Hua; Gong, Libo; Dong, Guowen; Shen, Liang; Wang, Yuanpeng; Li, Qingbiao

    2017-07-01

    The purpose of this study is to investigate the effects of nano-sized or submicro Fe 2 O 3 /Fe 3 O 4 on the bioreduction of hexavalent chromium (Cr(VI)) and to evaluate the effects of nano-sized Fe 2 O 3 /Fe 3 O 4 on the microbial communities from the anaerobic flooding soil. The results indicated that the net decreases upon Cr(VI) concentration from biotic soil samples amended with nano-sized Fe 2 O 3 (317.1±2.1mg/L) and Fe 3 O 4 (324.0±22.2mg/L) within 21days, which were approximately 2-fold of Cr(VI) concentration released from blank control assays (117.1±5.6mg/L). Furthermore, the results of denaturing gradient gel electrophoresis (DGGE) and high-throughput sequencing indicated a greater variety of microbes within the microbial community in amendments with nano-sized Fe 2 O 3 /Fe 3 O 4 than the control assays. Especially, Proteobacteria occupied a predominant status on the phylum level within the indigenous microbial communities from chromium-contaminated soils. Besides, some partial decrease of soluble Cr(VI) in abiotic nano-sized Fe 2 O 3 /Fe 3 O 4 amendments was responsible for the adsorption of nano-sized Fe 2 O 3 /Fe 3 O 4 to soluble Cr(VI). Hence, the presence of nano-sized Fe 2 O 3 /Fe 3 O 4 could largely facilitate the mobilization and biotransformation of Cr(VI) from flooding soils by adsorption and bio-mediated processes. Copyright © 2017. Published by Elsevier B.V.

  1. Chemical characterization, nano-particle mineralogy and particle size distribution of basalt dust wastes

    Energy Technology Data Exchange (ETDEWEB)

    Dalmora, Adilson C. [Laboratory of Environmental Researches and Nanotechnology Development, Centro Universitário La Salle, Mestrado em Avaliação de Impactos Ambientais em Mineração. Victor Barreto, 2288 Centro 92010-000, Canoas, RS (Brazil); Institute for Environmental Assessment and Water Studies (IDÆA), Spanish National Research Council (CSIC), C/Jordi Girona 18-26, 08034 Barcelona (Spain); Ramos, Claudete G.; Oliveira, Marcos L.S. [Laboratory of Environmental Researches and Nanotechnology Development, Centro Universitário La Salle, Mestrado em Avaliação de Impactos Ambientais em Mineração. Victor Barreto, 2288 Centro 92010-000, Canoas, RS (Brazil); Teixeira, Elba C. [Fundação Estadual de Proteção Ambiental Henrique Luis Roessler, Porto Alegre, RS (Brazil); Kautzmann, Rubens M.; Taffarel, Silvio R. [Laboratory of Environmental Researches and Nanotechnology Development, Centro Universitário La Salle, Mestrado em Avaliação de Impactos Ambientais em Mineração. Victor Barreto, 2288 Centro 92010-000, Canoas, RS (Brazil); Brum, Irineu A.S. de [Universidade Federal do Rio Grande do Sul, Escola de Engenharia, Departamento de Metalurgia, Centro de Tecnologia, Av. Bento Gonçalves, 9500. Bairro Agronomia. CEP: 91501-970 Porto Alegre, RS (Brazil); and others

    2016-01-01

    Understanding the geochemistry of basalt alteration is central to the study of agriculture systems. Various nano-minerals play an important role in the mobilization of contaminants and their subsequent uptake by plants. We present a new analytical experimental approach in combination with an integrated analytical protocol designed to study basalt alteration processes. Recently, throughout the world, ultra-fine and nano-particles derived from basalt dust wastes (BDW) during “stonemeal” soil fertilizer application have been of great concern for their possible adverse effects on human health and environmental pollution. Samples of BDW utilized were obtained from companies in the Nova Prata mining district in southern Brazil for chemical characterization and nano-mineralogy investigation, using an integrated application of advanced characterization techniques such as X-ray diffraction (XRD), High Resolution-Transmission Electron microscopy (HR-TEM)/Energy Dispersive Spectroscopy (EDS)/(selected-area diffraction pattern) SAED, Field Emission-Scanning Electron Microscopy (FE-SEM/EDS), and granulometric distribution analysis. The investigation has revealed that BDW materials are dominated by SiO{sub 2}, Al{sub 2}O{sub 3}, and Fe{sub 2}O{sub 3,} with a complex micromineralogy including alkali feldspar, augite, barite, labradorite, hematite, heulandrite, gypsum, kaolinite, quartz, and smectite. In addition, we have identified a number of trace metals such as Cd, Cu, Cr, and Zn, that are preferentially concentrated into the finer, inhalable, dust fraction and, thus, could present a health hazard in the urban areas around the basalt mining zone. The implication of this observation is that use of these nanometric-sized particulates as soil fertilizer may present different health challenges to those of conventional fertilizers, inviting future work regarding the relative toxicities of these materials. Our investigation on the particle size distribution, nano

  2. Chemical characterization, nano-particle mineralogy and particle size distribution of basalt dust wastes

    International Nuclear Information System (INIS)

    Dalmora, Adilson C.; Ramos, Claudete G.; Oliveira, Marcos L.S.; Teixeira, Elba C.; Kautzmann, Rubens M.; Taffarel, Silvio R.; Brum, Irineu A.S. de

    2016-01-01

    Understanding the geochemistry of basalt alteration is central to the study of agriculture systems. Various nano-minerals play an important role in the mobilization of contaminants and their subsequent uptake by plants. We present a new analytical experimental approach in combination with an integrated analytical protocol designed to study basalt alteration processes. Recently, throughout the world, ultra-fine and nano-particles derived from basalt dust wastes (BDW) during “stonemeal” soil fertilizer application have been of great concern for their possible adverse effects on human health and environmental pollution. Samples of BDW utilized were obtained from companies in the Nova Prata mining district in southern Brazil for chemical characterization and nano-mineralogy investigation, using an integrated application of advanced characterization techniques such as X-ray diffraction (XRD), High Resolution-Transmission Electron microscopy (HR-TEM)/Energy Dispersive Spectroscopy (EDS)/(selected-area diffraction pattern) SAED, Field Emission-Scanning Electron Microscopy (FE-SEM/EDS), and granulometric distribution analysis. The investigation has revealed that BDW materials are dominated by SiO 2 , Al 2 O 3 , and Fe 2 O 3, with a complex micromineralogy including alkali feldspar, augite, barite, labradorite, hematite, heulandrite, gypsum, kaolinite, quartz, and smectite. In addition, we have identified a number of trace metals such as Cd, Cu, Cr, and Zn, that are preferentially concentrated into the finer, inhalable, dust fraction and, thus, could present a health hazard in the urban areas around the basalt mining zone. The implication of this observation is that use of these nanometric-sized particulates as soil fertilizer may present different health challenges to those of conventional fertilizers, inviting future work regarding the relative toxicities of these materials. Our investigation on the particle size distribution, nano-particle mineralogy and chemical

  3. Study of carbon-doped micro and nano sized alumina for radiation dosimetry applications

    International Nuclear Information System (INIS)

    Fontainha, C. C. P.; Alves, N.; Ferraz, W. B.; Faria, L. O.

    2017-10-01

    New materials have been widely investigated for ionizing radiation dosimetry for medical procedures. Carbon-doped doped alumina (Al 2 O 3 :C) have been proposed as thermoluminescent and photo luminescent dosimeters. In the present study nano and micro-sized alumina doped with different percentages of carbon, sintered under different atmosphere conditions, at temperatures ranging from 1300 to 1750 degrees Celsius, were sintered and their dosimetric characteristics for gamma fields were investigated. Among the investigated sample preparation methods, the micro-sized alumina doped with 0.01% of carbon and sintered at 1700 degrees Celsius under reducing atmosphere has presented the best Tl output, comparable to the best Tl sensitivities ever reported to alumina and better efficiency than the nano-sized alumina synthesized in this study. The influence of humidity in the Tl signal has been evaluated to be -4.0%. The micro-sized alumina obtained by the methodology used in this work is a suitable candidate for application in X and gamma radiation dosimetry. (Author)

  4. Dispersive solid-phase imprinting of proteins for the production of plastic antibodies

    DEFF Research Database (Denmark)

    Ashley, Jon; Feng, Xiaotong; Halder, Arnab

    2018-01-01

    We describe a novel dispersive solid-phase imprinting technique for the production of nano-sized molecularly imprinted polymers (nanoMIPs) as plastic antibodies. The template was immobilized on in-house synthesized magnetic microspheres instead of conventional glass beads. As a result, high...

  5. Plasma-arc reactor for production possibility of powdered nano-size materials

    International Nuclear Information System (INIS)

    Hadzhiyski, V; Mihovsky, M; Gavrilova, R

    2011-01-01

    Nano-size materials of various chemical compositions find increasing application in life nowadays due to some of their unique properties. Plasma technologies are widely used in the production of a range of powdered nano-size materials (metals, alloys, oxides, nitrides, carbides, borides, carbonitrides, etc.), that have relatively high melting temperatures. Until recently, the so-called RF-plasma generated in induction plasma torches was most frequently applied. The subject of this paper is the developments of a new type of plasma-arc reactor, operated with transferred arc system for production of disperse nano-size materials. The new characteristics of the PLASMALAB reactor are the method of feeding the charge, plasma arc control and anode design. The disperse charge is fed by a charge feeding system operating on gravity principle through a hollow cathode of an arc plasma torch situated along the axis of a water-cooled wall vertical tubular reactor. The powdered material is brought into the zone of a plasma space generated by the DC rotating transferred plasma arc. The arc is subjected to Auto-Electro-Magnetic Rotation (AEMR) by an inductor serially connected to the anode circuit. The anode is in the form of a water-cooled copper ring. It is mounted concentrically within the cylindrical reactor, with its lower part electrically insulated from it. The electric parameters of the arc in the reactor and the quantity of processed charge are maintained at a level permitting generation of a volumetric plasma discharge. This mode enables one to attain high mean mass temperature while the processed disperse material flows along the reactor axis through the plasma zone where the main physico-chemical processes take place. The product obtained leaves the reactor through the annular anode, from where it enters a cooling chamber for fixing the produced nano-structure. Experiments for AlN synthesis from aluminium power and nitrogen were carried out using the plasma reactor

  6. Photogenerated cathode protection properties of nano-sized TiO2/WO3 coating

    International Nuclear Information System (INIS)

    Zhou Minjie; Zeng Zhenou; Zhong Li

    2009-01-01

    Nano-sized TiO 2 /WO 3 bilayer coatings were prepared on type 304 stainless steel substrate by sol-gel method. The performance of photo-electrochemical and photogenerated cathode protection of the coating was investigated by the electrochemical method. The results show that the bilayer coating with four TiO 2 layers and three WO 3 layers exhibits the highest photo-electrochemical efficiency and the best corrosion resistance property. Type 304 stainless steel with the coating can maintain cathode protection for 6 h in the dark after irradiation by UV illumination for 1 h. In addition, the mechanism of the photogenerated cathode protection for the bilayer coating was also explored.

  7. Flexible single-layer ionic organic-inorganic frameworks towards precise nano-size separation

    Science.gov (United States)

    Yue, Liang; Wang, Shan; Zhou, Ding; Zhang, Hao; Li, Bao; Wu, Lixin

    2016-02-01

    Consecutive two-dimensional frameworks comprised of molecular or cluster building blocks in large area represent ideal candidates for membranes sieving molecules and nano-objects, but challenges still remain in methodology and practical preparation. Here we exploit a new strategy to build soft single-layer ionic organic-inorganic frameworks via electrostatic interaction without preferential binding direction in water. Upon consideration of steric effect and additional interaction, polyanionic clusters as connection nodes and cationic pseudorotaxanes acting as bridging monomers connect with each other to form a single-layer ionic self-assembled framework with 1.4 nm layer thickness. Such soft supramolecular polymer frameworks possess uniform and adjustable ortho-tetragonal nanoporous structure in pore size of 3.4-4.1 nm and exhibit greatly convenient solution processability. The stable membranes maintaining uniform porous structure demonstrate precisely size-selective separation of semiconductor quantum dots within 0.1 nm of accuracy and may hold promise for practical applications in selective transport, molecular separation and dialysis systems.

  8. High burn rate solid composite propellants

    Science.gov (United States)

    Manship, Timothy D.

    High burn rate propellants help maintain high levels of thrust without requiring complex, high surface area grain geometries. Utilizing high burn rate propellants allows for simplified grain geometries that not only make production of the grains easier, but the simplified grains tend to have better mechanical strength, which is important in missiles undergoing high-g accelerations. Additionally, high burn rate propellants allow for a higher volumetric loading which reduces the overall missile's size and weight. The purpose of this study is to present methods of achieving a high burn rate propellant and to develop a composite propellant formulation that burns at 1.5 inches per second at 1000 psia. In this study, several means of achieving a high burn rate propellant were presented. In addition, several candidate approaches were evaluated using the Kepner-Tregoe method with hydroxyl terminated polybutadiene (HTPB)-based propellants using burn rate modifiers and dicyclopentadiene (DCPD)-based propellants being selected for further evaluation. Propellants with varying levels of nano-aluminum, nano-iron oxide, FeBTA, and overall solids loading were produced using the HTPB binder and evaluated in order to determine the effect the various ingredients have on the burn rate and to find a formulation that provides the burn rate desired. Experiments were conducted to compare the burn rates of propellants using the binders HTPB and DCPD. The DCPD formulation matched that of the baseline HTPB mix. Finally, GAP-plasticized DCPD gumstock dogbones were attempted to be made for mechanical evaluation. Results from the study show that nano-additives have a substantial effect on propellant burn rate with nano-iron oxide having the largest influence. Of the formulations tested, the highest burn rate was a 84% solids loading mix using nano-aluminum nano-iron oxide, and ammonium perchlorate in a 3:1(20 micron: 200 micron) ratio which achieved a burn rate of 1.2 inches per second at 1000

  9. NANO CRYSTALLINE ZnO CATALYZED ONE POT THREE ...

    African Journals Online (AJOL)

    advances in nanoscience and nanotechnology have led to new research interests in using nanometer-sized particles as .... dichloromethane and then filtered to separate the nano ZnO catalyst. ..... 104, 4063. 31. Matsubara, K.; Fons, P.; Iwata, K.; Yamada, A.; Sakurai, K.; Tampo, N.; Niki, S. Thin Solid. Films 2003, 431, 369.

  10. Single-step Preparation of Nano-homogeneous NiO/YSZ Comp osite Ano de for Solid Oxide Fuel Cells

    Institute of Scientific and Technical Information of China (English)

    Jung-Hoon Song; Mi Young Park; Hye Won Park; Hyung-Tae Lim

    2013-01-01

    Homogeneous co-precipitation and hydrothermal treatment were used to prepare nano-and highly dispersed NiO/YSZ (yttria-stabilized zirconia) composite powders. Composite powders of size less than 100 nm were successfully prepared. This process did not require separate sintering of the YSZ and NiO to be used as the raw materials for solid oxide fuel cells. The performance of a cell fabricated using the new powders (max. power density∼0.87 W/cm2) was higher than that of a cell fabricated using conventional powders (max. power density∼0.73 W/cm2). Co-precipitation and hydrothermal treatment proved to be very effective processes for reducing cell production costs as well as improving cell performance.

  11. Performance and Structural Evolution of Nano-Scale Infiltrated Solid Oxide Fuel Cell Cathodes

    Science.gov (United States)

    Call, Ann Virginia

    Nano-structured mixed ionic and electronic conducting (MIEC) materials have garnered intense interest in electrode development for solid oxide fuel cells due to their high surface areas which allow for effective catalytic activity and low polarization resistances. In particular, composite solid oxide fuel cell (SOFC) cathodes consisting of ionic conducting scaffolds infiltrated with MIEC nanoparticles have exhibited some of the lowest reported polarization resistances. In order for cells utilizing nanostructured moRPhologies to be viable for commercial implementation, more information on their initial performance and long term stability is necessary. In this study, symmetric cell cathodes were prepared via wet infiltration of Sr0.5Sm 0.5CoO3 (SSC) nano-particles via a nitrate process into porous Ce0.9Gd0.1O1.95 (GDC) scaffolds to be used as a model system to investigate performance and structural evolution. Detailed analysis of the cells and cathodes was carried out using electrochemical impedance spectroscopy (EIS). Initial polarization resistances (RP) as low as 0.11 O cm2 at 600ºC were obtained for these SSC-GDC cathodes, making them an ideal candidate for studying high performance nano-structured electrodes. The present results show that the infiltrated cathode microstructure has a direct impact on the initial performance of the cell. Small initial particle sizes and high infiltration loadings (up to 30 vol% SSC) improved initial RP. A simple microstructure-based electrochemical model successfully explained these trends in RP. Further understanding of electrode performance was gleaned from fitting EIS data gathered under varying temperatures and oxygen partial pressures to equivalent circuit models. Both RQ and Gerischer impedance elements provided good fits to the main response in the EIS data, which was associated with the combination of oxygen surface exchange and oxygen diffusion in the electrode. A gas diffusion response was also observed at relatively

  12. Solid strong base K-Pt/NaY zeolite nano-catalytic system for completed elimination of formaldehyde at room temperature

    Science.gov (United States)

    Song, Shaoqing; Wu, Xi; Lu, Changhai; Wen, Meicheng; Le, Zhanggao; Jiang, Shujuan

    2018-06-01

    Solid strong base nano-catalytic system of K-modification NaY zeolite supported 0.08% Pt (K-Pt/NaY) were constructed for eliminating HCHO at room temperature. In the catalytic process, activation energy over K-Pt/NaY nano-catalytic system was greatly decreased along with the enhanced reaction rate. Characterization and catalytic tests revealed the surface electron structure of K-Pt/NaY was improved, as reflected by the enhanced HCHO adsorption capability, high sbnd OH concentration, and low-temperature reducibility. Therefore, the optimal K-Pt/NaY showed high catalytic efficiency and strong H2O tolerance for HCHO elimination by directly promoting the reaction between active sbnd OH and formate species. These results may suggest a new way for probing the advanced solid strong base nano-catalytic system for the catalytic elimination of indoor HCHO.

  13. Effects of serum on cytotoxicity of nano- and micro-sized ZnO particles

    Energy Technology Data Exchange (ETDEWEB)

    Hsiao, I-Lun; Huang, Yuh-Jeen, E-mail: yjhuang@mx.nthu.edu.tw [National Tsing Hua University, Department of Biomedical Engineering and Environmental Sciences (China)

    2013-09-15

    Although an increasing number of in vitro studies are being published regarding the cytotoxicity of nanomaterials, the components of the media for toxicity assays have often varied according to the needs of the scientists. Our aim for this study was to evaluate the influence of serum-in this case, fetal bovine serum-in a cell culture medium on the toxicity of nano-sized (50-70 nm) and micro-sized (<1 {mu}m) ZnO on human lung epithelial cells (A549). The nano- and micro-sized ZnO both exhibited their highest toxicity when exposed to serum-free media, in contrast to exposure in media containing 5 or 10 % serum. This mainly comes not only from the fact that ZnO particles in the serum-free media have a higher dosage-per-cell ratio, which results from large aggregates of particles, rapid sedimentation, absence of protein protection, and lower cell growth rate, but also that extracellular Zn{sup 2+} release contributes to cytotoxicity. Although more extracellular Zn{sup 2+} release was observed in serum-containing media, it did not contribute to nano-ZnO cytotoxicity. Furthermore, non-dissolved particles underwent size-dependent particle agglomeration, resulting in size-dependent toxicity in both serum-containing and serum-free media. A low correlation between cytotoxicity and inflammation endpoints in the serum-free medium suggested that some signaling pathways were changed or induced. Since cell growth, transcription behavior for protein production, and physicochemical properties of ZnO particles all were altered in serum-free media, we recommend the use of a serum-containing medium when evaluating the cytotoxicity of NPs.

  14. Kinetic model for transformation from nano-sized amorphous $TiO_2$ to anatase

    OpenAIRE

    Madras, Giridhar; McCoy, Benjamin J

    2006-01-01

    We propose a kinetic model for the transformation of nano-sized amorphous $TiO_2$ to anatase with associated coarsening by coalescence. Based on population balance (distribution kinetics) equations for the size distributions, the model applies a first-order rate expression for transformation combined with Smoluchowski coalescence for the coarsening particles. Size distribution moments (number and mass of particles) lead to dynamic expressions for extent of reaction and average anatase particl...

  15. Effect of nano size 3% wt TaC particles dispersion in two different metallic matrix composites

    International Nuclear Information System (INIS)

    Gomes, U.U.; Oliveira, L.A.; Souza, C.P.; Menezes, R.C.; Furukava, M.; Torres, Y.

    2009-01-01

    This work studies the characteristics of two different metallic matrixes composites, ferritic and austenitic steels, reinforced with 3% wt nano size tantalum carbide by powder metallurgy. The starting powders were characterized by X-ray diffraction (XRD) and scanning electron microscopy (SEM). The effects of the nano sized carbide dispersion on the matrix microstructures and its consequences on the mechanical properties were identified. The preliminary results showed that the sintering were influenced by morphology and the distribution of carbide and the alloys. (author)

  16. Characterisation of micro-sized and nano-sized tungsten oxide-epoxy composites for radiation shielding of diagnostic X-rays.

    Science.gov (United States)

    Azman, N Z Noor; Siddiqui, S A; Low, I M

    2013-12-01

    Characteristics of X-ray transmissions were investigated for epoxy composites filled with 2-10 vol% WO3 loadings using synchrotron X-ray absorption spectroscopy (XAS) at 10-40 keV. The results obtained were used to determine the equivalent X-ray energies for the operating X-ray tube voltages of mammography and radiology machines. The results confirmed the superior attenuation ability of nano-sized WO3-epoxy composites in the energy range of 10-25 keV when compared to their micro-sized counterparts. However, at higher synchrotron radiation energies (i.e., 30-40 keV), the X-ray transmission characteristics were similar with no apparent size effect for both nano-sized and micro-sized WO3-epoxy composites. The equivalent X-ray energies for the operating X-ray tube voltages of the mammography unit (25-49 kV) were in the range of 15-25 keV. Similarly, for a radiology unit operating at 40-60 kV, the equivalent energy range was 25-40 keV, and for operating voltages greater than 60 kV (i.e., 70-100 kV), the equivalent energy was in excess of 40 keV. The mechanical properties of epoxy composites increased initially with an increase in the filler loading but a further increase in the WO3 loading resulted in deterioration of flexural strength, modulus and hardness. © 2013.

  17. Fabrication of nano-sized metal patterns on flexible polyethylene-terephthalate substrate using bi-layer nanoimprint lithography

    Energy Technology Data Exchange (ETDEWEB)

    Hwang, Seon Yong; Jung, Ho Yong [Department of Materials Science and Engineering, Korea University, Seoul, 136-701 (Korea, Republic of); Jeong, Jun-Ho [Nano-Mechanical Systems Research Center, Korea Institute of Machinery and Materials, Yuseong-gu Daejeon, 305-343 (Korea, Republic of); Lee, Heon, E-mail: heonlee@korea.ac.k [Department of Materials Science and Engineering, Korea University, Seoul, 136-701 (Korea, Republic of)

    2009-05-29

    Polymer films are widely used as a substrate for displays and for solar cells since they are cheap, transparent and flexible, and their material properties are easy to design. Polyethylene-terephthalate (PET) is especially useful for various applications requiring transparency, flexibility and good thermal and chemical resistance. In this study, nano-sized metal patterns were fabricated on flexible PET film by using nanoimprint lithography (NIL). Water-soluble poly-vinyl alcohol (PVA) resin was used as a planarization and sacrificial layer for the lift-off process, as it does not damage the PET films and can easily be etched off by using oxygen plasma. NIL was used to fabricate the nano-sized patterns on the non-planar or flexible substrate. Finally, a nano-sized metal pattern was successfully formed by depositing the metal layer over the imprinted resist patterns and applying the lift-off process, which is economic and environmentally friendly, to the PET films.

  18. Origin of Capacity Fading in Nano-Sized Co3O4Electrodes: Electrochemical Impedance Spectroscopy Study

    Directory of Open Access Journals (Sweden)

    Kang Jin-Gu

    2008-01-01

    Full Text Available Abstract Transition metal oxides have been suggested as innovative, high-energy electrode materials for lithium-ion batteries because their electrochemical conversion reactions can transfer two to six electrons. However, nano-sized transition metal oxides, especially Co3O4, exhibit drastic capacity decay during discharge/charge cycling, which hinders their practical use in lithium-ion batteries. Herein, we prepared nano-sized Co3O4with high crystallinity using a simple citrate-gel method and used electrochemical impedance spectroscopy method to examine the origin for the drastic capacity fading observed in the nano-sized Co3O4anode system. During cycling, AC impedance responses were collected at the first discharged state and at every subsequent tenth discharged state until the 100th cycle. By examining the separable relaxation time of each electrochemical reaction and the goodness-of-fit results, a direct relation between the charge transfer process and cycling performance was clearly observed.

  19. Surface modification and particles size distribution control in nano-CdS/polystyrene composite film

    International Nuclear Information System (INIS)

    Min Zhirong; Ming Qiuzhang; Hai Chunliang; Han Minzeng

    2003-01-01

    Preparation of nano-CdS particles with surface thiol modification by microemulsion method and their influences on the particle size distribution in highly filled polystyrene-based composites were studied. The modified nano-CdS was characterized by X-ray photoelectron spectroscopy (XPS), light absorption and emission measurements to reveal the morphologies of the surface modifier, which are consistent with the surface molecules packing calculation. The morphologies of the surface modifier exerted a great influence not only on the optical performance of the particles themselves, but also on the size distribution of the particle in polystyrene matrix. A monolayer coverage with tightly packed thiol molecules was believed to be most effective in promoting a uniform particle size distribution and eliminating the surface defects that cause radiationless recombination. Control of the particles size distribution in polystyrene can be attained by adjusting surface coverage status of the thiol molecules based on the strong interaction between the surface modifier and the matrix

  20. The nanorod approach: GaN NanoLEDs for solid state lighting

    Energy Technology Data Exchange (ETDEWEB)

    Waag, Andreas; Wang, Xue; Fuendling, Soenke; Ledig, Johannes; Erenburg, Milena; Neumann, Richard; Al Suleiman, Mohamed; Merzsch, Stephan; Wei, Jiandong; Li, Shunfeng; Wehmann, Hergo H. [Institut fuer Halbleitertechnik, TU Braunschweig, Hans-Sommer-Strasse 66, 38106 Braunschweig (Germany); Bergbauer, Werner; Strassburg, Martin [OSRAM Opto Semiconductors GmbH, Leibnizstr. 4, 93055 Regensburg (Germany); Trampert, Achim; Jahn, Uwe; Riechert, Henning [Paul-Drude-Institut fuer Festkoerperelektronik, Hausvogteiplatz 5-7, 10117 Berlin (Germany)

    2011-07-15

    Vertically aligned GaN nanorods have recently obtained substantial interest as a new approach to solid state lighting. In comparison to conventional planar LEDs, 3D NanoLEDs are expected to offer substantial advantageous: very low defect density, quasi free-standing, no strain due to mismatch of thermal expansion coefficients, no substrate bending even when grown on large area silicon. Core-shell strategies are another very interesting aspect. The active LED surface per wafer could be increased by more than one order of magnitude. However, most of these advantages have not yet been proven in real devices, which would include a quantitative comparison of light emission. Related to the 3D character, there are also technological risks. In the following we will discuss the main developments which have paved the way up to this point, including a detailed discussion of possible benefits and risks connected with the NanoLED approach (copyright 2011 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim) (orig.)

  1. Targeted Therapy for Acute Autoimmune Myocarditis with Nano-Sized Liposomal FK506 in Rats.

    Directory of Open Access Journals (Sweden)

    Keiji Okuda

    Full Text Available Immunosuppressive agents are used for the treatment of immune-mediated myocarditis; however, the need to develop a more effective therapeutic approach remains. Nano-sized liposomes may accumulate in and selectively deliver drugs to an inflammatory lesion with enhanced vascular permeability. The aims of this study were to investigate the distribution of liposomal FK506, an immunosuppressive drug encapsulated within liposomes, and the drug's effects on cardiac function in a rat experimental autoimmune myocarditis (EAM model. We prepared polyethylene glycol-modified liposomal FK506 (mean diameter: 109.5 ± 4.4 nm. We induced EAM by immunization with porcine myosin and assessed the tissue distribution of the nano-sized beads and liposomal FK506 in this model. After liposomal or free FK506 was administered on days 14 and 17 after immunization, the cytokine expression in the rat hearts along with the histological findings and hemodynamic parameters were determined on day 21. Ex vivo fluorescent imaging revealed that intravenously administered fluorescent-labeled nano-sized beads had accumulated in myocarditic but not normal hearts on day 14 after immunization and thereafter. Compared to the administration of free FK506, FK506 levels were increased in both the plasma and hearts of EAM rats when liposomal FK506 was administered. The administration of liposomal FK506 markedly suppressed the expression of cytokines, such as interferon-γ and tumor necrosis factor-α, and reduced inflammation and fibrosis in the myocardium on day 21 compared to free FK506. The administration of liposomal FK506 also markedly ameliorated cardiac dysfunction on day 21 compared to free FK506. Nano-sized liposomes may be a promising drug delivery system for targeting myocarditic hearts with cardioprotective agents.

  2. Targeted Therapy for Acute Autoimmune Myocarditis with Nano-Sized Liposomal FK506 in Rats.

    Science.gov (United States)

    Okuda, Keiji; Fu, Hai Ying; Matsuzaki, Takashi; Araki, Ryo; Tsuchida, Shota; Thanikachalam, Punniyakoti V; Fukuta, Tatsuya; Asai, Tomohiro; Yamato, Masaki; Sanada, Shoji; Asanuma, Hiroshi; Asano, Yoshihiro; Asakura, Masanori; Hanawa, Haruo; Hao, Hiroyuki; Oku, Naoto; Takashima, Seiji; Kitakaze, Masafumi; Sakata, Yasushi; Minamino, Tetsuo

    2016-01-01

    Immunosuppressive agents are used for the treatment of immune-mediated myocarditis; however, the need to develop a more effective therapeutic approach remains. Nano-sized liposomes may accumulate in and selectively deliver drugs to an inflammatory lesion with enhanced vascular permeability. The aims of this study were to investigate the distribution of liposomal FK506, an immunosuppressive drug encapsulated within liposomes, and the drug's effects on cardiac function in a rat experimental autoimmune myocarditis (EAM) model. We prepared polyethylene glycol-modified liposomal FK506 (mean diameter: 109.5 ± 4.4 nm). We induced EAM by immunization with porcine myosin and assessed the tissue distribution of the nano-sized beads and liposomal FK506 in this model. After liposomal or free FK506 was administered on days 14 and 17 after immunization, the cytokine expression in the rat hearts along with the histological findings and hemodynamic parameters were determined on day 21. Ex vivo fluorescent imaging revealed that intravenously administered fluorescent-labeled nano-sized beads had accumulated in myocarditic but not normal hearts on day 14 after immunization and thereafter. Compared to the administration of free FK506, FK506 levels were increased in both the plasma and hearts of EAM rats when liposomal FK506 was administered. The administration of liposomal FK506 markedly suppressed the expression of cytokines, such as interferon-γ and tumor necrosis factor-α, and reduced inflammation and fibrosis in the myocardium on day 21 compared to free FK506. The administration of liposomal FK506 also markedly ameliorated cardiac dysfunction on day 21 compared to free FK506. Nano-sized liposomes may be a promising drug delivery system for targeting myocarditic hearts with cardioprotective agents.

  3. Preparation of nano-sized {alpha}-Al{sub 2}O{sub 3} from oil shale ash

    Energy Technology Data Exchange (ETDEWEB)

    An, Baichao; Wang, Wenying; Ji, Guijuan; Gan, Shucai; Gao, Guimei; Xu, Jijing; Li, Guanghuan [College of Chemistry, Jilin University, Changchun 130026 (China)

    2010-01-15

    Oil shale ash (OSA), the residue of oil shale semi-coke roasting, was used as a raw material to synthesize nano-sized {alpha}-Al{sub 2}O{sub 3}. Ultrasonic oscillation pretreatment followed by azeotropic distillation was employed for reducing the particle size of {alpha}-Al{sub 2}O{sub 3}. The structural characterization at molecular and nanometer scales was performed using X-ray diffraction (XRD), transmission electron microscopy (TEM), respectively. The interaction between alumina and n-butanol was characterized by Fourier transform infrared spectroscopy (FT-IR). The results revealed that the crystalline phase of alumina nanoparticles was regular and the well dispersed alumina nanoparticles had a diameter of 50-80 nm. In addition, the significant factors including injection rate of carbon oxide (CO{sub 2}), ultrasonic oscillations, azeotropic distillation and surfactant were investigated with respect to their effects on the size of the alumina particles. (author)

  4. Semiconductor Nano wires and Nano tubes: From Fundamentals to Diverse Applications

    International Nuclear Information System (INIS)

    Xiong, Q.; Grimes, C.A.; Zacharias, M.; Morral, A.F.; Hiruma, K.; Shen, G.

    2012-01-01

    written by K. Tateno et al. also reviews the vapor-liquid-solid (VLS-) grown core-multi shell Ga(In)P/GaAs/GaP nano wires on Si substrates and introduces an interesting phenomenon of formation of flat-top nano wires achieved by using small-sized Au particles in one growth procedure. The remaining papers illustrate the research on metal oxides semiconducting materials which are well known for wide band gap and transparent conducting properties

  5. Preparation of soft-agglomerated nano-sized ceramic powders by sol-gel combustion process

    International Nuclear Information System (INIS)

    Feng, Q.; Ma, X.H.; Yan, Q.Z.; Ge, C.C.

    2009-01-01

    The soft-agglomerated Gd 2 BaCuO 5 (Gd211) nano-powders were synthesized by sol-gel combustion process with binary ligand and the special pretreatment on gel. The mechanism of the formation of weakly agglomerated structure was studied in detail. The results showed that network structure in gelation process was found to be a decisive factor for preventing agglomeration of colloidal particles. The removal of free water, coordinated water, and most of hydroxyl groups during pretreatment further inhibited the formation of hydrogen bonds between adjacent particles. The soft-agglomeration of the particles was confirmed by isolated particles in calcined Gd211 powders and in green compact, a narrow monomodal pore size distribution of the green compact and the low agglomeration coefficient of the calcined Gd211 powder. Extension this process to synthesis of BaCeO 3 , BaTiO 3 and Ce 0.8 Sm 0.2 O 1.9 powders, also led to weakly agglomerated nano-powders. It suggests that this method represents a powerful and facile method for the creation of doped and multi-component nano-sized ceramic powders.

  6. Microstructure and mechanical properties of aluminum–fly ash nano composites made by ultrasonic method

    International Nuclear Information System (INIS)

    Narasimha Murthy, I.; Venkata Rao, D.; Babu Rao, J.

    2012-01-01

    Highlights: ► Nano structured fly ash has been produced by 30 h milling time. ► Al–fly ash nano composites were produced by ultrasonic cavitation route. ► A homogeneous distribution of nano fly ash particles was observed in the matrix. ► No additional contamination in the nano composites from the atmosphere. ► Presence of nano fly ash leads to improvement in the strength of the composites. -- Abstract: In this paper an attempt has been made to modify the micro sized fly ash into nano structured fly ash using high energy ball mill. Ball milling was carried out for the total duration of 30 h. The sample was taken out after every 5 h of milling for characterizing. The nano structured fly ash was characterized for its crystallite size and lattice strain by using X-ray diffractometer. It was found that a steady decrease in the crystallite size and increased lattice strain was observed with milling time; the crystallite size at 30 h milling time was found to be 23 nm. The fresh fly ash particles are mostly spherical in shape; whereas the shape of the 30 h milled fly ash particles is irregular and the surface morphology is rough. Al–fly ash nano composites were produced by ultrasonic cavitation route successfully. Scanning electron microscopy images of nano composites reveal a homogeneous distribution of the nano fly ash particles in the AA 2024 matrix. Energy dispersive spectroscopy analysis of nano composites reveals that the fabricated nano composite did not contain any additional contamination from the atmosphere. As the amount of nano fly ash is increasing the hardness of the composite also increasing. The nano fly ash addition leads to improvement in the compression strength of the composites.

  7. Controlled synthesis of thorium and uranium oxide nano-crystals

    International Nuclear Information System (INIS)

    Hudry, Damien; Apostolidis, Christos; Walter, Olaf; Gouder, Thomas; Courtois, Eglantine; Kubel, Christian; Meyer, Daniel

    2013-01-01

    Very little is known about the size and shape effects on the properties of actinide compounds. As a consequence, the controlled synthesis of well-defined actinide-based nano-crystals constitutes a fundamental step before studying their corresponding properties. In this paper, we report on the non-aqueous surfactant-assisted synthesis of thorium and uranium oxide nano-crystals. The final characteristics of thorium and uranium oxide nano-crystals can be easily tuned by controlling a few experimental parameters such as the nature of the actinide precursor and the composition of the organic system (e.g., the chemical nature of the surfactants and their relative concentrations). Additionally, the influence of these parameters on the outcome of the synthesis is highly dependent on the nature of the actinide element (thorium versus uranium). By using optimised experimental conditions, monodisperse isotropic uranium oxide nano-crystals with different sizes (4.5 and 10.7 nm) as well as branched nano-crystals (overall size ca. 5 nm), nano-dots (ca. 4 nm) and nano-rods (with ultra-small diameters of 1 nm) of thorium oxide were synthesised. (authors)

  8. Development of nano-sized {alpha}-Al{sub 2}O{sub 3}:C films for application in digital radiology

    Energy Technology Data Exchange (ETDEWEB)

    Silva, Edna C., E-mail: edca@cdtn.b [Universidade Federal de Minas Gerais (DEN/UFMG), Belo Horizonte (Brazil). Dept. de Engenharia Nuclear; Fontainha, Crissia C. [Universidade Federal de Minas Gerais (UFMG), Belo Horizonte (Brazil). Dept. de Propedeutica Complemetar; Oliveira, Vitor H.; Ferraz, Wilmar B.; Faria, Luiz O. [Centro de Desenvolvimento da Tecnologia Nuclear (CDTN/CNEN-MG), Belo Horizonte, MG (Brazil)

    2011-07-01

    Ceramic materials are widely used as sensors for ionizing radiation. In nuclear applications, the alpha-alumina doped with carbon ({alpha}-Al{sub 2}O{sub 3}:C) is the most widely ceramic used because of its excellent optically stimulated luminescence (OSL) and thermoluminescent (TL) properties applied to detection of ionizing radiation. Another application of OSL and TL materials are in Digital Radiography, with ceramic/polymeric film composites. Recently, Computed Radiography (CR) devices based on OSL materials are replacing the old conventional film radiography. In this study we investigate the thermoluminescence of nano-sized {alpha}-Al{sub 2}O{sub 3} samples doped with different percentages of carbon, sintered in reducing atmospheres at temperatures ranging from 1300 to 1750 deg C. The results indicate that the nano-sized {alpha}-Al{sub 2}O{sub 3}:C materials have a luminescent response that could be due to both OSL and RPL properties, but without application to radiation dosimetry. Moreover, the results indicate that micro-sized {alpha}-Al{sub 2}O{sub 3}:C, doped with 0.5% carbon, and nano-sized ones doped with 2% of carbon, present thermoluminescent signal around 30 to 100 times the TL output signal of commercial TLD-100, the most used TL dosimeter in the world. The results indicate that these ceramic nano-particles have great potential for use in Digital Radiography based on thermoluminescent film imaging, being able to provide image resolutions much higher than the micro-sized {alpha}-Al{sub 2}O{sub 3}:C, in view of their improved resolution provided by nano-particulates. (author)

  9. Effects of confinement in meso-porous silica and carbon nano-structures

    International Nuclear Information System (INIS)

    Leon, V.

    2006-07-01

    Physico-chemical properties of materials can be strongly modified by confinement because of the quantum effects that appear at such small length scales and also because of the effects of the confinement itself. The aim of this thesis is to show that both the nature of the confining material and the size of the pores and cavities have a strong impact on the confined material. We first show the effect of the pore size of the host meso-porous silica on the temperature of the solid-solid phase transition of silver selenide, a semiconducting material with enhanced magnetoresistive properties under non-stoichiometric conditions. Narrowing the pores from 20 nm to 2 nm raises the phase transition temperature from 139 C to 146 C. This result can be explained by considering the interaction between the confining and confined materials as a driving force. The effects of confinement are also studied in the case of hydrogen and deuterium inside cavities of organized carbon nano-structures. The effects that appear in the adsorption/desorption cycles are much stronger with carbon nano-horns as the host material than with C60 pea-pods and single-walled carbon nano-tubes. (author)

  10. Forging of metallic nano-objects for the fabrication of submicron-size components

    International Nuclear Information System (INIS)

    Roesler, J; Mukherji, D; Schock, K; Kleindiek, S

    2007-01-01

    In recent years, nanoscale fabrication has developed considerably, but the fabrication of free-standing nanosize components is still a great challenge. The fabrication of metallic nanocomponents utilizing three basic steps is demonstrated here. First, metallic alloys are used as factories to produce a metallic raw stock of nano-objects/nanoparticles in large numbers. These objects are then isolated from the powder containing thousands of such objects inside a scanning electron microscope using manipulators, and placed on a micro-anvil or a die. Finally, the shape of the individual nano-object is changed by nanoforging using a microhammer. In this way free-standing, high-strength, metallic nano-objects may be shaped into components with dimensions in the 100 nm range. By assembling such nanocomponents, high-performance microsystems can be fabricated, which are truly in the micrometre scale (the size ratio of a system to its component is typically 10:1)

  11. Effects of exposure to nano and bulk sized TiO2 and CuO in Lemna minor.

    Science.gov (United States)

    Dolenc Koce, Jasna

    2017-10-01

    Nanoparticles of TiO 2 and CuO are among most commonly used nanoparticles, and elevated concentrations of them are expected to be found in all environments, including aquatic. A standard growth inhibition test ISO/CD 20079 was used to determine the toxicity of nano sized and larger micro sized (bulk) particles in the concentrations of 0.1, 1, 10, 100 and 1000 μM CuO and TiO 2 on common duckweed (Lemna minor L.). Both nano and bulk CuO particles caused changes in the structure and function of treated plants. The number of fronds and colonies decreased by as much as 78%, the length of roots and fronds decreased by 99% and 14%, respectively. Furthermore, photochemical efficiency was reduced by up to 35%, and the activities of antioxidative enzymes guaiacol peroxidase, ascorbate peroxidase and glutathione reductase increased by more than 240%. The altered physiological state of the CuO exposed plants was also reflected in the elevated occurrence of necrosis and bleaching in the duckweed colonies. Nano sized particles of CuO proved more phytotoxic than bulk particles, and the effects of both studied CuO sizes were concentration dependent. On the other hand, both bulk and nano sized particles of TiO 2 caused no severe phytotoxic effects, there was no concentration dependence and they could be considered as non-harmful to common duckweed. Copyright © 2017 Elsevier Masson SAS. All rights reserved.

  12. Superior model for fault tolerance computation in designing nano-sized circuit systems

    Energy Technology Data Exchange (ETDEWEB)

    Singh, N. S. S., E-mail: narinderjit@petronas.com.my; Muthuvalu, M. S., E-mail: msmuthuvalu@gmail.com [Fundamental and Applied Sciences Department, Universiti Teknologi PETRONAS, Bandar Seri Iskandar, Perak (Malaysia); Asirvadam, V. S., E-mail: vijanth-sagayan@petronas.com.my [Electrical and Electronics Engineering Department, Universiti Teknologi PETRONAS, Bandar Seri Iskandar, Perak (Malaysia)

    2014-10-24

    As CMOS technology scales nano-metrically, reliability turns out to be a decisive subject in the design methodology of nano-sized circuit systems. As a result, several computational approaches have been developed to compute and evaluate reliability of desired nano-electronic circuits. The process of computing reliability becomes very troublesome and time consuming as the computational complexity build ups with the desired circuit size. Therefore, being able to measure reliability instantly and superiorly is fast becoming necessary in designing modern logic integrated circuits. For this purpose, the paper firstly looks into the development of an automated reliability evaluation tool based on the generalization of Probabilistic Gate Model (PGM) and Boolean Difference-based Error Calculator (BDEC) models. The Matlab-based tool allows users to significantly speed-up the task of reliability analysis for very large number of nano-electronic circuits. Secondly, by using the developed automated tool, the paper explores into a comparative study involving reliability computation and evaluation by PGM and, BDEC models for different implementations of same functionality circuits. Based on the reliability analysis, BDEC gives exact and transparent reliability measures, but as the complexity of the same functionality circuits with respect to gate error increases, reliability measure by BDEC tends to be lower than the reliability measure by PGM. The lesser reliability measure by BDEC is well explained in this paper using distribution of different signal input patterns overtime for same functionality circuits. Simulation results conclude that the reliability measure by BDEC depends not only on faulty gates but it also depends on circuit topology, probability of input signals being one or zero and also probability of error on signal lines.

  13. Superior model for fault tolerance computation in designing nano-sized circuit systems

    International Nuclear Information System (INIS)

    Singh, N. S. S.; Muthuvalu, M. S.; Asirvadam, V. S.

    2014-01-01

    As CMOS technology scales nano-metrically, reliability turns out to be a decisive subject in the design methodology of nano-sized circuit systems. As a result, several computational approaches have been developed to compute and evaluate reliability of desired nano-electronic circuits. The process of computing reliability becomes very troublesome and time consuming as the computational complexity build ups with the desired circuit size. Therefore, being able to measure reliability instantly and superiorly is fast becoming necessary in designing modern logic integrated circuits. For this purpose, the paper firstly looks into the development of an automated reliability evaluation tool based on the generalization of Probabilistic Gate Model (PGM) and Boolean Difference-based Error Calculator (BDEC) models. The Matlab-based tool allows users to significantly speed-up the task of reliability analysis for very large number of nano-electronic circuits. Secondly, by using the developed automated tool, the paper explores into a comparative study involving reliability computation and evaluation by PGM and, BDEC models for different implementations of same functionality circuits. Based on the reliability analysis, BDEC gives exact and transparent reliability measures, but as the complexity of the same functionality circuits with respect to gate error increases, reliability measure by BDEC tends to be lower than the reliability measure by PGM. The lesser reliability measure by BDEC is well explained in this paper using distribution of different signal input patterns overtime for same functionality circuits. Simulation results conclude that the reliability measure by BDEC depends not only on faulty gates but it also depends on circuit topology, probability of input signals being one or zero and also probability of error on signal lines

  14. Improved Light Conversion Efficiency Of Dye-Sensitized Solar Cell By Dispersing Submicron-Sized Granules Into The Nano-Sized TiO2 Layer

    Directory of Open Access Journals (Sweden)

    Song S.A.

    2015-06-01

    Full Text Available In this work, TiO2 nanoparticles and submicron-sized granules were synthesized by a hydrothermal method and spray pyrolysis, respectively. Submicron-sized granules were dispersed into the nano-sized TiO2 layer to improve the light conversion efficiency. Granules showed better light scattering, but lower in terms of the dye-loading quantity and recombination resistance compared with nanoparticles. Consequently, the nano-sized TiO2 layer had higher cell efficiency than the granulized TiO2 layer. When dispersed granules into the nanoparticle layer, the light scattering was enhanced without the loss of dye-loading quantities. The dispersion of granulized TiO2 led to increase the cell efficiency up to 6.51%, which was about 5.2 % higher than that of the electrode consisting of only TiO2 nanoparticles. Finally, the optimal hydrothermal temperature and dispersing quantity of granules were found to be 200°C and 20 wt%, respectively.

  15. THE EFFECT OF NANO-TITANIA ADDITION ON THE PROPERTIES OF HIGH-ALUMINA LOW-CEMENT SELF-FLOWING REFRACTORY CASTABLES

    Directory of Open Access Journals (Sweden)

    Sasan Otroj

    2011-12-01

    Full Text Available The self-flow characteristics and properties of high-alumina low-cement refractory castables added with nano-titania particles are investigated. For this reason, the reactive alumina in the castable composition is substituted by nano-titania powder in 0-1 %wt. range. The microstructures, phase composition, physical and mechanical properties of these refractory castables at different temperatures are studied. The results show that the addition of nano-titania particles has great effect on the self-flow characteristics, phase composition, physical and mechanical properties of these refractory castables. With increase of nano-titania particles in castable composition, the self-flow value and working time tend to decrease. With addition of 0.5 wt.% nano-titania in the castable composition, the mechanical strength of castable in all firing temperatures tends to increase. It is attributed to the formation of CA6 phase and enhanced ceramic bonding. Nano-titania particles can act as a nucleating agent for hibonite phase and decrease the formation temperature of hibonite. Because of perovskite phase formation, the addition of 1 wt.% nano-titania can decrease the mechanical strength of castable after firing.

  16. Membrane separation using nano-pores; Nano poa wo riyoshita makubunri

    Energy Technology Data Exchange (ETDEWEB)

    Manabe, S. [Fukuoka Women`s Univ., Fukuoka (Japan)

    1995-08-01

    The membrane constituted by nano-pore only (NF membrane) is sold on the market recently as the membranes used for the matter separations in addition to the reverse osmosis membrane for changing seawater into fresh water, dialysis membrane used for artificial kidney, ultrafiltration membrane used for the separation and condensation of protein and the micro-filter used for removing microbe. It is possible for the membrane constituted by nano-pore to remove the virus with the size being from 20 to 300 nm. In this paper, the pore structure of NF membrane is explained, and then its application as the membrane for removing virus is described. Especially, it is possible for NF membrane to remove the virus with smallest size (parvovirus, etc.), prion albumen (bovine serum pathogen, etc.) and the special gene such as cancer, and it is further applied to the condensation and refining of virus and genes. The broader application of nano-pore to the control of the transportation of micro-particles in the future is expected. 3 refs., 2 figs.

  17. Effect of nano/micro-Ag compound particles on the bio-corrosion, antibacterial properties and cell biocompatibility of Ti-Ag alloys.

    Science.gov (United States)

    Chen, Mian; Yang, Lei; Zhang, Lan; Han, Yong; Lu, Zheng; Qin, Gaowu; Zhang, Erlin

    2017-06-01

    In this research, Ti-Ag alloys were prepared by powder metallurgy, casting and heat treatment method in order to investigate the effect of Ag compound particles on the bio-corrosion, the antibacterial property and the cell biocompatibility. Ti-Ag alloys with different sizes of Ag or Ag-compounds particles were successfully prepared: small amount of submicro-scale (100nm) Ti 2 Ag precipitates with solid solution state of Ag, large amount of nano-scale (20-30nm) Ti 2 Ag precipitates with small amount of solid solution state of Ag and micro-scale lamellar Ti 2 Ag phases, and complete solid solution state of Ag. The mechanical tests indicated that both nano/micro-scale Ti 2 Ag phases had a strong dispersion strengthening ability and Ag had a high solid solution strengthening ability. Electrochemical results shown the Ag content and the size of Ag particles had a limited influence on the bio-corrosion resistance although nano-scale Ti 2 Ag precipitates slightly improved corrosion resistance. It was demonstrated that the nano Ag compounds precipitates have a significant influence on the antibacterial properties of Ti-Ag alloys but no effect on the cell biocompatibility. It was thought that both Ag ions release and Ti 2 Ag precipitates contributed to the antibacterial ability, in which nano-scale and homogeneously distributed Ti 2 Ag phases would play a key role in antibacterial process. Copyright © 2017 Elsevier B.V. All rights reserved.

  18. Characterization and preliminary toxicity assay of nano-titanium dioxide additive in sugar-coated chewing gum.

    Science.gov (United States)

    Chen, Xin-Xin; Cheng, Bin; Yang, Yi-Xin; Cao, Aoneng; Liu, Jia-Hui; Du, Li-Jing; Liu, Yuanfang; Zhao, Yuliang; Wang, Haifang

    2013-05-27

    Nanotechnology shows great potential for producing food with higher quality and better taste through including new additives, improving nutrient delivery, and using better packaging. However, lack of investigations on safety issues of nanofood has resulted in public fears. How to characterize engineered nanomaterials in food and assess the toxicity and health impact of nanofood remains a big challenge. Herein, a facile and highly reliable separation method of TiO2 particles from food products (focusing on sugar-coated chewing gum) is reported, and the first comprehensive characterization study on food nanoparticles by multiple qualitative and quantitative methods is provided. The detailed information on nanoparticles in gum includes chemical composition, morphology, size distribution, crystalline phase, particle and mass concentration, surface charge, and aggregation state. Surprisingly, the results show that the number of food products containing nano-TiO2 (TiO2 in gum is nano-TiO2 , and it is unexpectedly easy to come out and be swallowed by a person who chews gum. Preliminary cytotoxicity assays show that the gum nano-TiO2 particles are relatively safe for gastrointestinal cells within 24 h even at a concentration of 200 μg mL(-1) . This comprehensive study demonstrates accurate physicochemical property, exposure, and cytotoxicity information on engineered nanoparticles in food, which is a prerequisite for the successful safety assessment of nanofood products. Copyright © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  19. Spin-torque oscillation in large size nano-magnet with perpendicular magnetic fields

    Energy Technology Data Exchange (ETDEWEB)

    Luo, Linqiang, E-mail: LL6UK@virginia.edu [Department of Physics, University of Virginia, Charlottesville, VA 22904 (United States); Kabir, Mehdi [Department of Electrical & Computer Engineering, University of Virginia, Charlottesville, VA 22904 (United States); Dao, Nam; Kittiwatanakul, Salinporn [Department of Materials Science & Engineering, University of Virginia, Charlottesville, VA 22904 (United States); Cyberey, Michael [Department of Electrical Engineering, University of Virginia, Charlottesville, VA 22904 (United States); Wolf, Stuart A. [Department of Physics, University of Virginia, Charlottesville, VA 22904 (United States); Department of Materials Science & Engineering, University of Virginia, Charlottesville, VA 22904 (United States); Institute of Defense Analyses, Alexandria, VA 22311 (United States); Stan, Mircea [Department of Electrical & Computer Engineering, University of Virginia, Charlottesville, VA 22904 (United States); Lu, Jiwei [Department of Materials Science & Engineering, University of Virginia, Charlottesville, VA 22904 (United States)

    2017-06-15

    Highlights: • 500 nm size nano-pillar device was fabricated by photolithography techniques. • A magnetic hybrid structure was achieved with perpendicular magnetic fields. • Spin torque switching and oscillation was demonstrated in the large sized device. • Micromagnetic simulations accurately reproduced the experimental results. • Simulations demonstrated the synchronization of magnetic inhomogeneities. - Abstract: DC current induced magnetization reversal and magnetization oscillation was observed in 500 nm large size Co{sub 90}Fe{sub 10}/Cu/Ni{sub 80}Fe{sub 20} pillars. A perpendicular external field enhanced the coercive field separation between the reference layer (Co{sub 90}Fe{sub 10}) and free layer (Ni{sub 80}Fe{sub 20}) in the pseudo spin valve, allowing a large window of external magnetic field for exploring the free-layer reversal. A magnetic hybrid structure was achieved for the study of spin torque oscillation by applying a perpendicular field >3 kOe. The magnetization precession was manifested in terms of the multiple peaks on the differential resistance curves. Depending on the bias current and applied field, the regions of magnetic switching and magnetization precession on a dynamical stability diagram has been discussed in details. Micromagnetic simulations are shown to be in good agreement with experimental results and provide insight for synchronization of inhomogeneities in large sized device. The ability to manipulate spin-dynamics on large size devices could be proved useful for increasing the output power of the spin-transfer nano-oscillators (STNOs).

  20. TRANSPORT AND DEPOSITION OF NANO-SIZE PARTICLES IN THE UPPER HUMAN RESPIRATORY AIRWAYS

    Science.gov (United States)

    TRANSPORT AND DEPOSITION OF NANO-SIZE PARTICLES IN THE UPPER HUMAN RESPIRATORY AIRWAYS. Zhe Zhang*, Huawei Shi, Clement Kleinstreuer, Department of Mechanical and Aerospace Engineering, North Carolina State University, Raleigh, NC 27695-7910; Chong S. Kim, National Health and En...

  1. Investigation on the formation of Cu-Fe nano crystalline super-saturated solid solution developed by mechanical alloying

    Energy Technology Data Exchange (ETDEWEB)

    Mojtahedi, M., E-mail: m.mojtahedi@gmail.com [School of Materials Science and Engineering, Iran University of Science and Technology, Narmak, Tehran 16846-13114 (Iran, Islamic Republic of); Goodarzi, M.; Aboutalebi, M.R. [School of Materials Science and Engineering, Iran University of Science and Technology, Narmak, Tehran 16846-13114 (Iran, Islamic Republic of); Ghaffari, M. [Department of Electrical and Electronics Engineering, UNAM-Institute of Materials Science and Nanotechnology, Bilkent University, Ankara 06800 (Turkey); Soleimanian, V. [Department of Physics, Faculty of Science, Shahrekord University, P.O. Box 115, Shahrekord (Iran, Islamic Republic of)

    2013-02-15

    Highlights: Black-Right-Pointing-Pointer The deformation of the mechanically alloyed Cu-Fe powder is anisotropic. Black-Right-Pointing-Pointer The Rietveld method is more proper and results in smaller crystallite size than the Scherer and Williamson-Hall methods. Black-Right-Pointing-Pointer A dual phase super saturated solid solution achieved after 96 h of milling of the mixtures with 30, 50 and 70 wt.% of Iron. Black-Right-Pointing-Pointer A final proportion of approximately 85% FCC and 15% BCC structure obtained in all of the applied compositions. - Abstract: In this study, the formation of super saturated solid solution in the binary Cu-Fe system was investigated. Three powder blends with 30, 50 and 70 wt.% of Fe were milled for different times to 96 h. The variations of lattice parameter and inter-planar spacing were calculated and analyzed using X-ray diffraction analysis (XDA). The anisotropy of lattice deformation in the FCC phase was studied and the obtained results were compared to milled pure Cu powder. Furthermore, crystallite size was calculated using Scherer formula in comparison with Rietveld full profile refinement method. Considering the previous studies about the formation of non-equilibrium FCC and BCC phases, the phase evolution has been discussed and the proportion of each phase was calculated using Rietveld refinement method. Supplementary studies on the evolution of microstructure and formation of solid solution were carried out using high resolution transmission electron microscopy (HRTEM). Finally, high angle annular dark field (HAADF) imaging was utilized to find out the level of homogeneity in the resulting phases. While true alloying takes place in each phase, the final structure consists of both FCC and BCC nano-crystallites.

  2. [In vivo study on influence of a discrete nano-hydroxyapatite on leukemia P388 tissue in BALB/C mice].

    Science.gov (United States)

    Li, Ge; Huang, Jian-ming; Aoki, Hideki; Li, Yan; Zhang, Rong; Deng, Bi-fang

    2007-09-01

    To study the influence of a discrete nano-hydroxyapatite crystal (nano-HAp) on lymphatic leukemia P388 behavior by in vivo techniques. A nano-HAp was prepared by a neutralization reaction of 0.1 mol calcium hydroxide suspension and 0.06 mol phosphoric acid solutions at room temperature over pH7. The various doses of the nano-HAp only and the nano-HAp mixture with cyclophosphamide (CY) were injected into mice inoculated with solid tumor lymphatic leukemia P388 and dispersed into PRMI 1640 media harvested the leukemia P388 cells. Sixty P388 BALB/C mice were randomly grouped; 36 of them were used as nano-HAp treated groups and 24 mice as the control groups. The leukemia growth in the mice was examined morphologically, histopathologically and under a transmission electron microscope (TEM). The nano-HAp was identified as a hydroxyapatite by an X-ray diffractometry (XRD) and a Fourier transform infrared spectroscopy (FTIR). The morphology and sizes were observed under a TEM. The tissue growth inhibition ratio (weight%) of solid lymphatic leukemia P388 bearing mice treated with nano-HAp at doses 35 mg/kg, 53 mg/kg and nano-HAp (53 mg/kg) combined with CY (35 mg/kg) in 3 consecutive days via intraperitineal injections were 14.95%, 32.67% and 60.45% respectively. Apoptosis of P388 cell cocultured with nano-HAp was confirmed by TEM. The tissue growth restriction of solid tumor lymphatic leukemia P388 was greater after an injection of nano-HAp only or nano-HAp mixed with CY than that obtained after injection with physiological saline solution as a control (P < 0.01), and the tissue growth restriction of solid tumor after an injection of nano-HAp combined with CY was greater than that obtained after nano-HAp or CY injection only (P < 0.01).

  3. Spectral absorption of unpolarized light through nano-materials in the absence of a magnetic field

    Directory of Open Access Journals (Sweden)

    Luminosu I.

    2008-01-01

    Full Text Available A study of optical properties, such as light absorption, of a colloidal nano-material, provides information on the biphasic, solid - liquid system microstructure. The nano-material under study is a magnetic liquid (ferrofluid. The disperser agent is petroleum mineral oil and the dispersed material is a brown spar powder (nano-particles. The stabilizer is oleic acid. Light absorption through ferrofluid samples reveals the tendency of solid particles in a colloidal solution to form aggregates. The paper emphasizes the linear dependence between the spectral absorption coefficient, concentration and wavelength. The aggregates cause deviations of the extinction coefficient from values according to the Bouger-Lambert-Beer law. Fe3O4 aggregates sized 58.76 nm are formed in the system. The average number of nano-particles forming aggregates is 6. The magnetic liquid to be studied is secure stable and, thus, trustful in technological and biological applications.

  4. Nano sized Particles of Silica and Its Derivatives for Applications in Various Branches of Food and Nutrition Sectors

    International Nuclear Information System (INIS)

    Kasaai, M. R.

    2015-01-01

    Nano sized particles of silica and its derivatives have been identified as versatile for a broad range of science, technology, and engineering applications. In this paper, an effort has been made to provide a short review from the available literature information on their applications in various branches of food and nutrition sectors. The information provided in this paper describes various parameters affecting their performances and efficiencies. The properties and applications of nano silica and its derivatives have been compared with micro silica and bulk-silica for their performances. The use of nano sized particles of silica and its derivatives provides a number of advantages. Their efficiencies and performances are significantly higher than those of the traditional ones

  5. Structure and electromagnetic properties of NiZn spinel ferrite with nano-sized ZnAl{sub 2}O{sub 4} additions

    Energy Technology Data Exchange (ETDEWEB)

    Zheng, Zongliang, E-mail: zzlma@163.com; Zhang, Huaiwu; Yang, Qinghui; Jia, Lijun

    2015-11-05

    In this study, nanocrystalline ZnAl{sub 2}O{sub 4} (ZA) (x = 0–20 wt%) were introduced into Ni{sub 0.4}Zn{sub 0.6}Fe{sub 2}O{sub 4} ferrite (NZ) by a solid-state reaction method combining a sol–gel auto-combustion method. The effects of ZA addition on the crystalline phase formation, microstructures, magnetic and dielectric properties were systematically investigated. X-ray diffraction and scanning electron microscope results reveal that the added ZA can fully solve into the NZ to form a ceramic with single-phase cubic spinel structure, and the grain size decreases obviously as x > 5 wt%. Meanwhile, the magnetic and dielectric properties exhibit significantly dependent on the ZA addition content. With the increasing addition level of ZA from 0 to 20 wt%, the initial permeability μ{sub i} is found increased initially and then decreased with the maximum 679 at x = 0.5 wt%. For the samples with x ≤ 5 wt%, permittivity ε′ is relatively higher at low frequencies (ε′ = 91–138 at 1 MHz) and dielectric loss tan δ{sub ε} shows distinct peak behavior. When x reaches 10 wt%, however, the ε′ and tan δ{sub ε} show very stable spectra from 1 MHz to 1 GHz. - Highlights: • Various amount of nanocrystalline ZnAl{sub 2}O{sub 4} (ZA) were introduced into NiZn ferrite. • NiZn ferrite can form single-phase spinel ceramic materials with ZA additives. • ZA has significant effects on magnetic and dielectric properties of the ceramics. • It provides a new method for fabricating NiZn ferrite with tunable properties.

  6. Aluminum Templates of Different Sizes with Micro-, Nano- and Micro/Nano-Structures for Cell Culture

    Directory of Open Access Journals (Sweden)

    Ming-Liang Yen

    2017-10-01

    Full Text Available This study investigates the results of cell cultures on aluminum (Al templates with flat-structures, micro-structures, nano-structures and micro/nano-structures. An Al template with flat-structure was obtained by electrolytic polishing; an Al template with micro-structure was obtained by micro-powder blasting; an Al template with nano-structure was obtained by aluminum anodization; and an Al template with micro/nano-structure was obtained by micro-powder blasting and then anodization. Osteoblast-like cells were cultured on aluminum templates with various structures. The microculture tetrazolium test assay was utilized to assess the adhesion, elongation, and proliferation behaviors of cultured osteoblast-like cells on aluminum templates with flat-structures, micro-structures, nano-structures, and micro/nano-structures. The results showed that the surface characterization of micro/nano-structure of aluminum templates had superhydrophilic property, and these also revealed that an aluminum template with micro/nano-structure could provide the most suitable growth situation for cell culture.

  7. Size-dependent nonlinear bending of micro/nano-beams made of nanoporous biomaterials including a refined truncated cube cell

    Science.gov (United States)

    Sahmani, S.; Aghdam, M. M.

    2017-12-01

    Morphology and pore size plays an essential role in the mechanical properties as well as the associated biological capability of a porous structure made of biomaterials. The objective of the current study is to predict the Young's modulus and Poisson's ratio of nanoporous biomaterials including refined truncated cube cells based on a hyperbolic shear deformable beam model. Analytical relationships for the mechanical properties of nanoporous biomaterials are given as a function of the refined cell's dimensions. After that, the size dependency in the nonlinear bending behavior of micro/nano-beams made of such nanoporous biomaterials is analyzed using the nonlocal strain gradient elasticity theory. It is assumed that the micro/nano-beam has one movable end under axial compression in conjunction with a uniform distributed lateral load. The Galerkin method together with an improved perturbation technique is employed to propose explicit analytical expression for nonlocal strain gradient load-deflection curves of the micro/nano-beams made of nanoporous biomaterials subjected to uniform transverse distributed load. It is found that through increment of the pore size, the micro/nano-beam will undergo much more deflection corresponding to a specific distributed load due to the reduction in the stiffness of nanoporous biomaterial. This pattern is more prominent for lower value of applied axial compressive load at the free end of micro/nano-beam.

  8. The Effect of Nano-TiC Addition on Sintered Nd-Fe-B Permanent Magnets

    DEFF Research Database (Denmark)

    Mural, Zorjana; Kollo, Lauri; Xia, Manlong

    2017-01-01

    This paper addresses the effect of nano-TiC addition on sintered Nd-Fe-B permanent magnets. TiC nanoparticles were added to sintered Nd-Fe-B magnets with a specific aim to improve the Curie temperature and thermal stability. A standard powder metallurgy route was adopted to prepare the magnets....... It was found that introducing nano-TiC prior to jet milling was effective as the nanoparticles dispersed in the final alloy, concentcalcrating in the neodymium-rich phase of the magnets. Magnets with optimal properties were obtained with the addition of 1 wt% TiC nanoparticles. The hysteresis loop...

  9. Synthesis of Silica Nanoparticles by Sol-Gel: Size-Dependent Properties, Surface Modification, and Applications in Silica-Polymer Nano composites-A Review

    International Nuclear Information System (INIS)

    Ismail, A.R.; Vejayakumaran, P.

    2012-01-01

    Application of silica nanoparticles as fillers in the preparation of nano composite of polymers has drawn much attention, due to the increased demand for new materials with improved thermal, mechanical, physical, and chemical properties. Recent developments in the synthesis of monodispersed, narrow-size distribution of nanoparticles by sol-gel method provide significant boost to development of silica-polymer nano composites. This paper is written by emphasizing on the synthesis of silica nanoparticles, characterization on size-dependent properties, and surface modification for the preparation of homogeneous nano composites, generally by sol-gel technique. The effect of nano silica on the properties of various types of silica-polymer composites is also summarized.

  10. Experimental equivalent cluster-size distributions in nano-metric volumes of liquid water

    International Nuclear Information System (INIS)

    Grosswendt, B.; De Nardo, L.; Colautti, P.; Pszona, S.; Conte, V.; Tornielli, G.

    2004-01-01

    Ionisation cluster-size distributions in nano-metric volumes of liquid water were determined for alpha particles at 4.6 and 5.4 MeV by measuring cluster-size frequencies in small gaseous volumes of nitrogen or propane at low gas pressure as well as by applying a suitable scaling procedure. This scaling procedure was based on the mean free ionisation lengths of alpha particles in water and in the gases measured. For validation, the measurements of cluster sizes in gaseous volumes and the cluster-size formation in volumes of liquid water of equivalent size were simulated by Monte Carlo methods. The experimental water-equivalent cluster-size distributions in nitrogen and propane are compared with those in liquid water and show that cluster-size formation by alpha particles in nitrogen or propane can directly be related to those in liquid water. (authors)

  11. Surface Modification, Characterization and Photocatalytic Performance of Nano-Sized Titania Modified with Silver and Bentonite Clay

    Directory of Open Access Journals (Sweden)

    Neetu Divya

    2009-12-01

    Full Text Available In many textile industries dyes are used as coloring agents. Advanced oxidation processes are used for degrading or removing color from dye baths. Catalysts play a key role in these industries for the treatment of water. Solid catalysts are usually composed of metals that form supports onto the surface and create metal particles with high surface areas. TiO2 composites containing transition metal ions (silver and/or bentonite clay were prepared. Photocatalytic efficiencies have been investigated for the degradation of Orange G an azo dye. Various analytical techniques were used to characterize the surface properties of nano-sized titania modified using silver and/or bentonite clay. Scanning electron microscopy (SEM, Transmission electron microscopy (TEM, X-ray diffraction (XRD and FTIR analyses showed that TiO2 (10 ± 2 nm and Ag (2 to 3 nm particles were supported on the surface of the bentonite clay and the size was in the range of 100 ± 2 nm. The modified catalysts P-25 TiO2/Bentonite/Ag and P-25 TiO2/Ag were found to be very active for the photocatalytic decomposition of Orange G. The percent decolorization in 60 min was 98% with both P-25 TiO2/Ag and P-25 TiO2/Bentonite/Ag modified catalysts. Whereas mineralization achieved in 9 hr were 68% and 71% with P-25 TiO2/Bentonite/Ag and P-25 TiO2/Ag catalyst respectively. © 2009 BCREC UNDIP. All rights reserved[Received: 30 October 2009, Revised: 20 November 2009, Accepted: 21 November 2009][How to Cite: N. Divya, A. Bansal, A. K. Jana. (2009. Surface Modification, Characterization and Photocatalytic Performance of Nano-Sized Titania Modified with Silver and Bentonite Clay. Bulletin of Chemical Reaction Engineering and Catalysis, 4(2: 43-53.  doi:10.9767/bcrec.4.2.1249.43-53][How to Link/ DOI: http://dx.doi.org/10.9767/bcrec.4.2.1249.43-53 || or local: http://ejournal.undip.ac.id/index.php/bcrec/article/view/1249

  12. Nano size crystals of goethite, α-FeOOH: Synthesis and thermal transformation

    Science.gov (United States)

    Christensen, Axel Nørlund; Jensen, Torben R.; Bahl, Christian R. H.; DiMasi, Elaine

    2007-04-01

    An aqueous suspension of amorphous iron(III) hydroxide was kept at room temperature (298 K) for 23 years. During this period of time the pH of the liquid phase changed from 4.3 to 2.85, and nano size crystals of goethite, α-FeOOH crystallised from the amorphous iron(III) hydroxide. Transmission electron microscopy (TEM) investigations, Mössbauer spectra, and powder X-ray diffraction using Co K α radiation showed that the only iron containing crystalline phase present in the recovered product was α-FeOOH. The size of these nano particles range from 10 to 100 nm measured by TEM. The thermal decomposition of α-FeOOH was investigated by time-resolved in situ synchrotron radiation powder X-ray diffraction and the data showed that the sample of α-FeOOH transformed to α-Fe 2O 3 in the temperature range 444-584 K. A quantitative phase analysis shows the increase in scattered X-ray intensity from α-Fe 2O 3 to follow the decrease of intensity from α-FeOOH in agreement with the topotactic phase transition.

  13. Extremely fine structured cathode for solid oxide fuel cells using Sr-doped LaMnO3 and Y2O3-stabilized ZrO2 nano-composite powder synthesized by spray pyrolysis

    Science.gov (United States)

    Shimada, Hiroyuki; Yamaguchi, Toshiaki; Sumi, Hirofumi; Nomura, Katsuhiro; Yamaguchi, Yuki; Fujishiro, Yoshinobu

    2017-02-01

    A solid oxide fuel cell (SOFC) for high power density operation was developed with a microstructure-controlled cathode using a nano-composite powder of Sr-doped LaMnO3 (LSM) and Y2O3-stabilized ZrO2 (YSZ) synthesized by spray pyrolysis. The individual LSM-YSZ nano-composite particles, formed by crystalline and amorphous nano-size LSM and YSZ particles, showed spherical morphology with uniform particle size. The use of this powder for cathode material led to an extremely fine microstructure, in which all the LSM and YSZ grains (approximately 100-200 nm) were highly dispersed and formed their own network structures. This microstructure was due to the two phase electrode structure control using the powder, namely, nano-order level in each particle and micro-order level between particles. An anode-supported SOFC with the LSM-YSZ cathode using humidified H2 as fuel and ambient air as oxidant exhibited high power densities, such as 1.29 W cm-2 under a voltage of 0.75 V and a maximum power density of 2.65 W cm-2 at 800 °C. Also, the SOFC could be stably operated for 250 h with no degradation, even at a high temperature of 800 °C.

  14. Fabrication of nano-sized magnetic tunnel junctions using lift-off process assisted by atomic force probe tip.

    Science.gov (United States)

    Jung, Ku Youl; Min, Byoung-Chul; Ahn, Chiyui; Choi, Gyung-Min; Shin, Il-Jae; Park, Seung-Young; Rhie, Kungwon; Shin, Kyung-Ho

    2013-09-01

    We present a fabrication method for nano-scale magnetic tunnel junctions (MTJs), employing e-beam lithography and lift-off process assisted by the probe tip of atomic force microscope (AFM). It is challenging to fabricate nano-sized MTJs on small substrates because it is difficult to use chemical mechanical planarization (CMP) process. The AFM-assisted lift-off process enables us to fabricate nano-sized MTJs on small substrates (12.5 mm x 12.5 mm) without CMP process. The e-beam patterning has been done using bi-layer resist, the poly methyl methacrylate (PMMA)/ hydrogen silsesquioxane (HSQ). The PMMA/HSQ resist patterns are used for both the etch mask for ion milling and the self-aligned mask for top contact formation after passivation. The self-aligned mask buried inside a passivation oxide layer, is readily lifted-off by the force exerted by the probe tip. The nano-MTJs (160 nm x 90 nm) fabricated by this method show clear current-induced magnetization switching with a reasonable TMR and critical switching current density.

  15. Polymer X-ray refractive nano-lenses fabricated by additive technology.

    Science.gov (United States)

    Petrov, A K; Bessonov, V O; Abrashitova, K A; Kokareva, N G; Safronov, K R; Barannikov, A A; Ershov, P A; Klimova, N B; Lyatun, I I; Yunkin, V A; Polikarpov, M; Snigireva, I; Fedyanin, A A; Snigirev, A

    2017-06-26

    The present work demonstrates the potential applicability of additive manufacturing to X-Ray refractive nano-lenses. A compound refractive lens with a radius of 5 µm was produced by the two-photon polymerization induced lithography. It was successfully tested at the X-ray microfocus laboratory source and a focal spot of 5 μm was measured. An amorphous nature of polymer material combined with the potential of additive technologies may result in a significantly enhanced focusing performance compared to the best examples of modern X-ray compound refractive lenses.

  16. The effect of nano-TiC addition on sintered Nd-Fe-B permanent magnets

    International Nuclear Information System (INIS)

    Mural, Zorjana; Kollo, Lauri; Xia, Manlong; Bahl, Christian R.H.; Abrahamsen, Asger Bech; Bez, Henrique Neves; Link, Joosep; Veinthal, Renno

    2017-01-01

    This paper addresses the effect of nano-TiC addition on sintered Nd-Fe-B permanent magnets. TiC nanoparticles were added to sintered Nd-Fe-B magnets with a specific aim to improve the Curie temperature and thermal stability. A standard powder metallurgy route was adopted to prepare the magnets. It was found that introducing nano-TiC prior to jet milling was effective as the nanoparticles dispersed in the final alloy, concentcalcrating in the neodymium-rich phase of the magnets. Magnets with optimal properties were obtained with the addition of 1 wt% TiC nanoparticles. The hysteresis loop for such magnets showed an improved shape and VSM analysis a coercivity value of 1188 kA/m, a remanence value of 0.96 T and a maximum energy product of 132 kJ/m 3 . The maximum working point and the Curie temperature of the developed magnets were 373 K and 623 K respectively. - Highlights: • Improvement of thermal stability of Nd-Fe-B magnets by introducing nano-TiC prior sintering is proposed. • The mechanism relies on nano-TiC particles behaving as grain growth inhibitors between thin RE-rich phase regions. • The concentration of up to 1 wt% of nano-TiC appears to increase coercivity without a significant decrease in remanence. • The maximum working point and the Curie temperature of the developed magnets are 373 K and 623 K respectively.

  17. The effect of nano-TiC addition on sintered Nd-Fe-B permanent magnets

    Energy Technology Data Exchange (ETDEWEB)

    Mural, Zorjana, E-mail: zorjana.mural@ttu.ee [Department of Materials Engineering, Tallinn University of Technology, Ehitajate tee 5, 19086 Tallinn (Estonia); Kollo, Lauri [Department of Materials Engineering, Tallinn University of Technology, Ehitajate tee 5, 19086 Tallinn (Estonia); Xia, Manlong; Bahl, Christian R.H. [Department of Energy Conversion and Storage, Technical University of Denmark, Frederiksborgvej 399, 4000 Roskilde (Denmark); Abrahamsen, Asger Bech [Department of Wind Energy, Technical University of Denmark, Frederiksborgvej 399, 4000 Roskilde (Denmark); Bez, Henrique Neves [Department of Energy Conversion and Storage, Technical University of Denmark, Frederiksborgvej 399, 4000 Roskilde (Denmark); Link, Joosep [National Institute of Chemical Physics and Biophysics, Akadeemia tee 23, 12618 Tallinn (Estonia); Veinthal, Renno [Department of Materials Engineering, Tallinn University of Technology, Ehitajate tee 5, 19086 Tallinn (Estonia)

    2017-05-01

    This paper addresses the effect of nano-TiC addition on sintered Nd-Fe-B permanent magnets. TiC nanoparticles were added to sintered Nd-Fe-B magnets with a specific aim to improve the Curie temperature and thermal stability. A standard powder metallurgy route was adopted to prepare the magnets. It was found that introducing nano-TiC prior to jet milling was effective as the nanoparticles dispersed in the final alloy, concentcalcrating in the neodymium-rich phase of the magnets. Magnets with optimal properties were obtained with the addition of 1 wt% TiC nanoparticles. The hysteresis loop for such magnets showed an improved shape and VSM analysis a coercivity value of 1188 kA/m, a remanence value of 0.96 T and a maximum energy product of 132 kJ/m{sup 3}. The maximum working point and the Curie temperature of the developed magnets were 373 K and 623 K respectively. - Highlights: • Improvement of thermal stability of Nd-Fe-B magnets by introducing nano-TiC prior sintering is proposed. • The mechanism relies on nano-TiC particles behaving as grain growth inhibitors between thin RE-rich phase regions. • The concentration of up to 1 wt% of nano-TiC appears to increase coercivity without a significant decrease in remanence. • The maximum working point and the Curie temperature of the developed magnets are 373 K and 623 K respectively.

  18. Determination of grain size by XRD profile analysis and TEM counting in nano-structured Cu

    International Nuclear Information System (INIS)

    Zhong Yong; Ping Dehai; Song Xiaoyan; Yin Fuxing

    2009-01-01

    In this work, a serial of pure copper sample with different grain sizes from nano- to micro-scale were prepared by sparkle plasma sintering (SPS) and following anneal treatment at 873 K and 1073 K, respectively. The grain size distributions of these samples were determined by both X-ray diffraction (XRD) profile analysis and transmission electronic microscope (TEM) micrograph counting. Although these two methods give similar distributions of grain size in the case of as-SPS sample with nano-scale grain size (around 10 nm), there are apparent discrepancies between the grain size distributions of the annealed samples obtained from XRD and TEM, especially for the sample annealed at 1073 K after SPS with micro-scale grain size (around 2 μm), which TEM counting provides much higher values of grain sizes than XRD analysis does. It indicates that for large grain-sized material, XRD analysis lost its validity for determination of grain size. It might be due to some small sized substructures possibly existed in even annealed (large grain-sized) samples, whereas there is no substructures in as-SPS (nanocrystalline) sample. Moreover, it has been found that the effective outer cut-off radius R e derived from XRD analysis coincides with the grain sizes given by TEM counting. The potential relationship between grain size and R e was discussed in the present work. These results might provide some new hints for deeper understanding of the physical meaning of XRD analysis and the parameters derived.

  19. Exposure to nano-size titanium dioxide causes oxidative damages in human mesothelial cells: The crystal form rather than size of particle contributes to cytotoxicity.

    Science.gov (United States)

    Hattori, Kenji; Nakadate, Kazuhiko; Morii, Akane; Noguchi, Takumi; Ogasawara, Yuki; Ishii, Kazuyuki

    2017-10-14

    Exposure to nanoparticles such as carbon nanotubes has been shown to cause pleural mesothelioma similar to that caused by asbestos, and has become an environmental health issue. Not only is the percutaneous absorption of nano-size titanium dioxide particles frequently considered problematic, but the possibility of absorption into the body through the pulmonary route is also a concern. Nevertheless, there are few reports of nano-size titanium dioxide particles on respiratory organ exposure and dynamics or on the mechanism of toxicity. In this study, we focused on the morphology as well as the size of titanium dioxide particles. In comparing the effects between nano-size anatase and rutile titanium dioxide on human-derived pleural mesothelial cells, the anatase form was shown to be actively absorbed into cells, producing reactive oxygen species and causing oxidative damage to DNA. In contrast, we showed for the first time that the rutile form is not easily absorbed by cells and, therefore, does not cause oxidative DNA damage and is significantly less damaging to cells. These results suggest that with respect to the toxicity of titanium dioxide particles on human-derived mesothelial cells, the crystal form rather than the particle size has a greater effect on cellular absorption. Also, it was indicated that the difference in absorption is the primary cause of the difference in the toxicity against mesothelial cells. Copyright © 2017 Elsevier Inc. All rights reserved.

  20. [Drug delivery systems using nano-sized drug carriers].

    Science.gov (United States)

    Nakayama, Masamichi; Okano, Teruo

    2005-07-01

    Nanotechnology has attracted great attention all over the world in recent several years and has led to the establishment of the novel technical field of "nanomedicine" through collaboration with advanced medical technology. Particularly, site-specific drug targeting using particle drug carrier systems has made substantial progress and been actively developed. This review explains the essential factors (size and chemical character) of drug carriers to allow long circulation in the bloodstream avoiding the reticuloendothelial system, and shows the present status and future perspective of several types of nano-carrier systems (water-soluble polymer, liposome and polymeric micelle). We also introduce the novel concept of multi-targeting system (combination of two or more targeting methodologies) for ideal drug therapies.

  1. Nano-dot and nano-pit fabrication on a GaAs substrate by a pulse applied AFM

    International Nuclear Information System (INIS)

    Kim, H C; Yu, J S; Ryu, S H

    2012-01-01

    The nano-patterning characteristics of GaAs is investigated using a pulse applied atomic force microscope (AFM). Very short range voltage pulses of micro to nano-seconds’ duration are applied to a conductive diamond-coated silicon (Si) tip in contact mode, to regulate the created feature size. The effects of pulse conditions such as pulse voltage, duration, frequency, offset voltage, anodization time, and applied tip pressure on nano-dot generation are characterized, based on the experiments. An interesting phenomenon, nano-pit creation instead of nano-dot creation, is observed when the applied pulse duration is less than 100 μs. Pulse frequency and offset voltage are also involved in nano-pit generation. The electrical spark discharge between the tip and the GaAs's surface is the most probable cause of the nano-pit creation and its generation mechanism is explained by considering the relevant pulse parameters. Nano-pits over 15 nm in depth are acquired on the GaAs substrate by adjusting the pulse conditions. This research facilitates the fabrication of more complex nano-structures on semiconductor materials since nano-dots and nano-pits could be easily made without any additional post-processes. (paper)

  2. Combined addition of nano diamond and nano SiO2, an effective method to improve the in-field critical current density of MgB2 superconductor

    International Nuclear Information System (INIS)

    Rahul, S.; Varghese, Neson; Vinod, K.; Devadas, K.M.; Thomas, Syju; Anees, P.; Chattopadhyay, M.K.; Roy, S.B.; Syamaprasad, U.

    2011-01-01

    Highlights: → Both nano diamond and nano SiO 2 caused significant modifications in the structural properties of pure MgB 2 sample. → Reduction in T C for the best codoped sample was approximately 2 K. → The best codoped sample yielded a J C , an order of magnitude more than the undoped one at 5 K and 8 T. → The enhanced flux pinning capability provided by the additives is responsible for the improved in-field J C . -- Abstract: MgB 2 bulk samples added with nano SiO 2 and/or nano diamond were prepared by powder-in-sealed-tube (PIST) method and the effects of addition on structural and superconducting properties were studied. X-ray diffraction (XRD) analysis revealed that the addition caused systematic reduction in 'a' lattice parameter due to the substitution of C atoms at B sites and the strain caused by reacted intragrain nano particles of Mg 2 Si as evinced by transmission electron microscope image. Scanning electron microscopy images showed distinct microstructural variations with SiO 2 /diamond addition. It was evident from DC magnetization measurements that the in-field critical current density [J C (H)] of doped samples did not fall drastically like the undoped sample. Among the doped samples the J C (H) of co-doped samples were significantly higher and the best co-doped sample yielded a J C , an order of magnitude more than the undoped one at 5 K and 8 T.

  3. Nano-sized precipitation and properties of a low carbon niobium micro-alloyed bainitic steel

    Energy Technology Data Exchange (ETDEWEB)

    Xie, Z.J. [School of Materials Science and Engineering, University of Science and Technology Beijing, Beijing 100083 (China); Department of Materials Science and Engineering, McMaster University, Hamilton L8S 4L8 (Canada); Ma, X.P. [Department of Materials Science and Engineering, McMaster University, Hamilton L8S 4L8 (Canada); Shang, C.J., E-mail: cjshang@ustb.edu.cn [School of Materials Science and Engineering, University of Science and Technology Beijing, Beijing 100083 (China); Wang, X.M. [School of Materials Science and Engineering, University of Science and Technology Beijing, Beijing 100083 (China); Subramanian, S.V. [Department of Materials Science and Engineering, McMaster University, Hamilton L8S 4L8 (Canada)

    2015-08-12

    The present work focuses on microstructure evolution and precipitation strengthening during tempering at region of 550–680 °C to elucidate the structure–property relationship in the steel. The effect of tempering on the development of a 700 MPa grade high strength hot rolled cost-effective bainitic steel was studied for infrastructure applications. Granular bainite with dispersed martenisit–austenite (M–A) constituents in the bainitic ferrite matrix was obtained after hot rolling and air cooling to room temperature. The decomposition of M–A constituents to cementite carbides and the precipitation of nano-sized NbC carbides in bainitic matrix on tempering were characterized by scanning electron microscopy (SEM) and transmission electron microscopy (TEM). Nano-sized precipitates of NbC precipitated during tempering were in average diameter of ~4.1–6.1 nm. There were ~86–173 MPa increases in yield strength after tempering at region of 550–680 °C. It is noticeable that those nano-sized NbC precipitates provide an effective way to significantly increase the strength of the low carbon bainitic steel. High yield strength of 716 MPa with high ductility (uniform elongation of 9.3% and total elongation of 22.4%), low yield to tensile ratio of 0.9 and good low temperature toughness of 47 J (half thickness) at –40 °C was obtained after tempering at 680 °C for 30 min.

  4. All-Solid-State Textile Batteries Made from Nano-Emulsion Conducting Polymer Inks for Wearable Electronics

    Directory of Open Access Journals (Sweden)

    Tapani Ryhänen

    2012-08-01

    Full Text Available A rollable and all-solid-state textile lithium battery based on fabric matrix and polymer electrolyte that allows flexibility and fast-charging capability is reported. When immerged into poly(3,4-ethylenedioxythiophene (PEDOT nano-emulsion inks, an insulating fabric is converted into a conductive battery electrode for a fully solid state lithium battery with the highest specific energy capacity of 68 mAh/g. This is superior to most of the solid-state conducting polymer primary and/or secondary batteries reported. The bending radius of such a textile battery is less than 1.5 mm while lightening up an LED. This new material combination and inherent flexibility is well suited to provide an energy source for future wearable and woven electronics.

  5. Highly selective solid phase extraction and preconcentration of Azathioprine with nano-sized imprinted polymer based on multivariate optimization and its trace determination in biological and pharmaceutical samples

    Energy Technology Data Exchange (ETDEWEB)

    Davarani, Saied Saeed Hosseiny, E-mail: ss-hosseiny@cc.sbu.ac.ir [Faculty of Chemistry, Shahid Beheshti University, G. C., P.O. Box 19839-4716, Tehran (Iran, Islamic Republic of); Rezayati zad, Zeinab [Faculty of Chemistry, Shahid Beheshti University, G. C., P.O. Box 19839-4716, Tehran (Iran, Islamic Republic of); Taheri, Ali Reza; Rahmatian, Nasrin [Islamic Azad University, Ilam Branch, Ilam (Iran, Islamic Republic of)

    2017-02-01

    In this research, for first time selective separation and determination of Azathioprine is demonstrated using molecularly imprinted polymer as the solid-phase extraction adsorbent, measured by spectrophotometry at λ{sub max} 286 nm. The selective molecularly imprinted polymer was produced using Azathioprine and methacrylic acid as a template molecule and monomer, respectively. A molecularly imprinted solid-phase extraction procedure was performed in column for the analyte from pharmaceutical and serum samples. The synthesized polymers were characterized by infrared spectroscopy (IR), field emission scanning electron microscopy (FESEM). In order to investigate the effect of independent variables on the extraction efficiency, the response surface methodology (RSM) based on Box–Behnken design (BBD) was employed. The analytical parameters such as precision, accuracy and linear working range were also determined in optimal experimental conditions and the proposed method was applied to analysis of Azathioprine. The linear dynamic range and limits of detection were 2.5–0.01 and 0.008 mg L{sup ‐1} respectively. The recoveries for analyte were higher than 95% and relative standard deviation values were found to be in the range of 0.83–4.15%. This method was successfully applied for the determination of Azathioprine in biological and pharmaceutical samples. - Graphical abstract: A new-nano sized imprinted polymer was synthesized and applied as sorbent in SPE in order to selective recognition, preconcentration, and determination of Azathioprine with the response surface methodology based on Box–Behnken design and was successfully investigated for the clean-up of human blood serum and pharmaceutical samples. - Highlights: • The nanosized-imprinted polymer has been synthesized by precipitation polymerization technique. • A molecularly imprinted solid-phase extraction procedure was performed for determination of Azathioprine. • The Azathioprine

  6. Highly selective solid phase extraction and preconcentration of Azathioprine with nano-sized imprinted polymer based on multivariate optimization and its trace determination in biological and pharmaceutical samples

    International Nuclear Information System (INIS)

    Davarani, Saied Saeed Hosseiny; Rezayati zad, Zeinab; Taheri, Ali Reza; Rahmatian, Nasrin

    2017-01-01

    In this research, for first time selective separation and determination of Azathioprine is demonstrated using molecularly imprinted polymer as the solid-phase extraction adsorbent, measured by spectrophotometry at λ max 286 nm. The selective molecularly imprinted polymer was produced using Azathioprine and methacrylic acid as a template molecule and monomer, respectively. A molecularly imprinted solid-phase extraction procedure was performed in column for the analyte from pharmaceutical and serum samples. The synthesized polymers were characterized by infrared spectroscopy (IR), field emission scanning electron microscopy (FESEM). In order to investigate the effect of independent variables on the extraction efficiency, the response surface methodology (RSM) based on Box–Behnken design (BBD) was employed. The analytical parameters such as precision, accuracy and linear working range were also determined in optimal experimental conditions and the proposed method was applied to analysis of Azathioprine. The linear dynamic range and limits of detection were 2.5–0.01 and 0.008 mg L ‐1 respectively. The recoveries for analyte were higher than 95% and relative standard deviation values were found to be in the range of 0.83–4.15%. This method was successfully applied for the determination of Azathioprine in biological and pharmaceutical samples. - Graphical abstract: A new-nano sized imprinted polymer was synthesized and applied as sorbent in SPE in order to selective recognition, preconcentration, and determination of Azathioprine with the response surface methodology based on Box–Behnken design and was successfully investigated for the clean-up of human blood serum and pharmaceutical samples. - Highlights: • The nanosized-imprinted polymer has been synthesized by precipitation polymerization technique. • A molecularly imprinted solid-phase extraction procedure was performed for determination of Azathioprine. • The Azathioprine-molecular imprinting

  7. Kinetics of solid-gas reactions characterized by scanning AC nano-calorimetry with application to Zr oxidation

    International Nuclear Information System (INIS)

    Xiao, Kechao; Lee, Dongwoo; Vlassak, Joost J.

    2014-01-01

    Scanning AC nano-calorimetry is a recently developed experimental technique capable of measuring the heat capacity of thin-film samples of a material over a wide range of temperatures and heating rates. Here, we describe how this technique can be used to study solid-gas phase reactions by measuring the change in heat capacity of a sample during reaction. We apply this approach to evaluate the oxidation kinetics of thin-film samples of zirconium in air. The results confirm parabolic oxidation kinetics with an activation energy of 0.59 ± 0.03 eV. The nano-calorimetry measurements were performed using a device that contains an array of micromachined nano-calorimeter sensors in an architecture designed for combinatorial studies. We demonstrate that the oxidation kinetics can be quantified using a single sample, thus enabling high-throughput mapping of the composition-dependence of the reaction rate.

  8. Nano-modification to improve the ductility of cementitious composites

    International Nuclear Information System (INIS)

    Yeşilmen, Seda; Al-Najjar, Yazin; Balav, Mohammad Hatam; Şahmaran, Mustafa; Yıldırım, Gürkan; Lachemi, Mohamed

    2015-01-01

    Effect of nano-sized mineral additions on ductility of engineered cementitious composites (ECC) containing high volumes of fly ash was investigated at different hydration degrees. Various properties of ECC mixtures with different mineral additions were compared in terms of microstructural properties of matrix, fiber-matrix interface, and fiber surface to assess improvements in ductility. Microstructural characterization was made by measuring pore size distributions through mercury intrusion porosimetry (MIP). Hydration characteristics were assessed using thermogravimetric analysis/differential thermal analysis (TGA/DTA), and fiber-matrix interface and fiber surface characteristics were assessed using scanning electron microscopy (SEM) through a period of 90 days. Moreover, compressive and flexural strength developments were monitored for the same period. Test results confirmed that mineral additions could significantly improve both flexural strength and ductility of ECC, especially at early ages. Cheaper Nano-CaCO 3 was more effective compared to nano-silica. However, the crystal structure of CaCO 3 played a very important role in the range of expected improvements

  9. Nano crystals for Electronic and Optoelectronic Applications

    International Nuclear Information System (INIS)

    Zhu, T.; Cloutier, S.G.; Ivanov, I; Knappenberger Jr, K.L.; Robel, I.; Zhang, F

    2012-01-01

    Electronic and optoelectronic devices, from computers and smart cell phones to solar cells, have become a part of our life. Currently, devices with featured circuits of 45 nm in size can be fabricated for commercial use. However, further development based on traditional semiconductor is hindered by the increasing thermal issues and the manufacturing cost. During the last decade, nano crystals have been widely adopted in various electronic and optoelectronic applications. They provide alternative options in terms of ease of processing, low cost, better flexibility, and superior electronic/optoelectronic properties. By taking advantage of solution-processing, self-assembly, and surface engineering, nano crystals could serve as new building blocks for low-cost manufacturing of flexible and large area devices. Tunable electronic structures combined with small exciton binding energy, high luminescence efficiency, and low thermal conductivity make nano crystals extremely attractive for FET, memory device, solar cell, solid-state lighting/display, photodetector, and lasing applications. Efforts to harness the nano crystal quantum tunability have led to the successful demonstration of many prototype devices, raising the public awareness to the wide range of solutions that nano technology can provide for an efficient energy economy. This special issue aims to provide the readers with the latest achievements of nano crystals in electronic and optoelectronic applications, including the synthesis and engineering of nano crystals towards the applications and the corresponding device fabrication, characterization and computer modeling.

  10. Olefin metathesis in nano-sized systems

    Directory of Open Access Journals (Sweden)

    Denise Méry

    2011-01-01

    Full Text Available The interplay between olefin metathesis and dendrimers and other nano systems is addressed in this mini review mostly based on the authors’ own contributions over the last decade. Two subjects are presented and discussed: (i The catalysis of olefin metathesis by dendritic nano-catalysts via either covalent attachment (ROMP or, more usefully, dendrimer encapsulation – ring closing metathesis (RCM, cross metathesis (CM, enyne metathesis reactions (EYM – for reactions in water without a co-solvent and (ii construction and functionalization of dendrimers by CM reactions.

  11. Fabrication of high-aspect-ratio nano structures using a nano x-ray shadow mask

    International Nuclear Information System (INIS)

    Kim, Yong Chul; Lee, Seung S

    2008-01-01

    This paper describes a novel method for the fabrication of high-aspect-ratio nano structures (HAR-nano structures) using a nano x-ray shadow mask and deep x-ray lithography (DXRL). The nano x-ray shadow mask is fabricated by depositing an x-ray absorber layer (Au, 3 µm) onto the back side of a nano shadow mask. The nano shadow mask is produced with nano-sized apertures whose dimensions are reduced to several tens of nanometers by the accumulation of low-stress silicon nitride (Si x N y ) using the LPCVD process on the shadow mask. A shadow mask containing apertures with a size of 1 µm is fabricated on a bulk micromachined Si x N y membrane. The thickness of an absorber layer must be in the range of several tens of micrometers in order to obtain a contrast of more than 100 for the conventional DXRL process at the Pohang Light Source (PLS). However, a 3 µm thick absorber layer can provide a sufficient contrast if the modified DXRL of the central beam-stop method is used, which blocks high-energy x-rays. A nano shadow mask with 30 nm sized apertures is fabricated and a nano x-ray shadow mask with 250 nm sized apertures is fabricated by depositing a 3 µm thick absorber layer on a nano shadow mask with 500 nm sized apertures. HAR-nano structures (circles with a diameter of 420 nm and lines with a width of 274 nm) with aspect ratios of over 10:1 on a 3.2 µm SU-8 are successfully fabricated by using the nano x-ray shadow mask and the central beam-stop method

  12. Effect of microscopic structure on deformation in nano-sized copper and Cu/Si interfacial cracking

    Energy Technology Data Exchange (ETDEWEB)

    Sumigawa, Takashi, E-mail: sumigawa@cyber.kues.kyoto-u.ac.jp; Nakano, Takuya; Kitamura, Takayuki

    2013-03-01

    The purpose of this work is to examine the effect of microscopic structure on the mechanical properties of nano-sized components (nano-components). We developed a bending specimen with a substructure that can be observed by means of a transmission electron microscope (TEM). We examined the plastic behavior of a Cu bi-crystal and the Cu/Si interfacial cracking in a nano-component. TEM images indicated that an initial plastic deformation takes place near the interface edge (the junction between the Cu/Si interface and the surface) in the Cu film with a high critical resolved shear stress (400–420 MPa). The deformation developed preferentially in a single grain. Interfacial cracking took place at the intersection between the grain boundary and the Cu/Si interface, where a high stress concentration existed due to deformation mismatch. These results indicate that the characteristic mechanical behavior of a nano-component is governed by the microscopic stress field, which takes into account the crystallographic structure. - Highlights: ► A nano-component specimen including a bi-crystal copper layer was prepared. ► A loading test with in-situ transmission electron microscopy was conducted. ► The plastic and cracking behaviors were governed by microscopic stress. ► Stress defined under continuum assumption was still present in nano-components.

  13. Significance of size dependent and material structure coupling on the characteristics and performance of nanocrystalline micro/nano gyroscopes

    Science.gov (United States)

    Larkin, K.; Ghommem, M.; Abdelkefi, A.

    2018-05-01

    Capacitive-based sensing microelectromechanical (MEMS) and nanoelectromechanical (NEMS) gyroscopes have significant advantages over conventional gyroscopes, such as low power consumption, batch fabrication, and possible integration with electronic circuits. However, inadequacies in the modeling of these inertial sensors have presented issues of reliability and functionality of micro-/nano-scale gyroscopes. In this work, a micromechanical model is developed to represent the unique microstructure of nanocrystalline materials and simulate the response of micro-/nano-gyroscope comprising an electrostatically-actuated cantilever beam with a tip mass at the free end. Couple stress and surface elasticity theories are integrated into the classical Euler-Bernoulli beam model in order to derive a size-dependent model. This model is then used to investigate the influence of size-dependent effects on the static pull-in instability, the natural frequencies and the performance output of gyroscopes as the scale decreases from micro-to nano-scale. The simulation results show significant changes in the static pull-in voltage and the natural frequency as the scale of the system is decreased. However, the differential frequency between the two vibration modes of the gyroscope is observed to drastically decrease as the size of the gyroscope is reduced. As such, the frequency-based operation mode may not be an efficient strategy for nano-gyroscopes. The results show that a strong coupling between the surface elasticity and material structure takes place when smaller grain sizes and higher void percentages are considered.

  14. Separation of Trace Amount Zn (II Using Additional Carbonyl and Carboxyl Groups Functionalized-Nano Graphene

    Directory of Open Access Journals (Sweden)

    A. Moghimi

    2013-01-01

    Full Text Available A novel and selective method for the fast determination of trace amounts of Zn(IIions in water samples has been developed.  The first additional carbonyl and carboxyl functionalized-nano graphene (SPFNano graphene. The presence of additional carbonyl and carboxyl groups located at the edge of the sheets makes GO sheets strongly hydrophilic, allowing them to readily swell and disperse in water. Based on these oxygen functionalities, different model structures of GO were used as absorbent for extraction of Zn (II   ions by solid phase extraction method. The complexes were eluted with HNO3 (2M10% V.V-1 methanol in acetone and determined the analyte by flame atomic absorption spectrometry.  The procedure is based on the selective formation of Zn (II at optimum pH by elution with organic eluents and determination by flame atomic absorption spectrometry. The method is based on complex formation on the surface of the ENVI-18 DISKTM disks modified carbonyl and carboxyl functionalized-nano graphene oxide molecules covalently bonded together followed by stripping of the retained species by minimum amounts of appropriate organic solvents. The elution is efficient and quantitative. The effect of potential interfering ions, pH, SPFNano graphene, amount, stripping solvent, and sample flow rate were also investigated. Under the optimal experimental conditions, the break-through volume was found to about 1000mL providing a preconcentration factor of 500. The maximum capacity of the disks was found to be 456± 3 µg for Zn2+.The limit of detection of the proposed method is 5ng per 1000mL.The method was applied to the extraction and recovery of Zn in different water samples.

  15. A new nanocomposite polymer electrolyte based on poly(vinyl alcohol) incorporating hypergrafted nano-silica

    KAUST Repository

    Hu, Xian-Lei

    2012-01-01

    Solid-state nanocomposite polymer electrolytes based on poly(vinyl alcohol)(PVA) incorporating hyperbranched poly(amine-ester) (HBPAE) grafted nano-silica (denoted as SiO2-g-HBPAE) have been prepared and investigated. Through surface pretreatment of nanoparticles, followed by Michael-addition and a self-condensation process, hyperbranched poly(amine-ester) was directly polymerized from the surface of nano-silica. Then the hypergrafted nanoparticles were added to PVA matrix, and blended with lithium perchlorate via mold casting method to fabricate nanocomposite polymer electrolytes. By introducing hypergrafted nanoparticles, ionic conductivity of solid composite is improved significantly at the testing temperature. Hypergrafted nano-silica may act as solid plasticizer, promoting lithium salt dissociation in the matrix as well as improving segmental motion of matrix. In addition, tensile testing shows that such materials are soft and tough even at room temperature. From the dielectric spectra of nanocomposite polymer electrolyte as the function of temperature, it can be deduced that Arrhenius behavior appears depending on the content of hypergrafted nano-silica and concentration of lithium perchlorate. At a loading of 15 wt% hypergrafted nano-silica and 54 wt% lithium perchlorate, promising ionic conductivities of PVA nanocomposite polymer electrolyte are achieved, about 1.51 × 10 -4 S cm-1 at 25 °C and 1.36 × 10-3 S cm-1 at 100 °C. © The Royal Society of Chemistry.

  16. Analysis of tecniques for measurement of the size distribution of solid particles

    Directory of Open Access Journals (Sweden)

    F. O. Arouca

    2005-03-01

    Full Text Available Determination of the size distribution of solid particles is fundamental for analysis of the performance several pieces of equipment used for solid-fluid separation. The main objective of this work is to compare the results obtained with two traditional methods for determination of the size grade distribution of powdery solids: the gamma-ray attenuation technique (GRAT and the LADEQ test tube technique. The effect of draining the suspension in the two techniques used was also analyzed. The GRAT can supply the particle size distribution of solids through the monitoring of solid concentration in experiments on batch settling of diluted suspensions. The results show that use of the peristaltic pump in the GRAT and the LADEQ methods produced a significant difference between the values obtained for the parameters of the particle size model.

  17. Hydrodeoxygenation of fatty acid esters catalyzed by Ni on nano-sized MFI type zeolites

    Energy Technology Data Exchange (ETDEWEB)

    Schreiber, Moritz W.; Rodriguez-Niño, Daniella; Gutiérrez, Oliver Y.; Lercher, Johannes A.

    2016-01-01

    The impact of support morphology and composition on the intrinsic activity of Ni supported on MFI-type zeolite was explored in the hydrodeoxygenation of methyl stearate, tristearate, and algae oil (mixture of triglycerides). The nano-sized structure of the support (self-pillared nanosheets) is beneficial for the activity of the catalysts. Higher Ni dispersion and concomitant higher reaction rates were obtained on nano-structured supports than on zeolite with conventional morphology. Rates normalized to accessible Ni atoms (TOF), however, varied little with support morphology. Acidity of the support increases the rate of Ni-catalyzed C-O hydrogenolysis per surface metal site.

  18. Nano-sized polystyrene affects feeding, behavior and physiology of brine shrimp Artemia franciscana larvae

    NARCIS (Netherlands)

    Bergami, Elisa; Bocci, Elena; Vannuccini, Maria Luisa; Monopoli, Marco; Salvati, Anna; Dawson, Kenneth A; Corsi, Ilaria

    Nano-sized polymers as polystyrene (PS) constitute one of the main challenges for marine ecosystems, since they can distribute along the whole water column affecting planktonic species and consequently disrupting the energy flow of marine ecosystems. Nowadays very little knowledge is available on

  19. Modulation of mesenchymal stem cell behavior by nano- and micro-sized β-tricalcium phosphate particles in suspension and composite structures

    Science.gov (United States)

    Smoak, Mollie; Hogan, Katie; Kriegh, Lisa; Chen, Cong; Terrell, LeKeith B.; Qureshi, Ammar T.; Todd Monroe, W.; Gimble, Jeffrey M.; Hayes, Daniel J.

    2015-04-01

    Interest has grown in the use of microparticles and nanoparticles for modifying the mechanical and biological properties of synthetic bone composite structures. Micro- and nano-sized calcium phosphates are of interest for their osteoinductive behavior. Engineered composites incorporating polymers and ceramics, such as poly-l-lactic acid (PLLA) and beta-tricalcium phosphate (β-TCP), for bone tissue regeneration have been well investigated for their proliferative and osteoinductive abilities. Only limited research has been done to investigate the effects of different sizes of β-TCP particles on human mesenchymal stromal cell behavior. As such, the aim of this study was to investigate the modulations of human adipose-derived stem cell (hASCs) behavior within cell/particle and cell/composite systems as functions of particle size, concentration, and exposure time. The incorporation of nanoscale calcium phosphate resulted in improved mechanical properties and osteogenic behavior within the scaffold compared to the microscale calcium phosphate additives. Particle exposure results indicate that cytotoxicity on hASCs correlates inversely with particle size and increases with the increasing exposure time and particle concentration. Composites with increasing β-TCP content, whether microparticles or nanoparticles, were less toxic than colloidal micro- and nano-sized β-TCP particles directly supplied to hASCs. The difference in viability observed as a result of varying exposure route is likely related to the increased cell-particle interactions in the direct exposure compared to the particles becoming trapped within the scaffold/polymer matrix.

  20. Modulation of mesenchymal stem cell behavior by nano- and micro-sized β-tricalcium phosphate particles in suspension and composite structures

    Energy Technology Data Exchange (ETDEWEB)

    Smoak, Mollie; Hogan, Katie; Kriegh, Lisa; Chen, Cong, E-mail: cchen19@tigers.lsu.edu; Terrell, LeKeith B.; Qureshi, Ammar T.; Todd Monroe, W. [Louisiana State University and LSU AgCenter, Department of Biological and Agricultural Engineering (United States); Gimble, Jeffrey M., E-mail: Jeffrey.Gimble@pbrc.edu [Tulane University School of Medicine, Center for Stem Cell Research & Regenerative Medicine (United States); Hayes, Daniel J., E-mail: danielhayes@lsu.edu [Louisiana State University and LSU AgCenter, Department of Biological and Agricultural Engineering (United States)

    2015-04-15

    Interest has grown in the use of microparticles and nanoparticles for modifying the mechanical and biological properties of synthetic bone composite structures. Micro- and nano-sized calcium phosphates are of interest for their osteoinductive behavior. Engineered composites incorporating polymers and ceramics, such as poly-l-lactic acid (PLLA) and beta-tricalcium phosphate (β-TCP), for bone tissue regeneration have been well investigated for their proliferative and osteoinductive abilities. Only limited research has been done to investigate the effects of different sizes of β-TCP particles on human mesenchymal stromal cell behavior. As such, the aim of this study was to investigate the modulations of human adipose-derived stem cell (hASCs) behavior within cell/particle and cell/composite systems as functions of particle size, concentration, and exposure time. The incorporation of nanoscale calcium phosphate resulted in improved mechanical properties and osteogenic behavior within the scaffold compared to the microscale calcium phosphate additives. Particle exposure results indicate that cytotoxicity on hASCs correlates inversely with particle size and increases with the increasing exposure time and particle concentration. Composites with increasing β-TCP content, whether microparticles or nanoparticles, were less toxic than colloidal micro- and nano-sized β-TCP particles directly supplied to hASCs. The difference in viability observed as a result of varying exposure route is likely related to the increased cell–particle interactions in the direct exposure compared to the particles becoming trapped within the scaffold/polymer matrix.

  1. Synthesis of nano-sized PbSe from octeno-1,2,3-selenadiazole

    International Nuclear Information System (INIS)

    Khanna, P.K.; Singh, Narendra; Charan, Shobhit; Viswanath, A.K.; Patil, K.R.

    2007-01-01

    Reaction between trioctylphosphine selenide (TOPSe), generated from an organo-selenium compound, i.e. octeno-1,2,3-selenadiazole in tri-octylphosphine (TOP), and lead acetate has resulted formation of PbSe nano-crystals (cubes). TOPSe generated from the current method is first of its kind approach and is a novel concept. Characteristic absorption bands between 1.8-2.1 μm in near infra-red spectrum (NIR) are observed from sonicated PbSe crystals. X-ray diffraction (XRD) pattern revealed rock-salt crystal structure of PbSe with crystallite size of less than 10 nm. Observations made by scanning electron microscopy (SEM) revealed well-defined particles of the cubical crystals. XPS analysis showed that nano-crystals of PbSe were prone to air-oxidation due to 'not-so-efficient' capping

  2. Nano Size Crystals of Geothite, alpha-FeOOH: Synthesis and Thermal Transformation

    Energy Technology Data Exchange (ETDEWEB)

    Christensen,A.; Jensen, T.; Bahl, C.; DiMasi, E.

    2007-01-01

    An aqueous suspension of amorphous iron(III) hydroxide was kept at room temperature (298 K) for 23 years. During this period of time the pH of the liquid phase changed from 4.3 to 2.85, and nano size crystals of goethite, {alpha}-FeOOH crystallized from the amorphous iron(III) hydroxide. Transmission electron microscopy (TEM) investigations, Moessbauer spectra, and powder X-ray diffraction using Co K{alpha} radiation showed that the only iron containing crystalline phase present in the recovered product was {alpha}-FeOOH. The size of these nano particles range from 10 to 100 nm measured by TEM. The thermal decomposition of {alpha}-FeOOH was investigated by time-resolved in situ synchrotron radiation powder X-ray diffraction and the data showed that the sample of {alpha}-FeOOH transformed to {alpha}-Fe{sub 2}O{sub 3} in the temperature range 444--584 K. A quantitative phase analysis shows the increase in scattered X-ray intensity from {alpha}-Fe{sub 2}O{sub 3} to follow the decrease of intensity from {alpha}-FeOOH in agreement with the topotactic phase transition.

  3. FINAL REPORT: Room Temperature Hydrogen Storage in Nano-Confined Liquids

    Energy Technology Data Exchange (ETDEWEB)

    VAJO, JOHN

    2014-06-12

    DOE continues to seek solid-state hydrogen storage materials with hydrogen densities of ≥6 wt% and ≥50 g/L that can deliver hydrogen and be recharged at room temperature and moderate pressures enabling widespread use in transportation applications. Meanwhile, development including vehicle engineering and delivery infrastructure continues for compressed-gas hydrogen storage systems. Although compressed gas storage avoids the materials-based issues associated with solid-state storage, achieving acceptable volumetric densities has been a persistent challenge. This project examined the possibility of developing storage materials that would be compatible with compressed gas storage technology based on enhanced hydrogen solubility in nano-confined liquid solvents. These materials would store hydrogen in molecular form eliminating many limitations of current solid-state materials while increasing the volumetric capacity of compressed hydrogen storage vessels. Experimental methods were developed to study hydrogen solubility in nano-confined liquids. These methods included 1) fabrication of composites comprised of volatile liquid solvents for hydrogen confined within the nano-sized pore volume of nanoporous scaffolds and 2) measuring the hydrogen uptake capacity of these composites without altering the composite composition. The hydrogen storage capacities of these nano-confined solvent/scaffold composites were compared with bulk solvents and with empty scaffolds. The solvents and scaffolds were varied to optimize the enhancement in hydrogen solubility that accompanies confinement of the solvent. In addition, computational simulations were performed to study the molecular-scale structure of liquid solvent when confined within an atomically realistic nano-sized pore of a model scaffold. Confined solvent was compared with similar simulations of bulk solvent. The results from the simulations were used to formulate a mechanism for the enhanced solubility and to guide the

  4. Progress in Effect of Nano-modified Coatings and Welding Process Parameters on Wear of Contact Tube for Non-copper Coated Solid Wires

    Directory of Open Access Journals (Sweden)

    LI Zhuo-xin

    2017-12-01

    Full Text Available Environment-friendly non-copper coated solid wire is the main developing trend for gas shielded solid wires, whereas wear of contact tube limits their wide application. The effect of nano-modified coatings and welding process parameters on wear of contact tube for non-copper coated solid wires was reviewed. It was found that the wear of contact tube can be reduced due to the formation of tribo-films on the rubbing surfaces of welding wires against contact tube; it is feasible to decrease contact tube wear when non-copper coated solid wires are coated with nano-modified lubricants, thereby displaying excellent lubricating and thermal or electrical conduction characteristics. The wear of contact tube increases with the increase of welding current. The wear of contact tube is worse in direct-current electrode positive (DCEP than in direct-current electrode negative (DCEN. Arc ablation and electrical erosion are the dominant wear mechanisms of contact tube.

  5. Enhanced electrochemical performance of nano-sized LiFePO4/C synthesized by an ultrasonic-assisted co-precipitation method

    International Nuclear Information System (INIS)

    Liu Youyong; Cao Chuanbao

    2010-01-01

    A simple and effective method, the ultrasonic-assisted co-precipitation method, was employed to synthesize nano-sized LiFePO 4 /C. A glucose solution was used as the carbon source to produce in situ carbon to improve the conductivity of LiFePO 4 . Ultrasonic irradiation was adopted to control the size and homogenize the LiFePO 4 /C particles. The sample was characterized by X-ray powder diffraction, field-emission scanning electron microscopy (FE-SEM), transmission electron microscopy (TEM) and high-resolution transmission electron microscopy (HRTEM). FE-SEM and TEM show that the as-prepared sample has a reduced particle size with a uniform size distribution, which is around 50 nm. A uniform amorphous carbon layer with a thickness of about 4-6 nm on the particle surface was observed, as shown in the HRTEM image. The electrochemical performance was demonstrated by the charge-discharge test and electrochemical impedance spectra measurements. The results indicate that the nano-sized LiFePO 4 /C presents enhanced discharge capacities (159, 147 and 135 mAh g -1 at 0.1, 0.5 and 2 C-rate, respectively) and stable cycling performance. This study offers a simple method to design and synthesis nano-sized cathode materials for lithium-ion batteries.

  6. Organic transistors fabricated by contact coating at liquid-solid interface for nano-structures

    Directory of Open Access Journals (Sweden)

    Yu-Wen Cheng

    2015-10-01

    Full Text Available A contact coating method is developed to cover the nano-channels with 100 nm or 200 nm diameter and 400 nm depth with a poly(4-vinylphenol (PVP. In such coating the nano-channels faces downwards and its vertical position is controlled by a motor. The surface is first lowered to be in immediate contact with the polyvinylpyrrolidone (PVPY water solution with concentration from 1 to 5 wt%, then pulled at the speed of 0.004 to 0.4 mm/s. By tuning the pulling speed and concentration we can realize conformal, filled, top-only, as well as floating film morphology. For a reproducible liquid detachment from the solid, the sample has a small tilt angle of 3 degree. Contact coating is used to cover the Al grid base of the vertical space-charge-limited transistor with PVPY. Poly(3-hexylthiophene-2,5-diyl (P3HT as the semiconductor. The transistor breakdown voltage is raised due to base coverage achieved by contact coating.

  7. Radiation induced nano structures

    International Nuclear Information System (INIS)

    Ibragimova, E.M.; Kalanov, M.U.; Khakimov, Z.

    2006-01-01

    Full text: Nanometer-size silicon clusters have been attracting much attention due to their technological importance, in particular, as promising building blocks for nano electronic and nano photonic systems. Particularly, silicon wires are of great of interest since they have potential for use in one-dimensional quantum wire high-speed field effect transistors and light-emitting devices with extremely low power consumption. Carbon and metal nano structures are studied very intensely due to wide possible applications. Radiation material sciences have been dealing with sub-micron objects for a long time. Under interaction of high energy particles and ionizing radiation with solids by elastic and inelastic mechanisms, at first point defects are created, then they form clusters, column defects, disordered regions (amorphous colloids) and finally precipitates of another crystal phase in the matrix. Such irradiation induced evolution of structure defects and phase transformations was observed by X-diffraction techniques in dielectric crystals of quartz and corundum, which exist in and crystal modifications. If there is no polymorphism, like in alkali halide crystals, then due to radiolysis halogen atoms are evaporated from the surface that results in non-stoichiometry or accumulated in the pores formed by metal vacancies in the sub-surface layer. Nano-pores are created by intensive high energy particles irradiation at first chaotically and then they are ordered and in part filled by inert gas. It is well-known mechanism of radiation induced swelling and embrittlement of metals and alloys, which is undesirable for construction materials for nuclear reactors. Possible solution of this problem may come from nano-structured materials, where there is neither swelling nor embrittlement at gas absorption due to very low density of the structure, while strength keeps high. This review considers experimental observations of radiation induced nano-inclusions in insulating

  8. Synthesis of a nano-crystalline solid acid catalyst from fly ash and its catalytic performance

    Energy Technology Data Exchange (ETDEWEB)

    Chitralekha Khatri; Ashu Rani [Government P.G. College, Kota (India). Environmental Chemistry Laboratory

    2008-10-15

    The synthesis of nano-crystalline activated fly ash catalyst (AFAC) with crystallite size of 12 nm was carried out by chemical and thermal treatment of fly ash, a waste material generated from coal-burning power plants. Fly ash was chemically activated using sulfuric acid followed by thermal activation at 600{sup o}C. The variation of surface and physico-chemical properties of the fly ash by activation methods resulted in improved acidity and therefore, catalytic activity for acid catalyzed reactions. The AFAC was characterized by X-ray diffraction, FT-IR spectroscopy, N{sub 2}-adsorption-desorption isotherm, scanning electron microscopy, flame atomic absorption spectrophotometry and sulfur content by CHNS/O elemental analysis. It showed amorphous nature due to high silica content (81%) and possessed high BET surface area (120 m{sup 2}/g). The catalyst was found to be highly active solid acid catalyst for liquid phase esterification of salicylic acid with acetic anhydride and methanol giving acetylsalicylic acid and methyl salicylate respectively. A maximum yield of 97% with high purity of acetylsalicylic acid (aspirin) and a very high conversion 87% of salicylic acid to methyl salicylate (oil of wintergreen) was obtained with AFAC. The surface acidity and therefore, catalytic activity in AFAC was originated by increased silica content, hydroxyl content and higher surface area as compared to fly ash. The study shows that coal generated fly ash can be converted into potential solid acid catalyst for acid catalyzed reactions. Furthermore, this catalyst may replace conventional environmentally hazardous homogeneous liquid acids making an ecofriendly; solvent free, atom efficient, solid acid based catalytic process. 27 refs., 5 figs., 2 tabs.

  9. Micro-structure and Mechanical Properties of Nano-TiC Reinforced Inconel 625 Deposited using LAAM

    Science.gov (United States)

    Bi, G.; Sun, C. N.; Nai, M. L.; Wei, J.

    In this paper, deposition of Ni-base Inconel 625 mixed with nano-TiC powders using laser aided additive manufacturing (LAAM) was studied. Micro-structure and mechanical properties were intensively investigated. The results showed that nano-size TiC distributed uniformly throughout the Ni- matrix. Inconel 625 can be reinforced by the strengthened grain boundaries with nano-size TiC. Improved micro-hardness and tensile properties were observed.

  10. Thorium/uranium mixed oxide nano-crystals: Synthesis, structural characterization and magnetic properties

    International Nuclear Information System (INIS)

    Hudry, Damien; Griveau, Jean-Christophe; Apostolidis, Christos; Colineau, Eric; Rasmussen, Gert; Walter, Olaf; Wang, Di; Venkata Sai Kiran Chakravadhaluna; Courtois, Eglantine; Kubel, Christian

    2014-01-01

    One of the primary aims of the actinide community within nano-science is to develop a good understanding similar to what is currently the case for stable elements. As a consequence, efficient, reliable and versatile synthesis techniques dedicated to the formation of new actinide-based nano-objects (e.g., nano-crystals) are necessary. Hence, a 'library' dedicated to the preparation of various actinide based nano-scale building blocks is currently being developed. Nano-scale building blocks with tunable sizes, shapes and compositions are of prime importance. So far, the non-aqueous synthesis method in highly coordinating organic media is the only approach which has demonstrated the capability to provide size and shape control of actinide-based nano-crystals (both for thorium and uranium, and recently extended to neptunium and plutonium). In this paper, we demonstrate that the non-aqueous approach is also well adapted to control the chemical composition of the nano-crystals obtained when mixing two different actinides. Indeed, the controlled hot co-injection of thorium acetylacetonate and uranyl acetate (together with additional capping agents) into benzyl ether can be used to synthesize thorium/uranium mixed oxide nano-crystals covering the full compositional spectrum. Additionally, we found that both size and shape are modified as a function of the thorium/uranium ratio. Finally, the magnetic properties of the different thorium/uranium mixed oxide nano-crystals were investigated. Contrary to several reports, we did not observe any ferromagnetic behavior. As a consequence, ferromagnetism cannot be described as a universal feature of nano-crystals of non-magnetic oxides as recently claimed in the literature. (authors)

  11. Effect of MgCl2 addition on the sintering behavior of MgAl2O4 spinel and formation of nano-particles

    Directory of Open Access Journals (Sweden)

    Mohammadi F.

    2014-01-01

    Full Text Available In this paper, the effect of MgCl2 addition on the sintering behavior of MgAl2O4 spinel produced via oxide mixture method was investigated. For this reason, the stoichiometric mixture of magnesite and calcined alumina as raw materials was calcined at 1100°C. The calcined mixture was milled, pressed and then, fired at 1300 and 1500°C after addition of various amounts of MgCl2. Besides, the physical properties, phase composition and microstructure of fired samples were investigated. The results showed that MgCl2 addition has great effect on the densification and particle size of spinel. Besides, MgCl2 addition increases the amount of spinel phase at all firing temperatures. Due to the decomposition of MgCl2 and then formation of ultra-fine MgO particles, the nano-sized spinel is formed on the surface of the larger spinel particles.

  12. Nano structural Features of Silver Nanoparticles Powder Synthesized through Concurrent Formation of the Nano sized Particles of Both Starch and Silver

    International Nuclear Information System (INIS)

    Hebeish, A.; El-Rafie, M.H.; El-Sheikh, M.A.; El-Naggar, M.E.

    2013-01-01

    Green innovative strategy was developed to accomplish silver nanoparticles formation of starch-silver nanoparticles (St-AgNPs) in the powder form. Thus, St-AgNPs were synthesized through concurrent formation of the nano sized particles of both starch and silver. The alkali dissolved starch acts as reducing agent for silver ions and as stabilizing agent for the formed AgNPs. The chemical reduction process occurred in water bath under high-speed homogenizer. After completion of the reaction, the colloidal solution of AgNPs coated with alkali dissolved starch was cooled and precipitated using ethanol. The powder precipitate was collected by centrifugation, then washed, and dried; St-AgNPs powder was characterized using state-of-the-art facilities including UV-vis spectroscopy, Transmission Electron Microscopy (TEM), particle size analyzer (PS), Polydispersity index (PdI), Zeta potential (ZP), XRD, FT-IR, EDX, and TGA. TEM and XRD indicate that the average size of pure AgNPs does not exceed 20 nm with spherical shape and high concentration of AgNPs (30000 ppm). The results obtained from TGA indicates that the higher thermal stability of starch coated AgNPS than that of starch nanoparticles alone. In addition to the data obtained from EDX which reveals the presence of AgNPs and the data obtained from particle size analyzer and zeta potential determination indicate that the good uniformity and the highly stability of St-AgNPs).

  13. Grain size and lattice parameter's influence on band gap of SnS thin nano-crystalline films

    Energy Technology Data Exchange (ETDEWEB)

    Gupta, Yashika [Department of Electronics, S.G.T.B. Khalsa College, University of Delhi, Delhi 110007 (India); Department of Electronic Science, University of Delhi-South Campus, New Delhi 110021 (India); Arun, P., E-mail: arunp92@physics.du.ac.in [Department of Electronics, S.G.T.B. Khalsa College, University of Delhi, Delhi 110007 (India); Naudi, A.A.; Walz, M.V. [Facultad de Ingeniería, Universidad Nacional de Entre Ríos, 3101 Oro Verde (Argentina); Albanesi, E.A. [Facultad de Ingeniería, Universidad Nacional de Entre Ríos, 3101 Oro Verde (Argentina); Instituto de Física del Litoral (CONICET-UNL), Guemes 3450, 3000 Santa Fe (Argentina)

    2016-08-01

    Tin sulphide nano-crystalline thin films were fabricated on glass and Indium Tin Oxide (ITO) substrates by thermal evaporation method. The crystal structure orientation of the films was found to be dependent on the substrate. Residual stress existed in the films due to these orientations. This stress led to variation in lattice parameter. The nano-crystalline grain size was also found to vary with film thickness. A plot of band-gap with grain size or with lattice parameter showed the existence of a family of curves. This implied that band-gap of SnS films in the preview of the present study depends on two parameters, lattice parameter and grain size. The band-gap relation with grain size is well known in the nano regime. Experimental data fitted well with this relation for the given lattice constants. The manuscript uses theoretical structure calculations for different lattice constants and shows that the experimental data follows the trend. Thus, confirming that the band gap has a two variable dependency. - Highlights: • Tin sulphide films are grown on glass and ITO substrates. • Both substrates give differently oriented films. • The band-gap is found to depend on grain size and lattice parameter. • Using data from literature, E{sub g} is shown to be two parameter function. • Theoretical structure calculations are used to verify results.

  14. Study on Size-Dependent Young’s Modulus of a Silicon Nano beam by Molecular Dynamics Simulation

    International Nuclear Information System (INIS)

    Yu, H.; Sun, C.; Zhang, W.W.; Lei, S.Y.; Huang, K.A.

    2013-01-01

    Young’s modulus of a silicon nano beam with a rectangular cross-section is studied by molecular dynamics method. Dynamic simulations are performed for doubly clamped silicon nano beams with lengths ranging from 4.888 to 12.491 nm and cross-sections ranging from 1.22 nm ×1.22 nm to 3.39 nm × 3.39 nm. The results show that Young’s moduli of such small silicon nano beams are much higher than the value of Young’s modulus for bulk silicon. Moreover, the resonant frequency and Young’s modulus of the Si nano beam are strongly dependent not only on the size of the nano beam but also on surface effects. Young’s modulus increases significantly with the decreasing of the thickness of the silicon nano beam. This result qualitatively agrees with one of the conclusions based on a semi continuum model, in which the surface relaxation and the surface tension were taken into consideration. The impacts of the surface reconstruction with (2 ×1) dimmers on the resonant frequency and Young’s modulus are studied in this paper too. It is shown that the surface reconstruction makes the silicon nano beam stiffer than the one without the surface reconstruction, resulting in a higher resonant frequency and a larger Young’s modulus

  15. Comparison of the tribology performance of nano-diesel soot and graphite particles as lubricant additives

    International Nuclear Information System (INIS)

    Zhang, Zu-chuan; Cai, Zhen-bing; Peng, Jin-fang; Zhu, Min-hao

    2016-01-01

    The tribology behavior of exhaust diesel soot as a lubricant additive was investigated and then compared with that of a selection of commercial nano-graphite particles. Specifically, 0.01 wt% particles were dispersed in PAO4 oil with 1 wt% sorbitan monooleate (Span 80) as a dispersing agent, and wear tests based on the ball against plate mode were conducted at various temperatures. Different analytical techniques (e.g. transmission electron, scanning electron and infrared microscopy; energy dispersive x-ray and Raman spectroscopy; and charge measurement) were employed to characterize the chemistry and morphology of the additives and their tribology performance. The oil containing only 0.01 wt% diesel soot clearly improved wear resistance over 60 °C. In particular, at 100 °C the wear rate decreased by approximately 90% compared to the function of base oil. In the same test conditions, diesel soot exhibited better anti-wear performance than nano-graphite at high temperatures. The potential measure showed that the nano-graphite had positive charge and the diesel soot had negative charge. Electrochemical action may play an important role in the lubricant mechanisms of diesel soot and graphite as oil additives. (paper)

  16. Nano-sized LiFePO4/C composite with core-shell structure as cathode material for lithium ion battery

    International Nuclear Information System (INIS)

    Liu, Yang; Zhang, Min; Li, Ying; Hu, Yemin; Zhu, Mingyuan; Jin, Hongming; Li, Wenxian

    2015-01-01

    Graphical abstract: Nano-sized LiFePO4/C composite with core-shell structure was fabricated via a well-designed approach as cathode material forlithium ion battery. The nano-sized LiFePO4/C composite with whole carbon shell coating layer showed an excellent electrical performance. - Abstract: Nano-sized composite with LiFePO 4 -core and carbon-shell was synthesized via a facile route followed by heat treatment at 650 °C. X-ray diffraction (XRD) shows that the core is well crystallized LiFePO 4 . The electron microscopy (SEM and TEM) observations show that the core-shell structured LiFePO 4 /C composite coating with whole carbon shell layer of ∼2.8 nm, possesses a specific surface area of 51 m 2 g −1 . As cathode material for lithium ion battery, the core-shell LiFePO 4 /C composite exhibits high initial capacity of 161 mAh g −1 at 0.1 C, excellent high-rate discharge capacity of 135 mAh g −1 at 5 C and perfect cycling retention of 99.6% at 100 th cycle. All these promising results should be contributed to the core-shell nanostructure which prevents collapse of the particle structure in the long-term charge and discharge cycles, as well as the large surface area of the nano-sized LiFePO 4 /C composite which enhances the electronic conductivity and shortens the distance of lithium ion diffusion

  17. Crystallization kinetics of Ga metallic nano-droplets under As flux

    International Nuclear Information System (INIS)

    Bietti, S; Somaschini, C; Sanguinetti, S

    2013-01-01

    We present an experimental investigation of the crystallization dynamics of Ga nano-droplets under As flux. The transformation of the metallic Ga contained in the droplets into a GaAs nano-island proceeds by increasing the size of a tiny ring of GaAs which is formed just after the Ga deposition at the rim of a droplet. The GaAs crystallization rate depends linearly on the liquid–solid interface area. The maximum growth rate is set by the As flux impinging on the droplet, thus showing an efficient As incorporation and transport despite the predicted low solubility of the As in metallic Ga at the crystallization temperatures. (paper)

  18. Engineered nano particles: Nature, behavior, and effect on the environment.

    Science.gov (United States)

    Goswami, Linee; Kim, Ki-Hyun; Deep, Akash; Das, Pallabi; Bhattacharya, Satya Sundar; Kumar, Sandeep; Adelodun, Adedeji A

    2017-07-01

    Increased application of engineered nano particles (ENPs) in production of various appliances and consumer items is increasing their presence in the natural environment. Although a wide variety of nano particles (NPs) are ubiquitously dispersed in ecosystems, risk assessment guidelines to describe their ageing, direct exposure, and long-term accumulation characteristics are poorly developed. In this review, we describe what is known about the life cycle of ENPs and their impact on natural systems and examine if there is a cohesive relationship between their transformation processes and bio-accessibility in various food chains. Different environmental stressors influence the fate of these particles in the environment. Composition of solid media, pore size, solution chemistry, mineral composition, presence of natural organic matter, and fluid velocity are some environmental stressors that influence the transformation, transport, and mobility of nano particles. Transformed nano particles can reduce cell viability, growth and morphology, enhance oxidative stress, and damage DNA in living organisms. Copyright © 2017 Elsevier Ltd. All rights reserved.

  19. Localized melt-scan strategy for site specific control of grain size and primary dendrite arm spacing in electron beam additive manufacturing

    International Nuclear Information System (INIS)

    Raghavan, Narendran; Simunovic, Srdjan; Dehoff, Ryan; Plotkowski, Alex; Turner, John; Kirka, Michael; Babu, Suresh

    2017-01-01

    In addition to design geometry, surface roughness, and solid-state phase transformation, solidification microstructure plays a crucial role in controlling the performance of additively manufactured components. Crystallographic texture, primary dendrite arm spacing (PDAS), and grain size are directly correlated to local solidification conditions. We have developed a new melt-scan strategy for inducing site specific, on-demand control of solidification microstructure. We were able to induce variations in grain size (30 μm–150 μm) and PDAS (4 μm - 10 μm) in Inconel 718 parts produced by the electron beam additive manufacturing system (Arcam ® ). A conventional raster melt-scan resulted in a grain size of about 600 μm. The observed variations in grain size with different melt-scan strategies are rationalized using a numerical thermal and solidification model which accounts for the transient curvature of the melt pool and associated thermal gradients and liquid-solid interface velocities. The refinement in grain size at high cooling rates (>10 4  K/s) is also attributed to the potential heterogeneous nucleation of grains ahead of the epitaxially growing solidification front. The variation in PDAS is rationalized using a coupled numerical-theoretical model as a function of local solidification conditions (thermal gradient and liquid-solid interface velocity) of the melt pool.

  20. Role of surface on the size-dependent mechanical properties of copper nano-wire under tensile load: A molecular dynamics simulation

    Science.gov (United States)

    Liu, Wei-Ting; Hsiao, Chun-I.; Hsu, Wen-Dung

    2014-01-01

    In this study we have used atomistic simulations to investigate the role of surface on the size-dependent mechanical properties of nano-wires. In particular, we have performed computational investigation on single crystal face-centered cubic copper nano-wires with diameters ranging from 2 to 20 nm. The wire axis for all the nano-wires are considered along the [0 0 1] direction. Characterization of the initial optimized structures revealed clear differences in interatomic spacing, stress, and potential energy in all the nano-wires. The mechanical properties with respect to wire diameter are evaluated by applying tension along the [0 0 1] direction until yielding. We have discussed the stress-strain relationships, Young's modulus, and the variation in potential energy from surface to the center of the wire for all the cases. Our results indicate that the mechanical response (including yield strain, Young's modulus, and resilience) is directly related to the proportion of surface to bulk type atoms present in each nano-wire. Thus the size-dependent mechanical properties of single crystal copper nano-wire within elastic region are attributed to the surface to volume ratio (surface effect). Using the calculated response, we have formulated a mathematical relationship, which predicts the nonlinear correlation between the mechanical properties and the diameter of the wire.

  1. The effect of nano-size ZrO2 powder addition on the microstructure and superconducting properties of single-domain Y-Ba-Cu-O bulk superconductors

    International Nuclear Information System (INIS)

    Iida, K; Babu, N H; Reddy, E S; Shi, Y-H; Cardwell, D A

    2005-01-01

    The effect of nano-size ZrO 2 powder addition on the microstructure and superconducting properties of Y-Ba-Cu-O single grain bulk superconductors has been investigated. Significant pushing phenomena of Y 2 BaCuO 5 (Y-211) particles, particularly in the c growth sector, were observed even with a small amount of ZrO 2 added to the precursor powder. An increase in Y-211 particle pushing was observed with increasing ZrO 2 content, leading to an inhomogeneous bulk microstructure. In addition, a growth cycle consisting of a Y-211 free layer-porous narrow layer-Y-211 high concentration layer was observed for samples prepared with 0.25 wt% ZrO 2 in both the a and c growth sectors. The extent of the growth of single grain Y-Ba-Cu-O (YBCO) decreased with increasing ZrO 2 content due to increased pushing of Y-211 particles towards molten liquid. The superconducting transition temperature, T c , of the ZrO 2 containing YBCO samples was sharp but depressed slightly (by up to 1 K) compared with an undoped YBCO grain, indicating a relative insensitivity of T c to ZrO 2 content. Finally, the sensitivity of critical current density, J c , to applied magnetic field in large grain bulk YBCO containing ZrO 2 was observed to depend critically on position due to the inhomogeneous sample microstructure

  2. Influence of Parameters of a Printing Plate on Photoluminescence of Nano photonic Printed Elements of Novel Packaging

    International Nuclear Information System (INIS)

    Sarapulova, O.; Sherstiuk, V.

    2015-01-01

    In order to produce nano photonic elements for smart packaging, we investigated the influence of the parameters of screen and offset gravure printing plates on features of printed application of coatings with nano photonic components and on parameters of their photoluminescence. To determine the dependence of luminescence intensity on the thickness of solid coating, we carried out the formation of nano photonic solid surfaces by means of screen printing with different layer thickness on polypropylene film. The obtained analytical dependencies were used to confirm the explanation of the processes that occur during the fabrication of nano photonic coverings with offset gravure printing plates. As a result of experimental studies, it was determined that the different character of the dependency of total luminescence intensity of nano photonic elements from the percentage of a pad is explained by the use of different types of offset gravure printing plates, where the size of raster points remains constant in one case and changes in the other case, while the depth of the printing elements accordingly changes or remains constant. To obtain nano photonic areas with predetermined photo luminescent properties, the influence of investigated factors on changes of photo luminescent properties of nano photonic printed surfaces should be taken into consideration

  3. The influence of size on the toxicity of an encapsulated pesticide: a comparison of micron- and nano-sized capsules.

    Science.gov (United States)

    Meredith, Alicea N; Harper, Bryan; Harper, Stacey L

    2016-01-01

    Encapsulation technology involves entrapping a chemical active ingredient (a.i.) inside a hollow polymeric shell and has been applied to commercial pesticide manufacturing for years to produce capsule suspension (CS) formulations with average particle sizes in the micron-scale. The few literature sources that investigate the environmental fate and toxicity to non-target organisms of encapsulated commercially available pesticide products with regard to capsule size report on average sizes between 20 and 50 μm. Here, we have identified a CS formulation with an average capsule size of approximately 2 μm with some capsules extending into the nanometer scale (~200 nm). Determining how carrier size influences toxicity is important to understanding if current pesticide risk assessments are sufficient to protect against products that incorporate encapsulation technology. Here, a commercial pyrethroid CS pesticide with lambda-cyhalothrin (λ-Cy) as the a.i. was separated into two suspensions, a fraction consisting of nano-sized capsules (~250 nm) and a fraction of micron-sized capsules (~2200 nm) in order to investigate the influence of capsule size on toxicity to embryonic zebrafish, Danio rerio. Toxicity was evaluated 24h after exposure to equivalent amounts of a.i. by the presence and severity of pyrethroid-specific tremors, 14 sublethal developmental impacts and mortality. Fish exposed to greater than 20 μg a.i. L(-1) technical λ-Cy or formulated product experienced curvature of the body axis, pericardial edema, craniofacial malformations, and mortality. Exposure to the unfractionated formulation, micro fraction, nano fraction and technical a.i. resulted in no significant differences in the occurrence of sublethal impacts or mortality; however, the technical a.i. exposure resulted in significantly less fish experiencing tremors and shorter tremors compared to any of the formulated product exposures. This suggests that the capsule size does not influence the toxic

  4. Electrochemical construction of a bio-inspired micro/nano-textured structure with cell-sized microhole arrays on biomedical titanium to enhance bioactivity

    International Nuclear Information System (INIS)

    Liang, Jianhe; Song, Ran; Huang, Qiaoling; Yang, Yun; Lin, Longxiang; Zhang, Yanmei; Jiang, Pinliang; Duan, Hongping; Dong, Xiang; Lin, Changjian

    2015-01-01

    Highlights: • The bio-inspired structure mimicked mulit-level structures of natural bone. • Ordered cell-sized microhole arrays were employed as microscale structure. • High surface roughness and superhydrophilicity were achieved on the titanium surface. • The bio-inspired titanium surface showed superior ability of biomineralization. • Cell responses were enhanced on the bio-inspired micro/nano-texutred surface. - Abstract: Biomimetic surface design of medical implants is vitally crucial to improve cellular responses and the integration of tissue onto materials. In this study, a novel hierarchical cell-sized microhole array combined with a nano-network structure was fabricated on a medical titanium surface to mimic multi-level bone structure. A three-step procedure was developed as follows: 1) electrochemical self-organization of etching on titanium substrate to create highly ordered cell-sized microhole arrays, 2) suitable dual acid etching to increase the roughness of the microholes, and then 3) electrochemical anodization in a NaOH electrolyte to construct a nano-network porous titania layer on the above micro-roughened surface. The bio-inspired micro/nano-textured structure presented the enhanced wettability and superhydrophilicity. The ability of in vitro biomineralization and corrosion resistance of the bio-inspired micro/nano-textured structure were enhanced after annealing treatment. More importantly, the bio-inspired micro/nano-textured structure on the titanium surface possessed a favourable interfacial environment to enhance attachment and proliferation of human osteoblast-like MG63 cells. All of the results demonstrated that such a bio-inspired surface of micro/nano-textured porous TiO 2 is a most promising candidate for the next generation of titanium implants

  5. Development and characterization of nanopore system for nano-vesicle analysis

    Science.gov (United States)

    Goyal, Gaurav

    Nano-vesicles have recently attracted a lot of attention in research and medical communities and are very promising next-generation drug delivery vehicles. This is due to their biocompatibility, biodegradability and their ability to protect drug cargo and deliver it to site-specific locations, while maintaining the desired pharmacokinetic profile. The interaction of these drug loaded vesicles with the recipient cells via adsorption, endocytosis or receptor mediated internalization involve significant bending and deformation and is governed by mechanical properties of the nano-vesicles. Currently, the mechanical characteristics of nano-vesicles are left unexplored because of the difficulties associated with vesicle analysis at sub-100 nm length scale. The need for a complete understanding of nano-vesicle interaction with each other and the recipient cells warrants development of an analytical tool capable of mechanical investigation of individual vesicles at sub-100 nm scale. This dissertation presents investigation of nano-vesicle deformability using resistive pulse sensing and solid-state nanopore devices. The dissertation is divided into four chapters. Chapter 1 discusses the motivation, specific aims and presents an overview of nanoparticle characterization techniques, resistive pulse sensing background and principles, techniques for fabricating solid-state nanopores, as well the deformation behavior of giant vesicles when placed in electric field. Chapter 2 is dedicated to understanding of the scientific principles governing transport of sub-100 nm particles in dilute solutions. We investigated the translocation of rigid nanoparticles through nanopores at salt concentrations exosomes derived from human breast cancer cell line. Exosomes also exhibit co-translocational deformation behavior; however, they appear to be less affected by the deforming force inside the nanopore compared to the DOPC liposomes. We believe, the results of this research will bring about a

  6. Combined addition of nano diamond and nano SiO{sub 2}, an effective method to improve the in-field critical current density of MgB{sub 2} superconductor

    Energy Technology Data Exchange (ETDEWEB)

    Rahul, S.; Varghese, Neson; Vinod, K.; Devadas, K.M.; Thomas, Syju; Anees, P. [National Institute for Interdisciplinary Science and Technology (CSIR), Trivandrum 695019 (India); Chattopadhyay, M.K.; Roy, S.B. [Magnetic and Superconducting Materials Section, Raja Ramanna Centre for Advanced Technology, Indore 452013 (India); Syamaprasad, U., E-mail: syamcsir@gmail.com [National Institute for Interdisciplinary Science and Technology (CSIR), Trivandrum 695019 (India)

    2011-11-15

    Highlights: {yields} Both nano diamond and nano SiO{sub 2} caused significant modifications in the structural properties of pure MgB{sub 2} sample. {yields} Reduction in T{sub C} for the best codoped sample was approximately 2 K. {yields} The best codoped sample yielded a J{sub C}, an order of magnitude more than the undoped one at 5 K and 8 T. {yields} The enhanced flux pinning capability provided by the additives is responsible for the improved in-field J{sub C}. -- Abstract: MgB{sub 2} bulk samples added with nano SiO{sub 2} and/or nano diamond were prepared by powder-in-sealed-tube (PIST) method and the effects of addition on structural and superconducting properties were studied. X-ray diffraction (XRD) analysis revealed that the addition caused systematic reduction in 'a' lattice parameter due to the substitution of C atoms at B sites and the strain caused by reacted intragrain nano particles of Mg{sub 2}Si as evinced by transmission electron microscope image. Scanning electron microscopy images showed distinct microstructural variations with SiO{sub 2}/diamond addition. It was evident from DC magnetization measurements that the in-field critical current density [J{sub C}(H)] of doped samples did not fall drastically like the undoped sample. Among the doped samples the J{sub C}(H) of co-doped samples were significantly higher and the best co-doped sample yielded a J{sub C}, an order of magnitude more than the undoped one at 5 K and 8 T.

  7. Nano-plastics in the aquatic environment.

    Science.gov (United States)

    Mattsson, K; Hansson, L-A; Cedervall, T

    2015-10-01

    The amount of plastics released to the environment in modern days has increased substantially since the development of modern plastics in the early 1900s. As a result, concerns have been raised by the public about the impact of plastics on nature and on, specifically, aquatic wildlife. Lately, much attention has been paid to macro- and micro-sized plastics and their impact on aquatic organisms. However, micro-sized plastics degrade subsequently into nano-sizes whereas nano-sized particles may be released directly into nature. Such particles have a different impact on aquatic organisms than larger pieces of plastic due to their small size, high surface curvature, and large surface area. This review describes the possible sources of nano-sized plastic, its distribution and behavior in nature, the impact of nano-sized plastic on the well-being of aquatic organisms, and the difference of impact between nano- and micro-sized particles. We also identify research areas which urgently need more attention and suggest experimental methods to obtain useful data.

  8. Chemical Functionalization, Self-Assembly, and Applications of Nano materials and Nano composites 2014

    International Nuclear Information System (INIS)

    Yan, X.; Jiao, T.; Balan, L.; Chen, X.; Hu, M.Z.; Liu, W.

    2014-01-01

    The growing interests in nano materials and nano composites call for the development of processing techniques to obtain multiple functionalization nano structures and achieve the tailoring of specific features of the nanometer size. Functional nano materials and nano composites will expand the applied range of the original material and at the same time promote the development of inter discipline. Thus, the chemical functionalization and bottom-up assemblies of nano materials and subsequent applications will accelerate the development of nano science and nano technology.

  9. Effects of ultrasonic vibration on microstructure and mechanical properties of nano-sized SiC particles reinforced Al-5Cu composites.

    Science.gov (United States)

    Li, Jianyu; Lü, Shulin; Wu, Shusen; Gao, Qi

    2018-04-01

    Ultrasonic vibration (UV) treatment has been successfully applied to improve the particles distribution of nano-sized SiC particles (SiC p ) reinforced Al-5Cu alloy matrix composites which were prepared by combined processes of dry high energy ball milling and squeeze casting. When UV treatment is applied, the distribution of nano-sized SiC p has been greatly improved. After UV for 1 min, large particles aggregates are broken up into small aggregates due to effects of cavitation and the acoustic streaming. After UV for 5 min, all the particles aggregates are dispersed and the particles are uniformly distributed in the composites. Compared with the Al-5Cu matrix alloy, the ultimate tensile strength, yield strength and elongation of the 1 wt% nano-sized SiC p /Al-5Cu composites treated by UV for 5 min are 270 MPa, 173 MPa and 13.3%, which are increased by 7.6%, 6.8% and 29%, respectively. The improvements of mechanical properties after UV are attributed to the uniform distribution of nano particles, grain refinement of aluminum matrix alloy and reduction of porosity in the composites. Copyright © 2017 Elsevier B.V. All rights reserved.

  10. Solid structures of the stepwise self-assembled copillar[5]arene-based supramolecular polymers

    International Nuclear Information System (INIS)

    Park, Yeon Sil; Hwang, Seong Min; Shin, Jae Yeon; Paek, Kyung Soo

    2016-01-01

    Development of supramolecular polymer has attracted much interest because of their interesting properties such as stimuli-responsiveness, recycling, self-healing and degradability, and their consequential applications. The essential feature of this class of polymers is the self-assembly of discrete monomeric subunits via non-covalent interactions or dynamic covalent bonds. Among the many monomeric subunits, pillar[n]arenes have been ideal building blocks for the fabrication of polymeric supramolecules because of their intrinsic characteristics. The ring-shaped morphologies in supramolecular polymer P are probably due to the tendency of the end-to-end connection in the solid state of long flexible supramolecular chains. The size increase of nano-rings as the stepwise addition increases might be due to the fact that the linear supramolecular polymer P in solution seems to be maintained until the nano-ring formation by solidification

  11. Solid structures of the stepwise self-assembled copillar[5]arene-based supramolecular polymers

    Energy Technology Data Exchange (ETDEWEB)

    Park, Yeon Sil; Hwang, Seong Min; Shin, Jae Yeon; Paek, Kyung Soo [Dept. of Chemistry, Soongsil University, Seoul (Korea, Republic of)

    2016-10-15

    Development of supramolecular polymer has attracted much interest because of their interesting properties such as stimuli-responsiveness, recycling, self-healing and degradability, and their consequential applications. The essential feature of this class of polymers is the self-assembly of discrete monomeric subunits via non-covalent interactions or dynamic covalent bonds. Among the many monomeric subunits, pillar[n]arenes have been ideal building blocks for the fabrication of polymeric supramolecules because of their intrinsic characteristics. The ring-shaped morphologies in supramolecular polymer P are probably due to the tendency of the end-to-end connection in the solid state of long flexible supramolecular chains. The size increase of nano-rings as the stepwise addition increases might be due to the fact that the linear supramolecular polymer P in solution seems to be maintained until the nano-ring formation by solidification.

  12. From Gold Nano-particles through Nano-wire to Gold Nano-layers on Substrate

    Czech Academy of Sciences Publication Activity Database

    Švorčík, V.; Kolská, Z.; Slepička, P.; Siegel, J.; Hnatowicz, Vladimír

    2010-01-01

    Roč. 2010, G (2010), s. 1-57. ISBN 978-1-61668-009-1 Institutional support: RVO:61389005 Keywords : thin films * Au nano layers * AFM Subject RIV: BM - Solid Matter Physics ; Magnetism https://www.novapublishers.com/catalog/product_info.php?products_id=12909

  13. Transparent, flexible supercapacitors from nano-engineered carbon films

    Science.gov (United States)

    Jung, Hyun Young; Karimi, Majid B.; Hahm, Myung Gwan; Ajayan, Pulickel M.; Jung, Yung Joon

    2012-10-01

    Here we construct mechanically flexible and optically transparent thin film solid state supercapacitors by assembling nano-engineered carbon electrodes, prepared in porous templates, with morphology of interconnected arrays of complex shapes and porosity. The highly textured graphitic films act as electrode and current collector and integrated with solid polymer electrolyte, function as thin film supercapacitors. The nanostructured electrode morphology and the conformal electrolyte packaging provide enough energy and power density for the devices in addition to excellent mechanical flexibility and optical transparency, making it a unique design in various power delivery applications.

  14. Nano-sized graphene flakes: insights from experimental synthesis and first principles calculations.

    Science.gov (United States)

    Lin, Pin-Chun; Chen, Yi-Rui; Hsu, Kuei-Ting; Lin, Tzu-Neng; Tung, Kuo-Lun; Shen, Ji-Lin; Liu, Wei-Ren

    2017-03-01

    In this study, we proposed a cost-effective method for preparing graphene nano-flakes (GNFs) derived from carbon nanotubes (CNTs) via three steps (pressing, homogenization and sonication exfoliation processes). Scanning electron microscopy (SEM), transmission electron microscopy (TEM), atomic force microscopy (AFM), laser scattering, as well as ultraviolet-visible and photoluminescence (PL) measurements were carried out. The results indicated that the size of as-synthesized GNFs was approximately 40-50 nm. Furthermore, we also used first principles calculations to understand the transformation from CNTs to GNFs from the viewpoints of the edge formation energies of GNFs in different shapes and sizes. The corresponding photoluminescence measurements of GNFs were carried out in this work.

  15. Microstructure and properties of SA 106B carbon steel after treatment of the melt with nano-sized TiC particles

    International Nuclear Information System (INIS)

    Park, Jin-Ju; Hong, Sung-Mo; Park, Eun-Kwang; Kim, Kyeong-Yeol; Lee, Min-Ku; Rhee, Chang-Kyu

    2014-01-01

    Carbon steel dispersed with nano-sized TiC ceramic particles was fabricated using the liquid metal casting process by means of their ex-situ introduction. For this purpose, the nano-sized TiC powders with an initial average size of 40 nm were first mechanically activated with two metal powders (Fe, Ni) and then introduced externally into the molten carbon steel during the casting process. According to the chemical composition analysis, 90% of the initial TiC nanoparticles were discovered within the cast carbon steel. Compared to cast carbon steel without TiC nanoparticles, the grain size refinement and mechanical property enhancement were achieved. Atom probe tomographic analysis revealed that the TiC nanoparticles were approximately 30 nm in size in the carbon steel matrix with a number density of 1.49×10 21 m −3

  16. Rational molecular dynamics scheme for predicting optimum concentration loading of nano-additive in phase change materials

    Directory of Open Access Journals (Sweden)

    Monisha Rastogi

    2015-10-01

    Full Text Available The present study deals with the diffusion and phase transition behaviour of paraffin reinforced with carbon nano-additives namely graphene oxide (GO and surface functionalized single walled carbon nanotubes (SWCNT. Bulk disordered systems of paraffin hydrocarbons impregnated with carbon nano-additives have been generated in realistic equilibrium conformations for potential application as latent heat storage systems. Ab initio molecular dynamics(MD in conjugation with COMPASS forcefield has been implemented using periodic boundary conditions. The proposed scheme allows determination of optimum nano-additive loading for improving thermo-physical properties through analysis of mass, thermal and transport properties; and assists in determination of composite behaviour and related performance from microscopic point of view. It was observed that nanocomposites containing 7.8 % surface functionalised SWCNT and 55% GO loading corresponds to best latent heat storage system. The propounded methodology could serve as a by-pass route for economically taxing and iterative experimental procedures required to attain the optimum composition for best performance. The results also hint at the large unexplored potential of ab-initio classical MD techniques for predicting performance of new nanocomposites for potential phase change material applications.

  17. Rational molecular dynamics scheme for predicting optimum concentration loading of nano-additive in phase change materials

    Science.gov (United States)

    Rastogi, Monisha; Vaish, Rahul; Madhar, Niyaz Ahamad; Shaikh, Hamid; Al-Zahrani, S. M.

    2015-10-01

    The present study deals with the diffusion and phase transition behaviour of paraffin reinforced with carbon nano-additives namely graphene oxide (GO) and surface functionalized single walled carbon nanotubes (SWCNT). Bulk disordered systems of paraffin hydrocarbons impregnated with carbon nano-additives have been generated in realistic equilibrium conformations for potential application as latent heat storage systems. Ab initio molecular dynamics(MD) in conjugation with COMPASS forcefield has been implemented using periodic boundary conditions. The proposed scheme allows determination of optimum nano-additive loading for improving thermo-physical properties through analysis of mass, thermal and transport properties; and assists in determination of composite behaviour and related performance from microscopic point of view. It was observed that nanocomposites containing 7.8 % surface functionalised SWCNT and 55% GO loading corresponds to best latent heat storage system. The propounded methodology could serve as a by-pass route for economically taxing and iterative experimental procedures required to attain the optimum composition for best performance. The results also hint at the large unexplored potential of ab-initio classical MD techniques for predicting performance of new nanocomposites for potential phase change material applications.

  18. Magnetic high throughput screening system for the development of nano-sized molecularly imprinted polymers for controlled delivery of curcumin.

    Science.gov (United States)

    Piletska, Elena V; Abd, Bashar H; Krakowiak, Agata S; Parmar, Anitha; Pink, Demi L; Wall, Katie S; Wharton, Luke; Moczko, Ewa; Whitcombe, Michael J; Karim, Kal; Piletsky, Sergey A

    2015-05-07

    Curcumin is a versatile anti-inflammatory and anti-cancer agent known for its low bioavailability, which could be improved by developing materials capable of binding and releasing drug in a controlled fashion. The present study describes the preparation of magnetic nano-sized Molecularly Imprinted Polymers (nanoMIPs) for the controlled delivery of curcumin and their high throughput characterisation using microtitre plates modified with magnetic inserts. NanoMIPs were synthesised using functional monomers chosen with the aid of molecular modelling. The rate of release of curcumin from five polymers was studied under aqueous conditions and was found to correlate well with the binding energies obtained computationally. The presence of specific monomers was shown to be significant in ensuring effective binding of curcumin and to the rate of release obtained. Characterisation of the polymer particles was carried out using dynamic light scattering (DLS) technique and scanning electron microscopy (SEM) in order to establish the relationship between irradiation time and particle size. The protocols optimised during this study could be used as a blueprint for the development of nanoMIPs capable of the controlled release of potentially any compound of interest.

  19. Synthesis and electrochemical performance of surface-modified nano-sized core/shell tin particles for lithium ion batteries

    International Nuclear Information System (INIS)

    Schmuelling, Guido; Meyer, Hinrich-Wilhelm; Placke, Tobias; Winter, Martin; Oehl, Nikolas; Knipper, Martin; Kolny-Olesiak, Joanna; Plaggenborg, Thorsten; Parisi, Jürgen

    2014-01-01

    Tin is able to lithiate and delithiate reversibly with a high theoretical specific capacity, which makes it a promising candidate to supersede graphite as the state-of-the-art negative electrode material in lithium ion battery technology. Nevertheless, it still suffers from poor cycling stability and high irreversible capacities. In this contribution, we show the synthesis of three different nano-sized core/shell-type particles with crystalline tin cores and different amorphous surface shells consisting of SnO x and organic polymers. The spherical size and the surface shell can be tailored by adjusting the synthesis temperature and the polymer reagents in the synthesis, respectively. We determine the influence of the surface modifications with respect to the electrochemical performance and characterize the morphology, structure, and thermal properties of the nano-sized tin particles by means of high-resolution transmission electron microscopy, x-ray diffraction, and thermogravimetric analysis. The electrochemical performance is investigated by constant current charge/discharge cycling as well as cyclic voltammetry. (paper)

  20. Support vector machine to predict diesel engine performance and emission parameters fueled with nano-particles additive to diesel fuel

    Science.gov (United States)

    Ghanbari, M.; Najafi, G.; Ghobadian, B.; Mamat, R.; Noor, M. M.; Moosavian, A.

    2015-12-01

    This paper studies the use of adaptive Support Vector Machine (SVM) to predict the performance parameters and exhaust emissions of a diesel engine operating on nanodiesel blended fuels. In order to predict the engine parameters, the whole experimental data were randomly divided into training and testing data. For SVM modelling, different values for radial basis function (RBF) kernel width and penalty parameters (C) were considered and the optimum values were then found. The results demonstrate that SVM is capable of predicting the diesel engine performance and emissions. In the experimental step, Carbon nano tubes (CNT) (40, 80 and 120 ppm) and nano silver particles (40, 80 and 120 ppm) with nanostructure were prepared and added as additive to the diesel fuel. Six cylinders, four-stroke diesel engine was fuelled with these new blended fuels and operated at different engine speeds. Experimental test results indicated the fact that adding nano particles to diesel fuel, increased diesel engine power and torque output. For nano-diesel it was found that the brake specific fuel consumption (bsfc) was decreased compared to the net diesel fuel. The results proved that with increase of nano particles concentrations (from 40 ppm to 120 ppm) in diesel fuel, CO2 emission increased. CO emission in diesel fuel with nano-particles was lower significantly compared to pure diesel fuel. UHC emission with silver nano-diesel blended fuel decreased while with fuels that contains CNT nano particles increased. The trend of NOx emission was inverse compared to the UHC emission. With adding nano particles to the blended fuels, NOx increased compared to the net diesel fuel. The tests revealed that silver & CNT nano particles can be used as additive in diesel fuel to improve complete combustion of the fuel and reduce the exhaust emissions significantly.

  1. Adaptive neuro-fuzzy inference system (ANFIS) to predict CI engine parameters fueled with nano-particles additive to diesel fuel

    Science.gov (United States)

    Ghanbari, M.; Najafi, G.; Ghobadian, B.; Mamat, R.; Noor, M. M.; Moosavian, A.

    2015-12-01

    This paper studies the use of adaptive neuro-fuzzy inference system (ANFIS) to predict the performance parameters and exhaust emissions of a diesel engine operating on nanodiesel blended fuels. In order to predict the engine parameters, the whole experimental data were randomly divided into training and testing data. For ANFIS modelling, Gaussian curve membership function (gaussmf) and 200 training epochs (iteration) were found to be optimum choices for training process. The results demonstrate that ANFIS is capable of predicting the diesel engine performance and emissions. In the experimental step, Carbon nano tubes (CNT) (40, 80 and 120 ppm) and nano silver particles (40, 80 and 120 ppm) with nanostructure were prepared and added as additive to the diesel fuel. Six cylinders, four-stroke diesel engine was fuelled with these new blended fuels and operated at different engine speeds. Experimental test results indicated the fact that adding nano particles to diesel fuel, increased diesel engine power and torque output. For nano-diesel it was found that the brake specific fuel consumption (bsfc) was decreased compared to the net diesel fuel. The results proved that with increase of nano particles concentrations (from 40 ppm to 120 ppm) in diesel fuel, CO2 emission increased. CO emission in diesel fuel with nano-particles was lower significantly compared to pure diesel fuel. UHC emission with silver nano-diesel blended fuel decreased while with fuels that contains CNT nano particles increased. The trend of NOx emission was inverse compared to the UHC emission. With adding nano particles to the blended fuels, NOx increased compared to the net diesel fuel. The tests revealed that silver & CNT nano particles can be used as additive in diesel fuel to improve combustion of the fuel and reduce the exhaust emissions significantly.

  2. Wear behaviour of A356 aluminium alloy reinforced with micron and nano size SiC particles

    CSIR Research Space (South Africa)

    Camagu, ST

    2013-07-01

    Full Text Available A method for producing metal matrix composites MMC was successfully implemented for mixing nano and low micron (“Hybrid”) sized SiC reinforcing particles in an aluminium alloy matrix. Due to the improved specific modulus and strength, MMC...

  3. Nano-crystallization of steel wire and its wear behavior

    Energy Technology Data Exchange (ETDEWEB)

    Xu, Y.H. [School of Electromechanical Engineering, Xian University of Architecture and Technology, Xian 716000 (China) and School of Materials Science and Engineering, Northwestern Polytecnical University, Xian 710072 (China)], E-mail: xuyunhua@vip.163.com; Peng, J.H. [School of Electromechanical Engineering, Xian University of Architecture and Technology, Xian 716000 (China); Fang, L. [State Key Laboratory for Mechanical Behavior of Materials, Xian Jiaotong University, Xian 710049 (China)

    2008-06-15

    As carbon steel wire is widely used in civil engineering and industry, it is quite important to increase its strength. In the present paper, a severe cold drawing approach is applied to increase strength and is shown to produce nano grains. With increasing true strain, the tensile strength increases continuously and the cementite flake thickness decreases correspondingly. It is observed by transmission electron microscopy that a significant amount of cementite flakes have been fragmented and dissolved at true strains. Finally, the grains are transformed to nano-sized crystals. Additionally, the cold drawn nano-sized steel wire has been knitted and filled with polyurethane to produce a composite material. Three-body abrasive wear tests show that the wear resistance of the test material is even better than that of high-Cr white cast irons.

  4. Nano-crystallization of steel wire and its wear behavior

    International Nuclear Information System (INIS)

    Xu, Y.H.; Peng, J.H.; Fang, L.

    2008-01-01

    As carbon steel wire is widely used in civil engineering and industry, it is quite important to increase its strength. In the present paper, a severe cold drawing approach is applied to increase strength and is shown to produce nano grains. With increasing true strain, the tensile strength increases continuously and the cementite flake thickness decreases correspondingly. It is observed by transmission electron microscopy that a significant amount of cementite flakes have been fragmented and dissolved at true strains. Finally, the grains are transformed to nano-sized crystals. Additionally, the cold drawn nano-sized steel wire has been knitted and filled with polyurethane to produce a composite material. Three-body abrasive wear tests show that the wear resistance of the test material is even better than that of high-Cr white cast irons

  5. Effect of addition of different nano-clays on the fumed silica-polyethylene glycol based shear-thickening fluids

    Science.gov (United States)

    Singh, Mansi; Mehta, Rajeev; Verma, Sanjeev K.; Biswas, Ipsita

    2018-01-01

    A comparative study of the rheology of shear thickening suspensions of 20% fumed silica in polyethylene glycol (PEG200) with different nano clays as additives has been done. The nano-clays used are montmorillonite (MMT), Closite15A, Kaolin and Halloysite clay. The objective was to study the effect of relatively cost-effective clays as a partial substitute of silica. Specifically, the effect of type, concentration, temperature and frequency were considered. The results indicate that the shear thickening properties of Closite15A as additive in temperature ranges of 25 °C-45 °C performs the best and Halloysite performs best at higher (55 °C) and lower temperatures (5, 15 °C). The elasticity effects in dynamic experiments were markedly enhanced by Halloysite clay addition. Addition of MMT, however, led to insignificant enhancement in critical viscosity in steady-state as well as dynamic state-rheology. Interestingly, shear thickening fluid (STF) with all clay except MMT was stable after storing for more than a month. These findings indicate that the introduction of nano-clay as additives is a promising and cost effective method for enhancing the STF behavior which can be utilized in high impact resistant (about 3000% strain and 300 rad s-1 frequency) applications.

  6. Synthesis and characterization of nano hydroxyapatite using reverse micro emulsions as nano reactors

    International Nuclear Information System (INIS)

    Amin, S.; Siddique, T.

    2015-01-01

    In the present work reverse micro emulsion has been employed as nano reactors to synthesize nano crystalline Hydroxyapatite (HA). Two precursors; calcium and phosphate with different counter ions of each were used for the synthesis of HA at two different temperatures. To maintain the emulsified nano reactor, cyclohexane, TX-100 and 1-butanol including phosphate precursor was the continuous phase while aqueous Ca precursor solution was taken as the dispersed phase. Nano crystalline particles thus produced were evaluated on the basis of synthesis route, counter ions and temperature. It has been shown that emulsified nano reactors control the morphology, particle size and minimize phase transformation of HA. Characterizations of nano powder of HA are carried out using x-ray diffraction (XRD), Fourier transform infra-red spectroscopy (FTIR), and scanning electron microscopy (SEM). HA crystallite size was found to be in the range of 20-25 nm whereas the morphology of nano particles changed from spheres to rods. (author)

  7. Nano- and micro-electromechanical systems fundamentals of nano- and microengineering

    CERN Document Server

    Lyshevski, Sergey Edward

    2005-01-01

    NANOTECHNOLOGY AND MICROTECHNOLOGY (NANO- AND MICRO- SCIENCE, ENGINEERING AND TECHNOLOGY), AND BEYOND Introduction and Overview: From Micro- to Nano- and Beyond to Stringo-Scale Introductory Definitions to the Subjects Current Developments and Needs for Coherent Revolutionary Developments Societal Challenges and Implications NANO- AND MICROSCALE SYSTEMS, DEVICES, AND STRUCTURES Sizing Features: From Micro- to Nano-, and from Nano- to Stringo-Scale MEMS and NEMS Definitions Introduction to Taxonomy of Nano- and Microsystem Synthesis and Design Introduction to Design and Optimization of Nano- and Microsystems in the Behavioral Domain NANO- AND MICROSYSTEMS: CLASSIFICATION AND CONSIDERATION Biomimetics, Biological Analogies,and Design of NEMS and MEMS Micro- and Nanoelectromechanical Systems: Scaling Laws and Mathematical Modeling MEMS Examples and MEMS Architectures Introduction to Microfabrication and Micromachining FUNDAMENTALS OF MICROFABRICATION AND MEMS FABRICATION TECHNOLOGIES Introducti...

  8. Flame Retardant Effect of Nano Fillers on Polydimethylsiloxane Composites.

    Science.gov (United States)

    Jagdale, Pravin; Salimpour, Samera; Islam, Md Hujjatul; Cuttica, Fabio; Hernandez, Francisco C Robles; Tagliaferro, Alberto; Frache, Alberto

    2018-02-01

    Polydimethylsiloxane has exceptional fire retardancy characteristics, which make it a popular polymer in flame retardancy applications. Flame retardancy of polydimethylsiloxane with different nano fillers was studied. Polydimethylsiloxane composite fire property varies because of the shape, size, density, and chemical nature of nano fillers. In house made carbon and bismuth oxide nano fillers were used in polydimethylsiloxane composite. Carbon from biochar (carbonised bamboo) and a carbon by-product (carbon soot) were selected. For comparative study of nano fillers, standard commercial multiwall carbon nano tubes (functionalised, graphitised and pristine) as nano fillers were selected. Nano fillers in polydimethylsiloxane positively affects their fire retardant properties such as total smoke release, peak heat release rate, and time to ignition. Charring and surface ceramization are the main reasons for such improvement. Nano fillers in polydimethylsiloxane may affect the thermal mobility of polymer chains, which can directly affect the time to ignition. The study concludes that the addition of pristine multiwall carbon nano tubes and bismuth oxide nano particles as filler in polydimethylsiloxane composite improves the fire retardant property.

  9. Nano-Reinforcement of Interfaces in Prepreg-Based Composites Using a Carbon Nanotubes Spraying Method

    KAUST Repository

    Almuhammadi, Khaled

    2012-01-01

    of epoxy resins used as matrix materials for CFRP composites can be increased by the addition of nano-sized fillers such as Carbon nanotubes (CNTs). CNTs are particularly well suited for this purpose because of their nano-scale diameter and high aspect

  10. Microwave Assisted Synthesis of ZnO Nanoparticles: Effect of Precursor Reagents, Temperature, Irradiation Time, and Additives on Nano-ZnO Morphology Development

    Directory of Open Access Journals (Sweden)

    Gastón P. Barreto

    2013-01-01

    Full Text Available The effect of different variables (precursor reagents, temperature, irradiation time, microwave radiation power, and additives addition on the final morphology of nano-ZnO obtained through the microwave assisted technique has been investigated. The characterization of the samples has been carried out by field emission scanning electron microscopy (FE-SEM in transmission mode, infrared (FTIR, UV-Vis spectroscopy, and powder X-ray diffraction (XRD. The results showed that all the above-mentioned variables influenced to some extent the shape and/or size of the synthetized nanoparticles. In particular, the addition of an anionic surfactant (sodium di-2-ethylhexyl-sulfosuccinate (AOT to the reaction mixture allowed the synthesis of smaller hexagonal prismatic particles (100 nm, which show a significant increase in UV absorption.

  11. The Effect of Nano sized Carbon Black on the Physical and Thermomechanical Properties of Al2O3-SiC-SiO2-C Composite

    International Nuclear Information System (INIS)

    Amin, M.H.; Ebrahimabadi, M.A.; Rahimipour, M.R.

    2009-01-01

    The effects of using nano sized carbon black in the range of 010 weight percentages on the physical and thermomechanical properties of Al 2 O 3 -Si C-SiO 2 graphite refractory composites were investigated. Nano sized carbon black addition improved the relative heat resistance and oxidation resistance of composites. The bulk density of the composites is reduced with increasing carbon black (CB) content. Increase in CB content first causes an increase in the apparent porosity, but at more than 3 wt % amount of CB, a decrease of apparent porosity was observed. The cold crushing strength (CCS) increased with increasing CB content in samples fired at 800 degree C and in samples fired at 1500 degree C when the content is increased to 3 wt %, but the CCS decreased with increasing CB content in samples fired at 1500 degree C when the CB content was less than 3 wt %. The composite without CB exhibits the highest value of CCS at firing temperature of 1500 degree C.

  12. Size-dependent magnetic and structural properties of CoCrFeO4 nano-powder prepared by solution self-combustion

    Science.gov (United States)

    Sijo, A. K.; Dutta, Dimple P.

    2018-04-01

    The study reports the tuning of magnetic and structural properties of nano-sized CoCrFeO4 via post-annealing treatment. CoCrFeO4 nano-powder has been prepared by solution self-combustion method. The structural and magnetic properties have been studied over a range of annealing temperatures (300-900 °C). The formation of the phase pure CoCrFeO4 spinel has been confirmed from powder XRD analysis. The crystallite size is observed to increase with an increase in annealing temperature. On annealing, the value of magnetic parameters-remanence, coercivity and saturation magnetization have enhanced. All the samples exhibit irreversibility at low-temperature measurements.

  13. Dynamic effect of total solid content, low substrate/inoculum ratio and particle size on solid-state anaerobic digestion.

    Science.gov (United States)

    Motte, J-C; Escudié, R; Bernet, N; Delgenes, J-P; Steyer, J-P; Dumas, C

    2013-09-01

    Among all the process parameters of solid-state anaerobic digestion (SS-AD), total solid content (TS), inoculation (S/X ratio) and size of the organic solid particles can be optimized to improve methane yield and process stability. To evaluate the effects of each parameter and their interactions on methane production, a three level Box-Behnken experimental design was implemented in SS-AD batch tests degrading wheat straw by adjusting: TS content from 15% to 25%, S/X ratio (in volatile solids) between 28 and 47 and particle size with a mean diameter ranging from 0.1 to 1.4mm. A dynamic analysis of the methane production indicates that the S/X ratio has only an effect during the start-up phase of the SS-AD. During the growing phase, TS content becomes the main parameter governing the methane production and its strong interaction with the particle size suggests the important role of water compartmentation on SS-AD. Copyright © 2013 Elsevier Ltd. All rights reserved.

  14. Support for the initial attachment, growth and differentiation of MG-63 cells: a comparison between nano-size hydroxyapatite and micro-size hydroxyapatite in composites

    Directory of Open Access Journals (Sweden)

    Filová E

    2014-08-01

    Full Text Available Elena Filová,1 Tomáš Suchý,2,3 Zbynek Sucharda,2 Monika Šupová,2 Margit Žaloudková,2 Karel Balík,2 Vera Lisá,1 Miroslav Šlouf,4 Lucie Bacáková11Department of Biomaterials and Tissue Engineering, Institute of Physiology, 2Department of Composite and Carbon Materials, Institute of Rock Structure and Mechanics, Academy of Sciences of the Czech Republic, 3Laboratory of Biomechanics, Department of Mechanics, Biomechanics and Mechatronics, Faculty of Mechanical Engineering, CTU in Prague, 4Department of Morphology and Rheology of Polymer Materials, Institute of Macromolecular Chemistry, Academy of Sciences of the Czech Republic, Prague, Czech RepublicAbstract: Hydroxyapatite (HA is considered to be a bioactive material that favorably influences the adhesion, growth, and osteogenic differentiation of osteoblasts. To optimize the cell response on the hydroxyapatite composite, it is desirable to assess the optimum concentration and also the optimum particle size. The aim of our study was to prepare composite materials made of polydimethylsiloxane, polyamide, and nano-sized (N or micro-sized (M HA, with an HA content of 0%, 2%, 5%, 10%, 15%, 20%, 25% (v/v (referred to as N0–N25 or M0–M25, and to evaluate them in vitro in cultures with human osteoblast-like MG-63 cells. For clinical applications, fast osseointegration of the implant into the bone is essential. We observed the greatest initial cell adhesion on composites M10 and N5. Nano-sized HA supported cell growth, especially during the first 3 days of culture. On composites with micro-size HA (2%–15%, MG-63 cells reached the highest densities on day 7. Samples M20 and M25, however, were toxic for MG-63 cells, although these composites supported the production of osteocalcin in these cells. On N2, a higher concentration of osteopontin was found in MG-63 cells. For biomedical applications, the concentration range of 5%–15% (v/v nano-size or micro-size HA seems to be optimum

  15. Reflection characterization of nano-sized dielectric structure in Morpho butterfly wings

    Science.gov (United States)

    Zhu, Dong

    2017-10-01

    Morpho butterflies living in Central and South America are well-known for their structural-colored blue wings. The blue coloring originates from the interaction of light with nano-sized dielectric structures that are equipped on the external surface of scales covering over their wings. The high-accuracy nonstandard finite-difference time domain (NS-FDTD) method is used to investigate the reflection characterization from the nanostructures. In the NS-FDTD calculation, a computational model is built to mimic the actual tree-like multilayered structures wherever possible using the hyperbolic tangent functions. It is generally known that both multilayer interference and diffraction grating phenomena can occur when light enters the nano-sized multilayered structure. To answer the question that which phenomenon is mainly responsible for the blue coloring, the NS-FDTD calculation is performed under various incidence angles at wavelengths from 360 to 500 nm. The calculated results at one incident wavelength under different incidence angles are visualized in a two-dimensional mapping image, where horizontal and vertical axes are incidence and reflection angles, respectively. The images demonstrate a remarkable transition from a ring-like pattern at shorter wavelengths to a retro-reflection pattern at longer wavelengths. To clarify the origin of the pattern transition, the model is separated into several simpler parts and compared their mapping images with the theoretical diffraction calculations. It can be concluded that the blue coloring at longer wavelengths is mainly caused by the cooperation of multilayer interference and retro-reflection while the effect of diffraction grating is predominant at shorter wavelengths.

  16. Rapid fabrication of an ordered nano-dot array by the combination of nano-plastic forming and annealing methods

    International Nuclear Information System (INIS)

    Yoshino, Masahiko; Ohsawa, Hiroki; Yamanaka, Akinori

    2011-01-01

    In this paper, a new fabrication method for an ordered nano-dot array is developed. Combination of coating, nano-plastic forming and annealing processes is studied to produce uniformly sized and ordered gold nano-dot array on a quartz glass substrate. The experimental results reveal that patterning of a groove grid on the gold-coated substrate with NPF is effective to obtain the ordered gold nano-dot array. In the proposed fabrication process, the size of the gold nano-dot can be controlled by adjusting the groove grid size. A minimum gold nano-dot array fabricated on a quartz-glass substrate was 93 nm in diameter and 100 nm in pitch. Furthermore, the mechanism of nano-dot array generation by the presented process is investigated. Using a theoretical model it is revealed that the proposed method is capable of fabrication of smaller nano-dots than 10 nm by controlling process conditions adequately.

  17. Removing Pathogens Using Nano-Ceramic-Fiber Filters

    Science.gov (United States)

    Tepper, Frederick; Kaledin, Leonid

    2005-01-01

    A nano-aluminum-oxide fiber of only 2 nanometers in diameter was used to develop a ceramic-fiber filter. The fibers are electropositive and, when formulated into a filter material (NanoCeram(TradeMark)), would attract electro-negative particles such as bacteria and viruses. The ability to detect and then remove viruses as well as bacteria is of concern in space cabins since they may be carried onboard by space crews. Moreover, an improved filter was desired that would polish the effluent from condensed moisture and wastewater, producing potable drinking water. A laboratory- size filter was developed that was capable of removing greater than 99.9999 percent of bacteria and virus. Such a removal was achieved at flow rates hundreds of times greater than those through ultraporous membranes that remove particles by sieving. Because the pore size of the new filter was rather large as compared to ultraporous membranes, it was found to be more resistant to clogging. Additionally, a full-size cartridge is being developed that is capable of serving a full space crew. During this ongoing effort, research demonstrated that the filter media was a very efficient adsorbent for DNA (deoxyribonucleic acid), RNA (ribonucleic acid), and endotoxins. Since the adsorption is based on the charge of the macromolecules, there is also a potential for separating proteins and other particulates on the basis of their charge differences. The separation of specific proteins is a major new thrust of biotechnology. The principal application of NanoCeram filters is based on their ability to remove viruses from water. The removal of more than 99.9999 percent of viruses was achieved by a NanoCeram polishing filter added to the effluent of an existing filtration device. NanoCeram is commercially available in laboratory-size filter discs and in the form of a syringe filter. The unique characteristic of the filter can be demonstrated by its ability to remove particulate dyes such as Metanyl yellow. Its

  18. From Nano Structure to Systems: Fabrication and Characterization

    International Nuclear Information System (INIS)

    Uda Hashim

    2011-01-01

    Currently, the interest in nano technology research has been grown rapidly. With the latest technology, it is possible to arrange atoms into structures that are only a few nanometers in size. Dimension for nano structure is between 0.1 and 100nm where the actual size of 1nm is equal to 10-9 m or just about a few atoms thick. In other word, a nano structure is an object which it size is about four atom diameters or 1/50000 of a human hair. Due to the connecting of a patterned silicon substrate with biomolecules and the small size and large surface-to-volume ratio, it opens much new possibility for assembling nano structures.The ultimate goal is to fabricate devices that have every atom in the right place. Such technology would give the opportunity to minimize the size of a device and to reduce the material, energy and time necessary to perform its task. Potential applications include electrical circuits, mechanical devices and medical instruments. There are two most important nano structures that are extensively studied and researched in various organizations which are nano wire and nano gap. Nano wires is a new class of nano structure that have attracted attention and great research interest in the last few years because of their potential applications in nano technology such as nano electronic, nano mechanical and biomedical engineering. Fabrication of Nano wires is one of the great challenges today. Conventional lithography methods are not capable to produce Nano wires and even with advance nano lithography sizes below 100 nm may not easily be achieved. Nano wire can be produced in two approaches, which are top down and bottom-up method. Very small nano wires which can be produced by using top-down nano fabrication methods are Scanning Electron Microscope (SEM) based Electron Beam Lithography (EBL) method, and Spacer Patterning Lithography (SPL) method. The top-down nano fabrication method based on EBL was the design of the Nano wires Pattern Design (NPD). The

  19. Des (bio)nano-composites utilisés dans le traitement d'eaux contaminées par de l'arsenic/gentamicine ou pour des applications médicales

    OpenAIRE

    He , Jing

    2013-01-01

    Bionanocomposites represent an emerging group of nano-structured hybrid materials. They are formed by the combination of natural polymers and inorganic solids and show at least one dimension on the nanometer scale (Darder et al., 2007). These hybrid materials retain the structural and functional properties of nano-structured materials. Meanwhile, the presence of biopolymer can reduce the public health and environmental risk of nano-sized material. The properties inherent to the biopolymers, t...

  20. [Preparation of nano-nacre artificial bone].

    Science.gov (United States)

    Chen, Jian-ting; Tang, Yong-zhi; Zhang, Jian-gang; Wang, Jian-jun; Xiao, Ying

    2008-12-01

    To assess the improvements in the properties of nano-nacre artificial bone prepared on the basis of nacre/polylactide acid composite artificial bone and its potential for clinical use. The compound of nano-scale nacre powder and poly-D, L-lactide acid (PDLLA) was used to prepare the cylindrical hollow artificial bone, whose properties including raw material powder scale, pore size, porosity and biomechanical characteristics were compared with another artificial bone made of micron-scale nacre powder and PDLLA. Scanning electron microscope showed that the average particle size of the nano-nacre powder was 50.4-/+12.4 nm, and the average pore size of the artificial bone prepared using nano-nacre powder was 215.7-/+77.5 microm, as compared with the particle size of the micron-scale nacre powder of 5.0-/+3.0 microm and the pore size of the resultant artificial bone of 205.1-/+72.0 microm. The porosities of nano-nacre artificial bone and the micron-nacre artificial bone were (65.4-/+2.9)% and (53.4-/+2.2)%, respectively, and the two artificial bones had comparable compressive strength and Young's modulus, but the flexural strength of the nano-nacre artificial bone was lower than that of the micro-nacre artificial bone. The nano-nacre artificial bone allows better biodegradability and possesses appropriate pore size, porosity and biomechanical properties for use as a promising material in bone tissue engineering.

  1. About Nano-JASMINE Satellite System and Project Status

    Science.gov (United States)

    Sako, Nobutada

    Intelligent Space Systems Laboratory, The University of Tokyo (ISSL) and National Astronomical Observatory of Japan (NAO) have been developing a small infrared astrometry satellite named “Nano-JASMINE”. The satellite size is about 50cm cubic and 20kg, which plays a pre-cursor role of JASMINE Project which is programmed by NAO and JAXA. In addition, since there has been only one astrometry satellite HIPPARCOS by ESA in the past, Nano-JASMINE is also expected to achieve certain scientific results in the field of astrometry. In this project, ISSL aims to develop new advanced small satellite bus system whose performance is comparable to that of 100-500kg sized satellites, including attitude stability of 1 arc-second and thermal stability of the mission subsystem of 1 mK. This paper overviews the Nano-JASMINE bus system with emphasis on attitude and thermal control systems.

  2. Nonlinear primary resonance of micro/nano-beams made of nanoporous biomaterials incorporating nonlocality and strain gradient size dependency

    Science.gov (United States)

    Sahmani, S.; Aghdam, M. M.

    2018-03-01

    A wide range of biological applications such as drug delivery, biosensors and hemodialysis can be provided by nanoporous biomaterials due to their uniform pore size as well as considerable pore density. In the current study, the size dependency in the nonlinear primary resonance of micro/nano-beams made of nanoporous biomaterials is anticipated. To accomplish this end, a refined truncated cube is introduced to model the lattice structure of nanoporous biomaterial. Accordingly, analytical expressions for the mechanical properties of material are derived as functions of pore size. After that, based upon a nonlocal strain gradient beam model, the size-dependent nonlinear Duffing type equation of motion is constructed. The Galerkin technique together with the multiple time-scales method is employed to obtain the nonlocal strain gradient frequency-response and amplitude-response related to the nonlinear primary resonance of a micro/nano-beam made of the nanoporous biomaterial with different pore sizes. It is indicated that the nonlocality causes to decrease the response amplitudes associated with the both bifurcation points of the jump phenomenon, while the strain gradient size dependency causes to increase them. Also, it is found that increasing the pore size leads to enhance the nonlinearity, so the maximum deflection of response occurs at higher excitation frequency.

  3. Nano-formulations of drugs: Recent developments, impact and challenges.

    Science.gov (United States)

    Jeevanandam, Jaison; Chan, Yen San; Danquah, Michael K

    2016-01-01

    Nano-formulations of medicinal drugs have attracted the interest of many researchers for drug delivery applications. These nano-formulations enhance the properties of conventional drugs and are specific to the targeted delivery site. Dendrimers, polymeric nanoparticles, liposomes, nano-emulsions and micelles are some of the nano-formulations that are gaining prominence in pharmaceutical industry for enhanced drug formulation. Wide varieties of synthesis methods are available for the preparation of nano-formulations to deliver drugs in biological system. The choice of synthesis methods depend on the size and shape of particulate formulation, biochemical properties of drug, and the targeted site. This article discusses recent developments in nano-formulation and the progressive impact on pharmaceutical research and industries. Additionally, process challenges relating to consistent generation of nano-formulations for drug delivery are discussed. Copyright © 2016 Elsevier B.V. and Société Française de Biochimie et Biologie Moléculaire (SFBBM). All rights reserved.

  4. Prevention of dental erosion of a sports drink by nano-sized hydroxyapatite in situ study.

    Science.gov (United States)

    Min, Ji Hyun; Kwon, Ho Keun; Kim, Baek Il

    2015-01-01

    To evaluate the inhibitory effects of the sports drink containing nano-sized hydroxyapatite (nano-HA) on dental erosion in situ. The study had a single-blind, two-treatment crossover design. The two treatment groups were a control group (CG; Powerade only) and an experimental group (EG; 0.25% wt/vol nano-HA was added to Powerade). Ten subjects wore removable palatal appliances containing bovine enamel specimens. The appliances were immersed in each drink for 10 mins, 4 times a day for 10 days. The tooth surface microhardness (SMH) was tested, and the erosion depth and the morphology of the tooth surface were observed. The data were analysed by repeated measures anova and t-test. Between the baseline and the 10th day, SMH was decreased by 80% in the specimens of the CG (P erosion depth of 12.70 ± 4.66 μm and an irregular tooth surface were observed on the 10th day in the specimens of the CG. No dental erosions, however, was observed in the specimens of the EG. The sports drink containing 0.25% nano-HA was effective in preventing dental erosion in situ. © 2014 BSPD, IAPD and John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  5. Role of the anisotropy in the interactions between nano- and micro-sized particles

    OpenAIRE

    Rovigatti, Lorenzo

    2012-01-01

    The present Thesis focuses on the thermodynamic and dynamic behaviour of anisotropically interacting colloids by means of theoretical and numerical techniques. Colloidal suspensions, i.e. micro-- and nano--sized particles dispersed in a continuous phase, are a topic of great interest in several fields, including material science, soft matter and biophysics. Common in everyday life in the form of soap, milk, cream, etc., colloids have been used for decades as models for atomic and molecula...

  6. Co-Assembled Supported Catalysts: Synthesis of Nano-Structured Supported Catalysts with Hierarchic Pores through Combined Flow and Radiation Induced Co-Assembled Nano-Reactors

    Directory of Open Access Journals (Sweden)

    Galip Akay

    2016-05-01

    Full Text Available A novel generic method of silica supported catalyst system generation from a fluid state is presented. The technique is based on the combined flow and radiation (such as microwave, thermal or UV induced co-assembly of the support and catalyst precursors forming nano-reactors, followed by catalyst precursor decomposition. The transformation from the precursor to supported catalyst oxide state can be controlled from a few seconds to several minutes. The resulting nano-structured micro-porous silica supported catalyst system has a surface area approaching 300 m2/g and X-ray Diffraction (XRD-based catalyst size controlled in the range of 1–10 nm in which the catalyst structure appears as lamellar sheets sandwiched between the catalyst support. These catalyst characteristics are dependent primarily on the processing history as well as the catalyst (Fe, Co and Ni studied when the catalyst/support molar ratio is typically 0.1–2. In addition, Ca, Mn and Cu were used as co-catalysts with Fe and Co in the evaluation of the mechanism of catalyst generation. Based on extensive XRD, Scanning Electron Microscopy (SEM and Transmission Electron Microscopy (TEM studies, the micro- and nano-structure of the catalyst system were evaluated. It was found that the catalyst and silica support form extensive 0.6–2 nm thick lamellar sheets of 10–100 nm planar dimensions. In these lamellae, the alternate silica support and catalyst layer appear in the form of a bar-code structure. When these lamellae structures pack, they form the walls of a micro-porous catalyst system which typically has a density of 0.2 g/cm3. A tentative mechanism of catalyst nano-structure formation is provided based on the rheology and fluid mechanics of the catalyst/support precursor fluid as well as co-assembly nano-reactor formation during processing. In order to achieve these structures and characteristics, catalyst support must be in the form of silane coated silica nano

  7. Preparation of ultra-fine powders from polysaccharide-coated solid lipid nanoparticles and nanostructured lipid carriers by innovative nano spray drying technology.

    Science.gov (United States)

    Wang, Taoran; Hu, Qiaobin; Zhou, Mingyong; Xue, Jingyi; Luo, Yangchao

    2016-09-10

    In this study, five polysaccharides were applied as natural polymeric coating materials to prepare solid lipid nanoparticles (SLN) and nanostructure lipid carriers (NLC), and then the obtained lipid colloidal particles were transformed to solid powders by the innovative nano spray drying technology. The feasibility and suitability of this new technology to generate ultra-fine lipid powder particles were evaluated and the formulation was optimized. The spray dried SLN powder exhibited the aggregated and irregular shape and dimension, but small, uniform, well-separated spherical powder particles of was obtained from NLC. The optimal formulation of NLC was prepared by a 20-30% oleic acid content with carrageenan or pectin as coating material. Therefore, nano spray drying technology has a potential application to produce uniform, spherical, and sub-microscale lipid powder particles when the formulation of lipid delivery system is appropriately designed. Copyright © 2016 Elsevier B.V. All rights reserved.

  8. Si-Ge Nano-Structured with Tungsten Silicide Inclusions

    Science.gov (United States)

    Mackey, Jon; Sehirlioglu, Alp; Dynys, Fred

    2014-01-01

    Traditional silicon germanium high temperature thermoelectrics have potential for improvements in figure of merit via nano-structuring with a silicide phase. A second phase of nano-sized silicides can theoretically reduce the lattice component of thermal conductivity without significantly reducing the electrical conductivity. However, experimentally achieving such improvements in line with the theory is complicated by factors such as control of silicide size during sintering, dopant segregation, matrix homogeneity, and sintering kinetics. Samples are prepared using powder metallurgy techniques; including mechanochemical alloying via ball milling and spark plasma sintering for densification. In addition to microstructural development, thermal stability of thermoelectric transport properties are reported, as well as couple and device level characterization.

  9. Fundamental Issues of Nano-fluid Behavior

    International Nuclear Information System (INIS)

    Williams, Wesley C.

    2006-01-01

    This paper will elucidate some of the behaviors of nano-fluids other than the abnormal conductivity enhancement, which are of importance to the experimental and engineering use of nano-fluids. Nano-fluid is the common name of any sol colloid involving nano-scale (less than 100 nm) sized particles dispersed within a base fluid. It has been shown previously that the dispersion of nano-particulate metallic oxides into water can increase thermal conductivity up to 30-40% over that of the base fluid and anomalously more than the mere weighed average of the colloid. There is a great potential for the use of nano-fluids as a way to enhance fluid/thermal energy transfer systems. Due to the recentness of nano-fluid science, there are still many issues which have not been fully investigated. This paper should act as a primer for the basic understanding of nano-fluid behavior. Particle size and colloid stability are of key importance to the functionality of nano-fluids. The pH and concentration/loading of nano-fluids can alter the size of the nano-particles and also the stability of the fluids. It will be shown through experiment and colloid theory the importance of these parameters. Furthermore, most of the existing literature uses volume percentage as the measure of particle loading, which can often be misleading. There will be discussion of this and other misleading ideas in nano-fluid science. (author)

  10. Self-aligned periodic Ni nano dots embedded in nano-oxide layer

    International Nuclear Information System (INIS)

    Doi, M.; Izumi, M.; Kawasaki, S.; Miyake, K.; Sahashi, M.

    2007-01-01

    The Ni nano constriction dots embedded in the Ta-nano-oxide layer (NOL) was prepared by the ion beam sputtering (IBS) method. After the various conditions of the oxidations, the structural analyses of the NOL were performed by RHEED, AES and in situ STM/AFM observations. From the current image of the conductive AFM for NOL, the periodically aligned metallic dots with the size around 5-10 nm were successfully observed. The mechanism of the formation of the self-organized aligned Ni nano constriction dots is discussed from the standpoint of the grain size, the crystal orientation, the preferred oxidation of Ta at the diffused interface

  11. Thermal shock behavior of nano-sized SiC particulate reinforced AlON composites

    Energy Technology Data Exchange (ETDEWEB)

    Zhao, X.J. [Department of Materials Science and Engineering, School of Materials and Metallurgy, Northeastern University, Shenyang, Liaoning 110004 (China); Department of Mechanical and Industrial Engineering, Ryerson University, Toronto, Ontario M5B 2K3 (Canada); Ru, H.Q., E-mail: ruhq@smm.neu.edu.cn [Department of Materials Science and Engineering, School of Materials and Metallurgy, Northeastern University, Shenyang, Liaoning 110004 (China); Chen, D.L., E-mail: dchen@ryerson.ca [Department of Mechanical and Industrial Engineering, Ryerson University, Toronto, Ontario M5B 2K3 (Canada); Zhang, N.; Liang, B. [Key Laboratory of Advanced Materials Manufacturing Technology of Liaoning Province, Shenyang University, Shenyang, Liaoning 110044 (China)

    2012-03-25

    Highlights: Black-Right-Pointing-Pointer Addition of nano-SiC particles enhances residual strength and critical temperature. Black-Right-Pointing-Pointer Young's modulus decreases with increasing quenching temperature. Black-Right-Pointing-Pointer Linear relationship between residual strength and thermal shock times is obtained. Black-Right-Pointing-Pointer Rougher fracture surfaces in the SiC-AlON composites are observed. - Abstract: Aluminum oxynitride (AlON) has been considered as a potential ceramic material for high-performance structural and advanced refractory applications. Thermal shock resistance is a major concern and an important performance index of high-temperature ceramics. While silicon carbide (SiC) particles have been proven to improve mechanical properties of AlON ceramic, the high-temperature thermal shock behavior was unknown. The aim of this investigation was to identify the thermal shock resistance and underlying mechanisms of AlON ceramic and 8 wt% SiC-AlON composites over a temperature range between 175 Degree-Sign C and 275 Degree-Sign C. The residual strength and Young's modulus after thermal shock decreased with increasing quenching temperature and thermal shock times due to large temperature gradients and thermal stresses caused by abrupt water-quenching. A linear relationship between the residual strength and thermal shock times was observed in both pure AlON and SiC-AlON composites. The addition of nano-sized SiC particles increased both residual strength and critical temperature from 200 Degree-Sign C in the monolithic AlON to 225 Degree-Sign C in the SiC-AlON composites due to the toughening effect, the lower coefficient of thermal expansion and higher thermal conductivity of SiC. The enhancement of the thermal shock resistance in the SiC-AlON composites was directly related to the change of fracture mode from intergranular cracking along with cleavage-type fracture in the AlON to a rougher fracture surface with ridge

  12. Validation of a particle tracking analysis method for the size determination of nano- and microparticles

    Science.gov (United States)

    Kestens, Vikram; Bozatzidis, Vassili; De Temmerman, Pieter-Jan; Ramaye, Yannic; Roebben, Gert

    2017-08-01

    Particle tracking analysis (PTA) is an emerging technique suitable for size analysis of particles with external dimensions in the nano- and sub-micrometre scale range. Only limited attempts have so far been made to investigate and quantify the performance of the PTA method for particle size analysis. This article presents the results of a validation study during which selected colloidal silica and polystyrene latex reference materials with particle sizes in the range of 20 nm to 200 nm were analysed with NS500 and LM10-HSBF NanoSight instruments and video analysis software NTA 2.3 and NTA 3.0. Key performance characteristics such as working range, linearity, limit of detection, limit of quantification, sensitivity, robustness, precision and trueness were examined according to recommendations proposed by EURACHEM. A model for measurement uncertainty estimation following the principles described in ISO/IEC Guide 98-3 was used for quantifying random and systematic variations. For nominal 50 nm and 100 nm polystyrene and a nominal 80 nm silica reference materials, the relative expanded measurement uncertainties for the three measurands of interest, being the mode, median and arithmetic mean of the number-weighted particle size distribution, varied from about 10% to 12%. For the nominal 50 nm polystyrene material, the relative expanded uncertainty of the arithmetic mean of the particle size distributions increased up to 18% which was due to the presence of agglomerates. Data analysis was performed with software NTA 2.3 and NTA 3.0. The latter showed to be superior in terms of sensitivity and resolution.

  13. Electrodeposition of nano-sized bismuth on copper foil as electrocatalyst for reduction of CO{sub 2} to formate

    Energy Technology Data Exchange (ETDEWEB)

    Lv, Weixin; Zhou, Jing; Bei, Jingjing [School of Chemistry and Chemical Engineering, Yancheng Institute of Technology, Yancheng, 224051 (China); Zhang, Rui, E-mail: zhangrui@ycit.cn [School of Chemistry and Chemical Engineering, Yancheng Institute of Technology, Yancheng, 224051 (China); Wang, Lei [Key Laboratory of Functional Inorganic Material Chemistry, Ministry of Education of the People’s Republic of China, Heilongjiang University, Harbin, 150080 (China); Xu, Qi [School of Chemistry and Chemical Engineering, Yancheng Institute of Technology, Yancheng, 224051 (China); Wang, Wei, E-mail: wangw@ycit.edu.cn [School of Chemistry and Chemical Engineering, Yancheng Institute of Technology, Yancheng, 224051 (China)

    2017-01-30

    Highlights: • Bi/Cu electrode was prepared by depositing nano-sized Bi catalyst on Cu foil. • The Bi/Cu electrode can reduce CO{sub 2} to formate with a low overpotential. • The energy efficiency for reduction of CO{sub 2} to formate can reach to 50%. • A Tafel slope of 128 mV decade{sup −1} was observed for producing formate. - Abstract: Electrochemical reduction of carbon dioxide (CO{sub 2}) to formate is energetically inefficient because high overpotential is required for reduction of CO{sub 2} to formate on most traditional catalysts. In this paper, a novel nano-sized Bi-based electrocatalyst deposited on a Cu foil has been synthesized, which can be used as a cathode for electrochemical reduction of CO{sub 2} to formate with a low overpotential (0.69 V) and a high selectivity (91.3%). The electrocatalyst can show excellent catalytic performance toward reduction of CO{sub 2} which can probably be attributed to the nano-sized structure and the surface oxide layer. The energy efficiency for reduction of CO{sub 2} to formate can reach to 50% when an Ir{sub x}Sn{sub y}Ru{sub z}O{sub 2}/Ti electrode is used as anode, it is one of the highest values found in the literatures and very practicable for sustainable fuel synthesis.

  14. Micro-/Nano- sized hydroxyapatite directs differentiation of rat bone marrow derived mesenchymal stem cells towards an osteoblast lineage

    Science.gov (United States)

    Huang, Yan; Zhou, Gang; Zheng, Lisha; Liu, Haifeng; Niu, Xufeng; Fan, Yubo

    2012-03-01

    Regenerative medicine consisting of cells and materials provides a new way for the repair and regeneration of tissues and organs. Nano-biomaterials are highlighted due to their advantageous features compared with conventional micro-materials. The aim of this study is to investigate the effects of micro-/nano- sized hydroxyapatite (μ/n-HA) on the osteogenic differentiation of rat bone marrow derived mesenchymal stem cells (rBMSCs). μ/n-HA were prepared by a microwave synthesizer and precipitation method, respectively. Different sizes of μ/n-HA were characterized by IR, XRD, SEM, TEM and co-cultured with rBMSCs. It was shown that rBMSCs expressed higher levels of osteoblast-related markers by n-HA than μ-HA stimulation. The size of HA is an important factor for affecting the osteogenic differentiation of rBMSCs. This provides a new avenue for mechanistic studies of stem cell differentiation and a new approach to obtain more committed differentiated cells.

  15. Semi-solid high pressure die casting of metal matrix composites produced by liquid state processing

    CSIR Research Space (South Africa)

    Ivanchev, L

    2012-10-01

    Full Text Available stirring. The composite was then transferred to a High Pressure Die Casting (HPDC) machine in the semi-solid state. The micron size particles were found to be predominantly in the intergranular eutectic while the nano-particles were predominantly...

  16. Preparation and characterization of nano fluids: Influence of variables on its stability, agglomeration state and physical properties

    International Nuclear Information System (INIS)

    Mondragon, R.; Julia, J. E.; Barba, A.; Jarque, J. C.

    2014-01-01

    In recent years it has spread the use of suspensions containing nano metre sized particles, known as nano fluids, in many applications owing the good properties having nanocrystalline materials. One of the main advantages of using nano fluids is its high stability, which causes the particles do not settle over long periods of time. This stability depends on the preparation conditions such as pH, the presence of electrolytes or the solids content. Moreover, there are a number of physical properties which are influenced and altered by agglomeration of the particles. This article will analyze all the variables that affect agglomeration of the particles, nano fluids stability and properties from which it can obtain information on the state of suspension. It then lays out the different methods of dispersion of nanoparticles and their effectiveness. (Author)

  17. Role of specimen size upon the measured toughness of cellular solids

    International Nuclear Information System (INIS)

    Christodoulou, I; Tan, P J

    2013-01-01

    It is well known that the mechanical properties of cellular solids depend critically upon the specimen size and that a 'sufficiently' large test specimen is needed to obtain representative bulk values. Notwithstanding, the fracture toughness of cellular solids is still measured experimentally based on standards, such as the ASTM E399 and E813, developed for solid materials that do not possess an intermediate, 'cell-level' length scale. Experimental data in the literature appears to show that the toughness of stochastic 3D foams is, also, size-dependent. This paper presents the results of a detailed finite element (FE) study that will quantify, and identify the physical origin of, the size-dependent effect. Three-point bending of a single-edge notched (or SEN(B)) specimen, with a 2D Voronoi micro-architecture, is modelled numerically to obtain estimates of fracture toughness which are compared to those obtained with a 'boundary-layer' analysis

  18. Hybrid composites of nano-sized zero valent iron and covalent organic polymers for groundwater contaminant degradation

    DEFF Research Database (Denmark)

    Mines, Paul D.; Byun, J.; Hwang, Yuhoon

    Zero valent iron is commonly used in a variety of treatment technologies (e.g. permeable reactive barriers), though recently a heavier focus has been placed on nano-sized zero valent iron (nZVI). Having superior reductive properties and large surface areas, nZVI is ideal for the degradation of ch...

  19. In tube-solid phase microextraction-nano liquid chromatography: Application to the determination of intact and degraded polar triazines in waters and recovered struvite.

    Science.gov (United States)

    Serra-Mora, P; Jornet-Martinez, N; Moliner-Martinez, Y; Campíns-Falcó, P

    2017-09-01

    In-tube solid-phase microextraction (IT-SPME) coupled to miniaturized liquid chromatography (LC) techniques are attractive mainly due to the column efficiency improvement, sensitivity enhancement and reduction of solvent consumption. In addition, the nanomaterials based sorbents can play a key role in the improvement of the extraction efficiency taking into account their interesting physical and chemical properties. Thus, in this work the performance of IT-SPME coupled to nano LC (NanoLC) has been compared with the performance of IT-SPME coupled to capillary LC (CapLC) with similar configurations for the determination of polar triazines including their degradation products. In both cases, a DAD detector was used. Different extractive phases such as TRB-5, TRB-5/c-SWNTs, TRB-5/c-MWNTs capillary columns have been tested. The dimensions of the capillary columns were 0.32mm id×40cm length and 0.1 or 0.075mm i.d.×15cm length for the couplings with CapLC and NanoLC, respectively. The processed volume was 4mL for CapLC and 0.5mL for NanoLC. The elution was carried out with ACN:H 2 O (30:70, v/v). IT-SPME-NanoLC has shown a higher performance than IT-SPME-CapLC for the target analytes demonstrating the enhancement of the extraction efficiency with the former configuration. A new phase TEOS-MTEOS-SiO 2 NPs has been also proposed for IT-SPME-NanoLC, which improves the retention of polar compounds. Compared with previously published works, improved LODs were achieved (0.025-0.5μgL -1 ). The practical application of the proposed procedure has been demonstrated for the analysis of water samples and recovered struvite samples from wastewater treatment plants. Therefore, the proposed procedure can be an alternative method for regulatory purposes. Copyright © 2017 Elsevier B.V. All rights reserved.

  20. Wetting kinetics of water nano-droplet containing non-surfactant nanoparticles: A molecular dynamics study

    International Nuclear Information System (INIS)

    Lu, Gui; Hu, Han; Sun, Ying; Duan, Yuanyuan

    2013-01-01

    In this Letter, dynamic wetting of water nano-droplets containing non-surfactant gold nanoparticles on a gold substrate is examined via molecular dynamics simulations. The results show that the addition of non-surfactant nanoparticles hinders the nano-second droplet wetting process, attributed to the increases in both surface tension of the nanofluid and friction between nanofluid and substrate. The droplet wetting kinetics decreases with increasing nanoparticle loading and water-particle interaction energy. The observed wetting suppression and the absence of nanoparticle ordering near the contact line of nano-sized droplets differ from the wetting behaviors reported from nanofluid droplets of micron size or larger

  1. Influence of Poly (Ethylene Glycol) and Oleylamine on the Formation of Nano to Micron Size Spherical SiO2 Particles

    Science.gov (United States)

    We report an eco-friendly synthesis of well–controlled, nano-to-micron-size, spherical SiO2 particles using non-hazardous solvent and a byproducts-producing system. It was found that the morphology and size of spherical SiO2 particles are controlled by adjusting the concentration...

  2. Size effect on magnetic properties of a nano-graphene bilayer structure: A Monte Carlo study

    Energy Technology Data Exchange (ETDEWEB)

    Masrour, R. [Laboratory of Materials, Process, Environment and Quality, Cady Ayyad University, National School of Applied Sciences, Safi (Morocco); Laboratoire de Magnetisme et Physique des Hautes Energies L.M.P.H.E.URAC 12, Universite Mohammed V-Agdal, Faculte des Sciences, B.P. 1014 Rabat (Morocco); Bahmad, L., E-mail: bahmad@fsr.ac.ma [Laboratoire de Magnetisme et Physique des Hautes Energies L.M.P.H.E.URAC 12, Universite Mohammed V-Agdal, Faculte des Sciences, B.P. 1014 Rabat (Morocco); Benyoussef, A. [Laboratoire de Magnetisme et Physique des Hautes Energies L.M.P.H.E.URAC 12, Universite Mohammed V-Agdal, Faculte des Sciences, B.P. 1014 Rabat (Morocco)

    2012-11-15

    In this paper we use the Monte Carlo simulations to investigate the magnetic properties of an Ising ferromagnetic-antiferromagnetic model. The system is based on a nano-graphene structure-like bilayer with two bloc sizes: N=24 and 42 spins. For each size N, the upper layer A is formed with spin -3/2, whereas the lower layer B is composed of spin -5/2. We only consider the first nearest-neighbor interactions between the sites i and j. The magnetic properties are studied, in the absence as well as in the presence of a crystal magnetic field, and an external magnetic field. The increasing temperature and crystal field as well as the inter-layer coupling constant, are also studied for this system sizes N=24 and 42 spins. The zero-field-cooled and the field cooled magnetization behaviors are investigated for different values of external magnetic field and a fixed value of exchange interaction between the two blocs. The magnetizations as well as the magnetic susceptibilities versus the temperature are used in order to obtain blocking temperature. The saturation magnetization and coercive field are also obtained for the two sizes of the studied system. It is found that the blocking temperature decreases on increasing the crystal magnetic field and/or the external magnetic field, for a fixed system size. On the other hand, it is found that the blocking temperature increases on increasing the system size from N=24 to 42 spins, for fixed values of external and the crystal magnetic fields. - Highlights: Black-Right-Pointing-Pointer Magnetic properties of an Ising ferromagnetic-antiferromagnetic bilayer is studied. Black-Right-Pointing-Pointer Monte Carlo simulations are used. Black-Right-Pointing-Pointer Zero-field-cooled (ZFC) and field cooled (FC) magnetization behaviors for nano-graphene are obtained.

  3. Nano- and microparticles and associated pollutants in stormwater runoff: effects of disc filtration with and without flocculant addition

    DEFF Research Database (Denmark)

    Nielsen, Katrine; Mørch-Madsen, Andreas; Mikkelsen, Peter Steen

    2014-01-01

    Danish municipalities work towards separating stormwater and sewage. But stormwater runoff may be heavily polluted and therefore it is needed to find Best Available Technologies (BAT) to source separate and treat stormwater before discharge into surface waters. The aim here was to determine...... for treating stormwater runoff. The micro-sized particles were found to be mainly 2.1-19 μm in diameter and nano-sized particles were also observed (86-228 nm). Although the flocculant increased the observed volume of the micro-sized particles by 46%, the majority of the particles where still

  4. Stress development in particulate, nano-composite and polymeric coatings

    Science.gov (United States)

    Jindal, Karan

    2009-12-01

    The main goal of this research is to study the stress, structural and mechanical property development during the drying of particulate coatings, nano-composite coatings and VOC compliant refinish clearcoats. The results obtained during this research establish the mechanism for the stress development during drying in various coating systems. Coating stress was measured using a controlled environment stress apparatus based on cantilever deflection principle. The stress evolution in alumina coatings made of 0.4 mum size alumina particles was studied and the effect of a lateral drying was investigated. The stress does not develop until the later stages of drying. A peak stress was observed during drying and the peak stress originates due to the formation of pendular rings between the particles. Silica nanocomposite coatings were fabricated from suspension of nano sized silicon dioxide particles (20 nm) and polyvinyl alcohol (PVA) polymer. The stress in silica nano-composite goes through maximum as the amount of polymer in the coating increases. The highest final stress was found to be ˜ 110MPa at a PVA content of 60 wt%. Observations from SEM, nitrogen gas adsorption, camera imaging, and nano-indentation were also studied to correlate the coatings properties during drying to measured stress. A model VOC compliant two component (2K) acrylic-polyol refinish clearcoat was prepared to study the effects of a new additive on drying, curing, rheology and stress development at room temperature. Most of the drying of the low VOC coatings occurred before appreciable (20%) crosslinking. Tensile stress developed in the same timeframe as drying and then relaxed over a longer time scale. Model low VOC coatings prepared with the additive had higher peak stresses than those without the additive. In addition, rheological data showed that the additive resulted in greater viscosity buildup during drying.

  5. Alternative chemical-based synthesis routes and characterization of nano-scale particles

    International Nuclear Information System (INIS)

    Brocchi, E.A.; Motta, M.S.; Solorzano, I.G.; Jena, P.K.; Moura, F.J.

    2004-01-01

    Different nano-scale particles have been synthesized by alternative routes: nitrates dehydratation and oxide, or co-formed oxides, reduction by hydrogen. Chemical-based synthesis routes are described and thermodynamics studies and kinetics data are presented to support the feasibility for obtaining single-phase oxides and co-formed two-phase oxides. In addition, the reduction reaction has been applied to successfully produce metal/ceramic nanocomposites. Structural characterization has been carried out by means of X-ray diffraction and, more extensively, transmission electron microscopy operating in conventional diffraction contrast mode (CTEM) and high-resolution mode (HRTEM). Nano-scale size distribution of oxide particles is well demonstrated together with their defect-free structure in the lower range, around 20 nm, size. Structural features related to the synthesized nano-composites are also presented

  6. Nano/micro particle beam for ceramic deposition and mechanical etching

    International Nuclear Information System (INIS)

    Chun, Doo-Man; Kim, Min-Saeng; Kim, Min-Hyeng; Ahn, Sung-Hoon; Yeo, Jun-Cheol; Lee, Caroline Sunyong

    2010-01-01

    Nano/micro particle beam (NPB) is a newly developed ceramic deposition and mechanical etching process. Additive (deposition) and subtractive (mechanical etching) processes can be realized in one manufacturing process using ceramic nano/micro particles. Nano- or micro-sized powders are sprayed through the supersonic nozzle at room temperature and low vacuum conditions. According to the process conditions, the ceramic powder can be deposited on metal substrates without thermal damage, and mechanical etching can be conducted in the same process with a simple change of process conditions and powders. In the present work, ceramic aluminum oxide (Al 2 O 3 ) thin films were deposited on metal substrates. In addition, the glass substrate was etched using a mask to make small channels. Deposited and mechanically etched surface morphology, coating thickness and channel depth were investigated. The test results showed that the NPB provides a feasible additive and subtractive process using ceramic powders.

  7. Characterization of coke deposited on nano-sized Pt-Pd/H-beta spent during long-chain paraffin hydroisomerization

    Energy Technology Data Exchange (ETDEWEB)

    Bauer, F.; Einicke, W.D.; Ficht, K.; Glaeser, R. [Leipzig Univ. (Germany). Inst. of Chemical Technology; Bertmer, M. [Leipzig Univ. (Germany). Inst. of Experimental Physics II; Kuchling, T. [Technische Univ. Bergakademie Freiberg (Germany). Inst. of Energy Process Engineering and Chemical Engineering

    2013-11-01

    The hydroisomerization of long-chain n-paraffins were studied in the temperature range 205- 230 C at p{sub H2}=50 bar using a bench scale trickle-bed continuous-flow reactor. The bimetallic catalysts consisted of mixtures of platinum and palladium supported on commercially available nano-sized zeolites Beta (n{sub Si}/n{sub Al} = 12 and 25) extruded with a binder ({gamma}-alumina). For hexadecane conversion, high yields to isomers (25 and 45 wt.% of mono- and multibranched isomers, respectively) without extensive cracking (>10 wt.%) were obtained at a conversion of 80 %. Long-term tests with C{sub 16}H{sub 34} and blends of solid n-paraffins for 30-60 days on stream clearly indicate that a minor loss in catalyst activity can easily be compensated by increasing the reaction temperature from 230 C to 235 C. The zeolite sample with a 'mild acidity' revealed low hydrocracking at isomerization yield up to 70 wt.% and high stability. Carbonaceous deposits formed during n-paraffin hydroisomerization were investigated by temperature-programmed oxidation, elemental analysis, ATR-FTIR and {sup 13}C MAS NMR spectroscopy showing the formation of low-temperature, hydrogen-rich coke. (orig.)

  8. Effect of nano-sized, elemental selenium supplement on the proteome of chicken liver.

    Science.gov (United States)

    Gulyas, G; Csosz, E; Prokisch, J; Javor, A; Mezes, M; Erdelyi, M; Balogh, K; Janaky, T; Szabo, Z; Simon, A; Czegledi, L

    2017-06-01

    The nano-sized (100-500 nm) selenium has higher bioavailability and relatively lower toxicity compared to other selenium forms. The objective of the present study was to compare liver proteome profiles of broiler chicken fed with control diet without Se supplementation and diet supplemented with nano-Se with 4.25 mg/kg DM. Differential proteome analyses were performed by two-dimensional gel electrophoresis (2D-PAGE) followed by tryptic digestion and protein identification by liquid chromatography-mass spectrometry (LC-MS). Seven hundred and eight spots were detected, and 18 protein spots showed significant difference in their intensity (p selenium supplementation induced a dietary stress. Selenium supplementation may influence the metabolism of fatty acids and carbohydrates and antioxidant system, and increase the quantity of cytoskeletal actin and the expression of actin regulatory protein as well. Journal of Animal Physiology and Animal Nutrition © 2016 Blackwell Verlag GmbH.

  9. Conductivity of laser printed copper structures limited by nano-crystal grain size and amorphous metal droplet shell

    International Nuclear Information System (INIS)

    Winter, Shoshana; Zenou, Michael; Kotler, Zvi

    2016-01-01

    We present a study of the morphology and electrical properties of copper structures which are printed by laser induced forward transfer from bulk copper. The percentage of voids and the oxidation levels are too low to account for the high resistivities (∼4 to 14 times the resistivity of bulk monocrystalline copper) of these structures. Transmission electron microscope (TEM) images of slices cut from the printed areas using a focused ion beam (FIB) show nano-sized crystal structures with grain sizes that are smaller than the electron free path length. Scattering from such grain boundaries causes a significant increase in the resistivity and can explain the measured resistivities of the structures. The TEM images also show a nano-amorphous layer (∼5 nm) at the droplet boundaries which also contributes to the overall resistivity. Such morphological characteristics are best explained by the ultrafast cooling rate of the molten copper droplets during printing. (paper)

  10. Characterization of the molecular distribution of drugs in glassy solid dispersions at the nano-meter scale, using differential scanning calorimetry and gravimetric water vapour sorption techniques.

    Science.gov (United States)

    van Drooge, D J; Hinrichs, W L J; Visser, M R; Frijlink, H W

    2006-03-09

    The molecular distribution in fully amorphous solid dispersions consisting of poly(vinylpyrrolidone) (PVP)-diazepam and inulin-diazepam was studied. One glass transition temperature (T(g)), as determined by temperature modulated differential scanning calorimetry (TMDSC), was observed in PVP-diazepam solid dispersions prepared by fusion for all drug loads tested (10-80 wt.%). The T(g) of these solid dispersions gradually changed with composition and decreased from 177 degrees C for pure PVP to 46 degrees C for diazepam. These observations indicate that diazepam was dispersed in PVP on a molecular level. However, in PVP-diazepam solid dispersions prepared by freeze drying, two T(g)'s were observed for drug loads above 35 wt.% indicating phase separation. One T(g) indicated the presence of amorphous diazepam clusters, the other T(g) was attributed to a PVP-rich phase in which diazepam was dispersed on a molecular level. With both the value of the latter T(g) and the DeltaC(p) of the diazepam glass transition the concentrations of molecular dispersed diazepam could be calculated (27-35 wt.%). Both methods gave similar results. Water vapour sorption (DVS) experiments revealed that the PVP-matrix was hydrophobised by the incorporated diazepam. TMDSC and DVS results were used to estimate the size of diazepam clusters in freeze dried PVP-diazepam solid dispersions, which appeared to be in the nano-meter range. The inulin-diazepam solid dispersions prepared by spray freeze drying showed one T(g) for drug loads up to 35 wt.% indicating homogeneous distribution on a molecular level. However, this T(g) was independent of the drug load, which is unexpected because diazepam has a lower T(g) than inulin (46 and 155 degrees C, respectively). For higher drug loads, a T(g) of diazepam as well as a T(g) of the inulin-rich phase was observed, indicating the formation of amorphous diazepam clusters. From the DeltaC(p) of the diazepam glass transition the amount of molecularly dispersed

  11. How fast are the ultra-fast nano-scale solid-liquid phase transitions induced by energetic particles in solids?

    International Nuclear Information System (INIS)

    Lopasso, E.M.; Caro, A.; Caro, M.

    2003-01-01

    We study the thermodynamic forces acting on the evolution of the nanoscale regions excited by collisions of energetic particles into solid targets. We analyze the role of diffusion, thermo-migration, and the liquidus-solidus two-phase field crossing, as the system cools down from the collision-induced melt under different conditions of energy deposition. To determine the relevance of these thermodynamic forces, solute redistribution is evaluated using molecular dynamics simulations of equilibrium Au-Ni solid solutions. At low collision energies, our results show that the quenching of spherical cascades is too fast to allow for solute redistribution according to equilibrium solidification as determined from the equilibrium phase diagram (zone refining effect), and only thermo-migration is observed. At higher energies instead, in the cylindrical symmetry of ion tracks, quenching rate is in a range that shows the combined effects of thermo-migration and solute redistribution that, depending on the material, can reinforce or cancel each other. These results are relevant for the interpretation of the early stage of radiation damage in alloys, and show that the combination of ultra-fast but nano-scale characteristics of these processes can still be described in terms of linear response of the perturbed system

  12. Photocatalytic Degradation of Malachite Green Using Nano-sized cerium-iron Oxide

    Directory of Open Access Journals (Sweden)

    K. L. Ameta

    2014-05-01

    Full Text Available Nano-sized cerium-iron oxide nanoparticles has been synthesized, characterized and explored as an efficient photocatalyst for the photocatalytic degradation of malachite green. The effects of different variables on degradation of dye were optimized such as the pH of the dye solution, dye concentration, amount of photocatalyst and light intensity. About 91% degradation of dye of 2×10-5 M concentration was observed after 2 hours at 8.5 pH and 600 Wm-2 light intensity. The reason for the high catalytic activity of the synthesized nanoparticles is ascribed to the high surface area which determines the active sites of the catalyst and accelerates the photocatalytic degradation.

  13. Nano and micro U1-xThxO2 solid solutions: From powders to pellets

    Science.gov (United States)

    Balice, Luca; Bouëxière, Daniel; Cologna, Marco; Cambriani, Andrea; Vigier, Jean-François; De Bona, Emanuele; Sorarù, Gian Domenico; Kübel, Christian; Walter, Olaf; Popa, Karin

    2018-01-01

    Nuclear fuels production, structural materials, separation techniques, and waste management, all may benefit from an extensive knowledge in the nano-nuclear technology. In this line, we present here the production of U1-xThxO2 (x = 0 to 1) mixed oxides nanocrystals (NC's) through the hydrothermal decomposition of the oxalates in hot compressed water at 250 °C. Particles of spherical shape and size of about 5.5-6 nm are obtained during the hydrothermal decomposition process. The powdery nanocrystalline products were consolidated by spark plasma sintering into homogeneous mixed oxides pellets with grain sizes in the 0.4 to 5.5 μm range. Grain growth and mechanical properties were studied as a function of composition and size. No grain size effect was observed on the hardness or elastic modulus.

  14. Agglomerated polymer monoliths with bimetallic nano-particles as flow-through micro-reactors

    International Nuclear Information System (INIS)

    Floris, P.; Twamley, B.; Nesterenko, P.N.; Paull, B.; Connolly, D.

    2012-01-01

    Polymer monoliths in capillary format have been prepared as solid supports for the immobilisation of platinum/palladium bimetallic nano-flowers. Optimum surface coverage of nano-flowers was realised by photografting the monoliths with vinyl azlactone followed by amination with ethylenediamine prior to nano-particle immobilisation. Field emission SEM imaging was used as a characterisation tool for evaluating nano-particle coverage, together with BET surface area analysis to probe the effect of nano-particle immobilisation upon monolith morphology. Ion exchange chromatography was also used to confirm the nature of the covalent attachment of nano-flowers on the monolithic surface. In addition, EDX and ICP analyses were used to quantify platinum and palladium on modified polymer monoliths. Finally the catalytic properties of immobilised bimetallic Pd/Pt nano-flowers were evaluated in flow-through mode, exploiting the porous interconnected flow-paths present in the prepared monoliths (pore diameter ∼ 1-2 μm). Specifically, the reduction of Fe (III) to Fe (II) and the oxidation of NADH to NAD+ were selected as model redox reactions. The use of a porous polymer monolith as an immobilisation substrate (rather than aminated micro-spheres) eliminated the need for a centrifugation step after the reaction. (author)

  15. Ductility Enhancement of Molybdenum Phase by Nano-sized Oxide Dispersions

    Energy Technology Data Exchange (ETDEWEB)

    Kang, Bruce

    2008-07-18

    The objective of this research is to understand and to remedy the impurity effects for room-temperature ductility enhancement of molybdenum (Mo) based alloys by the inclusion of nano-sized metal oxide dispersions. This research combines theoretical, computational, and experimental efforts. The results will help to formulate systematic strategies in searching for better composed Mo-based alloys with optimal mechanical properties. For this project, majority of the research effort was directed to atomistic modeling to identify the mechanisms responsible for the oxygen embrittling and ductility enhancement based on fundamental electronic structure analysis. Through first principles molecular dynamics simulations, it was found that the embrittling impurity species were attracted to the metal oxide interface, consistent with previous experiments. Further investigation on the electronic structures reveals that the presence of embrittling species degrades the quality of the metallic chemical bonds in the hosting matrix in a number of ways, the latter providing the source of ductility. For example, the spatial flexibility of the bonds is reduced, and localization of the impurity states occurs to pin the dislocation flow. Rice’s criterion has been invoked to explain the connections of electronic structure and mechanical properties. It was also found that when impurity species become attracted to the metal oxide interface, some of the detrimental effects are alleviated, thus explaining the observed ductility enhancement effects. These understandings help to develop predictive capabilities to facilitate the design and optimization of Mo and other high temperature alloys (e.g. ODS alloys) for fossil energy materials applications. Based on the theoretical and computational studies, the experimental work includes the preparation of Mo powders mixed with candidate nano-sized metal oxides, which were then vacuum hot-pressed to make the Mo alloys. Several powder mixing methods

  16. Characterization and Growth Mechanism of Nickel Nano wires Resulting from Reduction of Nickel Formate in Polyol Medium

    International Nuclear Information System (INIS)

    Logutenko, O.A.; Titkov, A.I.; Vorobyov, A.M.; Yukhin, Y.M.; Lyakhov, N.Z.

    2016-01-01

    Nickel linear nano structures were synthesized by reduction of nickel formate with hydrazine hydrate in ethylene glycol medium in the absence of any surfactants or capping agents for direction of the particles growth. The effect of the synthesis conditions such as temperature, reduction time, type of polyol, and nickel formate concentration on the reduction products was studied. The size and morphology of the nickel nano wires were characterized by X-ray diffraction, scanning, and transmission electron microscopy. It was shown that the nickel nano crystallites were wire-shaped with a face-center-cubic phase. Ethylene glycol was found to play a crucial role in the formation of the nickel nano wires. The possible growth processes of the wire-shaped particles taking place at 110 and 130 degree are discussed. It was shown that, under certain synthesis conditions, nickel nano wires grow on the surface of the crystals of the solid intermediate of nickel with hydrazine hydrate.

  17. Note: Experimental observation of nano-channel pattern in light sheet laser interference nanolithography system

    Energy Technology Data Exchange (ETDEWEB)

    Mohan, Kavya; Mondal, Partha Pratim, E-mail: partha@iap.iisc.ernet.in [Nanobioimaging Laboratory, Department of Instrumentation and Applied Physics, Indian Institute of Science, Bangalore 560012 (India)

    2016-06-15

    We experimentally observed nano-channel-like pattern in a light-sheet based interference nanolithography system. The optical system created nano-channel-like patterned illumination. Coherent counter-propagating light sheets are made to interfere at and near geometrical focus along the propagation z-axis. This results in the formation of nano-channel-like pattern (of size ≈ 300 nm and inter-channel periodicity of ≈337.5 nm) inside the sample due to constructive and destructive interference. In addition, the technique has the ability to generate large area patterning using larger light-sheets. Exciting applications are in the broad field of nanotechnology (nano-electronics and nano-fluidics).

  18. Assessment of Nano Cellulose from Peach Palm Residue as Potential Food Additive: Part II: Preliminary Studies.

    Science.gov (United States)

    Andrade, Dayanne Regina Mendes; Mendonça, Márcia Helena; Helm, Cristiane Vieira; Magalhães, Washington L E; de Muniz, Graciela Ines Bonzon; Kestur, Satyanarayana G

    2015-09-01

    High consumption of dietary fibers in the diet is related to the reduction of the risk of non-transmitting of chronic diseases, prevention of the constipation etc. Rich diets in dietary fibers promote beneficial effects for the metabolism. Considering the above and recognizing the multifaceted advantages of nano materials, there have been many attempts in recent times to use the nano materials in the food sector including as food additive. However, whenever new product for human and animal consumption is developed, it has to be tested for their effectiveness regarding improvement in the health of consumers, safety aspects and side effects. However, before it is tried with human beings, normally such materials would be assessed through biological tests on a living organism to understand its effect on health condition of the consumer. Accordingly, based on the authors' finding reported in a previous paper, this paper presents body weight, biochemical (glucose, cholesterol and lipid profile in blood, analysis of feces) and histological tests carried out with biomass based cellulose nano fibrils prepared by the authors for its possible use as food additive. Preliminary results of the study with mice have clearly brought out potential of these fibers for the said purpose.

  19. Research of lignite oxidation kinetic parameters modified by CuSO4 and NaNO3 initiation additives

    Directory of Open Access Journals (Sweden)

    Larionov Kirill

    2017-01-01

    Full Text Available An experimental study and subsequent analytical assessment of activation energy change in lignite oxidation process with addition of NaNO3 and CuSO4 mineral salts were conducted. The results showed that injection of catalytic additives leads to reduction of coal activation energy and reaction initial temperature.

  20. Preliminary assessment of water-based nano-fluids for use as coolants in PWRs

    International Nuclear Information System (INIS)

    Jacopo Buongiorno

    2005-01-01

    Full text of publication follows: The impact of using water-based fluids with small additions (<2% vol.) of nano-sized (10-100 nm) particle populations as coolants for current and advanced PWRs is evaluated. Such 'engineered' fluids (known as nano-fluids) are attractive because the presence of the nano-particles enhances energy transport considerably. As a result, nano-fluids are known to have (i) higher thermal conductivity than water (up to 20% depending on nano-particle material, size and volumetric fraction), (ii) higher heat transfer coefficients (up to 40%), (iii) higher CHF (up to 300% in pool boiling), and (iv) comparable pressure drop. Furthermore, nano-fluids appear to be very stable suspensions with little or no sedimentation, because of the small size of the dispersed particles and their typically low volumetric fractions. The ultimate objective of this work is to assess whether existing PWRs could be retro-fitted with a water-based nano-fluid coolant, to increase safety margins, reduce stored energy, and/or allow for power up-rates. Also, advanced PWRs could be designed with nano-fluids. The linear heat generation rate in PWRs is limited by a) fuel centerline melting, b) cladding overheating (CHF), and c) stored energy release following a large-break LOCA. Mechanisms b) and c) are usually the most limiting. For given geometry and linear power, it is obvious that the core with the nano-fluid coolant will have higher margins to CHF and LOCA limits. Conversely, for given margins, a higher linear power can be accommodated by the nano-fluid-cooled core. Standard thermal-hydraulic models for the PWR hot fuel pin (including a RELAP model for the LOCA) have been used to quantify the benefit of using nano-fluid coolants on the performance of a PWR. (author)

  1. Properties of copper matrix reinforced with nano- and micro-sized Al2O3 particles

    International Nuclear Information System (INIS)

    Rajkovic, Viseslava; Bozic, Dusan; Jovanovic, Milan T.

    2008-01-01

    The mixture of electrolytic copper powder with 5 wt.% of commercial Al 2 O 3 powder (average particle size: 15 and 0.75 μm, respectively) and the inert gas atomized prealloyed copper powder (average particle size: 30 μm) containing 2.5 wt.% aluminum were separately milled in air up to 20 h in the planetary ball mill. During milling aluminum in the prealloyed copper powders was oxidized in situ by internal oxidation with oxygen from the air forming very fine nano-sized Al 2 O 3 particles. The internal oxidation of 2.5 wt.% aluminum generated 4.7 wt.% of Al 2 O 3 in the copper matrix. Powders and compacts were characterized by light and scanning electron microscopy (SEM), electron probe microanalysis (EPMA) and X-ray diffraction analysis. Microhardness and electrical conductivity were also included in measurements. The microhardness of Cu-2.5 wt.% Al compacts was 3.6 times higher than that of compacts processed from electrolytic copper powder. This increase in microhardness is a consequence of a fine dispersion of Al 2 O 3 particles and refined grain structure. The average values of electrical conductivity of compacts processed from Cu-5 wt.% Al 2 O 3 and Cu-2.5 wt.% Al powders previously milled for 20 h and were 88% and 70% IACS, respectively, which is a rather significant increase if compared with values of 60% and 23% IACS of compacts processed from as-received and non-milled powders. The microhardness of 20-h milled compacts decreases with the heat treatment at 800 deg. C. Due to the effect of nano-sized Al 2 O 3 particles Cu-2.5 wt.% Al compacts show lower decrease in microhardness. The results are discussed in terms of the effect of Al 2 O 3 particle size and fine grain structure on the reinforcing of the copper matrix

  2. Sintering of nano crystalline α silicon carbide by doping with boron ...

    Indian Academy of Sciences (India)

    Sinterable nano silicon carbide powders of mean particle size (37 nm) were prepared by attrition milling and chemical processing of an acheson type alpha silicon carbide having mean particle size of 0.39 m (390 nm). Pressureless sintering of these powders was achieved by addition of boron carbide of 0.5 wt% together ...

  3. Investigation of effective parameters in preparation and controlling lithium fluoride nano size powder

    International Nuclear Information System (INIS)

    Naderi, S.; Sarraf Mamoory, F.; Riahi Noori, N.

    2007-01-01

    In this research, the reaction of LiOH + HF+LiF+H 2 O has been selected and some precipitation parameters such as pH, temperature, time, super saturation, q d agitation type have been studied, and controlled. The morphology, phase analysis and particle size of the resulting powders were analyzed by SEM, XRD and LPSA. Finally, at temperature 2S d ig C , pH of about 2-3, reaction time less than 1 sec, and agitation by ultrasonic bath, the pure nano lithium fluoride powders of about 100 nm were produced

  4. Fabrication and Characterization of Polymeric Hollow Fiber Membranes with Nano-scale Pore Sizes

    International Nuclear Information System (INIS)

    Amir Mansourizadeh; Ahmad Fauzi Ismail

    2011-01-01

    Porous polyvinylidene fluoride (PVDF) and polysulfide (PSF) hollow fiber membranes were fabricated via a wet spinning method. The membranes were characterized in terms of gas permeability, wetting pressure, overall porosity and water contact angle. The morphology of the membranes was examined by FESEM. From gas permeation test, mean pore sizes of 7.3 and 9.6 nm were obtained for PSF and PVDF membrane, respectively. Using low polymer concentration in the dopes, the membranes demonstrated a relatively high overall porosity of 77 %. From FESEM examination, the PSF membrane presented a denser outer skin layer, which resulted in significantly lower N 2 permeance. Therefore, due to the high hydrophobicity and nano-scale pore sizes of the PVDF membrane, a good wetting pressure of 4.5x10 -5 Pa was achieved. (author)

  5. Characterisation of nano- and micron-sized airborne and collected subway particles, a multi-analytical approach.

    Science.gov (United States)

    Midander, Klara; Elihn, Karine; Wallén, Anna; Belova, Lyuba; Karlsson, Anna-Karin Borg; Wallinder, Inger Odnevall

    2012-06-15

    Continuous daily measurements of airborne particles were conducted during specific periods at an underground platform within the subway system of the city center of Stockholm, Sweden. Main emphasis was placed on number concentration, particle size distribution, soot content (analyzed as elemental and black carbon) and surface area concentration. Conventional measurements of mass concentrations were conducted in parallel as well as analysis of particle morphology, bulk- and surface composition. In addition, the presence of volatile and semi volatile organic compounds within freshly collected particle fractions of PM(10) and PM(2.5) were investigated and grouped according to functional groups. Similar periodic measurements were conducted at street level for comparison. The investigation clearly demonstrates a large dominance in number concentration of airborne nano-sized particles compared to coarse particles in the subway. Out of a mean particle number concentration of 12000 particles/cm(3) (7500 to 20000 particles/cm(3)), only 190 particles/cm(3) were larger than 250 nm. Soot particles from diesel exhaust, and metal-containing particles, primarily iron, were observed in the subway aerosol. Unique measurements on freshly collected subway particle size fractions of PM(10) and PM(2.5) identified several volatile and semi-volatile organic compounds, the presence of carcinogenic aromatic compounds and traces of flame retardants. This interdisciplinary and multi-analytical investigation aims to provide an improved understanding of reported adverse health effects induced by subway aerosols. Copyright © 2012 Elsevier B.V. All rights reserved.

  6. Ignition dynamics and activation energies of metallic thermites: From nano- to micron-scale particulate composites

    Science.gov (United States)

    Hunt, Emily M.; Pantoya, Michelle L.

    2005-08-01

    Ignition behaviors associated with nano- and micron-scale particulate composite thermites were studied experimentally and modeled theoretically. The experimental analysis utilized a CO2 laser ignition apparatus to ignite the front surface of compacted nickel (Ni) and aluminum (Al) pellets at varying heating rates. Ignition delay time and ignition temperature as a function of both Ni and Al particle size were measured using high-speed imaging and microthermocouples. The apparent activation energy was determined from this data using a Kissinger isoconversion method. This study shows that the activation energy is significantly lower for nano- compared with micron-scale particulate media (i.e., as low as 17.4 compared with 162.5kJ /mol, respectively). Two separate Arrhenius-type mathematical models were developed that describe ignition in the nano- and the micron-composite thermites. The micron-composite model is based on a heat balance while the nanocomposite model incorporates the energy of phase transformation in the alumina shell theorized to be an initiating step in the solid-solid diffusion reaction and uniquely appreciable in nanoparticle media. These models were found to describe the ignition of the Ni /Al alloy for a wide range of heating rates.

  7. Effect of addition of Ag nano powder on mechanical properties of epoxy/polyaminoamide adduct coatings filled with conducting polymer

    Energy Technology Data Exchange (ETDEWEB)

    Samad, Ubair Abdus [Department of Chemical Engineering, College of Engineering, King Saud University, P. O. Box 800, Riyadh 11421 (Saudi Arabia); Center of excellence for research in engineering materials (CEREM), Advance Manufacturing Institute, King Saud University, P. O. Box 800, Riyadh 11421 (Saudi Arabia); Khan, Rawaiz [Department of Chemical Engineering, College of Engineering, King Saud University, P. O. Box 800, Riyadh 11421 (Saudi Arabia); Alam, Mohammad Asif [Center of excellence for research in engineering materials (CEREM), Advance Manufacturing Institute, King Saud University, P. O. Box 800, Riyadh 11421 (Saudi Arabia); Al-Othman, Othman Y. [Department of Chemical Engineering, College of Engineering, King Saud University, P. O. Box 800, Riyadh 11421 (Saudi Arabia); Deanship of Graduate Studies, The Saudi Electric University, P. O. Box 93499, Riyadh 11673 (Saudi Arabia); Al-Zahrani, Saeed M. [Center of excellence for research in engineering materials (CEREM), Advance Manufacturing Institute, King Saud University, P. O. Box 800, Riyadh 11421 (Saudi Arabia); SABIC Polymer Research Center (SPRC) and department of chemical engineering, college of engineering, King Saud University, P. O. Box 800, Riyadh 11421 (Saudi Arabia)

    2015-05-22

    In this study the effect of Ag Nano powder on mechanical properties of epoxy coatings filled with optimized ratio of conducting polymers (Polyaniline and Polyppyrole) was evaluated. Bisphenol A diglycidyl ether epoxy resin (DGEBA) along with polyaminoamide adduct (ARADUR 3282-1 BD) is used as curing agent under optimized stoichiometry values. Curing is performed at room temperature with different percentages of Nano filler. Glass and steel panels were used as coating substrate. Bird applicator was used to coat the samples in order to obtain thin film with wet film thickness (WFT) of about 70-90 µm. The samples were kept in dust free environment for about 7 days at room temperature for complete curing. The coated steel panels were used to evaluate the mechanical properties of coating such as hardness, scratch and impact tests whereas coated glass panels were used for measuring pendulum hardness of the coatings. To check the dispersion and morphology of Nano filler in epoxy matrix scanning electron microscopy (SEM) was used in addition Nano indentation was also performed to observe the effect of Nano filler on modulus of elasticity and hardness at Nano scale.

  8. Effect of addition of Ag nano powder on mechanical properties of epoxy/polyaminoamide adduct coatings filled with conducting polymer

    International Nuclear Information System (INIS)

    Samad, Ubair Abdus; Khan, Rawaiz; Alam, Mohammad Asif; Al-Othman, Othman Y.; Al-Zahrani, Saeed M.

    2015-01-01

    In this study the effect of Ag Nano powder on mechanical properties of epoxy coatings filled with optimized ratio of conducting polymers (Polyaniline and Polyppyrole) was evaluated. Bisphenol A diglycidyl ether epoxy resin (DGEBA) along with polyaminoamide adduct (ARADUR 3282-1 BD) is used as curing agent under optimized stoichiometry values. Curing is performed at room temperature with different percentages of Nano filler. Glass and steel panels were used as coating substrate. Bird applicator was used to coat the samples in order to obtain thin film with wet film thickness (WFT) of about 70-90 µm. The samples were kept in dust free environment for about 7 days at room temperature for complete curing. The coated steel panels were used to evaluate the mechanical properties of coating such as hardness, scratch and impact tests whereas coated glass panels were used for measuring pendulum hardness of the coatings. To check the dispersion and morphology of Nano filler in epoxy matrix scanning electron microscopy (SEM) was used in addition Nano indentation was also performed to observe the effect of Nano filler on modulus of elasticity and hardness at Nano scale

  9. Effect of addition of Ag nano powder on mechanical properties of epoxy/polyaminoamide adduct coatings filled with conducting polymer

    Science.gov (United States)

    Samad, Ubair Abdus; Khan, Rawaiz; Alam, Mohammad Asif; Al-Othman, Othman Y.; Al-Zahrani, Saeed M.

    2015-05-01

    In this study the effect of Ag Nano powder on mechanical properties of epoxy coatings filled with optimized ratio of conducting polymers (Polyaniline and Polyppyrole) was evaluated. Bisphenol A diglycidyl ether epoxy resin (DGEBA) along with polyaminoamide adduct (ARADUR 3282-1 BD) is used as curing agent under optimized stoichiometry values. Curing is performed at room temperature with different percentages of Nano filler. Glass and steel panels were used as coating substrate. Bird applicator was used to coat the samples in order to obtain thin film with wet film thickness (WFT) of about 70-90 µm. The samples were kept in dust free environment for about 7 days at room temperature for complete curing. The coated steel panels were used to evaluate the mechanical properties of coating such as hardness, scratch and impact tests whereas coated glass panels were used for measuring pendulum hardness of the coatings. To check the dispersion and morphology of Nano filler in epoxy matrix scanning electron microscopy (SEM) was used in addition Nano indentation was also performed to observe the effect of Nano filler on modulus of elasticity and hardness at Nano scale.

  10. Hierarchically structured superhydrophobic coatings fabricated by successive Langmuir-Blodgett deposition of micro-/nano-sized particles and surface silanization.

    Science.gov (United States)

    Tsai, Ping-Szu; Yang, Yu-Min; Lee, Yuh-Lang

    2007-11-21

    The present study demonstrates the creation of a stable, superhydrophobic surface by coupling of successive Langmuir-Blodgett (LB) depositions of micro- and nano-sized (1.5 µm/50 nm, 1.0 µm/50 nm, and 0.5 µm/50 nm) silica particles on a glass substrate with the formation of a self-assembled monolayer of dodecyltrichlorosilane on the surface of the particulate film. Particulate films, in which one layer of 50 nm particles was deposited over one to five sublayers of larger micro-sized particles, with hierarchical surface roughness and superhydrophobicity, were successfully fabricated. Furthermore, the present 'two-scale' (micro- and nano-sized particles) approach is superior to the previous 'one-scale' (micro-sized particles) approach in that both higher advancing contact angle and lower contact angle hysteresis can be realized. Experimental results revealed that the superhydrophobicity exhibited by as-fabricated particulate films with different sublayer particle diameters increases in the order of 0.5 µm>1.0 µm>1.5 µm. However, no clear trend between sublayer number and surface superhydrophobicity could be discerned. An explanation of superhydrophobicity based on the surface roughness introduced by two-scale particles is also proposed.

  11. Size-dependent and intra-band photoluminescence of NiS2 nano-alloys synthesized by microwave assisted hydrothermal technique

    CSIR Research Space (South Africa)

    Linganiso, C

    2013-03-01

    Full Text Available Synthesis of nickel disulfide (NiS2) nano-alloys capped and uncapped with hexadecylamine (HDA) was carried out. A cubic phase NiS2 formation was confirmed by X-ray diffraction (XRD) analysis. An average crystallite size of 35 nm was obtained...

  12. Development of plasticised nano-biocomposites of poly(hydroxybutyrate-co-hydroxyvalerate)/montmorillonite organically modified (PHBV/OMMT)

    International Nuclear Information System (INIS)

    Correa, M.C.; Pollet, E.; Averous, L.; Agnell, J.A.M.; Nascente, P.A.P.

    2010-01-01

    Several studies have aimed to improve the properties of biopolymers by the incorporation of nano-sized fillers, such as organo-modified montmorillonite (OMMT), to form nano-biocomposites. The objective of this work is to investigate the influence of acetyl tributyl citrate (ATBC) plasticizer with PHBV/OMMT nano-biocomposites aiming at improving their behavior. The materials PHBV, OMMT (C30B), and ATBC were provided by PHB Industrial S/A (Brazil), Southern Clay Products (USA), and Scandiflex S/A (Brazil), respectively. In this study the processing parameters and the formulations were controlled, pursuing materials with good mechanical and barrier properties with high biodegradability and with greater ease of processing. The analysis of the results obtained by TGA, GPC, WAXS, DSC, mechanical properties, and biodegradability lead to the conclusion that the addition of plasticizer in nanobiocomposites improved processability and did not influence the state of nano-sized load dispersion. It can be concluded that the addition of plasticizer is a good alternative to the processability of nanocomposites of PHAs. (author)

  13. Applications of Nano palm oil fuel ash and Nano fly ash in concrete

    Science.gov (United States)

    Hamada, Hussein M.; Jokhio, Gul Ahmed; Mat Yahaya, Fadzil; Humada, Ali M.

    2018-04-01

    This paper discusses the applications of Nano waste materials including palm oil fuel ash and fly ash in the concrete production. The implementation of nanotechnology has been instrumental in the development of significant interest among the stakeholders to improve the mechanical and chemical properties of materials involved in the production of concrete. Although many researchers have shown the potential of nanomaterials to increase strength and durability of concrete and improve its physical and chemical properties, there is still a knowledge gap regarding the preparation of Nano waste materials from agricultural waste to use as cement replacement instead of non-renewable materials. Therefore, it should be focused on to study Nano- waste materials to benefit from these characteristics during preparation of concrete mixtures. Therefore, this paper highlights the potential of waste materials in the Nano size to partially replace cement in concrete and achieve the same or better result than the traditional concrete. This paper recommends to conduct further experimental works to improve the concrete material properties by investigating the properties of waste materials in Nano size.

  14. NanoAODs

    CERN Document Server

    Husova, Lucia Anna

    2017-01-01

    The scientist on LHC experiment analyse a huge amount of data every day on the Grid. Thus new methods are requested, how to make the analysis more efficient. The NanoAOD is a derived dataset from AOD, where only information necessary for the analysis is stored. Thus the analysis can be more than two times faster, because of the smaller file size, which can be read faster on the Grid. The main goal of this summer student project was to help other users to start using NanoAODs by rewriting their user tasks. Two example users tasks were converted to NanoAODs and tested with the local train test. A speed up of 3.5 was reached. The results of the analysis tasks are identical independent if they use AODs or NanoAODs.

  15. Influence of palmitoyl pentapeptide and Ceramide III B on the droplet size of nanoemulsion

    Science.gov (United States)

    Sondari, Dewi; Haryono, Agus; Harmami, Sri Budi; Randy, Ahmad

    2010-05-01

    The influence of the Palmitoyl Pentapeptide (PPp) and Ceramide IIIB (Cm III B) as active ingredients on the droplet size of nano-emulsion was studied using different kinds of oil (avocado oil, sweet almond oil, jojoba oil, mineral oil and squalene). The formation of nano-emulsions were prepared in water mixed non ionic surfactant/oils system using the spontaneous emulsification mechanism. The aqueous solution, which consist of water and Tween® 20 as a hydrophilic surfactant was mixed homogenously. The organic solution, which consist of oil and Span® 80 as a lipophilic surfactant was mixed homogenously in ethanol. Ethanol was used as a water miscible solvent, which can help the formation of nano-emulsion. The oil phase (containing the blend of surfactant Span® 80, ethanol, oil and active ingredient) and the aqueous phase (containing water and Tween® 20) were separately prepared at room temperatures. The oil phase was slowly added into aqueous phase under continuous mechanical agitation (18000 rpm). All samples were subsequently homogenized with Ultra-Turrax for 30 minutes. The characterizations of nano-emulsion were carried out using photo-microscope and particle size analyzer. Addition of active ingredients on the formation of nano-emulsion gave smallest droplet size compared without active ingredients addition on the formation of nano-emulsion. Squalene oil with Palmitoyl Pentapeptide (PPm) and Ceramide IIIB (Cm IIIB) gave smallest droplet size (184.0 nm) compared without Palmitoyl Pentapeptide and Ceramide IIIB (214.9 nm), however the droplets size of the emulsion prepared by the other oils still in the range of nano-emulsion (below 500 nm). The stability of nano-emulsion was observed using two methods. In one method, the stability of nano-emulsion was observed for three months at temperature of 5°C and 50°C, while in the other method, the stability nano-emulsion was observed by centrifuged at 12000 rpm for 30 minutes. Nanoemulsion with active ingredient

  16. Health Effects Associated with Inhalation Exposure to Diesel Emission Generated with and without CeO2 Nano Fuel Additive

    Science.gov (United States)

    Diesel exhaust (DE) exposure induces adverse cardiopulmonary effects. Addition of nano cerium (Ce) oxide additive to diesel fuel (DECe) increases fuel burning efficiency resulting in altered emission characteristics and potentially altered health effects. We hypothesized that inh...

  17. Nervous System Injury in Response to Contact With Environmental, Engineered and Planetary Micro- and Nano-Sized Particles

    Directory of Open Access Journals (Sweden)

    Tatiana Borisova

    2018-06-01

    Full Text Available Nerve cells take a special place among other cells in organisms because of their unique function mechanism. The plasma membrane of nerve cells from the one hand performs a classical barrier function, thereby being foremost targeted during contact with micro- and nano-sized particles, and from the other hand it is very intensively involved in nerve signal transmission, i.e., depolarization-induced calcium-dependent compound exocytosis realized via vesicle fusion following by their retrieval and calcium-independent permanent neurotransmitter turnover via plasma membrane neurotransmitter transporters that utilize Na+/K+ electrochemical gradient as a driving force. Worldwide traveling air pollution particulate matter is now considered as a possible trigger factor for the development of a variety of neuropathologies. Micro- and nano-sized particles can reach the central nervous system during inhalation avoiding the blood–brain barrier, thereby making synaptic neurotransmission extremely sensitive to their influence. Neurosafety of environmental, engineered and planetary particles is difficult to predict because they possess other features as compared to bulk materials from which the particles are composed of. The capability of the particles to absorb heavy metals and organic neurotoxic molecules from the environment, and moreover, spontaneously interact with proteins and lipids in organisms and form biomolecular corona can considerably change the particles‘ features. The absorption capability occasionally makes them worldwide traveling particulate carriers for delivery of environmental neurotoxic compounds to the brain. Discrepancy of the experimental data on neurotoxicity assessment of micro- and nano-sized particles can be associated with a variability of systems, in which neurotoxicity was analyzed and where protein components of the incubation media forming particle biocorona can significantly distort and even eliminate factual particle

  18. Concrete surface with nano-particle additives for improved wearing resistance to increasing truck traffic.

    Science.gov (United States)

    2012-07-01

    This study focused on the use of nanotechnology in concrete to improve the wearing resistance of concrete. The nano : materials used were polymer cross-linked aerogels, carbon nanotubes, and nano-SiO2, nano-CaCO3, and nano-Al2O3 : particles. As an in...

  19. Nanoparticles by spray drying using innovative new technology: the Büchi nano spray dryer B-90.

    Science.gov (United States)

    Li, Xiang; Anton, Nicolas; Arpagaus, Cordin; Belleteix, Fabrice; Vandamme, Thierry F

    2010-10-15

    Spray drying technology is widely known and used to transform liquids (solutions, emulsions, suspension, slurries, pastes or even melts) into solid powders. Its main applications are found in the food, chemical and materials industries to enhance ingredient conservation, particle properties, powder handling and storage etc. However, spray drying can also be used for specific applications in the formulation of pharmaceuticals for drug delivery (e.g. particles for pulmonary delivery). Büchi is a reference in the development of spray drying technology, notably for laboratory scale devices. This study presents the Nano Spray Dryer B-90, a revolutionary new sprayer developed by Büchi, use of which can lower the size of the produced dried particles by an order of magnitude attaining submicron sizes. In this paper, results are presented with a panel of five representative polymeric wall materials (arabic gum, whey protein, polyvinyl alcohol, modified starch, and maltodextrin) and the potentials to encapsulate nano-emulsions, or to formulate nano-crystals (e.g. from furosemide) are also shown. Copyright © 2010 Elsevier B.V. All rights reserved.

  20. Study of nano-nitramine explosives: preparation, sensitivity and application

    Directory of Open Access Journals (Sweden)

    Jie Liu

    2014-06-01

    Full Text Available Nano-nitramine explosives (RDX, HMX, CL-20 are produced on a bi-directional grinding mill. The scanning electron microscope (SEM observations show that the prepared particles are semi-spherical, and the narrow size distributions are characterized using the laser particle size analyzer. Compared with the micron-sized samples, the nano-products show obvious decrease in friction and impact sensitivities. In the case of shock sensitivities, nano-products have lower values by 59.9% (RDX, 56.4% (HMX, and 58.1% (CL-20, respectively. When nano-RDX and nano-HMX are used in plastic bonded explosives (PBX as alternative materials of micron-sized particles, their shock sensitivities are significantly decreased by 24.5% (RDX and 22.9% (HMX, and their detonation velocities are increased by about 1.7%. Therefore, it is expected to promote the application of nano-nitramine explosives in PBXs and composite modified double-based propellants (CMDBs so that some of their properties would be improved.

  1. Microwave assisted synthesis of nano sized sulphate doped hydroxyapatite

    International Nuclear Information System (INIS)

    Alshemary, Ammar Z.; Goh, Yi-Fan; Akram, Muhammad; Razali, Ili Rabihah; Abdul Kadir, Mohammed Rafiq; Hussain, Rafaqat

    2013-01-01

    Highlights: ► Phase pure nano-sized sulphur doped hydroxyapatite has been synthesized. ► TEM analysis confirmed formation of needle shaped structure. ► Lattice parameters and cell volume increased with increase in sulphate doping. ► Crystallite size decreased as sulphate content inside the structure increased. ► Degree of crystallinity decreased with increase in sulphate substitution. - Abstract: Inorganic sulphate is required by all mammalian cells to function properly, it is the fourth most abundant anion in the human plasma. Sulphate ions are the major source of sulphur which is considered an important element for sustenance of life as it is present in the essential amino and is required by cells to function properly. In this study we have successfully substituted sulphate ions (SO 4 2− ) into hydroxyapatite (Ca 10 (PO 4 ) 6−x (SO 4 ) x (OH) 2−x ) lattice via ion exchange process with phosphate group. Concentration of SO 4 2− ions was varied between X = 0.05–0.5, using (Ca (NO 3 ) 2 ·4H 2 O), ((NH 4 ) 2 HPO 4 ) and (Na 2 SO 4 ) as starting materials. X-ray diffraction (XRD), Fourier transform IR spectroscopy (FTIR), showed that the substitution of SO 4 2− ions into the lattice resulted in peak broadening and reduced peak height due to the amorphous nature and reduced crystallinity of the resulting HA powder. Transmission electron microscopy (TEM) and field emission electron microscopy (FESEM) analysis confirmed the formation of needle shaped particles of 41 nm size with homogenous and uniform distribution of element within the HA structure

  2. The nano-BIon in nanostructure

    Energy Technology Data Exchange (ETDEWEB)

    Sepehri, Alireza, E-mail: alireza.sepehri@uk.ac.ir [Nano Research Center of the Ferdowsi University, Mashhad (Iran, Islamic Republic of); Faculty of Physics, Shahid Bahonar University, P.O. Box 76175, Kerman (Iran, Islamic Republic of)

    2016-04-01

    Recently, some authors have considered the superconductivity in nano-cubes and shown that by decreasing the size of these systems, superconductivity order parameter increases. In this research, we show that the same result can be obtained in a nano-BIon which is a configuration of two layers of cuprates connected by an electronic tube. This tube is a channel for transporting energy and matter inside a superconductor and acts as a wormhole in this system. This wormhole-like-tube is formed by decreasing the separation distance between layers of nano-cuprate and enhancing the cooper hopping pairing between layers. We estimate the critical temperature of superconductor and find that it depends on the size of nano-BIon and coupling between atoms in a layer. Also, we observe that external magnetic field generates a new tube which causes losing the energy density of nano-BIon between two layers and decreasing critical temperature of superconductor.

  3. THE INFLUENCE OF NANO-ADDITIVES ON THE PHYSICO-MECHANICAL PROPERTIES FIBER REINFORCED CONCRETE

    Directory of Open Access Journals (Sweden)

    Евгений Петрович Матус

    2018-02-01

    Full Text Available The paper discusses the current state of research of the effect of nanodispersed additives on the properties of fiber reinforced portland cement composites. The results of tests on the strength and viscosity of solutions and samples of fine-grained concrete based on cement binder and cement steel and basalt fiber, carbon nanotubes, silicates, nanosized powder of CaО and degidrol. The effect of methods of introduction of the mixture of nano-additives on the clutch fibers with the matrix. Analysis of experimental data showed the absence of a systematic positive effect of increasing the mechanical strength of the composites due to the introduction of carbon nanotubes.

  4. Modelling the Size Effects on the Mechanical Properties of Micro/Nano Structures

    Directory of Open Access Journals (Sweden)

    Amir Musa Abazari

    2015-11-01

    Full Text Available Experiments on micro- and nano-mechanical systems (M/NEMS have shown that their behavior under bending loads departs in many cases from the classical predictions using Euler-Bernoulli theory and Hooke’s law. This anomalous response has usually been seen as a dependence of the material properties on the size of the structure, in particular thickness. A theoretical model that allows for quantitative understanding and prediction of this size effect is important for the design of M/NEMS. In this paper, we summarize and analyze the five theories that can be found in the literature: Grain Boundary Theory (GBT, Surface Stress Theory (SST, Residual Stress Theory (RST, Couple Stress Theory (CST and Surface Elasticity Theory (SET. By comparing these theories with experimental data we propose a simplified model combination of CST and SET that properly fits all considered cases, therefore delivering a simple (two parameters model that can be used to predict the mechanical properties at the nanoscale.

  5. Sonochemical synthesis and characterization of nano-sized zinc(II coordination complex as a precursor for the preparation of pure-phase zinc(II oxide nanoparticles

    Directory of Open Access Journals (Sweden)

    Maryam Ranjbar

    2017-01-01

    Full Text Available In current study, nanoparticles and single crystals of a Zn(II coordination complex, [Zn(dmphI2](1, {dmph=2,9-dimethyl-1,10-phenanthroline(neocuproine}, have been synthesized by the reaction of zinc(II acetate, KI and neocuproine as ligand in methanol using sonochemical and heat gradient methods, respectively. The nanostructure of 1 was characterized by scanning electron microscopy (SEM, X-ray powder diffraction (XRD, FT-IR spectroscopy and elemental analyses, and the structure of compound 1 was determined by single-crystal X-ray diffraction. The thermal stability of nano-sized 1 has been studied by thermogravimetric (TG and differential thermal analyses (DTA. Structural determination of compound 1 reveals the Zn(II ion is four-coordinated in a distorted tetrahedral configuration by two N atoms from a 2,9-dimethyl-1,10-Phenanthroline ligand and two terminal I atoms. The effect of supercritical condition on stability, size and morphology of nano-structured compound 1 has also been studied. The XRD pattern of the residue obtained from thermal decomposition of nano-sized compound 1 at 600 °C under air atmosphere provided pure phase of ZnO with the average particles size of about 31 nm.

  6. Effect of Addition of Colloidal Silica to Films of Polyimide, Polyvinylpyridine, Polystyrene, and Polymethylmethacrylate Nano-Composites

    OpenAIRE

    Abdalla, Soliman; Al-Marzouki, Fahad; Obaid, Abdullah; Gamal, Salah

    2016-01-01

    Nano-composite films have been the subject of extensive work for developing the energy-storage efficiency of electrostatic capacitors. Factors such as polymer purity, nanoparticle size, and film morphology drastically affect the electrostatic efficiency of the dielectric material that forms the insulating film between the conductive electrodes of a capacitor. This in turn affects the energy storage performance of the capacitor. In the present work, we have studied the dielectric properties of...

  7. Development of a novel nano-sized anti-VEGFA nanobody with enhanced physicochemical and pharmacokinetic properties.

    Science.gov (United States)

    Khodabakhsh, Farnaz; Norouzian, Dariush; Vaziri, Behrouz; Ahangari Cohan, Reza; Sardari, Soroush; Mahboudi, Fereidoun; Behdani, Mahdi; Mansouri, Kamran; Mehdizadeh, Ardavan

    2017-08-25

    Since physiological and pathological processes occur at nano-environments, nanotechnology has considered as an efficient tool for designing of next generation specific biomolecules with enhanced pharmacodynamic and pharmacodynamic properties. In the current investigation, by control of the size and hydrodynamic volume at the nanoscale, for the first time, physicochemical and pharmacokinetic properties of an anti-VEGFA nanobody was remarkably improved by attachment of a Proline-Alanine-Serine (PAS) rich sequence. The results elucidated unexpected impressive effects of PAS sequence on physicochemical properties especially on size, hydrodynamics radius, and even solubility of nanobody. CD analysis revealed an increment in random coil structure of the PASylated protein in comparison to native one without any change in charge state or binding kinetic parameters of nanobody assessed by isoelectric focusing and surface plasmon resonance measurements, respectively. In vitro biological activities of nanobody were not affected by coupling of the PAS sequence. In contrast, the terminal half-life was significantly increased by a factor of 14 for the nanobody-PAS after single dose IV injection to the mice. Our study demonstrated that the control of size in the design of small therapeutic proteins has a promising effect on the stability and solubility, in addition to their physiochemical and pharmacokinetic properties. The designed new anti-VEGFA nanobody could promise a better therapeutic agent with a long administration intervals and lower dose, which in turn leads to a better patient compliance. Size adjustment of an anti-VEGF nanobody at the nanoscale by the attachment of a natural PAS polymer remarkably improves physicochemical properties, as well as a pharmacokinetic profile without any change in biological activity of the miniaturized antibody.

  8. Photocatalytic self-cleaning properties of cellulosic fibers modified by nano-sized zinc oxide

    Energy Technology Data Exchange (ETDEWEB)

    Moafi, Hadi Fallah; Shojaie, Abdollah Fallah, E-mail: a.f.shojaie@guilan.ac.ir; Zanjanchi, Mohammad Ali

    2011-03-31

    Nano-sized zinc oxide was synthesized and deposited onto cellulosic fibers using the sol-gel process at ambient temperature. The prepared materials were characterized using several techniques including scanning electron microscopy, transmission electron microscopy, diffuse reflectance spectroscopy, X-ray diffraction and thermogravimetric analysis. X-ray diffraction studies of the ZnO-coated fiber indicate formation of the hexagonal crystal phase which was satisfactory crystallized on the fiber surface. The electron micrographs show formation of zinc oxide nanoparticles within 10-15 nm in size which have been homogeneously dispersed on the fiber surface. The prepared materials show significant photocatalytic self-cleaning activity, which was monitored by diffuse reflectance spectroscopy. The photoactivity was studied upon measuring the photodegradation of methylene blue and eosin yellowish under UV-Vis irradiation. The photocatalytic activity of the treated fabrics was fully maintained performing several cycles of photodegradation.

  9. Photocatalytic self-cleaning properties of cellulosic fibers modified by nano-sized zinc oxide

    International Nuclear Information System (INIS)

    Moafi, Hadi Fallah; Shojaie, Abdollah Fallah; Zanjanchi, Mohammad Ali

    2011-01-01

    Nano-sized zinc oxide was synthesized and deposited onto cellulosic fibers using the sol-gel process at ambient temperature. The prepared materials were characterized using several techniques including scanning electron microscopy, transmission electron microscopy, diffuse reflectance spectroscopy, X-ray diffraction and thermogravimetric analysis. X-ray diffraction studies of the ZnO-coated fiber indicate formation of the hexagonal crystal phase which was satisfactory crystallized on the fiber surface. The electron micrographs show formation of zinc oxide nanoparticles within 10-15 nm in size which have been homogeneously dispersed on the fiber surface. The prepared materials show significant photocatalytic self-cleaning activity, which was monitored by diffuse reflectance spectroscopy. The photoactivity was studied upon measuring the photodegradation of methylene blue and eosin yellowish under UV-Vis irradiation. The photocatalytic activity of the treated fabrics was fully maintained performing several cycles of photodegradation.

  10. Creation of nano eye-drops and effective drug delivery to the interior of the eye

    Science.gov (United States)

    Ikuta, Yoshikazu; Aoyagi, Shigenobu; Tanaka, Yuji; Sato, Kota; Inada, Satoshi; Koseki, Yoshitaka; Onodera, Tsunenobu; Oikawa, Hidetoshi; Kasai, Hitoshi

    2017-03-01

    Nano eye-drops are a new type of ophthalmic treatment with increased potency and reduced side effects. Compounds in conventional eye-drops barely penetrate into the eye because the cornea, located at the surface of eye, has a strong barrier function for preventing invasion of hydrophilic or large-sized materials from the outside. In this work, we describe the utility of nano eye-drops utilising brinzolamide, a commercially available glaucoma treatment drug, as a target compound. Fabrication of the nanoparticles of brinzolamide prodrug increases the eye penetration rate and results in high drug efficacy, compared with that of commercially available brinzolamide eye-drops formulated as micro-sized structures. In addition, the resulting nano eye-drops were not toxic to the corneal epithelium after repeated administration for 1 week. The nano eye-drops may have applications as a next-generation ophthalmic treatment.

  11. Preparation and Characterization of Water-Based Nano-fluids for Nuclear Applications

    International Nuclear Information System (INIS)

    Williams, W.C.; Forrest, E.; Hu, L.W.; Buongiorno, J.

    2006-01-01

    As part of an effort to evaluate water-based nano-fluids for nuclear applications, preparation and characterization has been performed for nano-fluids being considered for MIT's nano-fluid heat transfer experiments. Three methods of generating these nano-fluids are available: creating them from chemical precipitation, purchasing the nano-particles in powder form and mixing them with the base fluid, and direct purchase of prepared nano-fluids. Characterization of nano-fluids includes colloidal stability, size distribution, concentration, and elemental composition. Quality control of the nano-fluids to be used for heat transfer testing is crucial; an exact knowledge of the fluid constituents is essential to uncovering mechanisms responsible for heat transport enhancement. Testing indicates that nano-fluids created by mixing a liquid with nano-particles in powder form are often not stable, although some degree of stabilization is obtainable with pH control and/or surfactant addition. Some commercially available prepared nano-fluids have been found to contain unacceptable levels of impurities and/or include a different weight percent of nano-particles compared to vendor specifications. Tools utilized to characterize and qualify nano-fluids for this study include neutron activation analysis (NAA), inductively-coupled plasma spectroscopy (ICP), transmission electron microscopy (TEM) imaging, thermogravimetric analysis (TGA) and dynamic light scattering (DLS). Preparation procedures and characterization results for selected nano-fluids will be discussed in detail. (authors)

  12. Selective and lithography-independent fabrication of 20 nm nano-gap electrodes and nano-channels for nanoelectrofluidics applications

    International Nuclear Information System (INIS)

    Zhang, J Y; Wang, X F; Wang, X D; Fan, Z C; Li, Y; Ji, An; Yang, F H

    2010-01-01

    A new method has been developed to selectively fabricate nano-gap electrodes and nano-channels by conventional lithography. Based on a sacrificial spacer process, we have successfully obtained sub-100-nm nano-gap electrodes and nano-channels and further reduced the dimensions to 20 nm by shrinking the sacrificial spacer size. Our method shows good selectivity between nano-gap electrodes and nano-channels due to different sacrificial spacer etch conditions. There is no length limit for the nano-gap electrode and the nano-channel. The method reported in this paper also allows for wafer scale fabrication, high throughput, low cost, and good compatibility with modern semiconductor technology.

  13. Meditations on the ubiquity and mutability of nano-sized materials in the environment.

    Science.gov (United States)

    Wiesner, Mark R; Lowry, Gregory V; Casman, Elizabeth; Bertsch, Paul M; Matson, Cole W; Di Giulio, Richard T; Liu, Jie; Hochella, Michael F

    2011-11-22

    A wide variety of nanomaterials can be found naturally occurring in the environment, although finding and characterizing these materials remains a challenge due to their size. Recent studies in the field have shown that natural nanomaterials are common in many geochemical systems. In this issue of ACS Nano, Hutchison and co-workers make us realize that manmade nanomaterials can often be practically identical to those that spontaneously form in the environment. This Perspective discusses the prevalence of nanomaterials in nature, including anthropogenic and naturally occurring nanomaterials, and the dynamic behavior of these materials in the environment. © 2011 American Chemical Society

  14. Synthesis of Metal Polymer Nano composites Using Ionizing Radiation

    International Nuclear Information System (INIS)

    Mostafa, R.S.S.

    2012-01-01

    we prepared a series of CdS/PVA and Ag/PVA nano composites via facile and novel synthetic steps. Our synthetic route is simpler; it does not need expensive oxidizing agents, surfactants, templates and complicated apparatus. The present work contains five chapters in addition to the list of figures, tables, abbreviations and references. The first two chapters are concerned with the introduction and reviews of previous studies. Chapter 3 describes the preparation methodology, experimental setup and techniques used in the CdS/PVA and Ag/PVA nano composites processing and analysis. CdS and Ag nanoparticles with different particle sizes were prepared via chemical method and gamma irradiation method. Several techniques were used to detect the structural changes of the nano composites due to interaction between CdS or Ag ions and PVA. These are: UV-Visible spectrophotometer, Transmission Electron microscope (TEM), X-ray diffraction (XRD), Fourier Transform Infrared (FTIR) Spectrophotometer, and thermogravimetric analysis. Chapter 4 includes the obtained results and their discussions: Ultraviolet/Visible spectroscopy (UV/VIS) investigated that the as-prepared nano composites have improved optical properties. Such incremented optical properties were attributed to the nano scale dispersion (nm). The improvement in the optical properties is considered to be dependent on, Cd 2+ :S 2- molar ratio, Ag concentration, Pva content and irradiation dose. The calculated band gap energies for CdS/PVA nano composites are higher than that of bulk of CdS indicating the strong quantum confinement. The increases in band gap energy have been attributed to the crystalline size dependent properties. Transmission electron microscope images illustrated that the nano structured CdS/PVA films were found to be dispersed spherical nanoparticles with good structural homogeneity and polydispersity at either lower concentration of CdCl 2 and/or irradiation dose. Nano rod structure of CdS accompanied

  15. Characterization of semi-solid processing of aluminium alloy 7075 with Sc and Zr additions

    Energy Technology Data Exchange (ETDEWEB)

    Rogal, Ł., E-mail: l.rogal@imim.pl [Institute of Metallurgy and Materials Science of the Polish Academy of Sciences, 25 Reymonta St., 30-059 Krakow (Poland); Dutkiewicz, J. [Institute of Metallurgy and Materials Science of the Polish Academy of Sciences, 25 Reymonta St., 30-059 Krakow (Poland); Atkinson, H.V. [The University of Leicester, Department of Engineering University Road, Leicester, LE1 7RH (United Kingdom); Lityńska-Dobrzyńska, L.; Czeppe, T. [Institute of Metallurgy and Materials Science of the Polish Academy of Sciences, 25 Reymonta St., 30-059 Krakow (Poland); Modigell, M. [RWTH Aachen—Department of Mechanical Process Engineering, 55 Templergraben St., Aachen (Germany)

    2013-09-15

    For thixoforming (semi-solid processing) it is necessary to have a fine globular microstructure in a semi-solid range. Here this has been obtained for 7075 aluminium alloy by addition of modifying agents: 0.5 weight % of scandium and zirconium. The thixoforming process was carried out at 632 °C which gave about 23 volume % of liquid phase. The microstructure of the thixo-formed part (a rotor) consisted of globular grains surrounded by precipitates of secondary phase. The average hardness of thixo-formed parts was 105 HV{sub 5} and the tensile strength 300 MPa. T6 heat treatments were performed with solutionisation at 450 °C for 30 min and 10 h. In both cases the ageing time was set as 18 h at 120 °C. The heat treatments led to an increase in average tensile strength up to 495 MPa. Transmission Electron Microscopy (TEM) analysis enabled the identification of precipitates of the metastable dispersoids of L1{sub 2}–Al{sub 3} (Zr, Sc) and η′ (MgZn{sub 2}) phases in the alloy after the thixoforming and T6 treatment. The measurements of rheological properties of 7075Al alloy with Sc and Zr additions in the semi-solid range indicated an increase of particle size and spheroidization leading to an observable decrease of viscosity during isothermal shearing. A shear rate jump experiment showed that with increasing shear rate the viscosity rapidly falls.

  16. Effects of confinement in meso-porous silica and carbon nano-structures; Etude des effets de confinement dans la silice mesoporeuse et dans certaines nanostructures carbonees

    Energy Technology Data Exchange (ETDEWEB)

    Leon, V

    2006-07-15

    Physico-chemical properties of materials can be strongly modified by confinement because of the quantum effects that appear at such small length scales and also because of the effects of the confinement itself. The aim of this thesis is to show that both the nature of the confining material and the size of the pores and cavities have a strong impact on the confined material. We first show the effect of the pore size of the host meso-porous silica on the temperature of the solid-solid phase transition of silver selenide, a semiconducting material with enhanced magnetoresistive properties under non-stoichiometric conditions. Narrowing the pores from 20 nm to 2 nm raises the phase transition temperature from 139 C to 146 C. This result can be explained by considering the interaction between the confining and confined materials as a driving force. The effects of confinement are also studied in the case of hydrogen and deuterium inside cavities of organized carbon nano-structures. The effects that appear in the adsorption/desorption cycles are much stronger with carbon nano-horns as the host material than with C60 pea-pods and single-walled carbon nano-tubes. (author)

  17. A Facile Method for Separating and Enriching Nano and Submicron Particles from Titanium Dioxide Found in Food and Pharmaceutical Products

    Science.gov (United States)

    Yang, Yu; Capco, David G.; Westerhoff, Paul

    2016-01-01

    Recent studies indicate the presence of nano-scale titanium dioxide (TiO2) as an additive in human foodstuffs, but a practical protocol to isolate and separate nano-fractions from soluble foodstuffs as a source of material remains elusive. As such, we developed a method for separating the nano and submicron fractions found in commercial-grade TiO2 (E171) and E171 extracted from soluble foodstuffs and pharmaceutical products (e.g., chewing gum, pain reliever, and allergy medicine). Primary particle analysis of commercial-grade E171 indicated that 54% of particles were nano-sized (i.e., < 100 nm). Isolation and primary particle analysis of five consumer goods intended to be ingested revealed differences in the percent of nano-sized particles from 32%‒58%. Separation and enrichment of nano- and submicron-sized particles from commercial-grade E171 and E171 isolated from foodstuffs and pharmaceuticals was accomplished using rate-zonal centrifugation. Commercial-grade E171 was separated into nano- and submicron-enriched fractions consisting of a nano:submicron fraction of approximately 0.45:1 and 3.2:1, respectively. E171 extracted from gum had nano:submicron fractions of 1.4:1 and 0.19:1 for nano- and submicron-enriched, respectively. We show a difference in particle adhesion to the cell surface, which was found to be dependent on particle size and epithelial orientation. Finally, we provide evidence that E171 particles are not immediately cytotoxic to the Caco-2 human intestinal epithelium model. These data suggest that this separation method is appropriate for studies interested in isolating the nano-sized particle fraction taken directly from consumer products, in order to study separately the effects of nano and submicron particles. PMID:27798677

  18. Effects of a Nano-Silica Additive on the Rock Erosion Characteristics of a SC-CO2 Jet under Various Operating Conditions

    Directory of Open Access Journals (Sweden)

    Man Huang

    2017-02-01

    Full Text Available In order to improve the erosion capacity of a supercritical carbon dioxide (SC-CO2 jet, the influence of a nano-silica additive on the rock erosion characteristics was experimentally investigated. By impinging the SC-CO2 jets with nano-silica mass fractions of 0 wt % (pure SC-CO2 jet, 3 wt %, 6 wt %, 9 wt %, 12 wt %, 15 wt %, and 18 wt % on specimens of red sandstone, the erosion volumes under various operating conditions were measured and analyzed. Results show that an appropriate amount of nano-silica additive can greatly enhance the erosion ability of a SC-CO2 jet. The effect on the erosion ability largely depends on the operating conditions. For instance, when the other conditions are fixed, 6 wt %, 9 wt %, 12 wt %, and 15 wt % were the optimum mass fractions, successively, with the inlet pressure increasing from 30 MPa to 60 MPa. With the increase in ambient pressure, the optimum mass fraction is unchanged under the constant inlet pressure, while it increases under the constant pressure drop. Additionally, the optimum mass fraction decreases when the fluid temperature increases. In addition, the optimal standoff distances are about five times the nozzle diameter of the nano-silica SC-CO2 jet, and three times for the pure jet. This research provides a new method for effectively enhancing the rock erosion performance of a SC-CO2 jet.

  19. Systemic antibody response to nano-size calcium phospate biocompatible adjuvant adsorbed HEV-71 killed vaccine

    OpenAIRE

    Saeed, Mohamed Ibrahim; Omar, Abd Rahaman; Hussein, Mohd Zobir; Elkhidir, Isam Mohamed; Sekawi, Zamberi

    2015-01-01

    Purpose Since 1980s, human enterovirus-71 virus (HEV-71) is one of the common infectious disease in Asian Pacific region since late 1970s without effective commercial antiviral or protective vaccine is unavailable yet. The work examines the role of vaccine adjuvant particle size and the route of administration on postvaccination antibody response towards HEV-71 vaccine adsorbed to calcium phosphate (CaP) adjuvant. Materials and Methods First, CaP nano-particles were compared to a commercial m...

  20. Indentation size effects in the nano- and micro-hardness of a Fe-based bulk metallic glass

    Energy Technology Data Exchange (ETDEWEB)

    Xu, F., E-mail: xufu@xtu.edu.cn; Ding, Y.H.; Deng, X.H.; Zhang, P.; Long, Z.L.

    2014-10-01

    Hardness of a Fe-based bulk metallic glass (BMG) was evaluated by both atomic force microscopy (AFM) nanoindentation (nano-hardness) and instrumented indentation with a traditional indenter setup (micro-hardness) under different maximum loads at room temperature. The nano-hardness and the micro-hardness were found to be comparable. For both of the indentation methods, indentation size effect (ISE) is detected as increase in hardness with decrease in indentation peak load. It is proposed that strain rate dependent softening, loading history and the lag between free volume creation and mechanical softening should be responsible for the ISE in this BMG. Furthermore, ISE is found to be more significant in AFM nanoindentation than in instrumented indentation. This can be explained by taking into account the effect of exerted peak load and the face angle of the indenter in a qualitative manner.

  1. Novel Selective Detection Method of Tumor Angiogenesis Factors Using Living Nano-Robots.

    Science.gov (United States)

    Al-Fandi, Mohamed; Alshraiedeh, Nida; Owies, Rami; Alshdaifat, Hala; Al-Mahaseneh, Omamah; Al-Tall, Khadijah; Alawneh, Rawan

    2017-07-14

    This paper reports a novel self-detection method for tumor cells using living nano-robots. These living robots are a nonpathogenic strain of E. coli bacteria equipped with naturally synthesized bio-nano-sensory systems that have an affinity to VEGF, an angiogenic factor overly-expressed by cancer cells. The VEGF-affinity/chemotaxis was assessed using several assays including the capillary chemotaxis assay, chemotaxis assay on soft agar, and chemotaxis assay on solid agar. In addition, a microfluidic device was developed to possibly discover tumor cells through the overexpressed vascular endothelial growth factor (VEGF). Various experiments to study the sensing characteristic of the nano-robots presented a strong response toward the VEGF. Thus, a new paradigm of selective targeting therapies for cancer can be advanced using swimming E. coli as self-navigator miniaturized robots as well as drug-delivery vehicles.

  2. Microwave assisted synthesis of nano sized sulphate doped hydroxyapatite

    Energy Technology Data Exchange (ETDEWEB)

    Alshemary, Ammar Z.; Goh, Yi-Fan; Akram, Muhammad; Razali, Ili Rabihah [Department of Chemistry, Faculty of Science, Universiti Teknologi Malaysia, 81310 UTM Skudai, Johor Darul Ta’zim (Malaysia); Abdul Kadir, Mohammed Rafiq [Medical Implant Technology Group, Faculty of Biomedical Engineering and Health Science, Universiti Teknologi Malaysia,81310 UTM Skudai, Johor Darul Ta’zim (Malaysia); Hussain, Rafaqat, E-mail: rafaqat@kimia.fs.utm.my [Ibnu Sina Institute for Fundamental Science Studies, Universiti Teknologi Malaysia, 81310 UTM Skudai, Johor DarulTa’zim (Malaysia)

    2013-06-01

    Highlights: ► Phase pure nano-sized sulphur doped hydroxyapatite has been synthesized. ► TEM analysis confirmed formation of needle shaped structure. ► Lattice parameters and cell volume increased with increase in sulphate doping. ► Crystallite size decreased as sulphate content inside the structure increased. ► Degree of crystallinity decreased with increase in sulphate substitution. - Abstract: Inorganic sulphate is required by all mammalian cells to function properly, it is the fourth most abundant anion in the human plasma. Sulphate ions are the major source of sulphur which is considered an important element for sustenance of life as it is present in the essential amino and is required by cells to function properly. In this study we have successfully substituted sulphate ions (SO{sub 4}{sup 2−}) into hydroxyapatite (Ca{sub 10}(PO{sub 4}){sub 6−x}(SO{sub 4}){sub x}(OH){sub 2−x}) lattice via ion exchange process with phosphate group. Concentration of SO{sub 4}{sup 2−} ions was varied between X = 0.05–0.5, using (Ca (NO{sub 3}){sub 2}·4H{sub 2}O), ((NH{sub 4}){sub 2}HPO{sub 4}) and (Na{sub 2}SO{sub 4}) as starting materials. X-ray diffraction (XRD), Fourier transform IR spectroscopy (FTIR), showed that the substitution of SO{sub 4}{sup 2−} ions into the lattice resulted in peak broadening and reduced peak height due to the amorphous nature and reduced crystallinity of the resulting HA powder. Transmission electron microscopy (TEM) and field emission electron microscopy (FESEM) analysis confirmed the formation of needle shaped particles of 41 nm size with homogenous and uniform distribution of element within the HA structure.

  3. Effect of lateral size of graphene nano-sheets on the mechanical properties and machinability of alumina nano-composites

    Czech Academy of Sciences Publication Activity Database

    Porwal, H.; Saggar, Richa; Tatarko, P.; Grasso, S.; Saunders, T.; Dlouhý, Ivo; Reece, M. J.

    2016-01-01

    Roč. 42, č. 6 (2016), s. 7533-7542 ISSN 0272-8842 EU Projects: European Commission(XE) 264526 Institutional support: RVO:68081723 Keywords : Alumina * Graphene nano-sheets * Nano-composites * Mechanical properties * Machinability Subject RIV: JL - Materials Fatigue, Friction Mechanics Impact factor: 2.986, year: 2016

  4. Wear characterization of nano-hydroxyapatite with addition of titanium (HA-Ti)

    Science.gov (United States)

    Rosmamuhamadani, R.; Arawi, A. Z. O.; Talari, M. K.; Mahat, M. M.; Bonnia, N. N.; Sabrina; Yahaya, M.; Sulaiman, S.; Ismail, M. I. S.

    2018-04-01

    Hydroxyapatite (Ca10 (PO4)6(OH)2, HA), is an attractive material of an inorganic compound whose chemical composition and crystallographic structures are similar to the composition of the bone. A natural source such as egg shells is composed of 94 wt. % of calcium carbonate (CaCO3), which can be calcined as calcium oxide (CaO) by the calcinations process. The efficient temperature to produce CaO is 900 °C for 2 hours. The synthesis of nano-HA was done by the mixing the diammonium phosphate (DAP) and calcium hydroxide (Ca(OH)2) and subjected into a microwave for 30 minutes at 1100 W irradiation power. Ball milling process was used for 30 minutes to mix the nano-HA with different compositions of titanium. These were pressed to form pallets by hand hydraulic pump (force=2300 psi). The pallets then were sintered at 1200 °C with the heating rate of 3 °C/min for 2 hours. The pallets were tested by several mechanical testing including hardness, compression strength and wear. From the results, HA-25wt. %Ti composite gave the highest hardness, compression and coefficient of friction for wear test values which were 89.6 Hv, 82.5MPa and 0.76μ respectively. It showed that by adding Ti to nano-HA, the mechanical properties of nano-HA could be enhanced. The microstructure analyses by optical micrograph showed that nano-HA-Ti particles displayed shape likes needle morphology. The particles showed the high tendency to form the agglomerations.

  5. Nano powders, components and coatings by plasma technique

    Science.gov (United States)

    McKechnie, Timothy N. (Inventor); Antony, Leo V. M. (Inventor); O'Dell, Scott (Inventor); Power, Chris (Inventor); Tabor, Terry (Inventor)

    2009-01-01

    Ultra fine and nanometer powders and a method of producing same are provided, preferably refractory metal and ceramic nanopowders. When certain precursors are injected into the plasma flame in a reactor chamber, the materials are heated, melted and vaporized and the chemical reaction is induced in the vapor phase. The vapor phase is quenched rapidly to solid phase to yield the ultra pure, ultra fine and nano product. With this technique, powders have been made 20 nanometers in size in a system capable of a bulk production rate of more than 10 lbs/hr. The process is particularly applicable to tungsten, molybdenum, rhenium, tungsten carbide, molybdenum carbide and other related materials.

  6. Nano powders, components and coatings by plasma technique

    Science.gov (United States)

    McKechnie, Timothy N [Brownsboro, AL; Antony, Leo V. M. [Huntsville, AL; O'Dell, Scott [Arab, AL; Power, Chris [Guntersville, AL; Tabor, Terry [Huntsville, AL

    2009-11-10

    Ultra fine and nanometer powders and a method of producing same are provided, preferably refractory metal and ceramic nanopowders. When certain precursors are injected into the plasma flame in a reactor chamber, the materials are heated, melted and vaporized and the chemical reaction is induced in the vapor phase. The vapor phase is quenched rapidly to solid phase to yield the ultra pure, ultra fine and nano product. With this technique, powders have been made 20 nanometers in size in a system capable of a bulk production rate of more than 10 lbs/hr. The process is particularly applicable to tungsten, molybdenum, rhenium, tungsten carbide, molybdenum carbide and other related materials.

  7. Decontamination of radioactive cesium in soil using nano-size metallic calcium dispersing

    International Nuclear Information System (INIS)

    Mitoma, Yoshiharu; Fukuoka, Takezo; Matsue, Hideaki; Kobayashi, Hidemasa; Shiraishi, Hiroaki; Kajitani, Mikio

    2013-01-01

    In Japan, the major concern on radioactive cesium ( 134 Cs and 137 Cs) deposition and soil contamination due to the emission form the Fukushima Dai-ichi nuclear power plant showed up after a massive quake on March 11, 2011. Soil contamination with radioactive cesium has a long-term radiological impact due to its long half-life (30 years for 137 Cs) and its high biological hazard. Therefore, much attention has been paid to decontaminate Cs-contaminated soil with washing and/or extraction by adopting solvents. However, such wet methods have some disadvantages, i.e. forming of secondary effluents and additional cost for their treatment. We have recently shown that the nano-size metallic calcium/calcium oxide/iron dispersing mixture (Fe-nCa) is most effective for heavy metals immobilization and volume reduction method under dry condition. Thus, we applied this method to treat real radioactive cesium contaminated soils in dry condition. Simple stirring of the contaminated soil with Fe-nCa achieved about above 90% of radioactive Cs decontamination rate and the volume reduction level also reached around 50-60%. In this paper, we showed the effectiveness of a Fe-nCa method for the rapid remediation and volume reduction method of real radioactive cesium contaminated soils under dry conditions and our challenges for sophistication applying machine and reagents. (author)

  8. Vaccine delivery system for tuberculosis based on nano-sized hepatitis B virus core protein particles

    Directory of Open Access Journals (Sweden)

    Dhanasooraj D

    2013-02-01

    Full Text Available Dhananjayan Dhanasooraj, R Ajay Kumar, Sathish MundayoorMycobacterium Research Group, Rajiv Gandhi Centre for Biotechnology, Kerala, IndiaAbstract: Nano-sized hepatitis B virus core virus-like particles (HBc-VLP are suitable for uptake by antigen-presenting cells. Mycobacterium tuberculosis antigen culture filtrate protein 10 (CFP-10 is an important vaccine candidate against tuberculosis. The purified antigen shows low immune response without adjuvant and tends to have low protective efficacy. The present study is based on the assumption that expression of these proteins on HBc nanoparticles would provide higher protection when compared to the native antigen alone. The cfp-10 gene was expressed as a fusion on the major immunodominant region of HBc-VLP, and the immune response in Balb/c mice was studied and compared to pure proteins, a mixture of antigens, and fusion protein-VLP, all without using any adjuvant. The humoral, cytokine, and splenocyte cell proliferation responses suggested that the HBc-VLP bearing CFP-10 generated an antigen-specific immune response in a Th1-dependent manner. By virtue of its self-adjuvant nature and ability to form nano-sized particles, HBc-VLPs are an excellent vaccine delivery system for use with subunit protein antigens identified in the course of recent vaccine research.Keywords: Mycobacterium tuberculosis, VLP, hepatitis B virus core particle, CFP-10, self-adjuvant, vaccine delivery

  9. Effect of alkali ions (Na+, K+, Cs+) on reaction mechanism of CZTS nano-particles synthesis

    Science.gov (United States)

    Kumar, Suresh; Altosaar, Mare; Grossberg, Maarja; Mikli, Valdek

    2018-04-01

    The control of morphology, elemental composition and phase composition of Cu2ZnSnS4 (CZTS) nano-crystals depends on the control of complex formation and surface stabilization of nano-particles in solution-based synthesis in oleylamine. At temperatures ≥280 °C, the control of nano-crystal's morphology and homogenous growth is difficult because of fast poly-nuclear growth occurring at higher temperatures. In the present work the effect of oleylamine complex formation with different alkali ions (Na+, K+ and Cs+) on nano-crystals growth at synthesis temperature of 280 °C was studied. It was found that nano-powders synthesized in the presence of Na+ and K+ ions showed the formation of crystals of different sizes - small nano-particles (18 nm-30 nm), large aggregated crystals (few nm to 1 μm) and large single crystals (1 μm - 4 μm). The presence of Cs+ ions in the nano-powder synthesis in oleylamine-metal precursor-CsOH solution promoted growth of nano-crystals of homogenous size. It is proposed that the formed oleylamine-Cs complexes a) enhance the formation and stabilization of oleylamine-metal (Cu, Zn and Sn) complexes before the injection of sulphur precursor into the oleylamine-metal precursor solution and b) after addition of sulphur stabilize the fast nucleated nano-particles and promote diffusion limited growth.

  10. Nano-Structuring of Solid Surface by EUV Ar8+ Laser

    International Nuclear Information System (INIS)

    Kolacek, K.; Prukner, V.; Schmidt, J

    2013-01-01

    Requirement of increased resolution is at present most loudly pronounced in microelectronics, which, following Moore´s law (doubling every two years the transistorcount that can be placed inexpensively on integrated circuit), commands a continuous upgrade of micro-/nano-lithography. Such upgrade indirectly influences processing speed, memory capacity, number and size of pixels in sensors, etc. The submitted paper demonstrates our first attempt for “direct (i.e. ablation) patterning” of PMMA by pulse, high-current, capillary-discharge-pumped Ar 8+ ion laser (λ = 46,9 nm). For focusing a long-focal spherical mirror (R = 2100 mm) covered by 14 double-layer Sc-Si coating was used. The ablated focal spots demonstrate not only that the energy of our laser is sufficient for such experiments, but also that the design of focusing optics must be more sophisticated: severe aberrations have been revealed – an irregular spot shape and strong astigmatism with astigmatic difference as large as 16 mm. Moreover, on the bottom of ablated spots a laserinduced periodic surface structure (LIPSS) has appeared. Finally, a direct patterning of quadratic hole 7,5x7,5 µm, standing in contact with PMMA substrate, has shown a strongly developed 2D diffraction pattern (period in the centre ∼125 nm). In conclusion there will be shown the design of a new (grazing incidence) focusing optics, and a new “nano-patterning” tool – grazing incidence interferometer, which enable to ablate a regular, in advance defined pattern. It is believed that this is the first step to application of this technique not only to nanolithography,but also e.g. to study of electron dynamics in superlattices. (author)

  11. Processing of micro-nano bacterial cellulose with hydrolysis method as a reinforcing bioplastic

    Science.gov (United States)

    Maryam, Maryam; Dedy, Rahmad; Yunizurwan, Yunizurwan

    2017-01-01

    Nanotechnology is the ability to create and manipulate atoms and molecules on the smallest of scales. Their size allows them to exhibit novel and significantly improved physical, chemical, biological properties, phenomena, and processes because of their size. The purpose of this research is obtaining micro-nano bacterial cellulose as reinforcing bioplastics. Bacterial cellulose (BC) was made from coconut water for two weeks. BC was dried and grinded. Bacterial cellulose was given purification process with NaOH 5% for 6 hours. Making the micro-nano bacterial cellulose with hydrolysis method. Hydrolysis process with hydrochloric acid (HCl) at the conditions 3,5M, 55°C, 6 hours. Drying process used spray dryer. The hydrolysis process was obtained bacterial cellulose with ±7 μm. The addition 2% micro-nano bacterial cellulose as reinforcing in bioplastics composite can improve the physical characteristics.

  12. Processing of micro-nano bacterial cellulose with hydrolysis method as a reinforcing bioplastic

    International Nuclear Information System (INIS)

    Maryam, Maryam; Yunizurwan, Yunizurwan; Dedy, Rahmad

    2017-01-01

    Nanotechnology is the ability to create and manipulate atoms and molecules on the smallest of scales. Their size allows them to exhibit novel and significantly improved physical, chemical, biological properties, phenomena, and processes because of their size. The purpose of this research is obtaining micro-nano bacterial cellulose as reinforcing bioplastics. Bacterial cellulose (BC) was made from coconut water for two weeks. BC was dried and grinded. Bacterial cellulose was given purification process with NaOH 5% for 6 hours. Making the micro-nano bacterial cellulose with hydrolysis method. Hydrolysis process with hydrochloric acid (HCl) at the conditions 3,5M, 55°C, 6 hours. Drying process used spray dryer. The hydrolysis process was obtained bacterial cellulose with ±7 μm. The addition 2% micro-nano bacterial cellulose as reinforcing in bioplastics composite can improve the physical characteristics. (paper)

  13. Hydrothermal synthesis and electrochemical properties of nano-sized Co-Sn alloy anodes for lithium ion batteries

    International Nuclear Information System (INIS)

    He Jianchao; Zhao Hailei; Wang Jing; Wang Jie; Chen Jingbo

    2010-01-01

    Research highlights: → Nano-sized Co-Sn alloys were synthesized by hydrothermal route. → Li 2 O and CoSn can buffer the large volume change associated with lithiation of Sn. → A two-step reaction mechanism of CoSn 2 alloy during cycling was confirmed. - Abstract: Nano-sized Co-Sn alloys with a certain amount of Sn oxides used as potential anode materials for lithium ion batteries were synthesized by hydrothermal route. The effects of hydrothermal conditions and post annealing on the phase compositions and the electrochemical properties of synthesized powders were characterized by means of X-ray diffraction (XRD), field-emission scanning electron microscopy (FESEM) with energy dispersive spectra (EDS) analysis and galvanostatic cycling tests. Prolonging the dwelling time at the same hydrothermal temperature can increase the content of Sn oxides, which will lead to a high initial irreversible capacity loss but a better cycling stability owing to the buffer effect of irreversible product Li 2 O. Heat-treatment can increase the crystallinity and cause the presence of a certain amount of inert CoSn component, which both have positive impact on the cycling stability of Co-Sn electrode. By comparison with the lithiation/delithiation processes of metal Sn, a two-step mechanism of CoSn 2 alloy during cycling was confirmed.

  14. Nano materials for Energy and Environmental Applications

    International Nuclear Information System (INIS)

    Srinivasan, S.; Kannan, A.M.; Kothurkar, N.; Khalil, Y.; Kuravi, S.

    2015-01-01

    Nano materials enabled technologies have been seamlessly integrated into applications such as aviation and space, chemical industry, optics, solar hydrogen, fuel cell, batteries, sensors, power generation, aeronautic industry, building/construction industry, automotive engineering, consumer electronics, thermoelectric devices, pharmaceuticals, and cosmetic industry. Clean energy and environmental applications often demand the development of novel nano materials that can provide shortest reaction pathways for the enhancement of reaction kinetics. Understanding the physicochemical, structural, microstructural, surface, and interface properties of nano materials is vital for achieving the required efficiency, cycle life, and sustain ability in various technological applications. Nano materials with specific size and shape such as nano tubes, nano fibers/nano wires, nano cones, nano composites, nano rods, nano islands, nanoparticles, nanospheres, and nano shells to provide unique properties can be synthesized by tuning the process conditions.

  15. Preparation and Characterization of Nano-structured Ceramic Powders Synthesized by Emulsion Combustion Method

    International Nuclear Information System (INIS)

    Takatori, Kazumasa; Tani, Takao; Watanabe, Naoyoshi; Kamiya, Nobuo

    1999-01-01

    The emulsion combustion method (ECM), a novel powder production process, was originally developed to synthesize nano-structured metal-oxide powders. Metal ions in the aqueous droplets were rapidly oxidized by the combustion of the surrounding flammable liquid. The ECM achieved a small reaction field and a short reaction period to fabricate the submicron-sized hollow ceramic particles with extremely thin wall and chemically homogeneous ceramic powder. Alumina, zirconia, zirconia-ceria solid solutions and barium titanate were synthesized by the ECM process. Alumina and zirconia powders were characterized to be metastable in crystalline phase and hollow structure. The wall thickness of alumina was about 10 nm. The zirconia-ceria powders were found to be single-phase solid solutions for a wide composition range. These powders were characterized as equiaxed-shape, submicron-sized chemically homogeneous materials. The powder formation mechanism was investigated through the synthesis of barium titanate powder with different metal sources

  16. Enhanced ductility of surface nano-crystallized materials by modulating grain size gradient

    International Nuclear Information System (INIS)

    Li, Jianjun; Soh, A K

    2012-01-01

    Surface nano-crystallized (SNC) materials with a graded grain size distribution on their surfaces have been attracting increasing scientific interest over the past few decades due to their good synergy of high strength and high ductility. However, to date most of the existing studies have focused on the individual contribution of three different aspects, i.e. grain size gradient (GSG), work-hardened region and surface compressive residual stresses, which were induced by surface severe plastic deformation processes, to the improved strength of SNC materials as compared with that of their coarse grained (CG) counterparts. And the ductility of these materials has hardly been studied. In this study, a combination of theoretical analysis and finite element simulations was used to investigate the role of GSG in tuning the ductility of SNC materials. It was found that the ductility of an SNC material can be comparable to that of its CG counterpart, while it simultaneously possessed a much higher strength than its CG core if the optimal GSG thickness and grain size of the topmost phase were adopted. A design map that can be used as a guideline for fabrication of SNC materials was also plotted. Our predictions were also compared with the corresponding experimental results. (paper)

  17. Complementary techniques for solid oxide cell characterisation on micro- and nano-scale

    International Nuclear Information System (INIS)

    Wiedenmann, D.; Hauch, A.; Grobety, B.; Mogensen, M.; Vogt, U.

    2009-01-01

    High temperature steam electrolysis by solid oxide electrolysis cells (SOEC) is a way with great potential to transform clean and renewable energy from non-fossil sources to synthetic fuels such as hydrogen, methane or dimethyl ether, which have been identified as promising alternative energy carriers. Also, as SOEC can operate in the reverse mode as solid oxide fuel cells (SOFC), during high peak hours e.g. hydrogen can be used in a very efficient way to reconvert chemically stored energy into electrical energy. As solid oxide cells (SOC) are working at high temperatures (700-900 o C), material degradation and evaporation can occur e.g. from the cell sealing material, leading to poisoning effects and aging mechanisms which are decreasing the cell efficiency and long-term durability. In order to investigate such cell degradation processes, thorough examination on SOC often requires the chemical and structural characterisation on the microscopic and the nanoscopic level. The combination of different microscope techniques like conventional scanning electron microscopy (SEM), electron-probe microanalysis (EPMA) and the focused ion-beam (FIB) preparation technique for transmission electron microscopy (TEM) allows performing post mortem analysis on a multi scale level of cells after testing. These complementary techniques can be used to characterize structural and chemical changes over a large and representative sample area (micro-scale) on the one hand, and also on the nano-scale level for selected sample details on the other hand. This article presents a methodical approach for the structural and chemical characterisation of changes in aged cathode-supported electrolysis cells produced at Riso DTU, Denmark. Also, results from the characterisation of impurities at the electrolyte/hydrogen interface caused by evaporation from sealing material are discussed. (author)

  18. Synthesis of supported metallic nano-particles and their use in air depollution

    International Nuclear Information System (INIS)

    Barrault, J.; Valange, S.; Tatibouet, J.M.; Thollon, St.; Herlin-Boime, N.; Giraud, S.; Ruiz, J.Ch.; Bergaya, B.; Joulin, J.P.; Delbianco, N.; Gabelica, Z.; Daturi, M.

    2009-01-01

    The main objectives of the 'NACACOMO' Consortium ('Nano-materials: Catalysts for the Conversion of organic Molecules. Uses in fine chemicals and environment protection ') consisted in generating novel catalysts composed of nanoparticles of metals (Pt, Pd, Ag...) and/or oxides (TiO 2 ...) stabilized and well distributed over the surface of a support (foams, ceramics), by monitoring both the particle size and the 'coating' process itself, using new technologies: CVD, plasma-spray, laser pyrolysis, supercritical preparation, which were compared to conventional soft chemistry recipes. The most accurate characterization of particle morphology, local structure, texture, spatial arrangement but also of their reactivity, were achieved by privileging the utilization of various in situ methods. Details on formation mechanisms of a solid nano-particle at the atomic level (nucleation, growth and particle (re)distribution over the support...) could be obtained in selected cases, with opportunities for scaling up and shaping. The (chemical) nature of the so-obtained nano-materials was monitored for selected catalytic applications involving the development of environmental friendly processes, such as oxidation of VOC, with a priority for aromatics and chlorinated compounds. (authors)

  19. Thermodynamic and structural properties of ball-milled mixtures composed of nano-structural graphite and alkali(-earth) metal hydride

    International Nuclear Information System (INIS)

    Miyaoka, Hiroki; Ichikawa, Takayuki; Fujii, Hironobu

    2007-01-01

    Hydrogen desorption properties of mechanically milled materials composed of nano-structural hydrogenated-graphite (C nano H x ) and alkali(-earth) metal hydride (MH; M = Na, Mg and Ca) were investigated from the thermodynamic and structural points of view. The hydrogen desorption temperature for all the C nano H x and MH composites was obviously lower than that of the corresponding each hydride. In addition, the desorption of hydrocarbons from C nano H x was significantly suppressed by making composite of C nano H x with MH, even though C nano H x itself thermally desorbs a considerably large amount of hydrocarbons. These results indicate that an interaction exists between C nano H x and MH, and hydrogen in both the phases is destabilized by a close contact between polar C-H groups in C nano H x and the MH solid phase. Moreover, a new type of chemical bonding between the nano-structural carbon (C nano ) and the Li, Ca, or Mg metal atoms may be formed after hydrogen desorption. Thus, the above metal-C-H system would be recognized as a new family of H-storage materials

  20. Nano-organocatalyst: magnetically retrievable ferrite-anchored glutathione for microwave-assisted Paal–Knorr reaction, aza-Michael addition, and pyrazole synthesis

    KAUST Repository

    Polshettiwar, Vivek; Varma, Rajender S.

    2010-01-01

    Postsynthetic Surface modification of magnetic nanoparticles by glutathione imparts desirable chemical functionality and enables the generation of catalytic sites on the surfaces of ensuing organocatalysts. In this article, we discuss the developments, unique activity, and high selectivity of nano-organocatalysts for microwave-assisted Paal-Knorr reaction, aza-Michael addition, and pyrazole synthesis. Their insoluble character Coupled with paramagnetic nature enables easy separation of these nano-catalysts from the reaction mixture using external magnet, which eliminates the requirement of catalyst filtration. Published by Elsevier Ltd.

  1. Avalanche size scaling in sheared three-dimensional amorphous solid

    DEFF Research Database (Denmark)

    Bailey, Nicholas; Schiøtz, Jakob; Lemaître, A.

    2007-01-01

    We study the statistics of plastic rearrangement events in a simulated amorphous solid at T=0. Events are characterized by the energy release and the "slip volume", the product of plastic strain and system volume. Their distributions for a given system size L appear to be exponential......, but a characteristic event size cannot be inferred, because the mean values of these quantities increase as L-alpha with alpha similar to 3/2. In contrast with results obtained in 2D models, we do not see simply connected avalanches. The exponent suggests a fractal shape of the avalanches, which is also evidenced...

  2. Fabrication of nano-structured UO2 fuel pellets

    International Nuclear Information System (INIS)

    Yang, Jae Ho; Kang, Ki Won; Rhee, Young Woo; Kim, Dong Joo; Kim, Jong Heon; Kim, Keon Sik; Song, Kun Woo

    2007-01-01

    Nano-structured materials have received much attention for their possibility for various functional materials. Ceramics with a nano-structured grain have some special properties such as super plasticity and a low sintering temperature. To reduce the fuel cycle costs and the total mass of spent LWR fuels, it is necessary to extend the fuel discharged burn-up. In order to increase the fuel burn-up, it is important to understand the fuel property of a highly irradiated fuel pellet. Especially, research has focused on the formation of a porous and small grained microstructure in the rim area of the fuel, called High Burn-up Structure (HBS). The average grain size of HBS is about 300nm. This paper deals with the feasibility study on the fabrication of nano-structured UO 2 pellets. The nano sized UO 2 particles are prepared by a combined process of a oxidation-reducing and a mechanical milling of UO 2 powder. Nano-structured UO 2 pellets (∼300nm) with a density of ∼93%TD can be obtained by sintering nano-sized UO 2 compacts. The SEM study reveals that the microstructure of the fabricated nano-structure UO 2 pellet is similar to that of HBS. Therefore, this bulk nano-structured UO 2 pellet can be used as a reference pellet for a measurement of the physical properties of HBS

  3. Influence of ZnO nano-particles addition on thermal analysis, microstructure evolution and tensile behavior of Sn–5.0 wt% Sb–0.5 wt% Cu lead-free solder alloy

    Energy Technology Data Exchange (ETDEWEB)

    Fouda, A.N., E-mail: alynabieh@yahoo.com [Physics Department, Faculty of Science, Suez-Canal University, 41522 Ismailia (Egypt); Eid, E.A., E-mail: dr_eid_hti@yahoo.com [Basic Science Department, Higher Technological Institute, 44629 10th of Ramadan City (Egypt)

    2015-04-24

    Sn–5 wt%Sb–0.5 wt%Cu (plain SSC505) and Sn–5 wt%Sb–0.5 wt%Cu–0.5 wt% ZnO (SSC-ZnO) composite solder alloys have been studied. The variation in thermal behavior, microstructure and tensile characteristics associated with mixing of 0.5 wt% ZnO nano-metric particles to plain SSC505 solder were investigated. A slight increment in the melting temperature [ΔT{sub m}=0.89 °C] was recorded using differential scanning calorimetry (DSC) after addition of ZnO. X-Ray diffraction (XRD) analysis confirmed the existence of β-Sn, SbSn and Cu{sub 6}Sn{sub 5} intermetallic compounds (IMCs) beside some of ZnO planes in SSC-ZnO composite solder. Field emission scanning electronic microscope (FE-SEM) investigation of SSC-ZnO composite solder revealed a homogenous uniform distribution, size refinement of IMCs and β-Sn grains. Addition of ZnO nano-metric particles into the plain SSC505 enhanced the yield stress σ{sub YS} by ~12% and improved the ultimate tensile strength σ{sub UTS} by ~13%. In addition, adding ZnO nano-metric particles was found to be effective for reducing ductility by ~43% of the plain solder due to the refinement of β-Sn grains within SSC-ZnO composite solder. - Highlights: • Melting point of SSC505-ZnO composite solder is slightly increased by 0.89 {sup ο}C compared with the plain SSC505 solder. • XRD and EDX analysis reflect the presence of SbSn, Cu{sub 6}Sn{sub 5} IMCs. • EF-SEM images of SSC-ZnO composite solder revealed homogenous uniform distribution of β-Sn grains and fine IMC particles. • A detectable improvement in the Young modulus, ultimate tensile strength and yield strength were observed after addition of 0.5 wt% ZnO nano-metric particles.

  4. Particle phase distribution of polycyclic aromatic hydrocarbons in stormwater — Using humic acid and iron nano-sized colloids as test particles

    DEFF Research Database (Denmark)

    Nielsen, Katrine; Kalmykova, Yuliya; Strömvall, Ann-Margret

    2015-01-01

    The distribution of polycyclic aromatic hydrocarbons (PAHs) in different particulate fractions in stormwater: Total, Particulate, Filtrated, Colloidal and Dissolved fractions, were examined and compared to synthetic suspensions of humic acid colloids and iron nano-sized particles. The distribution...

  5. The Effects of Solid Phase Additives on Sintering Properties of Alumina Bioceramic

    Institute of Scientific and Technical Information of China (English)

    WANG Xin-yu; LI Shi-pu; HE Jian-hua; JIANG Xin; LI Jian-hua

    2003-01-01

    In order to reduce the sintering temperature and improve the preparing conditions of alumina bioceramics,the Mg-Zr-Y composite solid phase additives were added into high purity Al2O3 micro-powder by chemical coprecipitation method.The powder was shaped under 200MPa cold isostatic pressure,and then the biscuits were sintered at 1600℃ under normal pressure.The sintered alumina materials were tested and the sintering mechanism was discussed.The results show that physical properties of the material were improved comparatively.The Mg-Zr-Y composite solid additives could promote the sintering of alumina bioceramics and the mechanism is solid phase sintering.

  6. Preparation and characterization of nano hydroxyapatite/polymeric composites materials. Part I

    Energy Technology Data Exchange (ETDEWEB)

    Mohamed, Khaled R., E-mail: kh_rezk1966@yahoo.com [Biomaterials Dept., National Research Centre, Dokki, Cairo (Egypt); El-Rashidy, Zenab M. [Biomaterials Dept., National Research Centre, Dokki, Cairo (Egypt); Salama, Aida A. [Biophysics Dept., Faulty of Science, El-Azhar Univ., Cairo (Egypt)

    2011-10-17

    Highlights: {yields} The formation and coating of CHA increased by increasing polymer content. {yields} The size of the prepared CHA was within nano-range scale. {yields} The composites had homogeneity and CHA formed within the polymeric matrix. - Abstract: The present study is focused on preparation of nano composite materials and the effect of citric acid on their different properties. The formation of nano HA and its interaction with chitosan (C), gelatin (G) polymers and citric acid (CA) materials were studied. The Fourier Transformed Infrared Spectroscopy (FT-IR), X-ray diffraction (XRD), thermo-gravimetric analysis (TGA), transmission electron microscope (TEM), and scanning electron microscope (SEM) were used to characterize these composite materials. The compressive strength (CS) was also measured to know the reinforcement of the prepared composites. The results show that carboxylic and amino groups play crucial role for HA formation on chitosan-gelatin polymeric matrix in the presence of citric acid (CA). The formation of nano HA particles and its average size of crystallite is increased with increase of CG content and decreased with addition of CA. Also, the HA formation and binding strength between its particles are improved into the composites especially with CA. The nano-composites containing the best ratio of nHA (70%) with CA (0.2 M) are promising for medical applications in the future.

  7. Nano-pyramid arrays for nano-particle trapping

    NARCIS (Netherlands)

    Sun, Xingwu; Veltkamp, Henk-Willem; Berenschot, Johan W.; Gardeniers, Johannes G.E.; Tas, Niels Roelof

    2016-01-01

    Abstract In this paper we present the drastic miniaturization of nano-wire pyramids fabricated by corner lithography. A particle trapping device was fabricated in a well-defined and symmetrical array. The entrance and exit hole-size can be tuned by adjusting fabrication parameters. We describe here

  8. Investigation of Luminescence Characteristics of Some Synthetic Nano phosphors and Possibility of Application in Mixed Field Radiation Detection

    International Nuclear Information System (INIS)

    Ahmed, N.Y.A.

    2013-01-01

    The work given in this thesis aimed at Fabrication of high quality nano phosphor particles for getting high sensitive thermoluminescence material to use as ionizing radiation dosimeter. Ca Sr S nano phosphor has been prepared by solid state diffusion reaction method. The prepared nano phosphor was then activated with proper addition of some rare earth elements (dysprosium and gadolinium) for the sake of improving its TL sensitivity. The doped Ca Sr S nano phosphor was then treated by different courses of heat annealing for dual sake and regeneration. High temperature and high gamma dose sensitization are also used to increase sensitivity of Ca Sr S doped. By this means the TL-intensity of treated samples proved about 24 times observed enhancement. The prepared Ca Sr S: Dy nano phosphor is very reliable as pure gamma dosimeter for various applications such as personal, environmental and clinical dosimetry.

  9. A Facile Method for Separating and Enriching Nano and Submicron Particles from Titanium Dioxide Found in Food and Pharmaceutical Products.

    Science.gov (United States)

    Faust, James J; Doudrick, Kyle; Yang, Yu; Capco, David G; Westerhoff, Paul

    2016-01-01

    Recent studies indicate the presence of nano-scale titanium dioxide (TiO2) as an additive in human foodstuffs, but a practical protocol to isolate and separate nano-fractions from soluble foodstuffs as a source of material remains elusive. As such, we developed a method for separating the nano and submicron fractions found in commercial-grade TiO2 (E171) and E171 extracted from soluble foodstuffs and pharmaceutical products (e.g., chewing gum, pain reliever, and allergy medicine). Primary particle analysis of commercial-grade E171 indicated that 54% of particles were nano-sized (i.e., E171 and E171 isolated from foodstuffs and pharmaceuticals was accomplished using rate-zonal centrifugation. Commercial-grade E171 was separated into nano- and submicron-enriched fractions consisting of a nano:submicron fraction of approximately 0.45:1 and 3.2:1, respectively. E171 extracted from gum had nano:submicron fractions of 1.4:1 and 0.19:1 for nano- and submicron-enriched, respectively. We show a difference in particle adhesion to the cell surface, which was found to be dependent on particle size and epithelial orientation. Finally, we provide evidence that E171 particles are not immediately cytotoxic to the Caco-2 human intestinal epithelium model. These data suggest that this separation method is appropriate for studies interested in isolating the nano-sized particle fraction taken directly from consumer products, in order to study separately the effects of nano and submicron particles.

  10. The many faces of nano in newspaper reporting

    Science.gov (United States)

    Boholm, Max; Boholm, Åsa

    2012-02-01

    The morpheme nano in languages such as Swedish and English is a constituent of many words. This article linguistically analyses the meaning potential of nano by focusing on word use in a Swedish newspaper corpus comprising 2,564 articles (1.6 million words) covering a 22-year period (1988-2010). Close to 400 word forms having nano as a constituent have been identified and analyzed. The results suggest that nano covers a broad and heterogeneous conceptual field: (i) as a prefix of the SI system; (ii) in relation to the scientific activities of nanoscience and nanotechnology, including their sub-processes and actors; and (iii) in relation to objects. The identified meanings of nano, besides the standard definition (i.e. `billionth part' in relation to SI units), are `operating at the nanometre level' in relation to activities and their actors and `nanometre sized' and `nanotechnological' in relation to objects; in addition, the less precise and non-technical meaning `very small' is identified. We discuss the implications of the findings for a hypothesis about media influence on public understanding of technology, suggesting that repeated findings in Europe and the USA of little self-reported understanding and knowledge of nanotechnology or nanoscience among the public make sense in light of the polysemy of nano reflected in its broad variety of verbal forms and usages.

  11. Comparative Study of Magnetic Ordering and Electrical Transport in Bulk and Nano-Grained Nd{sub 0.67}Sr{sub 0.33}MnO{sub 3} Manganites

    Energy Technology Data Exchange (ETDEWEB)

    Arun, B. [Materials Science and Technology Division, CSIR-National Institute for Interdisciplinary Science and Technology, Trivandrum (India); Academy of Scientific and Innovative Research (AcSIR), CSIR, Trivandrum (India); Suneesh, M.V. [Materials Science and Technology Division, CSIR-National Institute for Interdisciplinary Science and Technology, Trivandrum (India); Vasundhara, M., E-mail: vasu.mutta@gmail.com [Materials Science and Technology Division, CSIR-National Institute for Interdisciplinary Science and Technology, Trivandrum (India)

    2016-11-15

    We have prepared bulk and nano-sized Nd{sub 0.67}Sr{sub 0.33}MnO{sub 3} manganites by solid state and low-temperature mild solgel methods respectively. Both the compounds crystallized into an orthorhombic structure with Pbnm space group confirmed from Rietveld refinement of X-ray powder diffraction patterns. Nano-grained compound shows an average particle size of 22 nm with broad grain size distribution revealed from the Transmission electron micrographs. It appeared that the long range ferromagnetic order becomes unstable upon the reduction of the samples dimension down to nano meter scale. DC magnetization and AC susceptibility results showed frustration of spins in nano-grained compound and thereby it could lead to a cluster glass-like behaviour. Temperature dependence of electrical resistivity under different magnetic fields shows the broad maxima at higher temperatures and a low temperature upturn in both the compounds, however, the latter is more prominent in the nano grained compound. Combination of Kondo effect with electron and phonon interactions govern the low temperature resistivity and a small polaron hopping mechanism dominates at high temperatures for both the compounds. The magnetoresistance is understood by the effect of spin polarized tunneling through the grain boundary. The experimental results revealed that the reduction in particle size influences severely on the magnetic, electrical and magneto transport properties. - Highlights: • Long range ferromagnetic ordered state become unstable in case of nano compound. • It shows broad magnetic transition and cluster glass nature. • Kondo effect with electron-phonon interactions dominate the resistivity at low temperature.

  12. Ceramic compositions based on nano forsterite/nano magnesium aluminate spinel powders

    International Nuclear Information System (INIS)

    Khattab, R.M.; Wahsh, M.M.S.; Khalil, N.M.

    2015-01-01

    According to the wide applications in the field of chemical and engineering industries, forsterite (Mg_2SiO_4)/spinel (MgAl_2O_4) ceramic compositions were the matter of interest of several research works during the last three decades. This work aims at preparation and characterization of improved ceramic bodies based on forsterite and spinel nano powders through controlling the forsterite and spinel contents in the prepared mixes. These prepared ceramic compositions have been investigated through measuring the densification parameters, cold crushing strength as well as volume resistively. Nano spinel was added from 0 to 30 mass% on expense of nano forsterite matrix and fired at 1550 °C for 2 h. The phase composition of the fired samples was examined using x-ray diffraction (XRD) technique. The microstructure of some selected samples was shown using scanning electron microscope (SEM). A pronounced improvement in the sintering, mechanical properties and volume resistively were achieved with increasing of nano spinel addition up to 15 mass%. This is due to the improvement in the matrix of the prepared forsterite/spinel bodies as a result of well distribution of spinel in the forsterite matrix as depicted by SEM analysis. - Highlights: • Ceramic compositions based on nano forsterite/nano-MgAl_2O_4 spinel were synthesized. • CCS was improved (333.78 MPa) through 15 mass% of nano-MgAl_2O_4 spinel addition. • Volume resistivity was enhanced to 203*10"1"3 Ohm cm with 15 mass% of spinel addition. • Beyond 15 mass% spinel, CCS and volume resistivity were decreased.

  13. From zinc selenate to zinc selenide nano structures synthesized by reduction process

    International Nuclear Information System (INIS)

    Hutagalung, S.D.; Eng, S.T.; Ahmad, Z.A.; Ishak Mat; Yussof Wahab

    2009-01-01

    One-dimensional nano structure materials are very attractive because of their electronic and optical properties depending on their size. It is well known that properties of material can be tuned by reducing size to nano scale because at the small sizes, that they behave differently with its bulk materials and the band gap will control by the size. The tunability of the band gap makes nano structured materials useful for many applications. As one of the wide band gaps semiconductor compounds, zinc selenide (ZnSe) nano structures (nanoparticles, nano wires, nano rods) have received much attention for the application in optoelectronic devices, such as blue laser diode, light emitting diodes, solar cells and IR optical windows. In this study, ZnSe nano structures have been synthesized by reduction process of zinc selenate using hydrazine hydrate (N 2 H 4 .2H 2 O). The reductive agent of hydrazine hydrate was added to the starting materials of zinc selenate were heat treated at 500 degree Celsius for 1 hour under argon flow to form one-dimensional nano structures. The SEM and TEM images show the formation of nano composite-like structure, which some small nano bar and nano pellets stick to the rod. The x-ray diffraction and elemental composition analysis confirm the formation of mixture zinc oxide and zinc selenide phases. (author)

  14. The crystallization kinetic model of nano-CaCO3 in CO2-ammonia-phosphogypsum three-phase reaction system

    Science.gov (United States)

    Liu, Hao; Lan, Peiqiang; Lu, Shangqing; Wu, Sufang

    2018-06-01

    Phosphogypsum (PG) as a low-cost calcium resource was used to prepare nano-CaCO3 in a three-phase system by reactions. Based on the population balance equation, nano-CaCO3 crystal nucleation and growth model in the gas (CO2)-liquid (NH3·H2O)-solid (CaSO4) three-phase system was established. The crystallization kinetic model of nano-CaCO3 in CO2-NH3·H2O-CaSO4 reactions system was experimental developed over an optimized temperature range of 20-40 °C and CO2 flow rate range of 138-251 ml/min as rCaCO3 =kn 32 πM2γ3/3R3ρ2T3 (C -C∗)0.8/[ ln (C /C∗) ]3 + πρ/3M kg3 kn(C -C∗) 2t3 , where nano-CaCO3 nucleation rate constant was kn = 6.24 ×1019 exp(-15940/RT) and nano-CaCO3 growth rate constant was kg = 0.79 exp(-47650/RT) respectively. Research indicated that nucleation rates and growth rates both increased with the increasing of temperature and CO32- ion concentration. And crystal growth was dependent on temperature more than that of nucleation process because the activation energy of CaCO3 growth was bigger than that of CaCO3 nucleation. Decreasing the reaction temperature and CO2 flow rate was more beneficial for producing nano-size CaCO3 because of the lower CaCO3 growth rates. The deduced kinetic equation could briefly predict the average particle sizes of nano-CaCO3.

  15. Small angle neutron scattering study of nano sized microstructure in Fe-Cr ODS steels for gen IV in-core applications.

    Science.gov (United States)

    Han, Young-Soo; Mao, Xiadong; Jang, Jinsung

    2013-11-01

    The nano-sized microstructures in Fe-Cr oxide dispersion strengthened steel for Gen IV in-core applications were studied using small angle neutron scattering. The oxide dispersion strengthened steel was manufactured through hot isostatic pressing with various chemical compositions and fabrication conditions. Small angle neutron scattering experiments were performed using a 40 m small angle neutron scattering instrument at HANARO. Nano sized microstructures, namely, yttrium oxides and Cr-oxides were quantitatively analyzed by small angle neutron scattering. The yttrium oxides and Cr-oxides were also observed by transmission electron microscopy. The microstructural analysis results from small angle neutron scattering were compared with those obtained by transmission electron microscopy. The effects of the chemical compositions and fabrication conditions on the microstructure were investigated in relation to the quantitative microstructural analysis results obtained by small angle neutron scattering. The volume fraction of Y-oxide increases after fabrication, and this result is considered to be due to the formation of non-stochiometric Y-Ti-oxides.

  16. Stimulated Brillouin scattering of laser in semiconductor plasma embedded with nano-sized grains

    Energy Technology Data Exchange (ETDEWEB)

    Sharma, Giriraj, E-mail: grsharma@gmail.com [SRJ Government Girls’ College, Neemuch (M P) (India); Dad, R. C. [Government P G College, Mandsaur (M P) (India); Ghosh, S. [School of Studies in Physics, Vikram University, Ujjain, (M P) (India)

    2015-07-31

    A high power laser propagating through semiconductor plasma undergoes Stimulated Brillouin scattering (SBS) from the electrostrictively generated acoustic perturbations. We have considered that nano-sized grains (NSGs) ions are embedded in semiconductor plasma by means of ion implantation. The NSGs are bombarded by the surrounding plasma particles and collect electrons. By considering a negative charge on the NSGs, we present an analytically study on the effects of NSGs on threshold field for the onset of SBS and Brillouin gain of generated Brillouin scattered mode. It is found that as the charge on the NSGs builds up, the Brillouin gain is significantly raised and the threshold pump field for the onset of SBS process is lowered.

  17. Synthesis, characterization, and photo-physical properties of nano-crystallites of CdyZn1-yS semiconductors

    International Nuclear Information System (INIS)

    Cizeron, Joel

    1996-01-01

    This research thesis reports the study of the synthesis of particles of semiconductor with a hybrid composition (Cd y Zn 1-y S) in an inverse micellar system. This system is made of nano-scopic water droplets suspended in oil by Brownian movement. Inverse micelles of AOT/water/alkane have been successfully used in laboratory to synthesize semiconductor particles (CdS, Ag 2 S, AgI, PbS) and metallic particles (Ag, Cu, Co) with a diameter of few nanometers. The objective has been to demonstrate the feasibility of synthesises of solid solution with a composition controlled by colloidal techniques. It was then possible to identify new information on the mechanism which governs the size of semiconductor particles. Optical properties of these particles were then studied. These nano-particles exhibit a displacement of their exciton towards high energies; it is the so-called size quantum effect. This effect has been analysed for the particles and their fluorescence [fr

  18. Synthesis and Characterization of Nano-Sized Hexagonal and Spherical Nanoparticles of Zinc Oxide

    Directory of Open Access Journals (Sweden)

    M. A. Moghri Moazzen

    2012-09-01

    Full Text Available ZnO plays an important role in many semiconductors technological aspects.  Here,  direct  precipitation  method  was  employed  for  the synthesis of nano-sized hexagonal ZnO particles, which is based on chemical  reactions between  raw materials used  in  the  experiment. ZnO  nanoparticles  were  synthesized  by  calcinations  of  the  ZnO precursor precipitates  at 250  ˚C  for 3hours. The particle  size  and structure of the products have been confirmed by XRD. The FT-IR study  confirms  the  presence  of  functional  groups.  Also,  the morphology  and  size  distribution  of  ZnO  nanoparticles  was analyzed by TEM images. The optical properties were investigated by UV–Visible  spectroscopy. The XRD  results  show  that  the  size of  the prepared nanoparticles  is  in  the  range  of 20–40 nm, which this value  is  in good agreement with  the TEM  results. The FT-IR spectrum clearly indicates the formation of an interfacial chemical bond between Zn and O. Also  the UV absorption depends on  the particles  size  and morphology,  so  the  optical properties  enhances with  decreasing  nanoparticles  size.  Moreover  the  direct precipitation technique is a feasible method for production of ZnO nanopowders.

  19. Understanding dual precipitation strengthening in ultra-high strength low carbon steel containing nano-sized copper precipitates and carbides

    Science.gov (United States)

    Phaniraj, M. P.; Shin, Young-Min; Jung, Woo-Sang; Kim, Man-Ho; Choi, In-Suk

    2017-07-01

    Low carbon ferritic steel alloyed with Ti, Mo and Cu was hot rolled and interrupt cooled to produce nano-sized precipitates of copper and (Ti,Mo)C carbides. The steel had a tensile strength of 840 MPa, an increase in yield strength of 380 MPa over that of the plain carbon steel and reasonable ductility. Transmission electron microscopy and small angle neutron scattering were used to characterize size and volume fraction of the precipitates in the steels designed to form only copper precipitates and only (Ti,Mo)C carbides. The individual and combined precipitation strengthening contributions was calculated using the size and volume fraction of precipitates and compared with the measured values.

  20. The nano-fractal structured tungsten oxides films with high thermal stability prepared by the deposition of size-selected W clusters

    Energy Technology Data Exchange (ETDEWEB)

    Park, Eun Ji; Kim, Young Dok [Sungkyunkwan University, Department of Chemistry, Suwon (Korea, Republic of); Dollinger, Andreas; Huether, Lukas; Blankenhorn, Moritz; Koehler, Kerstine; Gantefoer, Gerd [Konstanz University, Department of Physics, Constance (Germany); Seo, Hyun Ook [Sangmyung University, Department of Chemistry and Energy Engineering, Seoul (Korea, Republic of)

    2017-06-15

    Size-selected W{sub n}{sup -} clusters (n = 1650) were deposited on the highly ordered pyrolytic graphite surface at room temperature under high vacuum conditions by utilizing a magnetron sputtering source and a magnet sector field. Moreover, geometrical structure and surface chemical states of deposited clusters were analyzed by in situ scanning tunneling microscopy (STM) and X-ray photoelectron spectroscopy, respectively. The formation of 2-D islands (lateral size ∝150 nm) with multiple dendritic arms was observed by STM, and the structure of the individual W{sub 1650} clusters survived within the dendritic arms. To study the thermal stability of the nano-fractal structure under the atmospheric conditions, the sample was brought to the ambient air conditions and sequentially post-annealed at 200, 300, and 500 C in the air. The nano-fractal structure was maintained after the 1st post-annealing process at 200 C for 1 h in the air, and the subsequent 2nd post-annealing at 300 C (for 1 h, in the air) also did not induce any noticeable change in the topological structure of the sample. The topological changes were observed only after the further post-annealing at a higher temperature (at 500 C, 1 h) in the air. We show high potential use of these nano-structured films of tungsten oxides in ambient conditions. (orig.)

  1. Physicochemical characterization of atorvastatin calcium/ezetimibe amorphous nano-solid dispersions prepared by electrospraying method.

    Science.gov (United States)

    Jahangiri, Azin; Barzegar-Jalali, Mohammad; Javadzadeh, Yousef; Hamishehkar, Hamed; Adibkia, Khosro

    2017-09-01

    In the present study, electrospraying was applied as a novel method for the fabrication of amorphous nano-solid dispersions (N-SDs) of atorvastatin calcium (ATV), ezetimibe (EZT), and ATV/EZT combination as poorly water-soluble drugs. N-SDs were prepared using polyvinylpyrrolidone K30 as an amorphous carrier in 1:1 and 1:5 drug to polymer ratios and the total solid (including drug and polymer) concentrations of 10 and 20% (w/v). The prepared formulations were further investigated for their morphological, physicochemical, and dissolution properties. Scanning electron microscopy studies indicated that the morphology and diameter of the electrosprayed samples (ESs) were influenced by the solution concentration and drug:polymer ratio, so that an increase in the solution concentration resulted in fiber formation while an increase in the polymer ratio led to enhancement of the particle diameter. Differential scanning calorimetry and X-ray powder diffraction studies together with in vitro dissolution test revealed that the ESs were present in an amorphous form with improved dissolution properties. Infrared spectroscopic studies showed hydrogen-bonding interaction between the drug and polymer in ESs. Since the electrospraying method benefits from the both amorphization and nanosizing effect, this novel approach seems to be an efficient method for the fabrication of N-SDs of poorly water-soluble drugs.

  2. SYNTHESIS AND CORROSION PROTECTION BEHAVIOR OF EPOXYTiO2-MICACEOUS IRON OXIDE NANO - COMPOSITE COATING ON St-37

    Directory of Open Access Journals (Sweden)

    M. R. Khorram

    2016-03-01

    Full Text Available The micro layers micaceous iron oxide and nano-TiO 2 were incorporated into the epoxy resin by mechanical mixing and sonication process. Optical micrographs showed that the number and diameter size of nanoparticle agglomerates were decreased by sonication. The structure and composition of the nanocomposite was determined using transmission electron microscopy which showed the presence of dispersed nano-TiO 2 in the polymer matrix. The anticorrosive properties of the synthesized nano-composites coating were investigated using salt spray, electrochemical impedance spectroscopy and polarization measurement. The EIS results showed that coating resistance increased by addition of micaceous iron oxide micro layers and nano-TiO 2 particles to the epoxy coatings. It was observed that higher corrosion protection of nanocomposite coatings obtained by the addition of 3 %wt micaceous iron oxide and 4%wt nano-TiO 2 into epoxy resin.

  3. Nano-crystals of cerium–hafnium binary oxide: Their size-dependent structure

    Energy Technology Data Exchange (ETDEWEB)

    Raitano, Joan M. [Department of Applied Physics and Applied Mathematics, Materials Science and Engineering Program, Columbia University, New York, NY 10027 (United States); Khalid, Syed [National Synchrotron Light Source, Brookhaven National Laboratory, Upton, NY 11973 (United States); Marinkovic, Nebojsa [Chemical Engineering Department, Columbia University, 500 W 120th St, Mudd 801, New York, NY 10027 (United States); Chan, Siu-Wai, E-mail: sc174@columbia.edu [Department of Applied Physics and Applied Mathematics, Materials Science and Engineering Program, Columbia University, New York, NY 10027 (United States)

    2015-09-25

    Highlights: • (1 − x)CeO{sub 2}–xHfO{sub 2} was precipitated (0 < x < 1) and calcined in air. • For x ⩽ 0.14, crystallites ⩽140 nm in size exhibit only the fluorite structure. • This low hafnia solubility is attributable to no auto-reduction (Ce{sup 3+} = 0). • The low solubility is also due to the high temperature required for homogenization. • Coarsening is lessened as Hf{sup 4+} ions slow cation diffusion in these crystallites. - Abstract: Cerium oxide (CeO{sub 2}, “ceria”) and hafnium oxide (HfO{sub 2}, “hafnia”) were aqueously co-precipitated and subsequently calcined to allow for homogenization. The size of the (1−x)CeO{sub 2}–xHfO{sub 2} crystallites, determined by the Scherrer equation, varied from 140 nm for x = 0 to 15 nm for x = 0.73. For x ⩽ 0.14, only cubic structures are visible in X-ray diffractograms, and the lattice parameters are consistent with the values expected for structurally cubic solid solutions of hafnia in ceria. At x = 0.26, tetragonal and monoclinic phases nucleated with the former not being observed in the bulk phase diagram for ceria–hafnia. Therefore, the solubility limit of the cubic structure is between x = 0.14 and x = 0.26 for 40–61 nm crystallites, the sizes of these respective compositions. More specifically, for the 40 nm crystallites of x = 0.26 (1 − x)CeO{sub 2}–xHfO{sub 2}, 15% of the hafnia remains in a structurally cubic solid solution with ceria based on the observed cubic lattice parameter. The compositional domain for the cubic fluorite structure in this study is narrower than other nanostructured (1 − x)CeO{sub 2}–xHfO{sub 2} studies, especially studies with crystallite sizes less than 10 nm, but wider than observed in the bulk and helps to expand the size regime over which the relationship between crystallite size and phase stability is known. The extent of this cubic-structure domain is mainly attributable to the intermediate crystallite size and the roughly zero Ce{sup 3

  4. Fabrication and thermomechanical properties of nano-SiC/carbon nano-tubes composites

    International Nuclear Information System (INIS)

    Lanfant, Briac

    2014-01-01

    Ceramic carbides materials such as SiC, due to their refractory nature and their low neutron absorption are believed to be promising candidates for high temperature nuclear or aerospace applications. However, SiC brittleness has limited its structural application. In this context this work examines in a first part the possibilities to perform dense nano-structured SiC matrix by SPS without the use of sintering additive. Indeed a reduction of grain size (below 100 nm) accompanied by a high final density seem to be the solutions to counteract the brittleness and thus to improve mechanical properties. Dense (95%) and nano-structured (grain size around 100 nm) SiC samples were obtained thanks to the realization of an effective dispersion technique and the study on the sintering parameters effect. High hardness (2200 Hv) and decent fracture toughness (3.0 MPa.m1/2) were achieved. This first work also showed the preponderant influence of recurrent pollutants (oxygen and carbon) found in SiC powders on the final microstructure and mechanical properties of sintered samples. The oxygen as silica or silicon oxycarbide seems to promote densification mechanisms while free carbon (3.5 %wt) causes lower grain size and densification state. Mechanical properties with carbon are also negatively impacted (950 Hv and 2.4 MPa.m1/2). Such degradation is due by the specific localization of carbon structure between the grains. In return of the expected mechanical properties improvement by reducing the grain size, the thermal conductivity is drastically decrease of due to the phonon scattering at the grain boundaries. With the aim of reducing this effect, a second study was initiated by introducing multi-walled carbon nano-tubes (MWCNTs) into the SiC matrix. The MWCNTs by exhibiting a high toughness could also help to enhance the mechanical properties. Green bodies with different amounts of well dispersed MWCNTs (0 %wt to 5 %wt) were realized. Like free carbon, MWCNTs are located between

  5. Microstructure engineering of Portland cement pastes and mortars through addition of ultrafine layer silicates

    DEFF Research Database (Denmark)

    Lindgreen, Holger; Geiker, Mette; Krøyer, Hanne

    2008-01-01

    Pozzolanic submicron-sized silica fume and the non-pozzolanic micron- and nano-sized layer silicates (clay minerals) kaolinite, smectite and palygorskite have been used as additives in Portland cement pastes and mortars. These layer silicates have different particle shape (needles and plates......), surface charge, and size (micron and nano). The structure of the resulting cement pastes and mortars has been investigated by atomic force microscopy (AFM), helium porosimetry, nitrogen adsorption (specific surface area and porosity), low-temperature calorimetry (LTC) and thermal analysis. The main result...... is that the cement paste structure and porosity can be engineered by addition of selected layer silicates having specific particle shapes and surface properties (e.g., charge and specific surface area). This seems to be due to the growth of calcium-silicate hydrates (C-S-H) on the clay particle surfaces...

  6. Surface characteristics, copper release, and toxicity of nano- and micrometer-sized copper and copper(II) oxide particles: a cross-disciplinary study.

    OpenAIRE

    Midander, Klara; Cronholm, Pontus; Karlsson, Hanna L.; Elihn, Karine; Moller, Lennart; Leygraf, Christofer; Wallinder, Inger Odnevall

    2009-01-01

    An interdisciplinary and multianalytical research effort is undertaken to assess the toxic aspects of thoroughly characterized nano- and micrometer-sized particles of oxidized metallic copper and copper(II) oxide in contact with cultivated lung cells, as well as copper release in relevant media. All particles, except micrometer-sized Cu, release more copper in serum-containing cell medium (supplemented Dulbecco's minimal essential medium) compared to identical exposures in phosphate-buffered ...

  7. Bacteria-assisted preparation of nano α-Fe2O3 red pigment powders from waste ferrous sulfate

    International Nuclear Information System (INIS)

    Li, Xiang; Wang, Chuankai; Zeng, Yu; Li, Panyu; Xie, Tonghui; Zhang, Yongkui

    2016-01-01

    Highlights: • A route to prepare nano α-Fe 2 O 3 red pigment from waste ferrous sulfate is proposed. • Acidithiobacillus ferrooxidans is introduced for accelerating iron oxidation. • The particle size of synthetic α-Fe 2 O 3 is ranged from 22 nm to 86 nm. • The prepared nano α-Fe 2 O 3 red pigment fulfills ISO 1248-2006. - Abstract: Massive ferrous sulfate with excess sulfuric acid is produced in titanium dioxide industry each year, ending up stockpiled or in landfills as solid waste, which is hazardous to environment and in urgent demand to be recycled. In this study, waste ferrous sulfate was used as a second raw material to synthesize nano α-Fe 2 O 3 red pigment powders with a bacteria-assisted oxidation process by Acidithiobacillus ferrooxidans. The synthesis route, mainly consisting of bio-oxidation, precipitation and calcination, was investigated by means of titration, thermogravimetric analysis (TGA), X-ray diffraction (XRD), scanning electron microscope (SEM) and X-ray fluorescence (XRF) to obtain optimum conditions. Under the optimum conditions, nano α-Fe 2 O 3 red pigment powders contained 98.24 wt.% of Fe 2 O 3 were successfully prepared, with a morphology of spheroidal and particle size ranged from 22 nm to 86 nm and averaged at 45 nm. Moreover, the resulting product fulfilled ISO 1248-2006, the standards of iron oxide pigments.

  8. Nano crystals-Related Synthesis, Assembly, and Energy Applications

    International Nuclear Information System (INIS)

    Dai, Q.; Hu, M.Z.; Yu, B.Z.; William, W.; Seo, J.

    2011-01-01

    Fundamental material properties have been dramatically altered in the nano scale regime because of quantum confinement effect. The unique size-tunable functionalities of nano materials make them involved in an extensive variety of energy applications, such as light-emitting diodes and solar cells. These applications have been demonstrated to cut energy consumption. In response to the ever-growing energy demands as well as the concerns of global warming, researchers are actively placing their enormous emphasis on the exploration of energy savings. During this exploration, the primary stage requires the design of appropriate strategies for the synthesis of high-quality nano crystals in terms of size uniformity and superior optical/electronic properties. Especially, there is a need to seek green-chemistry approaches for the synthesis of environmentally benign and user-friendly nano crystals. Another recent area of focus is the use of individual nano crystals as building blocks for self-assembly, providing new opportunities to improve the nano crystal performance

  9. Photoluminescent nano-sized ternary and quaternary complexes of thorium(IV)

    International Nuclear Information System (INIS)

    Baranwal, B.P.; Jain, A.K.; Varma, A.; Singh, A.K.; Fatma, T.

    2011-01-01

    Some ternary and quaternary complexes of thorium(IV) with the general formula [Th(OOCCH 3 ) 2-n (SB) n (OOCC 15 H 31 ) 2 ] (HSB=Schiff bases and n=1 or 2) have been synthesized by the stepwise substitutions of acetate ions from thorium(IV) acetate, first with straight chain carboxylic acid and then with Schiff bases. The complexes are characterized by elemental analyses, spectral (electronic, infrared, 1 H NMR, FAB mass, photoluminescence and powder XRD) and TEM studies. Conductance measurements indicated non-conducting behaviour of the complexes. Structural parameters from powder XRD data for complexes 5 and 6 which indicate poorly crystalline nano-sized triclinic particles. Electronic absorption spectra of the complexes showed π → π * and n → π * charge transfer transitions. All complexes displayed fluorescence and a correlation was sought between luminescence spectra of complexes in solution at room temperature. On the basis of physico-chemical studies, coordination number 8 was assigned for thorium(IV) in the complexes. The morphology and microstructure of the complexes were examined with transmission electron microscopy (TEM) and the selected area electron diffraction (SAED). (orig.)

  10. The crystallinity of calcium phosphate powders influenced by the conditions of neutralized procedure with citric acid additions

    International Nuclear Information System (INIS)

    Li Chengfeng

    2009-01-01

    Calcium phosphate powders with nano-sized crystallinity were synthesized by neutralization using calcium hydroxide and orthophosphoric acid with the assistance of citric acid. The influence of processing parameters, such as free or additive citric acid, synthetic temperature and ripening time, on the crystallinity of hydroxyapatite were investigated. The results of X-ray diffraction and microstructure observations showed that the crystallinity and morphology of nano-sized hydroxyapatite particles were influenced by the presence or absence of citric acid. It was found that the crystallinities and crystallite sizes of hydroxyapatite powders prepared with the additive citric acid increased with increasing synthetic temperature and ripening time. Especially, the crystallinities of (h k 0) planes were raised and more homogeneously grown particles were obtained with increasing synthetic temperature

  11. Demonstration of Ultra-Fast Switching in Nano metallic Resistive Switching Memory Devices

    International Nuclear Information System (INIS)

    Yang, Y.

    2016-01-01

    Interdependency of switching voltage and time creates a dilemma/obstacle for most resistive switching memories, which indicates low switching voltage and ultra-fast switching time cannot be simultaneously achieved. In this paper, an ultra-fast (sub-100 ns) yet low switching voltage resistive switching memory device (“nano metallic ReRAM”) was demonstrated. Experimental switching voltage is found independent of pulse width (intrinsic device property) when the pulse is long but shows abrupt time dependence (“cliff”) as pulse width approaches characteristic RC time of memory device (extrinsic device property). Both experiment and simulation show that the onset of cliff behavior is dependent on physical device size and parasitic resistance, which is expected to diminish as technology nodes shrink down. We believe this study provides solid evidence that nano metallic resistive switching memory can be reliably operated at low voltage and ultra-fast regime, thus beneficial to future memory technology.

  12. Effect of nano Ni additions on the structure and properties of Sn-9Zn and Sn-Zn-3Bi solders in Au/Ni/Cu ball grid array packages

    Energy Technology Data Exchange (ETDEWEB)

    Gain, Asit Kumar [Department of Electronic Engineering, City University of Hong Kong, Tat Chee Avenue, Kowloon Tong (Hong Kong); Chan, Y.C. [Department of Electronic Engineering, City University of Hong Kong, Tat Chee Avenue, Kowloon Tong (Hong Kong)], E-mail: eeycchan@cityu.edu.hk; Yung, Winco K.C. [Department of Industrial and Systems Engineering, The Hong Kong Polytechnic University, Hung Hom, Kowloon (Hong Kong)

    2009-05-25

    The effect of nano Ni additions in Sn-9Zn and Sn-8Zn-3Bi solders on their interfacial microstructures and shear loads with Au/Ni/Cu pad metallization in ball grid array (BGA) applications were investigated. After the addition of nano Ni powder in Sn-based lead-free solders, there were no significant changes in the interfacial microstructure. But, in the solder region a very fine Zn-rich phase was observed. Also on the fracture surfaces a fine Zn-Ni compound was found. After the addition of nano Ni powder in Sn-based solders, the shear loads were increased due to a refinement of the microstructure and in addition, ductile fracture surfaces were clearly observed. The shear loads of the plain Sn-9Zn and Sn-8Zn-3Bi solders after one reflow cycle were about 1798 g and 2059 g, respectively. After the addition of nano Ni powder, their loads were about 2172 g and 2212 g, respectively, after one reflow cycle and their shear loads after eight reflow cycles were about 2099 g and 2081 g, respectively.

  13. Effect of nano Ni additions on the structure and properties of Sn-9Zn and Sn-Zn-3Bi solders in Au/Ni/Cu ball grid array packages

    International Nuclear Information System (INIS)

    Gain, Asit Kumar; Chan, Y.C.; Yung, Winco K.C.

    2009-01-01

    The effect of nano Ni additions in Sn-9Zn and Sn-8Zn-3Bi solders on their interfacial microstructures and shear loads with Au/Ni/Cu pad metallization in ball grid array (BGA) applications were investigated. After the addition of nano Ni powder in Sn-based lead-free solders, there were no significant changes in the interfacial microstructure. But, in the solder region a very fine Zn-rich phase was observed. Also on the fracture surfaces a fine Zn-Ni compound was found. After the addition of nano Ni powder in Sn-based solders, the shear loads were increased due to a refinement of the microstructure and in addition, ductile fracture surfaces were clearly observed. The shear loads of the plain Sn-9Zn and Sn-8Zn-3Bi solders after one reflow cycle were about 1798 g and 2059 g, respectively. After the addition of nano Ni powder, their loads were about 2172 g and 2212 g, respectively, after one reflow cycle and their shear loads after eight reflow cycles were about 2099 g and 2081 g, respectively.

  14. Manufacture of Nano Structures in Polymer Material

    DEFF Research Database (Denmark)

    Hansen, Hans Nørgaard; Pedersen, H.C.; Staun, Jacob

    2003-01-01

    The incorporation of micro and nano technology into the products of the future is an area of increasing interest. The ideas for new products based on this technology often take their starting point in specific scientific fields whereas the subsequent design and product development not necessarily...... is based on a systematic approach including manufacturing processes and production system capabilities. The process chain associated with micro and nano injection moulding usually comprises silicon or photoresist mastering, electroforming and polymer processing. Additionally, if the produced polymer...... components are to be used in a microsystem, subsequent handling and assembly is necessary. The present paper describes the process chain related to the manufacture of optical gratings with nanometer-sized structures. The problems of each process step and the challenges of establishing a coherent production...

  15. Spin-resolved magnetic studies of focused ion beam etched nano-sized magnetic structures

    International Nuclear Information System (INIS)

    Li Jian; Rau, Carl

    2005-01-01

    Scanning ion microscopy with polarization analysis (SIMPA) is used to study the spin-resolved surface magnetic structure of nano-sized magnetic systems. SIMPA is utilized for in situ topographic and spin-resolved magnetic domain imaging as well as for focused ion beam (FIB) etching of desired structures in magnetic or non-magnetic systems. Ultra-thin Co films are deposited on surfaces of Si(1 0 0) substrates, and ultra-thin, tri-layered, bct Fe(1 0 0)/Mn/bct Fe(1 0 0) wedged magnetic structures are deposited on fcc Pd(1 0 0) substrates. SIMPA experiments clearly show that ion-induced electrons emitted from magnetic surfaces exhibit non-zero electron spin polarization (ESP), whereas electrons emitted from non-magnetic surfaces such as Si and Pd exhibit zero ESP, which can be used to calibrate sputtering rates in situ. We report on new, spin-resolved magnetic microstructures, such as magnetic 'C' states and magnetic vortices, found at surfaces of FIB patterned magnetic elements. It is found that FIB milling has a negligible effect on surface magnetic domain and domain wall structures. It is demonstrated that SIMPA can evolve into an important and efficient tool to study magnetic domain, domain wall and other structures as well as to perform magnetic depth profiling of magnetic nano-systems to be used in ultra-high density magnetic recording and in magnetic sensors

  16. Role of particle size and composition in metal adsorption by solids deposited on urban road surfaces

    International Nuclear Information System (INIS)

    Gunawardana, Chandima; Egodawatta, Prasanna; Goonetilleke, Ashantha

    2014-01-01

    Despite common knowledge that the metal content adsorbed by fine particles is relatively higher compared to coarser particles, the reasons for this phenomenon have gained little research attention. The research study discussed in the paper investigated the variations in metal content for different particle sizes of solids associated with pollutant build-up on urban road surfaces. Data analysis confirmed that parameters favourable for metal adsorption to solids such as specific surface area, organic carbon content, effective cation exchange capacity and clay forming minerals content decrease with the increase in particle size. Furthermore, the mineralogical composition of solids was found to be the governing factor influencing the specific surface area and effective cation exchange capacity. There is high quartz content in particles >150 μm compared to particles <150 μm. As particle size reduces below 150 μm, the clay forming minerals content increases, providing favourable physical and chemical properties that influence adsorption. -- Highlights: • Physico-chemical parameters investigated in build-up samples from 32 road surfaces. • Mineralogical composition primarily governs the physico-chemical characteristics. • High clay forming mineral content in fine solids increases SSA and ECEC. • Characteristics influenced by quartz and amorphous content with particle size. • High quartz content in coarse particles contributes reduced metal adsorption. -- The mineralogical composition of solids is the governing factor influencing metal adsorption to solids in pollutant build-up on urban surfaces

  17. Finite element analysis-based design of a fluid-flow control nano-valve

    International Nuclear Information System (INIS)

    Grujicic, M.; Cao, G.; Pandurangan, B.; Roy, W.N.

    2005-01-01

    A finite element method-based procedure is developed for the design of molecularly functionalized nano-size devices. The procedure is aimed at the single-walled carbon nano-tubes (SWCNTs) used in the construction of such nano-devices and utilizes spatially varying nodal forces to represent electrostatic interactions between the charged groups of the functionalizing molecules. The procedure is next applied to the design of a fluid-flow control nano-valve. The results obtained suggest that the finite element-based procedure yields the results, which are very similar to their molecular modeling counterparts for small-size nano-valves, for which both types of analyses are feasible. The procedure is finally applied to optimize the design of a larger-size nano-valve, for which the molecular modeling approach is not practical

  18. New Trend for Acceleration Solid Phase Extraction Process Based on Using Magnetic Nano-adsorbents along with Surface Functionalization through Microwave Assisted Solvent-free Technique.

    Science.gov (United States)

    Ahmed, Salwa A; Soliman, Ezzat M

    2015-01-01

    The use of a microwave assisted solvent-free technique for silica coating of iron magnetic nanoparticles (Fe3O4-MNPs) and their functionalization with three aliphatic diamines: 1,2-ethylenediamine (1,2EDA), 1,5-pentanediamine (1,5PDA) and 1.8-octanediamine (1,8-ODA), were successfully achieved in a very short time. Only 60 min were needed for the nano-adsorbent modification as compared with more than 1000 min using conventional methods under reflux conditions. Their surface characteristics (observed by TEM, XRD and FT-IR), in addition to Cu(II) adsorption capacities (1.805, 1.928 and 2.116 mmol g(-1)) and time of equilibration (5 s) were almost the same. Thus, the time required to accomplish the solid phase extraction process is greatly reduced. On the other hand, the phenomenon of the fast equilibration kinetics was successfully extended on using the functionalized aliphatic diamines magnetic nano-adsorbents as precursors for further microwave treatment. Three selective magnetic nano-adsorbents (Fe3O4-MNPs-SiO2-1,2EDA-3FSA, Fe3O4-MNPs-SiO2-1,5PDA-3FSA and Fe3O4-MNPs-SiO2-1,8ODA-3FSA) were obtained via the reaction with 3-formayl salicylic acid (3FSA) as a selective reagent for Fe(III). At 5 s contact time, they exhibited maximum Fe(III) uptake equal to 4.512, 4.987 and 5.367 mmol g(-1), respectively. Furthermore, modeling of values of metal uptake capacity obtained at different shaking time intervals supports pseudo-second order kinetics.

  19. Preparation of nano-iron oxide red pigment powders by use of cyanided tailings

    International Nuclear Information System (INIS)

    Li Dengxin; Gao Guolong; Meng Fanling; Ji Chong

    2008-01-01

    On one hand, cyanided tailings are one kind of pollutants. On the other hand, they contain a lot of valuable elements. So utilization of them can bring social and environmental benefits. In this paper, cyanided tailings were used to prepare nano-iron oxide red pigment powders by an ammonia process with urea as precipitant. At first, cyanided tailings were oxidized by nitric acid. Then, the oxidizing mixture was separated into solid and liquid parts. The liquid mixture was reduced by scrap iron and the impurity of it was removed by use of NH 3 .H 2 O. Then, the seed crystal of γ-FeOOH was obtained, when the pure liquid reacted with ammonia liquid at the selected experimental conditions. At last, nano-iron oxide red pigment powders were prepared. The structure, morphology and size distribution of seed crystal and iron oxide red were characterized systematically by means of X-ray diffraction (XRD), transmission electron microscope (TEM) and laser particle size analyzer (LPSA). The results revealed that typical iron oxide nanoparticles were α-Fe 2 O 3 with particle size of 50-70 nm. Furthermore, the factors that affected the hue and quality of the seed crystal and iron oxide red pigment were also discussed

  20. Prediction Surface Morphology of Nanostructure Fabricated by Nano-Oxidation Technology.

    Science.gov (United States)

    Huang, Jen-Ching; Chang, Ho; Kuo, Chin-Guo; Li, Jeen-Fong; You, Yong-Chin

    2015-12-04

    Atomic force microscopy (AFM) was used for visualization of a nano-oxidation technique performed on diamond-like carbon (DLC) thin film. Experiments of the nano-oxidation technique of the DLC thin film include those on nano-oxidation points and nano-oxidation lines. The feature sizes of the DLC thin film, including surface morphology, depth, and width, were explored after application of a nano-oxidation technique to the DLC thin film under different process parameters. A databank for process parameters and feature sizes of thin films was then established, and multiple regression analysis (MRA) and a back-propagation neural network (BPN) were used to carry out the algorithm. The algorithmic results are compared with the feature sizes acquired from experiments, thus obtaining a prediction model of the nano-oxidation technique of the DLC thin film. The comparative results show that the prediction accuracy of BPN is superior to that of MRA. When the BPN algorithm is used to predict nano-point machining, the mean absolute percentage errors (MAPE) of depth, left side, and right side are 8.02%, 9.68%, and 7.34%, respectively. When nano-line machining is being predicted, the MAPEs of depth, left side, and right side are 4.96%, 8.09%, and 6.77%, respectively. The obtained data can also be used to predict cross-sectional morphology in the DLC thin film treated with a nano-oxidation process.

  1. Nano-PCMs for passive electronic cooling applications

    Science.gov (United States)

    Colla, L.; Fedele, L.; Mancin, S.; Buonomo, B.; Ercole, D.; Manca, O.

    2015-11-01

    The present work aims at investigating a new challenging use of oxide (TiO2, Al2O3, etc.) nanoparticles to enhance the thermal properties: thermal conductivity, specific heat, and latent heat of pure paraffin waxes to obtain a new class of Phase Change Materials (PCMs), the so-called nano-PCMs. The nano-PCMs were obtained by seeding different amounts of oxide nanoparticles in a paraffin wax having a melting temperature of 45°C. The thermophysical properties such as latent heat and thermal conductivity were then measured to understand the effects of the nanoparticles on the thermal properties of both the solid and liquid PCM. Finally, a numerical comparison between the use of the pure paraffin wax and the nano-PCM in a typical electronics passive cooling device was implemented. Numerical simulations were carried out using the Ansys-Fluent 15.0 code. Results in terms of solid and liquid phase temperatures, melting time and junction temperature were reported. Moreover, a comparison with experimental results was also performed.

  2. Copper nano composites functionalized by bis-benzimidazole diamide ligand: Effect of size, co-anion dependent conductivity and band gap studies

    International Nuclear Information System (INIS)

    Singla, Manisha; Mohapatra, Subash Chandra; Ahmad, Sharif

    2012-01-01

    Copper (I) and copper (II) nano composites capped with a bis-benzimidazole diamide ligand were prepared by reverse micelle method and characterized using CHNS, FTIR, 1 H NMR, TEM and DLS studies. All particles were spherical ranging between 10 and 70 nm. They displayed a quasi reversible redox wave due to the Cu (II)/Cu (I) reduction process. The E g1 ′ values shift anodically as NO 3 − − − . Electrochemical HOMO and LUMO band gap (E g1 ′ ) for the nano composites were +1.80 (NO 3 − ), +2.80 (Cl − ) and +4.10 (SCN − ) eV, respectively. However, the optical band gap (E g1 ) for the nano composites was calculated from their absorption edges and lie between 1.77 and 4.13 eV. Fluorescence studies reveal that nano composites in themselves behave as an enhancer and quencher in respect to ligand, Quantum yield (φ) is varying from 0.008 to 0.02 photon. The activation energies range from 34 to 54 kJ mol −1 and are quite low in comparison to that of the free bis-benzimidazole diamide ligand (137 kJ mol −1 ). The lower activation energies further re-emphasize the nano size of these composites. At room temperature, the dc conductivity lies between 1 × 10 −4 –9.33 × 10 −4 S cm −1 [NO 3 − > SCN − > Cl − ] indicating them to be on the semiconductor insulator interface. The dielectric constant, dielectric loss and the ac conductivity were measured for all nano at room temperature and below the room temperature for the nano composite containing nitrate as co-anion. The conductivity was found to follow the correlated barrier hopping (CBH) mechanism; the exponent factor (s) varies from 0.5 to 1. -- Highlights: ► Nano composites of copper, capped by bis benzimidazole diamide ligand. ► Such copper nano composites have not been used in conductivity studies before. ► Conductance studies for these thus make this work unique. ► The dc conductivity of these composites is much higher than normal.

  3. Nano crystals-Related Synthesis, Assembly, and Energy Applications 2012

    International Nuclear Information System (INIS)

    Zou, B.; Yu, W.W.; Seo, J.; Zhu, T.; Hu, M.Z.

    2012-01-01

    During the past decades, nano crystals have attracted broad attention due to their unique shape- and size-dependent physical and chemical properties that differ drastically from their bulk counterparts. Hitherto, much effort has been dedicated to achieving rational controlling over the morphology, assembly, and related energy applications of the nano materials. Therefore, the ability to manipulate the morphology, size, and size distribution of inorganic nano materials is still an important goal in modern materials physics and chemistry. Especially, the world's demand for energy supply is causing a dramatic escalation of social and political unrest. Likewise, the environmental impact of the global climate change due to the combustion of fossil fuel is becoming increasingly alarming. These problems compel us to search for effective routes to build devices that can supply sustainable energy, with not only high efficiency but also environmental friendship. One of ways to relieve the energy crisis is to exploit devices based on renewable energy sources, such as solar energy and water power. Aiming at this exploration, the primary stage requires the design of appropriate strategies for the synthesis of high-quality nano crystals with respect to size uniformity and superior electrochemical performances. As a consequence, we organize the current special issue for Journal of Nano materials to provide the authors with a platform and readers with the latest achievements of nano crystals-related synthesis, assembly, and energy applications.

  4. Nano spray drying for encapsulation of pharmaceuticals.

    Science.gov (United States)

    Arpagaus, Cordin; Collenberg, Andreas; Rütti, David; Assadpour, Elham; Jafari, Seid Mahdi

    2018-05-17

    Many pharmaceuticals such as pills, capsules, or tablets are prepared in a dried and powdered form. In this field, spray drying plays a critical role to convert liquid pharmaceutical formulations into powders. In addition, in many cases it is necessary to encapsulate bioactive drugs into wall materials to protect them against harsh process and environmental conditions, as well as to deliver the drug to the right place and at the correct time within the body. Thus, spray drying is a common process used for encapsulation of pharmaceuticals. In view of the rapid progress of nanoencapsulation techniques in pharmaceutics, nano spray drying is used to improve drug formulation and delivery. The nano spray dryer developed in the recent years provides ultrafine powders at nanoscale and high product yields. In this paper, after explaining the concept of nano spray drying and understanding the key elements of the equipment, the influence of the process parameters on the final powders properties, like particle size, morphology, encapsulation efficiency, drug loading and release, will be discussed. Then, numerous application examples are reviewed for nano spray drying and encapsulation of various drugs in the early stages of product development along with a brief overview of the obtained results and characterization techniques. Copyright © 2018 Elsevier B.V. All rights reserved.

  5. A new route for the synthesis of submicron-sized LaB6

    International Nuclear Information System (INIS)

    Lihong, Bao; Wurentuya,; Wei, Wei; Tegus, O.

    2014-01-01

    Submicron crystalline LaB 6 has been successfully synthesized by a solid-state reaction of La 2 O 3 with NaBH 4 at 1200 °C. The effects of reaction temperature on the crystal structure, grain size and morphology were investigated by X-ray diffraction, scanning electron microscope and transmission electron microscope. It is found that when the reaction temperature is in the range of 1000–1100 °C, there are ultrafine nanoparticles and nanocrystals that coexist. When the reaction temperature elevated to 1200 °C, the grain morphology transformed from ultrafine nanoparticle to submicron crystals completely. High resolution transmission electron microscope images fully confirm the formation of LaB 6 cubic structure. - Highlights: • Single-phased LaB 6 have been synthesized by a solid-state reaction in a continuous evacuating process. • The reaction temperature has a important effect on the phase composition. • The grain size increase from nano-size to submicron with increasing reaction temperature

  6. Enhanced superconducting properties of MgB2 by carbon substitution using carbon containing nano additives

    International Nuclear Information System (INIS)

    Devadas, K.M.; Varghese, Neson; Vinod, K.; Rahul, S.; Thomas, Syju; Anooja, J.B.; Syamaprasad, U.; Sundaresan, A.; Roy, S.B.

    2010-01-01

    A comparative study on the effect of doping of nano carbon, nano diamond and nano SiC in MgB 2 is carried out. The J c (H) is significantly enhanced for all doped samples compared to the pure sample among which MgB 1.9 C 0.1 (nano C) exhibits the best J c (H) performance. The enhanced performance is due to the effective substitution of C at B site which is confirmed by the systematic decrease in both α axis and T c . (author)

  7. Mass transfer in nano-fluids: A review

    International Nuclear Information System (INIS)

    Ashrafmansouri, Seyedeh-Saba; Esfahany, Mohsen Nasr

    2014-01-01

    Growing attention has been recently paid to nano-fluids because of their potential for augmenting transfer processes - i.e., heat and mass transfer. Conflicting results have been reported in the literature on mass transfer in nano-fluids. The aim of this paper is to summarize the literature on mass transfer in nano-fluids stating the conflicts and possible reasons. Literature on mass transfer in nano-fluids has been reviewed in two sections. The first section concentrates on surveying mass diffusivity in nano-fluids while the second section focuses on convective mass transfer in nano-fluids. In each section, published articles, type of nano-fluids used, size and concentration range of nanoparticles, measurement methods, maximum observed enhancement, and suggested mass transport mechanisms are summarized. (authors)

  8. Nano structures for Medical Diagnostics Md

    International Nuclear Information System (INIS)

    Bellah, M.; Iqbal, S.M.; Bellah, M.; Iqbal, S.M.; Christensen, S.M.; Iqbal, S.M.; Iqbal, S.M.

    2012-01-01

    Nano technology is the art of manipulating materials on atomic or molecular scales especially to build nano scale structures and devices. The field is expanding quickly, and a lot of work is ongoing in the design, characterization, synthesis, and application of materials, structures, devices, and systems by controlling shape and size at nanometer scale. In the last few years, much work has been focused on the use of nano structures toward problems of biology and medicine. In this paper, we focus on the application of various nano structures and nano devices in clinical diagnostics and detection of important biological molecules. The discussion starts by introducing some basic techniques of micro-/nano scale fabrication that have enabled reproducible production of nano structures. The prospects, benefits, and limitations of using these novel techniques in the fields of bio detection and medical diagnostics are then discussed. Finally, the challenges of mass production and acceptance of nano technology by the medical community are considered.

  9. Preparation of UO{sub 2}, ThO{sub 2} and (Th,U)O{sub 2} pellets from photochemically-prepared nano-powders

    Energy Technology Data Exchange (ETDEWEB)

    Pavelková, Tereza [Czech Technical University in Prague, Faculty of Nuclear Sciences and Physical Engineering, Břehová 7, 115 19 Praha 1 (Czech Republic); Čuba, Václav, E-mail: vaclav.cuba@fjfi.cvut.cz [Czech Technical University in Prague, Faculty of Nuclear Sciences and Physical Engineering, Břehová 7, 115 19 Praha 1 (Czech Republic); Visser-Týnová, Eva de [Nuclear Research and Consultancy Group (NRG), Research & Innovation, Westerduinweg 3, 1755 LE Petten (Netherlands); Ekberg, Christian [Nuclear Chemistry/Industrial Materials Recycling, Chalmers University of Technology, SE-412 96 Göteborg (Sweden); Persson, Ingmar [Department of Chemistry and Biotechnology, Swedish University of Agricultural Sciences, P.O. Box 7015, SE-750 07 Uppsala (Sweden)

    2016-02-15

    Photochemically-induced preparation of nano-powders of crystalline uranium and/or thorium oxides and their subsequent pelletizing has been investigated. The preparative method was based on the photochemically induced formation of amorphous solid precursors in aqueous solution containing uranyl and/or thorium nitrate and ammonium formate. The EXAFS analyses of the precursors shown that photon irradiation of thorium containing solutions yields a compound with little long-range order but likely “ThO{sub 2} like” and the irradiation of uranium containing solutions yields the mixture of U(IV) and U(VI) compounds. The U-containing precursors were carbon free, thus allowing direct heat treatment in reducing atmosphere without pre-treatment in the air. Subsequent heat treatment of amorphous solid precursors at 300–550 °C yielded nano-crystalline UO{sub 2}, ThO{sub 2} or solid (Th,U)O{sub 2} solutions with high purity, well-developed crystals with linear crystallite size <15 nm. The prepared nano-powders of crystalline oxides were pelletized without any binder (pressure 500 MPa), the green pellets were subsequently sintered at 1300 °C under an Ar:H{sub 2} (20:1) mixture (UO{sub 2} and (Th,U)O{sub 2} pellets) or at 1600 °C in ambient air (ThO{sub 2} pellets). The theoretical density of the sintered pellets varied from 91 to 97%. - Highlights: • Photochemically prepared UO{sub 2}/ThO{sub 2} nano-powders were pelletized. • The nano-powders of crystalline oxides were pelletized without any binder. • Pellets were sintered at 1300 °C (UO{sub 2} and (Th,U)O{sub 2}) or 1600 °C (ThO{sub 2} pellets). • The theoretical density of the sintered pellets varies from 91 to 97%.

  10. Characterizing the recovery of a solid surface after tungsten nano-tendril formation

    Science.gov (United States)

    Wright, G. M.; van Eden, G. G.; Kesler, L. A.; De Temmerman, G.; Whyte, D. G.; Woller, K. B.

    2015-08-01

    Recovery of a flat tungsten surface from a nano-tendril surface is attempted through three techniques; a mechanical wipe, a 1673 K annealing, and laser-induced thermal transients. Results were determined through SEM imaging and elastic recoil detection to assess the helium content in the surface. The mechanical wipe leaves a ∼0.5 μm deep layer of nano-tendrils on the surface post-wipe regardless of the initial nano-tendril layer depth. Laser-induced thermal transients only significantly impact the surface morphology at heat loads of 35.2 MJ/m2 s1/2 or above, however a fully flat or recovered surface was not achieved for 100 transients at this heat load despite reducing the helium content by a factor of ∼7. A 1673 K annealing removes all detectable levels of helium but sub-surface voids/bubbles remain intact. The surface is recovered to a nearly flat state with only some remnants of nano-tendrils re-integrating into the surface remaining.

  11. Characterizing the recovery of a solid surface after tungsten nano-tendril formation

    International Nuclear Information System (INIS)

    Wright, G.M.; Eden, G.G. van; Kesler, L.A.; De Temmerman, G.; Whyte, D.G.; Woller, K.B.

    2015-01-01

    Recovery of a flat tungsten surface from a nano-tendril surface is attempted through three techniques; a mechanical wipe, a 1673 K annealing, and laser-induced thermal transients. Results were determined through SEM imaging and elastic recoil detection to assess the helium content in the surface. The mechanical wipe leaves a ∼0.5 μm deep layer of nano-tendrils on the surface post-wipe regardless of the initial nano-tendril layer depth. Laser-induced thermal transients only significantly impact the surface morphology at heat loads of 35.2 MJ/m 2 s 1/2 or above, however a fully flat or recovered surface was not achieved for 100 transients at this heat load despite reducing the helium content by a factor of ∼7. A 1673 K annealing removes all detectable levels of helium but sub-surface voids/bubbles remain intact. The surface is recovered to a nearly flat state with only some remnants of nano-tendrils re-integrating into the surface remaining

  12. Characterizing the recovery of a solid surface after tungsten nano-tendril formation

    Energy Technology Data Exchange (ETDEWEB)

    Wright, G.M., E-mail: wright@psfc.mit.edu [MIT Plasma Science and Fusion Center, 77 Massachusetts Ave., Cambridge, MA 02139 (United States); Eden, G.G. van [FOM Institute DIFFER, Dutch Institute For Fundamental Energy Research, Association EURATOM-FOM, Trilateral Euregion Cluster, Postbus 1207, 3430BE Nieuwegein (Netherlands); Kesler, L.A. [MIT Plasma Science and Fusion Center, 77 Massachusetts Ave., Cambridge, MA 02139 (United States); De Temmerman, G. [FOM Institute DIFFER, Dutch Institute For Fundamental Energy Research, Association EURATOM-FOM, Trilateral Euregion Cluster, Postbus 1207, 3430BE Nieuwegein (Netherlands); Whyte, D.G.; Woller, K.B. [MIT Plasma Science and Fusion Center, 77 Massachusetts Ave., Cambridge, MA 02139 (United States)

    2015-08-15

    Recovery of a flat tungsten surface from a nano-tendril surface is attempted through three techniques; a mechanical wipe, a 1673 K annealing, and laser-induced thermal transients. Results were determined through SEM imaging and elastic recoil detection to assess the helium content in the surface. The mechanical wipe leaves a ∼0.5 μm deep layer of nano-tendrils on the surface post-wipe regardless of the initial nano-tendril layer depth. Laser-induced thermal transients only significantly impact the surface morphology at heat loads of 35.2 MJ/m{sup 2} s{sup 1/2} or above, however a fully flat or recovered surface was not achieved for 100 transients at this heat load despite reducing the helium content by a factor of ∼7. A 1673 K annealing removes all detectable levels of helium but sub-surface voids/bubbles remain intact. The surface is recovered to a nearly flat state with only some remnants of nano-tendrils re-integrating into the surface remaining.

  13. Nano structural anodes for radiation detectors

    Science.gov (United States)

    Cordaro, Joseph V.; Serkiz, Steven M.; McWhorter, Christopher S.; Sexton, Lindsay T.; Retterer, Scott T.

    2015-07-07

    Anodes for proportional radiation counters and a process of making the anodes is provided. The nano-sized anodes when present within an anode array provide: significantly higher detection efficiencies due to the inherently higher electric field, are amenable to miniaturization, have low power requirements, and exhibit a small electromagnetic field signal. The nano-sized anodes with the incorporation of neutron absorbing elements (e.g., .sup.10B) allow the use of neutron detectors that do not use .sup.3He.

  14. Pulmonary adenocarcinomas appearing as part-solid ground-glass nodules: Is measuring solid component size a better prognostic indicator?

    Energy Technology Data Exchange (ETDEWEB)

    Hwang, Eui Jin; Ryu, Youngjin; Lee, Sang Min [Seoul National University Medical Research Center, Department of Radiology, Seoul National University College of Medicine, and Institute of Radiation Medicine, 101, Daehangno, Jongno-gu, Seoul (Korea, Republic of); Park, Chang Min; Goo, Jin Mo [Seoul National University Medical Research Center, Department of Radiology, Seoul National University College of Medicine, and Institute of Radiation Medicine, 101, Daehangno, Jongno-gu, Seoul (Korea, Republic of); Seoul National University, Cancer Research Institute, Seoul (Korea, Republic of); Kim, Young Tae [Seoul National University, Cancer Research Institute, Seoul (Korea, Republic of); Seoul National University College of Medicine, Department of Thoracic and Cardiovascular Surgery, Seoul (Korea, Republic of); Kim, Young Whan [Seoul National University College of Medicine, Division of Pulmonary and Critical Care Medicine, Department of Internal Medicine and Lung Institute, Seoul (Korea, Republic of)

    2014-10-02

    To assess whether measuring the solid portion of adenocarcinomas appearing as part-solid ground-glass nodules (GGNs) can predict a patient's prognosis accurately and how the prognosis corresponds to that of solid nodules. 501 patients (solid nodule group, 304; part-solid GGN group, 197) underwent curative surgery for stage I adenocarcinomas. Maximal diameters of the whole lesion including ground-glass opacities (D{sub whole}) and solid components only (D{sub solid}) were measured on CT. Disease-free survival (DFS) and overall survival (OS) were calculated from the date of surgery. D{sub solid} was a significant prognostic factor in the part-solid GGN group, while D{sub whole} was not. Part-solid GGNs with D{sub solid} ≤2 cm showed significantly better DFS (P = 0.016) and OS (P = 0.004) than solid nodules; however, those with D{sub solid} >2 cm did not show a significant difference. Hazard ratio (HR) for increase in D{sub solid} was significantly greater in part-solid GGNs than in solid nodules (P = 0.009). For OS, HR for increase in D{sub solid} was greater in part-solid GGNs than in solid nodule, which was marginally not significant (P = 0.060). D{sub solid} was better than D{sub whole} for prognosis prediction of adenocarcinomas appearing as part-solid GGNs. In addition, the influence of D{sub solid} on prognosis in the part-solid GGN group was greater than in the solid nodule group. (orig.)

  15. Influence of industrial solid waste addition on properties of soil-cement bricks

    OpenAIRE

    Siqueira, F. B.; Amaral, M. C.; Bou-Issa, R. A.; Holanda, J. N. F.

    2016-01-01

    Abstract The reuse of pollutant solid wastes produced in distinct industrial activities (avian eggshell waste and welding flux slag waste) as a source of alternative raw material for producing soil-cement bricks for civil construction was investigated. Soil-cement bricks containing up to 30 wt% of industrial solid waste were uniaxially pressed and cured for 28 days. Special emphasis is given on the influence of solid waste addition on the technical properties (as such volumetric shrinkage, wa...

  16. Nano Copper Induces Apoptosis in PK-15 Cells via a Mitochondria-Mediated Pathway.

    Science.gov (United States)

    Zhang, Hui; Chang, Zhenyu; Mehmood, Khalid; Abbas, Rao Zahid; Nabi, Fazul; Rehman, Mujeeb Ur; Wu, Xiaoxing; Tian, Xinxin; Yuan, Xiaodan; Li, Zhaoyang; Zhou, Donghai

    2018-01-01

    Nano-sized copper particles are widely used in various chemical, physical, and biological fields. However, earlier studies have shown that nano copper particles (40-100 μg/mL) can induce cell toxicity and apoptosis. Therefore, this study was conducted to investigate the role of nano copper in mitochondrion-mediated apoptosis in PK-15 cells. The cells were treated with different doses of nano copper (20, 40, 60, and 80 μg/mL) to determine the effects of apoptosis using acridine orange/ethidium bromide (AO/EB) fluorescence staining and a flow cytometry assay. The levels of malondialdehyde (MDA) and superoxide dismutase (SOD) in the PK-15 cells were examined using commercially available kits. Moreover, the mRNA levels of the Bax, Bid, Caspase-3, and CYCS genes were assessed by real-time PCR. The results revealed that nano copper exposure induced apoptosis and changed the mitochondrial membrane potential. In addition, nano copper significantly altered the levels of the Bax, Bid, Caspase-3, and CYCS genes at a concentration of 40 μg/mL. To summarize, nano copper significantly (P nano copper can play an important role in inducing the apoptotic pathway in PK-15 cells, which may be the mechanism by which nano copper induces nephrotoxicity.

  17. Nano-material aspects of shock absorption in bone joints.

    Science.gov (United States)

    Tributsch, H; Copf, F; Copf, P; Hindenlang, U; Niethard, F U; Schneider, R

    2010-01-01

    This theoretical study is based on a nano-technological evaluation of the effect of pressure on the composite bone fine structure. It turned out, that the well known macroscopic mechano-elastic performance of bones in combination with muscles and tendons is just one functional aspect which is critically supported by additional micro- and nano- shock damping technology aimed at minimising local bone material damage within the joints and supporting spongy bone material. The identified mechanisms comprise essentially three phenomena localised within the three-dimensional spongy structure with channels and so called perforated flexible tensulae membranes of different dimensions intersecting and linking them. Kinetic energy of a mechanical shock may be dissipated within the solid-liquid composite bone structure into heat via the generation of quasi-chaotic hydromechanic micro-turbulence. It may generate electro-kinetic energy in terms of electric currents and potentials. And the resulting specific structural and surface electrochemical changes may induce the compressible intra-osseal liquid to build up pressure dependent free chemical energy. Innovative bone joint prostheses will have to consider and to be adapted to the nano-material aspects of shock absorption in the operated bones.

  18. Self-Assembly, Pattern Formation and Growth Phenomena in Nano-Systems

    CERN Document Server

    Nepomnyashchy, Alexander A

    2006-01-01

    Nano-science and nano-technology are rapidly developing scientific and technological areas that deal with physical, chemical and biological processes that occur on nano-meter scale – one millionth of a millimeter. Self-organization and pattern formation play crucial role on nano-scales and promise new, effective routes to control various nano-scales processes. This book contains lecture notes written by the lecturers of the NATO Advanced Study Institute "Self-Assembly, Pattern Formation and Growth Phenomena in Nano-Systems" that took place in St Etienne de Tinee, France, in the fall 2004. They give examples of self-organization phenomena on micro- and nano-scale as well as examples of the interplay between phenomena on nano- and macro-scales leading to complex behavior in various physical, chemical and biological systems. They discuss such fascinating nano-scale self-organization phenomena as self-assembly of quantum dots in thin solid films, pattern formation in liquid crystals caused by light, self-organi...

  19. Influence of nano-dispersive modified additive on cement activity

    Energy Technology Data Exchange (ETDEWEB)

    Sazonova, Natalya, E-mail: n.a.sazonova@mail.ru; Badenikov, Artem, E-mail: rector@agta.ru; Ivanova, Elizaveta, E-mail: lisik-iva@mail.ru [Angarsk State Technical University, 60, Tchaykovsky St., 665835, Angarsk (Russian Federation); Skripnikova, Nelli, E-mail: nks2003@mail.ru [Tomsk State University of Architecture and Building, 2, Solyanaya Sq., 634003, Tomsk (Russian Federation)

    2016-01-15

    In the work the influence of single-walled carbon nanotubes (SWCNT) on the cement activity and the processes of structure formation of the hardened cement paste in different periods of hydration are studied. The changes in the kinetic curves of the sample strength growth modified with SWCNT in amount of 0.01 and 0.0005 % are stipulated by the results of differential scanning colorimetry, scanning electronic and ionic microscopy, X-ray-phase analysis. It was found that the nano-modified additive may increase in the axis compressive strength of the system by 1.4–6.3 fold relatively to the reference samples and may reach 179.6 MPa. It may intensify the hydration process of calcium silicates as well as influence on the matrix of hardened cement paste. The studies are conducted on the structural changes in the hardened cement paste, the time periods of increase and decrease of the compressive strength of the samples, the amount of the calcium hydroxide and tobermorite-like gel as well as the degree of hydration C{sub 3}S and β-C{sub 2}S.

  20. Control of the Nano-Particle Weight Ratio in Stainless Steel Micro and Nano Powders by Radio Frequency Plasma Treatment

    OpenAIRE

    Dong-Yeol Yang; Youngja Kim; Min Young Hur; Hae June Lee; Yong-Jin Kim; Tae-Soo Lim; Ki-Bong Kim; Sangsun Yang

    2015-01-01

    This study describes how to make stainless steel hybrid micro-nano-powders (a mixture of micro-powder and nano-powder) using an in situ one-step process via radio frequency (RF) thermal plasma treatment. Nano-particles attached to micro-powders were successfully prepared by RF thermal plasma treatment of stainless steel powder with an average size of 35 μm. The ratio of nano-powders is estimated with a two-dimensional fluid simulation that calculates the temperature profile influencing the r...

  1. Effect of high energy electron beam (10 MeV) on specific heat capacity of low-density polyethylene/hydroxyapatite nano-composite

    Energy Technology Data Exchange (ETDEWEB)

    Soltani, Z., E-mail: zhr_soltani@yahoo.com [Health Physics and Radiation Dosimetry Research Laboratory, Department of Energy Engineering and Physics, Amirkabir University of Technology, Tehran (Iran, Islamic Republic of); Ziaie, F. [Radiation Application Research School, Nuclear Science & Technology Research Institute, Tehran (Iran, Islamic Republic of); Ghaffari, M. [Polymer Group, Golestan University, Golestan (Iran, Islamic Republic of); Beigzadeh, A.M. [Radiation Application Research School, Nuclear Science & Technology Research Institute, Tehran (Iran, Islamic Republic of)

    2017-02-01

    In the present work, thermal properties of low density polyethylene (LDPE) and its nano composites are investigated. For this purpose LDPE reinforced with different weight percents of hydroxyapatite (HAP) powder which was synthesized via hydrolysis method are produced. The samples were irradiated with 10 MeV electron beam at doses of 75 to 250 kGy. Specific heat capacity measurement have been carried out at different temperatures, i.e. 25, 50, 75 and 100 °C using modulated temperature differential scanning calorimetry (MTDSC) apparatus and the effect of three parameters include of temperature, irradiation dose and the amount of HAP nano particles as additives on the specific heat capacity of PE/HAP have been investigated precisely. The MTDSC results indicate that the specific heat capacity have decreased by addition of nano sized HAP as reinforcement for LDPE. On the other hand, the effect of radiation dose is reduction in the specific heat capacity in all materials including LDPE and its nano composites. The HAP nano particles along with cross-link junctions due to radiation restrain the movement of the polymer chains in the vicinity of each particle and improve the immobility of polymer chains and consequently lead to reduction in specific heat capacity. Also, the obtained results confirm that the radiation effect on the specific heat capacity is more efficient than the reinforcing effect of nano-sized hydroxyapatite.

  2. Preparations and thermal properties of micro- and nano-BN dispersed HDPE composites

    International Nuclear Information System (INIS)

    Jung, Jinwoo; Kim, Jaewoo; Uhm, Young Rang; Jeon, Jae-Kyun; Lee, Sol; Lee, Hi Min; Rhee, Chang Kyu

    2010-01-01

    The thermal properties of micro-sized boron nitride (BN) and nano-sized BN dispersed high density polyethylene (HDPE) composites were investigated by means of differential scanning calorimetry (DSC) and thermo-gravimetric analysis (TGA). Nano-BN powder was prepared by using a ball mill process before it was mixed in HDPE. To enhance the dispersivity of nano-BN in the polymer matrix, the surfaces of the nano-particles were treated with low density polyethylene (LDPE) which was dissolved in the cyclohexane solvent. The average particle sizes of micro-BN powder and LDPE coated nano-BN powder were ∼10 μm and ∼100 nm respectively. Dispersion and distribution of 5 wt% and 20 wt% of micro-BN and nano-BN respectively mixed in HDPE were observed by using the scanning electron microscope (SEM). According to the thermal analyses of pure HDPE, micro-BN/HDPE, and nano-BN/HDPE, 20 wt% nano-BN/HDPE composite shows the lowest enthalpy of fusion (ΔH m ) and better thermal conductive characteristics compared to the others.

  3. Structural Characteristics of Bimetallic Catalysts Supported on Nano-Ceria

    Directory of Open Access Journals (Sweden)

    J. F. Bozeman

    2011-01-01

    Full Text Available Cu-Pt bimetal catalysts supported on nanocrystalline CeO2 (nano-ceria are synthesized via the low-cost sol-gel approach followed by impregnation processing. The average particle size of the catalytic composites is 63 nm. Ceria nanopowders sequentially impregnated in copper solution and then in Pt solution transformed into Pt-skin-structured Cu-Pt/ceria nanocomposite, based on the surface elemental and bulk compositional analyses. The ceria supporter has a fluorite structure, but the structure of Cu and Pt catalytic contents, not detected by X-ray diffraction spectroscopy due to the low loading level, is yet conclusive. The bimetallic catalytic nanocomposites may potentially serve as sulfur-tolerant anode in solid oxide fuel cells.

  4. Ultrasonic-assisted synthesis of nano lead(II) coordination polymer as precursors for preparation of lead(II) oxide nano-structures: Thermal, optical properties and XRD studies.

    Science.gov (United States)

    Ghavidelaghdam, Elham; Shahverdizadeh, Gholam Hossein; Motameni Tabatabai, Javad; Mirtamizdoust, Babak

    2018-04-01

    Nano structure of a lead (II) coordination polymer [Pb 2 (C 2 Cl 3 O 2 ) 2 (NO 3 ) 2 (C l2 H 8 N 2 ) 2 ] n (1), has been synthesized by a sonochemical method in different concentrations. The nano particles were characterized by scanning electron microscopy (SEM) X-ray powder diffraction (XRD), FT-IR spectroscopy and elemental analyses. The thermal stability of nano structure is closely investigated via thermal gravimetric (TGA), and compared with crystalline structure. The compounds are then heated to 600 °C to produce PbO nano particles. The resulting PbO is characterized through XRD and SEM analyses. Concentration of initial reagents effects on size and morphology of nano-structured compound 1 have been studied and show that low concentrations of initial reagents decreased particles size and leaded to uniform nano particles morphology. The photoluminescence properties of the prepared compound, as crystalline and as nanoparticles, have been investigated. The result showed a good correlation between the size and emission wavelength. Copyright © 2017. Published by Elsevier B.V.

  5. Alushta-2012. International Conference-School on Plasma Physics and Controlled Fusion and the Adjoint Workshop 'Nano-and micro-sized structures in plasmas'. Book of Abstracts

    International Nuclear Information System (INIS)

    Makhlaj, V.A.

    2012-01-01

    The Conference was devoted to a new valuable information about the present status of plasma physics and controlled fusion research. The main topics was : magnetic confinement systems; plasma heating and current drive; ITER and fusion reactor aspects; basic plasma physics; space plasma; plasma dynamics and plasma-wall interaction; plasma electronics; low temperature plasma and plasma technologies; plasma diagnostics; formation of nano-and micro-sized structures in plasmas; properties of plasmas with nano- and micro- objects

  6. Increased response to oxidative stress challenge of nano-copper-induced apoptosis in mesangial cells

    International Nuclear Information System (INIS)

    Xu, Pengjuan; Li, Zhigui; Zhang, Xiaochen; Yang, Zhuo

    2014-01-01

    Recently, many studies reported that nanosized copper particles (nano-Cu, the particle size was around 15–30 nm), one of the nanometer materials, could induce nephrotoxicity. To detect the effect of nano-Cu on mesangial cells (MCs), and investigate the underlying mechanism, MCs were treated with different concentrations of nano-Cu (1, 10, and 30 μg/mL) to determine the oxidative stress and apoptotic changes. It was revealed that nano-Cu could induce a decreased viability in MCs together with a significant increase in the number of apoptotic cells by using cell counting kit-8 assay and flow cytometry. The apoptotic morphological changes induced by nano-Cu in MCs were demonstrated by Hochest33342 staining. Results showed that nano-Cu induced the nuclear fragmentation in MCs. Meanwhile, nano-Cu significantly increased the levels of reactive oxygen species, especially increased the levels of H 2 O 2 . It also decreased the activity of total SOD enzyme. In addition, when pre-treated with N-(2-mercaptopropionyl)-glycine, the cell apoptosis induced by nano-Cu was significantly decreased. These results suggest that oxidative stress plays an important role in the nano-Cu toxicity in MCs, which may be the main mechanism of nano-Cu-induced nephrotoxicity

  7. Compression Properties and Electrical Conductivity of In-Situ 20 vol.% Nano-Sized TiCx/Cu Composites with Different Particle Size and Morphology.

    Science.gov (United States)

    Zhang, Dongdong; Bai, Fang; Sun, Liping; Wang, Yong; Wang, Jinguo

    2017-05-04

    The compression properties and electrical conductivity of in-situ 20 vol.% nano-sized TiC x /Cu composites fabricated via combustion synthesis and hot press in Cu-Ti-CNTs system at various particles size and morphology were investigated. Cubic-TiC x /Cu composite had higher ultimate compression strength (σ UCS ), yield strength (σ 0.2 ), and electric conductivity, compared with those of spherical-TiC x /Cu composite. The σ UCS , σ 0.2 , and electrical conductivity of cubic-TiC x /Cu composite increased by 4.37%, 20.7%, and 17.8% compared with those of spherical-TiC x /Cu composite (526 MPa, 183 MPa, and 55.6% International Annealed Copper Standard, IACS). Spherical-TiC x /Cu composite with average particle size of ~94 nm exhibited higher ultimate compression strength, yield strength, and electrical conductivity compared with those of spherical-TiC x /Cu composite with 46 nm in size. The σ UCS , σ 0.2 , and electrical conductivity of spherical-TiC x /Cu composite with average size of ~94 nm in size increased by 17.8%, 33.9%, and 62.5% compared with those of spherical-TiC x /Cu composite (417 MPa, 121 MPa, and 40.3% IACS) with particle size of 49 nm, respectively. Cubic-shaped TiC x particles with sharp corners and edges led to stress/strain localization, which enhanced the compression strength of the composites. The agglomeration of spherical-TiC x particles with small size led to the compression strength reduction of the composites.

  8. Biomolecular Nano-Flow-Sensor to Measure Near-Surface Flow

    Directory of Open Access Journals (Sweden)

    Noji Hiroyuki

    2009-01-01

    Full Text Available Abstract We have proposed and experimentally demonstrated that the measurement of the near-surface flow at the interface between a liquid and solid using a 10 nm-sized biomolecular motor of F1-ATPase as a nano-flow-sensor. For this purpose, we developed a microfluidic test-bed chip to precisely control the liquid flow acting on the F1-ATPase. In order to visualize the rotation of F1-ATPase, several hundreds nanometer-sized particle was immobilized at the rotational axis of F1-ATPase to enhance the rotation to be detected by optical microscopy. The rotational motion of F1-ATPase, which was immobilized on an inner surface of the test-bed chip, was measured to obtain the correlation between the near-surface flow and the rotation speed of F1-ATPase. As a result, we obtained the relationship that the rotation speed of F1-ATPase was linearly decelerated with increasing flow velocity. The mechanism of the correlation between the rotation speed and the near-surface flow remains unclear, however the concept to use biomolecule as a nano-flow-sensor was proofed successfully. (See supplementary material 1 Electronic supplementary material The online version of this article (doi:10.1007/s11671-009-9479-3 contains supplementary material, which is available to authorized users. Click here for file

  9. Rheological Behavior of Carbon Nano tubes as an Additive on Lithium Grease

    International Nuclear Information System (INIS)

    Mohamed, A.; Zaki, M.; Mohamed, A.; Khattab, A.A.; Osman, T.A.

    2013-01-01

    The rheological behaviors of carbon nano tubes (CNTs) as an additive on lithium grease at different concentrations were examined under various settings of shear rate, shear stress, and apparent viscosity. The results indicated that the optimum content of the CNTs was 2%. These experimental investigations were evaluated with a Brookfield Programmable Rheometer DV-III ULTRA. The results indicated that the shear, stress and apparent viscosity increase with the increase of CNTs concentration. The microstructure of CNTs and lithium grease was examined by high resolution transmission electron microscope (HRTEM) and scanning electron microscope (SEM). The results indicated that the microscopic structure of the lithium grease presents a more regular and homogeneous network structure, with long fibers, which confirms the rheological stability.

  10. Design and formulation of nano-sized spray dried efavirenz-part I: influence of formulation parameters

    Energy Technology Data Exchange (ETDEWEB)

    Katata, Lebogang, E-mail: lebzakate@yahoo.com; Tshweu, Lesego; Naidoo, Saloshnee; Kalombo, Lonji; Swai, Hulda [Materials Science and Manufacturing, Centre of Polymers and Composites, Council for Scientific and Industrial Research (South Africa)

    2012-11-15

    Efavirenz (EFV) is one of the first-line antiretroviral drugs recommended by the World Health Organisation for treating HIV. It is a hydrophobic drug that suffers from low aqueous solubility (4 {mu}g/mL), which leads to a limited oral absorption and low bioavailability. In order to improve its oral bioavailability, nano-sized polymeric delivery systems are suggested. Spray dried polycaprolactone-efavirenz (PCL-EFV) nanoparticles were prepared by the double emulsion method. The Taguchi method, a statistical design with an L{sub 8} orthogonal array, was implemented to optimise the formulation parameters of PCL-EFV nanoparticles. The types of sugar (lactose or trehalose), surfactant concentration and solvent (dichloromethane and ethyl acetate) were chosen as significant parameters affecting the particle size and polydispersity index (PDI). Small nanoparticles with an average particle size of less than 254 {+-} 0.95 nm in the case of ethyl acetate as organic solvent were obtained as compared to more than 360 {+-} 19.96 nm for dichloromethane. In this study, the type of solvent and sugar were the most influencing parameters of the particle size and PDI. Taguchi method proved to be a quick, valuable tool in optimising the particle size and PDI of PCL-EFV nanoparticles. The optimised experimental values for the nanoparticle size and PDI were 217 {+-} 2.48 nm and 0.093 {+-} 0.02.

  11. Design and formulation of nano-sized spray dried efavirenz-part I: influence of formulation parameters

    International Nuclear Information System (INIS)

    Katata, Lebogang; Tshweu, Lesego; Naidoo, Saloshnee; Kalombo, Lonji; Swai, Hulda

    2012-01-01

    Efavirenz (EFV) is one of the first-line antiretroviral drugs recommended by the World Health Organisation for treating HIV. It is a hydrophobic drug that suffers from low aqueous solubility (4 μg/mL), which leads to a limited oral absorption and low bioavailability. In order to improve its oral bioavailability, nano-sized polymeric delivery systems are suggested. Spray dried polycaprolactone-efavirenz (PCL-EFV) nanoparticles were prepared by the double emulsion method. The Taguchi method, a statistical design with an L 8 orthogonal array, was implemented to optimise the formulation parameters of PCL-EFV nanoparticles. The types of sugar (lactose or trehalose), surfactant concentration and solvent (dichloromethane and ethyl acetate) were chosen as significant parameters affecting the particle size and polydispersity index (PDI). Small nanoparticles with an average particle size of less than 254 ± 0.95 nm in the case of ethyl acetate as organic solvent were obtained as compared to more than 360 ± 19.96 nm for dichloromethane. In this study, the type of solvent and sugar were the most influencing parameters of the particle size and PDI. Taguchi method proved to be a quick, valuable tool in optimising the particle size and PDI of PCL-EFV nanoparticles. The optimised experimental values for the nanoparticle size and PDI were 217 ± 2.48 nm and 0.093 ± 0.02.

  12. Improved nano-particle tracking analysis

    International Nuclear Information System (INIS)

    Walker, John G

    2012-01-01

    Nano-particle tracking is a method to estimate a particle size distribution by tracking the movements of individual particles, using multiple images of particles moving under Brownian motion. A novel method to recover a particle size distribution from nano-particle tracking data is described. Unlike a simple histogram-based method, the method described is able to account for the finite number of steps in each particle track and consequently for the measurement uncertainty in the step-length data. Computer simulation and experimental results are presented to demonstrate the performance of the approach compared with the current method. (paper)

  13. Properties of forced convection experimental with silicon carbide based nano-fluids

    Science.gov (United States)

    Soanker, Abhinay

    With the advent of nanotechnology, many fields of Engineering and Science took a leap to the next level of advancements. The broad scope of nanotechnology initiated many studies of heat transfer and thermal engineering. Nano-fluids are one such technology and can be thought of as engineered colloidal fluids with nano-sized colloidal particles. There are different types of nano-fluids based on the colloidal particle and base fluids. Nano-fluids can primarily be categorized into metallic, ceramics, oxide, magnetic and carbon based. The present work is a part of investigation of the thermal and rheological properties of ceramic based nano-fluids. alpha-Silicon Carbide based nano-fluid with Ethylene Glycol and water mixture 50-50% volume concentration was used as the base fluid here. This work is divided into three parts; Theoretical modelling of effective thermal conductivity (ETC) of colloidal fluids, study of Thermal and Rheological properties of alpha-SiC nano-fluids, and determining the Heat Transfer properties of alpha-SiC nano-fluids. In the first part of this work, a theoretical model for effective thermal conductivity (ETC) of static based colloidal fluids was formulated based on the particle size, shape (spherical), thermal conductivity of base fluid and that of the colloidal particle, along with the particle distribution pattern in the fluid. A MATLAB program is generated to calculate the details of this model. The model is specifically derived for least and maximum ETC enhancement possible and thereby the lower and upper bounds was determined. In addition, ETC is also calculated for uniform colloidal distribution pattern. Effect of volume concentration on ETC was studied. No effect of particle size was observed for particle sizes below a certain value. Results of this model were compared with Wiener bounds and Hashin- Shtrikman bounds. The second part of this work is a study of thermal and rheological properties of alpha-Silicon Carbide based nano

  14. Preparation and characterization of nano-sized phase change emulsions as thermal energy storage and transport media

    International Nuclear Information System (INIS)

    Chen, J.; Zhang, P.

    2017-01-01

    Highlights: • The nano-sized phase change emulsions are prepared by using D-phase method. • The thermo-physical and transport properties are experimentally investigated. • The influence of surfactant on the melting temperature and latent heat of water is clarified. • The phase change emulsion can be used as the heat transfer fluid in a thermal energy storage system. - Abstract: Phase change emulsion (PCE) is a kind of two-phase heat transfer fluid with phase change material (PCM) dispersed in carrier fluid. It has received intensive attractions in recent years due to the fact that it can be used as both the thermal energy storage material and transport medium simultaneously in a thermal energy storage system. In the present study, nano-sized PCEs are prepared by the D-phase method with n-hexadecane and n-octadecane as PCMs. The thermo-physical and transport properties are characterized to facilitate the applications. The droplet size distribution of the PCE is measured by a Photon Correlation Spectroscopy, and the results show that the droplet size distributions are similar at different mass fractions. The rheological behavior and viscosity of the PCE are measured by a rheometer, which shows that the PCEs at mass fractions below 30.0 wt% are Newtonian fluids, and the viscosities are dependent on both the mass fraction and temperature. The differential scanning calorimetry (DSC) is employed to analyze the phase change characteristics of the PCE, and the results indicate large supercooling degree of water and PCM in the PCE. The melting temperature and latent heat of water in the PCE are much smaller than those of pure water. The thermal conductivities of the PCE with different mass fractions at different temperatures are measured by the transient hot-wire method. Furthermore, the energy transport characteristics of the PCEs are evaluated on the basis of the measured thermo-physical and transport properties. The results suggest that the PCEs show a drastic

  15. Nano-cellulose derived bioplastic biomaterial data for vehicle bio-bumper from banana peel waste biomass

    Directory of Open Access Journals (Sweden)

    A.B.M. Sharif Hossain

    2016-09-01

    Full Text Available The innovative study was carried out to produce nano-cellulose based bioplastic biomaterials for vehicle use coming after bioprocess technology. The data show that nano-cellulose particle size was 20 nm and negligible water absorption was 0.03% in the bioplastic. Moreover, burning test, size and shape characterizations, spray coating dye, energy test and firmness of bioplastic have been explored and compared with the standardization of synthetic vehicle plastic bumper following the American Society for Testing and Materials (ASTM. Tensile test was observed 120 MPa/kg m3. In addition to that pH and cellulose content were found positive in the bioplastic compared to the synthetic plastic. Chemical tests like K, CO3, Cl2, Na were determined and shown positive results compared to the synthetic plastic using the EN-14214 (European Norm standardization. Keywords: Nano-celluloses, Biopolymer, Banana peel waste, Biobumper

  16. Novel processing of bioglass ceramics from silicone resins containing micro- and nano-sized oxide particle fillers.

    Science.gov (United States)

    Fiocco, L; Bernardo, E; Colombo, P; Cacciotti, I; Bianco, A; Bellucci, D; Sola, A; Cannillo, V

    2014-08-01

    Highly porous scaffolds with composition similar to those of 45S5 and 58S bioglasses were successfully produced by an innovative processing method based on preceramic polymers containing micro- and nano-sized fillers. Silica from the decomposition of the silicone resins reacted with the oxides deriving from the fillers, yielding glass ceramic components after heating at 1000°C. Despite the limited mechanical strength, the obtained samples possessed suitable porous architecture and promising biocompatibility and bioactivity characteristics, as testified by preliminary in vitro tests. © 2013 Wiley Periodicals, Inc.

  17. Reactive oxygen species-related activities of nano-iron metal and nano-iron oxides.

    Science.gov (United States)

    Wu, Haohao; Yin, Jun-Jie; Wamer, Wayne G; Zeng, Mingyong; Lo, Y Martin

    2014-03-01

    Nano-iron metal and nano-iron oxides are among the most widely used engineered and naturally occurring nanostructures, and the increasing incidence of biological exposure to these nanostructures has raised concerns about their biotoxicity. Reactive oxygen species (ROS)-induced oxidative stress is one of the most accepted toxic mechanisms and, in the past decades, considerable efforts have been made to investigate the ROS-related activities of iron nanostructures. In this review, we summarize activities of nano-iron metal and nano-iron oxides in ROS-related redox processes, addressing in detail the known homogeneous and heterogeneous redox mechanisms involved in these processes, intrinsic ROS-related properties of iron nanostructures (chemical composition, particle size, and crystalline phase), and ROS-related bio-microenvironmental factors, including physiological pH and buffers, biogenic reducing agents, and other organic substances. Copyright © 2014. Published by Elsevier B.V.

  18. Size effects of nano-spaced basal stacking faults on the strength and deformation mechanisms of nanocrystalline pure hcp metals

    Science.gov (United States)

    Wang, Wen; Jiang, Ping; Yuan, Fuping; Wu, Xiaolei

    2018-05-01

    The size effects of nano-spaced basal stacking faults (SFs) on the tensile strength and deformation mechanisms of nanocrystalline pure cobalt and magnesium have been investigated by a series of large-scale 2D columnar and 3D molecular dynamics simulations. Unlike the strengthening effect of basal SFs on Mg alloys, the nano-spaced basal SFs are observed to have no strengthening effect on the nanocrystalline pure cobalt and magnesium from MD simulations. These observations could be attributed to the following two reasons: (i) Lots of new basal SFs are formed before (for cobalt) or simultaneously with (for magnesium) the other deformation mechanisms (i.e. the formation of twins and the edge dislocations) during the tensile deformation; (ii) In hcp alloys, the segregation of alloy elements and impurities at typical interfaces, such as SFs, can stablilise them for enhancing the interactions with dislocation and thus elevating the strength. Without such segregation in pure hcp metals, the edge dislocations can cut through the basal SFs although the interactions between the dislocations and the pre-existing SFs/newly formed SFs are observed. The nano-spaced basal SFs are also found to have no restriction effect on the formation of deformation twins.

  19. Spectroscopic investigation on assisted sonocatalytic damage of bovine serum albumin (BSA) by metronidazole (MTZ) under ultrasonic irradiation combined with nano-sized ZnO

    Science.gov (United States)

    Gao, Jingqun; Liu, Bin; Wang, Jun; Jin, Xudong; Jiang, Renzheng; Liu, Lijun; Wang, Baoxin; Xu, Yongnan

    2010-11-01

    The previous work proved that the bovine serum albumin (BSA) could be damaged under the combined action of ultrasonic irradiation and ZnO. In this work, the assisted sonocatalytic damage of BSA using metronidazole (MTZ) as a sensitizer was further investigated by means of UV-vis and fluorescence spectra. The results indicated that the adding of MTZ could obviously promote the sonocatalytic damage of BSA under ultrasonic irradiation in the presence of nano-sized ZnO powder. Furthermore, it was found that the damage degree of BSA was aggravated by some influencing factors except ionic kind and strength. In addition, the damage site of BSA was also studied with synchronous fluorescence technology. It was found that the damage site was mainly at tryptophan (Trp) residue.

  20. Modeling of changes in particle size distribution of solids in multistage separation systems

    Directory of Open Access Journals (Sweden)

    Lagereva E.A.

    2016-09-01

    Full Text Available The presented method of calculation of the separation of solid particles from gas streams to multistage separation sys-tems, consisting of a number of sequentially installed separational devices of various design and principle of operation. It is based on a separate analysis of the sequential processes of capture and transmission of individual fractions of solid particles of a polydisperse structure. The technique provides information about changes in particle size distribution of solids with the passage of the gas flow in the treatment system and allows you to specifically select the effective combination of different types of separators.

  1. A review on mechanical properties of magnesium based nano composites

    Science.gov (United States)

    Tarafder, Nilanjan; Prasad, M. Lakshmi Vara

    2018-04-01

    A review was done on Magnesium (Mg) based composite materials reinforced with different nano particles such as TiO2, Cu, Y2O3, SiC, ZrO2 and Al2O3. TiO2 and Al2O3 nanoparticles were synthesised by melt deposition process. Cu, Y2O3, SiC and ZrO2 nanoparticles were synthesised by powder metallurgy process. Composite microstructural characteristics shows that the nano-size reinforcements are uniformly distributed in the composite matrix and also minimum porosity with solid interfacial integrity. The mechanical properties showed yield strength improvement by 0.2 percentage and Ultimate tensile strength (UTS) was also improved for all the nano-particles. But UTS was adversely affected with TiO2 reinforcement while ductility was increased. With Cu reinforcement elastic modulus, hardness and fracture resistance increased and improved the co-efficient of thermal expansion (CTE) of Mg based matrix. By Y2O3 reinforcement hardness, fracture resistance was improved and ductility reached maximum by 0.22 volume percentage of Y2O3 and decreased with succeeding increase in Y2O3 reinforcement. The readings exposed that mechanical properties were gathered from the composite comprising 2.0 weight percentage of Y2O3. Ductility and fracture resistance increased with ZrO2 reinforcement in Mg matrix. Using Al2O3 as reinforcement in Mg composite matrix hardness, elastic modulus and ductility was increased but porosity reduced with well interfacial integrity. Dissipation of energy in the form of damping capacity was resolved by classical vibration theory. The result showed that an increasing up to 0.4 volume percentage alumina content increases the damping capacity up to 34 percent. In another sample, addition of 2 weight percentage nano-Al2O3 particles showed big possibility in reducing CTE from 27.9-25.9×10-6 K-1 in Magnesium, tensile and yield strength amplified by 40MPa. In another test, Mg/1.1Al2O3 nanocomposite was manufactured by solidification process followed by hot extrusion

  2. Evaluation of mechanical properties and nano-meso structures of 9–11%Cr ODS steels

    Energy Technology Data Exchange (ETDEWEB)

    Tanno, Takashi, E-mail: tanno.takashi@jaea.go.jp [Japan Atomic Energy Agency, Oarai, Ibaraki 311-1393 (Japan); Ohtsuka, Satoshi; Yano, Yasuhide; Kaito, Takeji [Japan Atomic Energy Agency, Oarai, Ibaraki 311-1393 (Japan); Oba, Yojiro; Ohnuma, Masato [National Institute for Materials Science, Tsukuba 305-1195 (Japan); Koyama, Shinichi; Tanaka, Kenya [Japan Atomic Energy Agency, Oarai, Ibaraki 311-1393 (Japan)

    2013-09-15

    Highlights: • We successfully manufactured 11Cr-ODS steels with residual α-ferrite controlled. • Dispersion conditions of nano oxide particles were quantitatively characterized. • Tungsten solid solution could improve only tensile strength of ODS steels at 973 K. • Oxide dispersion strengthening was dominant in creep strength of ODS steels at 973 K. -- Abstract: This study carried out mechanical tests and microstructural characterizations of several 9Cr and 11Cr-ODS tempered martensitic steels. From those results, the appropriate chemical composition range of 11Cr-ODS tempered martensitic steel was discussed from the viewpoint of high temperature strength improvement. It was shown that the residual α-ferrite fraction in 11Cr-ODS steel was successfully controlled to the same level as the 9Cr-ODS steel, which has excellent high temperature strength, by selecting the chemical compositions on the basis of the multi-component phase diagram. The tensile strength decreased with decreasing W content from 2.0 to 1.4 wt%. On the other hand, creep strength at 973 K did not degrade by the decreasing W content. Both tensile strength and creep strength increased with increasing population of the nano-sized oxide particles. Small angle X-ray scattering analysis revealed that titanium and excess oxygen contents were key parameters in order to improve the dispersion conditions of nano-sized oxide particles.

  3. Studies on structural properties of clay magnesium ferrite nano composite

    Energy Technology Data Exchange (ETDEWEB)

    Kaur, Manpreet, E-mail: manpreetchem@pau.edu; Singh, Mandeep [Department of Chemistry, Punjab Agricultural University, Ludhiana-141004 (India); Jeet, Kiran, E-mail: kiranjeet@pau.edu; Kaur, Rajdeep [Electron Microscopy and Nanoscience Laboratory, Punjab Agricultural University, Ludhiana-141004 (India)

    2015-08-28

    Magnesium ferrite-bentonite clay composite was prepared by sol-gel combustion method employing citric acid as complexing agent and fuel. The effect of clay on the structural properties was studied with X-ray diffraction (XRD), Fourier transform infrared (FT-IR) Spectroscopy, Scanning electron microscopy (SEM), SEM- Energy dispersive Spectroscope (EDS) and BET surface area analyzer. Decrease in particle size and density was observed on addition of bentonite clay. The BET surface area of nano composite containing just 5 percent clay was 74.86 m{sup 2}/g. Whereas porosity increased from 40.5 per cent for the pure magnesium ferrite to 81.0 percent in the composite showing that nano-composite has potential application as an adsorbent.

  4. Mechanical properties of cement concrete composites containing nano-metakaolin

    Science.gov (United States)

    Supit, Steve Wilben Macquarie; Rumbayan, Rilya; Ticoalu, Adriana

    2017-11-01

    The use of nano materials in building construction has been recognized because of its high specific surface area, very small particle sizes and more amorphous nature of particles. These characteristics lead to increase the mechanical properties and durability of cement concrete composites. Metakaolin is one of the supplementary cementitious materials that has been used to replace cement in concrete. Therefore, it is interesting to investigate the effectiveness of metakaolin (in nano scale) in improving the mechanical properties including compressive strength, tensile strength and flexural strength of cement concretes. In this experiment, metakaolin was pulverized by using High Energy Milling before adding to the concrete mixes. The pozzolan Portland cement was replaced with 5% and 10% nano-metakaolin (by wt.). The result shows that the optimum amount of nano-metakaolin in cement concrete mixes is 10% (by wt.). The improvement in compressive strength is approximately 123% at 3 days, 85% at 7 days and 53% at 28 days, respectively. The tensile and flexural strength results also showed the influence of adding 10% nano-metakaolin (NK-10) in improving the properties of cement concrete (NK-0). Furthermore, the Backscattered Electron images and X-Ray Diffraction analysis were evaluated to support the above findings. The results analysis confirm the pores modification due to nano-metakaolin addition, the consumption of calcium hydroxide (CH) and the formation of Calcium Silicate Hydrate (CSH) gel as one of the beneficial effects of amorphous nano-metakaolin in improving the mechanical properties and densification of microstructure of mortar and concrete.

  5. NanoTest™ NT600 – A device for analyses of mechanical properties of materials

    Czech Academy of Sciences Publication Activity Database

    Čtvrtlík, Radim; Stranyánek, Martin; Boháč, Petr; Jastrabík, Lubomír

    2006-01-01

    Roč. 13, č. 2 (2006), s. 90-93 ISSN 1211-5894 Institutional research plan: CEZ:AV0Z10100522 Keywords : nano -mechanical properties * nano indentation * thin films Subject RIV: BM - Solid Matter Physics ; Magnetism

  6. Sub-10-nm suspended nano-web formation by direct laser writing

    Science.gov (United States)

    Wang, Sihao; Yu, Ye; Liu, Hailong; Lim, Kevin T. P.; Madurai Srinivasan, Bharathi; Zhang, Yong Wei; Yang, Joel K. W.

    2018-06-01

    A diffraction-limited three-dimensional (3D) direct laser writing (DLW) system based on two-photon polymerization can routinely pattern structures at the 100 nm length scale. Several schemes have been developed to improve the patterning resolution of 3D DLW but often require customized resist formulations or multi-wavelength exposures. Here, we introduce a scheme to produce suspended nano-webs with feature sizes below 10 nm in IP-Dip resist using sub-threshold exposure conditions in a commercial DLW system. The narrowest suspended lines (nano-webs) measured 7 nm in width. Larger ∼20 nm nano-webs were patterned with ∼80% yield at increased laser powers. In addition, closely spaced nano-gaps with a center-to-center distance of 33 nm were produced by patterning vertically displaced suspended lines followed by metal deposition and liftoff. We provide hypotheses and present preliminary results for a mechanism involving the initiation of a percolative path and a strain-induced narrowing in the nano-web formation. Our approach allows selective features to be patterned with dimensions comparable to the sub-10 nm patterning capability of electron-beam lithography (EBL).

  7. The therapeutic effect of nano-encapsulated and nano-emulsion forms of carvacrol on experimental liver fibrosis.

    Science.gov (United States)

    Hussein, Jihan; El-Banna, Mona; Mahmoud, Khaled F; Morsy, Safaa; Abdel Latif, Yasmin; Medhat, Dalia; Refaat, Eman; Farrag, Abdel Razik; El-Daly, Sherien M

    2017-06-01

    The present study aimed to compare the therapeutic efficiency of nano-encapsulated and nano-emulsion carvacrol administration on liver injury in thioacetamide (TAA) treated rats. To fulfill our target, we used sixty male albino rats classified into six groups as follow: control, nano-encapsulated carvacrol, nano-emulsion carvacrol, thioacetamide, treated nano-encapsulated carvacrol and treated nano-emulsion carvacrol groups. Blood samples were collected from all groups and the separated serum was used for analysis of the following biochemical parameters; aspartate aminotransferase (AST), alanine aminotransferase (ALT), S100 B protein, alpha fetoprotein (AFP) and caspase-3. The levels of malondialdehyde (MDA), reduced glutathione (GSH), nitric oxide (NO), monocyte chemoattractant protein-1(MCP-1) and hydroxyproline content were all evaluated in liver tissue homogenate. Histopathological examinations for liver tissues were also performed. Thioacetamide induced hepatic damage in rats as revealed by the significant increase in the levels of serum ALT, AST and produced oxidative stress as displayed by the significant elevation in the levels of hepatic MDA and NO concomitant with a significant decrease in GSH. In addition, thioacetamide significantly increased serum S100B protein, alpha fetoprotein and caspase-3 along with hepatic MCP-1 and hydroxyproline; these results were confirmed by the histopathological investigation. In contrast, nano-encapsulated and nano-emulsion carvacrol were able to ameliorate these negative changes in the thioacetamide injected rats. However, the effect of the nano-encapsulated form of carvacrol was more prominent than the nano-emulsion form. Nano-encapsulated and nano-emulsion carvacrol can ameliorate thioacetamide induced liver injury. These results could be attributed to the potential anti-inflammatory, antioxidant, and anti-apoptotic activities of carvacrol in addition to the effectiveness of the encapsulation technique that can protect

  8. Solid-Phase Synthesis of Molecularly Imprinted Polymer Nanoparticles with a Reusable Template - "Plastic Antibodies".

    Science.gov (United States)

    Poma, Alessandro; Guerreiro, Antonio; Whitcombe, Michael J; Piletska, Elena V; Turner, Anthony P F; Piletsky, Sergey A

    2013-06-13

    Molecularly Imprinted Polymers (MIPs) are generic alternatives to antibodies in sensors, diagnostics and separations. To displace biomolecules without radical changes in infrastructure in device manufacture, MIPs should share their characteristics (solubility, size, specificity and affinity, localized binding domain) whilst maintaining the advantages of MIPs (low-cost, short development time and high stability) hence the interest in MIP nanoparticles. Herein we report a reusable solid-phase template approach (fully compatible with automation) for the synthesis of MIP nanoparticles and their precise manufacture using a prototype automated UV photochemical reactor. Batches of nanoparticles (30-400 nm) with narrow size distributions imprinted with: melamine (d = 60 nm, K d = 6.3 × 10 -8 m), vancomycin (d = 250 nm, K d = 3.4 × 10 -9 m), a peptide (d = 350 nm, K d = 4.8 × 10 -8 m) and proteins have been produced. Our instrument uses a column packed with glass beads, bearing the template. Process parameters are under computer control, requiring minimal manual intervention. For the first time we demonstrate the reliable re-use of molecular templates in the synthesis of MIPs (≥ 30 batches of nanoMIPs without loss of performance). NanoMIPs are produced template-free and the solid-phase acts both as template and affinity separation medium.

  9. Comparative study on nano-Zirconium Oxide Materials used in Nuclear Technology

    International Nuclear Information System (INIS)

    Khalil, T.; Dakroury, G.A.; Abou El-Nour, F.; Abdel-Khlik, M.

    2004-01-01

    Nano-ZrO 2 powders were prepared using two advanced methods, namely SoI-GeI and Gelation techniques. Y 2 O 3 , Ce0 2 and Mg0 were used as stabilizers during the preparation processes. The function of these materials is to stabilize the meta stable tetragonal Zr0 2 phase responsible for the nano character of produced materials. The applied experimental procedures proved to be suitable to produce nano powders composed of crystallites of few nano-meter size with an interfacial component formed by all atoms situated in the grain boundaries. These two structure components (nano-sized crystallites and boundaries) of comparable volume fractions are crucial for the nano-structure materials. Powder agglo-meration, contamination during processing and remaining of the residual pores in the bodies were overcome during the sintering process of the powder by special treatment. Different analytical procedures such as DTA-TG, specific surface area, pore size analysis, density, scanning electron microscopy (SEM) and transmission electron microscopy (TEM) were carried out for Zr0 2 produced by both SoI-GeI and Gelation techniques

  10. Synthesis and characterization of a-site doped LaTiO3 nano perovskites

    International Nuclear Information System (INIS)

    Bradha, M.; Ashok, Anuradha

    2013-01-01

    Nano-sized lanthanum titanate perovskites (La (1-x) A x TiO 3 ) (A= Ba, Sr, Ca) were prepared by sol-gel method and calcined at 800℃. The synthesised perovskites were characterized by Thermogravimetry/ Differential thermal analysis (TGA/DTA), X-ray diffraction (XRD) and High Resolution Transmission Electron Microscopy (HRTEM) etc. LaTiO 3 is a perovskite having prominent interest for a variety of applications such as dielectric, insulators, charge-transport properties etc. It is a defect perovskite, with transport properties varying from insulating to metallic based on oxygen stoichiometry. In a quest to observe the effect of the nano size on its properties, lanthanum titanate (LaTiO 3 ) nano perovskites with different dopants on the A-site were prepared by using sol-gel method. In the present work we discuss the synthesis and structural analysis of (La 0.8 A 0.2 TiO 3 ). Phase purity and structural analysis of the calcined samples were performed by powder X-ray diffraction (XRD, with CuKα radiation). In addition to this, morphology and crystal structure was examined by Transmission Electron Microscopy (TEM) using a JEOL JEM 2100 HRTEM. HRTEM studies indicate that the nano perovskites are of size around 20 nm. Ring pattern in SAED also confirms that the perovskite is polycrystalline/nanocrystalline. More detailed study on high resolution images and crystal structure shed light on the reason for the properties exhibited by this perovskites

  11. Nano-resonator frequency response based on strain gradient theory

    International Nuclear Information System (INIS)

    Miandoab, Ehsan Maani; Yousefi-Koma, Aghil; Pishkenari, Hossein Nejat; Fathi, Mohammad

    2014-01-01

    This paper aims to explore the dynamic behaviour of a nano-resonator under ac and dc excitation using strain gradient theory. To achieve this goal, the partial differential equation of nano-beam vibration is first converted to an ordinary differential equation by the Galerkin projection method and the lumped model is derived. Lumped parameters of the nano-resonator, such as linear and nonlinear springs and damper coefficients, are compared with those of classical theory and it is demonstrated that beams with smaller thickness display greater deviation from classical parameters. Stable and unstable equilibrium points based on classic and non-classical theories are also compared. The results show that, regarding the applied dc voltage, the dynamic behaviours expected by classical and non-classical theories are significantly different, such that one theory predicts the un-deformed shape as the stable condition, while the other theory predicts that the beam will experience bi-stability. To obtain the frequency response of the nano-resonator, a general equation including cubic and quadratic nonlinearities in addition to parametric electrostatic excitation terms is derived, and the analytical solution is determined using a second-order multiple scales method. Based on frequency response analysis, the softening and hardening effects given by two theories are investigated and compared, and it is observed that neglecting the size effect can lead to two completely different predictions in the dynamic behaviour of the resonators. The findings of this article can be helpful in the design and characterization of the size-dependent dynamic behaviour of resonators on small scales. (paper)

  12. Cost-Effective Fabrication of Inner-Porous Micro/Nano Carbon Structures.

    Science.gov (United States)

    Jiang, Shulan; Shi, Tielin; Tang, Zirong; Xi, Shuang

    2018-03-01

    This paper reports the fabrication of a new micro/nano carbon architecture array which owns the characteristics of inner-porous, desired conductivity and large effective surface area. The micro/nano inner-porous carbon structures were fabricated for the first time, with ordinary and cost-effective processes, including photolithography, oxygen plasma etching and pyrolysis. Firstly, micro/nano hierarchical photoresist structures array was generated through photolithography and oxygen plasma etching processes. By introducing a critical thin-film spin-coating step, and followed with carefully pyrolyzing process, the micro/nano photoresist structures were converted into innerporous carbon architectures with good electric connection which connected the carbon structures array together. Probably the inner-porous property can be attributed to the shrinkage difference between positive thin film and negative photoresist structures during pyrolyzing process. It is demonstrated that the simple method is effective to fabricate inner-porous carbon structures with good electric connection and the carbon structures can be used as electrochemical electrodes directly and without the addition of other pyrolysis or film coating processes. The electrochemical property of the carbon structures has been explored by cyclic voltammetric measurement. Compared with solid carbon microstructures array, the cyclic voltammetry curve of inner-porous carbon structures shows greatly enhanced current and improved charge-storage capability, indicating great potential in micro energy storage devices and bio-devices.

  13. Preparation, Characterization, and Modeling of Carbon Nano fiber/Epoxy Nano composites

    International Nuclear Information System (INIS)

    Sun, L.H.; Yang, Z.G.; Ounaies, Z.; Whalen, C.A.; Gao, X.L.

    2011-01-01

    There is a lack of systematic investigations on both mechanical and electrical properties of carbon nano fiber (CNF)-reinforced epoxy matrix nano composites. In this paper, an in-depth study of both static and dynamic mechanical behaviors and electrical properties of CNF/epoxy nano composites with various contents of CNFs is provided. A modified Halpin-Tsai equation is used to evaluate the Young's modulus and storage modulus of the nano composites. The values of Young's modulus predicted using this method account for the effect of the CNF agglomeration and fit well with those obtained experimentally. The results show that the highest tensile strength is found in the epoxy nano composite with a 1.0 wt % CNFs. The alternate-current (AC) electrical properties of the CNF/epoxy nano composites exhibit a typical insulator-conductor transition. The conductivity increases by four orders of magnitude with the addition of 0.1 wt % (0.058 vol %) CNFs and by ten orders of magnitude for nano composites with CNF volume fractions higher than 1.0 wt % (0.578 vol %). The percolation threshold (i.e., the critical CNF volume fraction) is found to be at 0.057 vol %.

  14. Particle size distribution of fly ash from co-incineration of bituminous coal with municipal solid waste

    Directory of Open Access Journals (Sweden)

    Cieślik Ewelina

    2018-01-01

    Full Text Available One of the source of air pollutants is emission from local coal-fired boiler-houses and domestic heating boilers. The consequence of incineration of municipal waste is the introduction of additional pollutants into the atmosphere, including fly ash. The aim of this work was to evaluate the particle size distribution of fly ash emitted by coal combustion and co-incineration of coal with municipal waste in a domestic 18 kW central heating boiler equipped with an automatic fuel feeder. Mixtures of bituminous coal with different types of solid waste (5, 10 and 15% of mass fraction were used. Solid waste types consisted of: printed, colored PE caps, fragmented cable trunking, fragmented car gaskets and shredded tires from trucks. During the incineration of a given mixture of municipal waste with bituminous coal, the velocity of exhaust gas was specified, the concentration and mass flow of fly ash were determined together with the physico-chemical parameters of the exhaust gas, the samples of emitted fly ash were taken as the test material. Particle size analysis of fly ash was performed using laser particle sizer Fritch Analysette 22. The PM10 share from all fly ashes from incineration of mixtures was about 100%. Differences were noted between PM2.5 and PM1.

  15. Particle size distribution of fly ash from co-incineration of bituminous coal with municipal solid waste

    Science.gov (United States)

    Cieślik, Ewelina; Konieczny, Tomasz; Bobik, Bartłomiej

    2018-01-01

    One of the source of air pollutants is emission from local coal-fired boiler-houses and domestic heating boilers. The consequence of incineration of municipal waste is the introduction of additional pollutants into the atmosphere, including fly ash. The aim of this work was to evaluate the particle size distribution of fly ash emitted by coal combustion and co-incineration of coal with municipal waste in a domestic 18 kW central heating boiler equipped with an automatic fuel feeder. Mixtures of bituminous coal with different types of solid waste (5, 10 and 15% of mass fraction) were used. Solid waste types consisted of: printed, colored PE caps, fragmented cable trunking, fragmented car gaskets and shredded tires from trucks. During the incineration of a given mixture of municipal waste with bituminous coal, the velocity of exhaust gas was specified, the concentration and mass flow of fly ash were determined together with the physico-chemical parameters of the exhaust gas, the samples of emitted fly ash were taken as the test material. Particle size analysis of fly ash was performed using laser particle sizer Fritch Analysette 22. The PM10 share from all fly ashes from incineration of mixtures was about 100%. Differences were noted between PM2.5 and PM1.

  16. Hydrophilic block copolymer-directed growth of lanthanum hydroxide nano-particles

    Energy Technology Data Exchange (ETDEWEB)

    Bouyer, F.; Sanson, N.; Gerardin, C. [Laboratoire de Materiaux Catalytiques et Catalyse en Chimie Organique, UMR 5618 CNRS-ENSCM-UM1, FR 1878, Institut Gerhardt, 34 - Montpellier (France); Destarac, M. [Centre de Recherches Rhodia Aubervilliers, 93 - Aubervilliers (France)

    2006-03-15

    Stable hairy lanthanum hydroxide nano-particles were synthesized in water by performing hydrolysis and condensation reactions of lanthanum cations in the presence of double hydrophilic poly-acrylic acid-b-polyacrylamide block copolymers (PAA-b-PAM). In the first step, the addition of asymmetric PAA-b-PAM copolymers (M{sub w,PAA} {<=} M{sub w,PAM}) to lanthanum salt solutions, both at pH = 5.5, induces the formation of monodispersed micellar aggregates, which are predominantly isotropic. The core of the hybrid aggregates is constituted of a lanthanum polyacrylate complex whose formation is due to bidentate coordination bonding between La{sup 3+} and acrylate groups, as shown by ATR-FTIR experiments and pH measurements. The size of the micellar aggregates depends on the molecular weight of the copolymer but is independent of the copolymer to metal ratio in solution. In the second step, the hydrolysis of lanthanum ions is induced by addition of a strong base such as sodium hydroxide. Either flocculated suspensions or stable anisotropic or spherical nano-particles of lanthanum hydrolysis products were obtained depending on the metal complexation ratio [acrylate]/[La]. The variation of that parameter also enables the control of the size of the core-corona nano-particles obtained by lanthanum hydroxylation. The asymmetry degree of the copolymer was shown to influence both the size and the shape of the particles. Elongated particles with a high aspect ratio, up to 10, were obtained with very asymmetric copolymers (M{sub w,PAM}/M{sub w,PAA}{>=}10) while shorter rice grain-like particles were obtained with a less asymmetric copolymer. The asymmetry degree also influences the value of the critical metal complexation degree required to obtain stable colloidal suspensions of polymer-stabilized lanthanum hydroxide. (authors)

  17. Effect of milling on the damping behavior of nano-structured copper

    Energy Technology Data Exchange (ETDEWEB)

    Srikanth, Narasimalu; Thein, Maung Aye; Gupta, Manoj

    2004-02-05

    In the present study, elemental Cu powder was mechanically milled (MMed) for 10 h to reduce the grain (crystalline) size in the nano-range (<100 nm). The mechanically milled powder (10 h-MMed) and elemental powder without mechanical milling (MM) (0 h-MMed) was consolidated by die-cold compaction and were further hot extruded at different temperatures to maintain a crystallite size within the nano-range. Further, the specimen was tested by a novel free-free type suspended beam arrangement, coupled with circle-fit approach to determine damping characteristics. The characterization results help to understand the effect of the nano-size grains on the overall damping capacity of the bulk samples compared to a normal micro-crystalline sample. Results show that the damping capacity of the nano-grained material increases due to the presence of process induced microstructural changes similar to the damping behavior of a micro-grain sized specimen.

  18. Synthesis, structural characterization and selectively catalytic properties of metal-organic frameworks with nano-sized channels: A modular design strategy

    International Nuclear Information System (INIS)

    Qiu Lingguang; Gu Lina; Hu Gang; Zhang Lide

    2009-01-01

    Modular design method for designing and synthesizing microporous metal-organic frameworks (MOFs) with selective catalytical activity was described. MOFs with both nano-sized channels and potential catalytic activities could be obtained through self-assembly of a framework unit and a catalyst unit. By selecting hexaaquo metal complexes and the ligand BTC (BTC=1,3,5-benzenetricarboxylate) as framework-building blocks and using the metal complex [M(phen) 2 (H 2 O) 2 ] 2+ (phen=1,10-phenanthroline) as a catalyst unit, a series of supramolecular MOFs 1-7 with three-dimensional nano-sized channels, i.e. [M 1 (H 2 O) 6 ].[M 2 (phen) 2 (H 2 O) 2 ] 2 .2(BTC).xH 2 O (M 1 , M 2 =Co(II), Ni(II), Cu(II), Zn(II), or Mn(II), phen=1,10-phenanthroline, BTC=1,3,5-benzenetricarboxylate, x=22-24), were synthesized through self-assembly, and their structures were characterized by IR, elemental analysis, and single-crystal X-ray diffraction. These supramolecular microporous MOFs showed significant size and shape selectivity in the catalyzed oxidation of phenols, which is due to catalytic reactions taking place in the channels of the framework. Design strategy, synthesis, and self-assembly mechanism for the construction of these porous MOFs were discussed. - Grapical abstract: A modular design strategy has been developed to synthesize microporous metal-organic frameworks with potential catalytic activity by self-assembly of the framework-building blocks and the catalyst unit

  19. Characterization and bioactivity of nano-submicro octacalcium phosphate/gelatin composite

    International Nuclear Information System (INIS)

    Miura, Kei-ichiro; Anada, Takahisa; Honda, Yoshitomo; Shiwaku, Yukari; Kawai, Tadashi; Echigo, Seishi; Takahashi, Tetsu; Suzuki, Osamu

    2013-01-01

    The present study was designed to investigate the physicochemical and bioactive properties of a nano-submicro sized octacalcium phosphate (OCP)-dispersed gelatin (Gel) composite (nano-submicro OCP/Gel) used as a bone substitute material in various bone defects. Well-grown, synthesized OCP was mechanically ground from 100 to 300 μm-sieved granules to particles that were approximately 500 nm in size. Then, 50 wt% of the nano-submicro OCP was mixed with porcine skin-derived acid extracted gelatin. The mixture was molded and lyophilized and then subjected to dehydrothermal crosslinking. X-ray diffraction (XRD) and Fourier transform infrared (FTIR) spectroscopy showed that the structure of OCP was retained even after mechanical grinding to a nano-submicro scale level as well as inclusion in the Gel matrix. The bioactivity of nano-submicro OCP/Gel was examined by immersing the composite in simulated body fluid (SBF) for 7 days and by implanting it in rat critical-sized calvaria defects for 8 weeks. The nano-submicro OCP tended to convert to low crystalline hydroxyapatite (HA) in SBF as assessed by XRD. The nano-submicro OCP/Gel exhibited osteoconductivity in vivo, yielding new bone formation that was closely associated with the implanted composite. These results suggest that the nano-submicro OCP/Gel composite exhibits similar osteoconductivity as observed in other OCP-based materials previously reported and could be used as a bone substitute material for repairing various defects in bone.

  20. Characterization and bioactivity of nano-submicro octacalcium phosphate/gelatin composite

    Energy Technology Data Exchange (ETDEWEB)

    Miura, Kei-ichiro [Division of Craniofacial Function Engineering, Tohoku University Graduate School of Dentistry, Sendai (Japan); Division of Oral and Maxillofacial Surgery, Tohoku University Graduate School of Dentistry, Sendai (Japan); Anada, Takahisa; Honda, Yoshitomo [Division of Craniofacial Function Engineering, Tohoku University Graduate School of Dentistry, Sendai (Japan); Shiwaku, Yukari [Division of Craniofacial Function Engineering, Tohoku University Graduate School of Dentistry, Sendai (Japan); Division of Advanced Prosthetic Dentistry, Tohoku University Graduate School of Dentistry, Sendai (Japan); Kawai, Tadashi; Echigo, Seishi; Takahashi, Tetsu [Division of Oral and Maxillofacial Surgery, Tohoku University Graduate School of Dentistry, Sendai (Japan); Suzuki, Osamu, E-mail: suzuki-o@m.tohoku.ac.jp [Division of Craniofacial Function Engineering, Tohoku University Graduate School of Dentistry, Sendai (Japan)

    2013-10-01

    The present study was designed to investigate the physicochemical and bioactive properties of a nano-submicro sized octacalcium phosphate (OCP)-dispersed gelatin (Gel) composite (nano-submicro OCP/Gel) used as a bone substitute material in various bone defects. Well-grown, synthesized OCP was mechanically ground from 100 to 300 μm-sieved granules to particles that were approximately 500 nm in size. Then, 50 wt% of the nano-submicro OCP was mixed with porcine skin-derived acid extracted gelatin. The mixture was molded and lyophilized and then subjected to dehydrothermal crosslinking. X-ray diffraction (XRD) and Fourier transform infrared (FTIR) spectroscopy showed that the structure of OCP was retained even after mechanical grinding to a nano-submicro scale level as well as inclusion in the Gel matrix. The bioactivity of nano-submicro OCP/Gel was examined by immersing the composite in simulated body fluid (SBF) for 7 days and by implanting it in rat critical-sized calvaria defects for 8 weeks. The nano-submicro OCP tended to convert to low crystalline hydroxyapatite (HA) in SBF as assessed by XRD. The nano-submicro OCP/Gel exhibited osteoconductivity in vivo, yielding new bone formation that was closely associated with the implanted composite. These results suggest that the nano-submicro OCP/Gel composite exhibits similar osteoconductivity as observed in other OCP-based materials previously reported and could be used as a bone substitute material for repairing various defects in bone.

  1. Window-assisted nanosphere lithography for vacuum micro-nano-electronics

    International Nuclear Information System (INIS)

    Li, Nannan; Pang, Shucai; Yan, Fei; Chen, Lei; Jin, Dazhi; Xiang, Wei; Zhang, De; Zeng, Baoqing

    2015-01-01

    Development of vacuum micro-nano-electronics is quite important for combining the advantages of vacuum tubes and solid-state devices but limited by the prevailing fabricating techniques which are expensive, time consuming and low-throughput. In this work, window-assisted nanosphere lithography (NSL) technique was proposed and enabled the low-cost and high-efficiency fabrication of nanostructures for vacuum micro-nano-electronic devices, thus allowing potential applications in many areas. As a demonstration, we fabricated high-density field emitter arrays which can be used as cold cathodes in vacuum micro-nano-electronic devices by using the window-assisted NSL technique. The details of the fabricating process have been investigated. This work provided a new and feasible idea for fabricating nanostructure arrays for vacuum micro-nano-electronic devices, which would spawn the development of vacuum micro-nano-electronics

  2. Competing Grain Boundary and Interior Deformation Mechanisms with Varying Sizes

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Wei [University of Tennessee (UT); Gao, Yanfei [ORNL; Nieh, T. G. [University of Tennessee, Knoxville (UTK)

    2018-01-01

    In typical coarse-grained alloys, the dominant plastic deformations are dislocation gliding or climbing, and material strengths can be tuned by dislocation interactions with grain boundaries, precipitates, solid solutions, and other defects. With the reduction of grain size, the increase of material strengths follows the classic Hall-Petch relationship up to nano-grained materials. Even at room temperatures, nano-grained materials exhibit strength softening, or called the inverse Hall-Petch effect, as grain boundary processes take over as the dominant deformation mechanisms. On the other hand, at elevated temperatures, grain boundary processes compete with grain interior deformation mechanisms over a wide range of the applied stress and grain sizes. This book chapter reviews and compares the rate equation model and the microstructure-based finite element simulations. The latter explicitly accounts for the grain boundary sliding, grain boundary diffusion and migration, as well as the grain interior dislocation creep. Therefore the explicit finite element method has clear advantages in problems where microstructural heterogeneities play a critical role, such as in the gradient microstructure in shot peening or weldment. Furthermore, combined with the Hall-Petch effect and its breakdown, the above competing processes help construct deformation mechanism maps by extending from the classic Frost-Ashby type to the ones with the dependence of grain size.

  3. Incineration of a Commercial Coating with Nano CeO2

    Science.gov (United States)

    Le Bihan, Olivier; Ounoughene, Ghania; Meunier, Laurent; Debray, Bruno; Aguerre-Chariol, Olivier

    2017-06-01

    The potential environmental risk arising from the incineration of waste containing nanomaterials is a new field which deserves further attention. Some recent studies have begun to focus on this topic but the data are incomplete. In addition, there is a need to consider real life waste. The present study gives some insight into the fate and behavior of a commercial coating containing a commercial additive (7% w/w) based on nano-CeO2 (aggregates of 10 to 40 nm, with elemental particles of 2-3 nm). The tests have been conducted with a system developed in the frame of the NanoFlueGas project. The test protocol was designed to respect the regulatory criteria of a good combustion in incineration plants (temperature around 850°C, highly ventilated combustion, at least 2 s residence time for the combustion gas in a post-combustion chamber at 850°C, and high oxygen/fuel contact). Time tracking by electric low pressure impaction (ELPI) shows that the incineration produces aerosol with number concentration dominated by sub-100 nm particles. Cerium is observed by TEM and EDS analysis but as a minor compound of a sub-group of particles. No nanoCeO2 particles have been observed in the aerosol. ICP-MS analysis indicates that the residual material consists mainly of CeO2 (60% of the mass). Observation by TEM establishes that this material is in the form of aggregates with individual particle of 40-200 nm and suggests that sintering occurred during incineration. As a conclusion, the lab scale incineration study led mainly to the release of nano-CeO2 in the residual material, as the major component. Its size distribution is different than the one of the nano-CeO2 observed in the initial sample before incineration. Additional research is needed to improve the understanding of nanoCeO2 behavior, and to integrate experiments at lab and real scale.

  4. Development of a Sensitive Electrochemical Enzymatic Reaction-Based Cholesterol Biosensor Using Nano-Sized Carbon Interdigitated Electrodes Decorated with Gold Nanoparticles.

    Science.gov (United States)

    Sharma, Deepti; Lee, Jongmin; Seo, Junyoung; Shin, Heungjoo

    2017-09-15

    We developed a versatile and highly sensitive biosensor platform. The platform is based on electrochemical-enzymatic redox cycling induced by selective enzyme immobilization on nano-sized carbon interdigitated electrodes (IDEs) decorated with gold nanoparticles (AuNPs). Without resorting to sophisticated nanofabrication technologies, we used batch wafer-level carbon microelectromechanical systems (C-MEMS) processes to fabricate 3D carbon IDEs reproducibly, simply, and cost effectively. In addition, AuNPs were selectively electrodeposited on specific carbon nanoelectrodes; the high surface-to-volume ratio and fast electron transfer ability of AuNPs enhanced the electrochemical signal across these carbon IDEs. Gold nanoparticle characteristics such as size and morphology were reproducibly controlled by modulating the step-potential and time period in the electrodeposition processes. To detect cholesterol selectively using AuNP/carbon IDEs, cholesterol oxidase (ChOx) was selectively immobilized via the electrochemical reduction of the diazonium cation. The sensitivity of the AuNP/carbon IDE-based biosensor was ensured by efficient amplification of the redox mediators, ferricyanide and ferrocyanide, between selectively immobilized enzyme sites and both of the combs of AuNP/carbon IDEs. The presented AuNP/carbon IDE-based cholesterol biosensor exhibited a wide sensing range (0.005-10 mM) and high sensitivity (~993.91 µA mM -1 cm -2 ; limit of detection (LOD) ~1.28 µM). In addition, the proposed cholesterol biosensor was found to be highly selective for the cholesterol detection.

  5. WATEQ3 geochemical model: thermodynamic data for several additional solids

    International Nuclear Information System (INIS)

    Krupka, K.M.; Jenne, E.A.

    1982-09-01

    Geochemical models such as WATEQ3 can be used to model the concentrations of water-soluble pollutants that may result from the disposal of nuclear waste and retorted oil shale. However, for a model to competently deal with these water-soluble pollutants, an adequate thermodynamic data base must be provided that includes elements identified as important in modeling these pollutants. To this end, several minerals and related solid phases were identified that were absent from the thermodynamic data base of WATEQ3. In this study, the thermodynamic data for the identified solids were compiled and selected from several published tabulations of thermodynamic data. For these solids, an accepted Gibbs free energy of formation, ΔG 0 /sub f,298/, was selected for each solid phase based on the recentness of the tabulated data and on considerations of internal consistency with respect to both the published tabulations and the existing data in WATEQ3. For those solids not included in these published tabulations, Gibbs free energies of formation were calculated from published solubility data (e.g., lepidocrocite), or were estimated (e.g., nontronite) using a free-energy summation method described by Mattigod and Sposito (1978). The accepted or estimated free energies were then combined with internally consistent, ancillary thermodynamic data to calculate equilibrium constants for the hydrolysis reactions of these minerals and related solid phases. Including these values in the WATEQ3 data base increased the competency of this geochemical model in applications associated with the disposal of nuclear waste and retorted oil shale. Additional minerals and related solid phases that need to be added to the solubility submodel will be identified as modeling applications continue in these two programs

  6. Nano-size metallic oxide particle synthesis in Fe-Cr alloys by ion implantation

    Science.gov (United States)

    Zheng, C.; Gentils, A.; Ribis, J.; Borodin, V. A.; Delauche, L.; Arnal, B.

    2017-10-01

    Oxide Dispersion Strengthened (ODS) steels reinforced with metal oxide nanoparticles are advanced structural materials for nuclear and thermonuclear reactors. The understanding of the mechanisms involved in the precipitation of nano-oxides can help in improving mechanical properties of ODS steels, with a strong impact for their commercialization. A perfect tool to study these mechanisms is ion implantation, where various precipitate synthesis parameters are under control. In the framework of this approach, high-purity Fe-10Cr alloy samples were consecutively implanted with Al and O ions at room temperature and demonstrated a number of unexpected features. For example, oxide particles of a few nm in diameter could be identified in the samples already after ion implantation at room temperature. This is very unusual for ion beam synthesis, which commonly requires post-implantation high-temperature annealing to launch precipitation. The observed particles were composed of aluminium and oxygen, but additionally contained one of the matrix elements (chromium). The crystal structure of aluminium oxide compound corresponds to non-equilibrium cubic γ-Al2O3 phase rather than to more common corundum. The obtained experimental results together with the existing literature data give insight into the physical mechanisms involved in the precipitation of nano-oxides in ODS alloys.

  7. Synthesis and structural characterization of nano-hydroxyapatite biomaterials prepared by microwave processing

    Science.gov (United States)

    Ramli, Rosmamuhamadani; Arawi, Ainaa Zafirah Omar; Talari, Mahesh Kumar; Mahat, Mohd Muzamir; Jais, Umi Sarah

    2012-07-01

    Synthetic hydroxyapatite, (HA, Ca10(PO4)6(OH)2), is an attractive and widely utilized bio-ceramic material for orthopedic and dental implants because of its close resemblance of native tooth and bone crystal structure. Synthetic HA exhibits excellent osteoconductive properties. Osteoconductivity means the ability to provide the appropriate scaffold or template for bone formation. Calcium phosphate biomaterials [(HA), tri-calcium phosphate (TCP) and biphasic calcium phosphate (HA/TCP)] with appropriate three-dimensional geometry are able to bind and concentrate endogenous bone morphogenetic proteins in circulation, and may become osteoinductive and can be effective carriers of bone cell seeds. This HA can be used in bio-implants as well as drug delivery application due to the unique properties of HA. Biomaterials synthesized from the natural species like mussel shells have additional benefits such as high purity, less expensive and high bio compatibility. In this project, HA-nanoparticles of different crystallite size were prepared by microwave synthesis of precursors. High purity CaO was extracted from the natural mussel shells for the synthesis of nano HA. Dried nano HA powders were analyzed using X-Ray Diffraction (XRD) technique for the determination of crystal structure and impurity content. Scanning Electron Microscopic (SEM) investigation was employed for the morphological investigation of nano HA powders. From the results obtained, it was concluded that by altering the irradiation time, nano HA powders of different crystallite sizes and morphologies could be produced. Crystallite sizes calculated from the XRD patterns are found to be in the range of 10-55 nm depending on the irradiation time.

  8. Preparation of Lipid Nano emulsions Incorporating Curcumin for Cancer Therapy

    International Nuclear Information System (INIS)

    Anuchapreeda, S.; Anuchapreeda, S.; Fukumori, Y.; Ichikawa, H.; Okonogi, S.

    2012-01-01

    The aim of this study was to develop a new formulation of a curcumin lipid nano emulsion having the smallest particle size, the highest loading, and a good physical stability for cancer chemotherapy. Curcumin lipid nano emulsions were prepared by a modified thin-film hydration method followed by sonication. Soybean oil, hydrogenated L-α-phosphatidylcholine from egg yolk, and co surfactants were used to formulate the emulsions. The resultant nano emulsions showed mean particle diameter of 47-55 nm, could incorporate 23-28 mg curcumin per 30 mL, and were stable in particle size for 60 days at 4 degree C. The cytotoxicity studies of curucumin solution and curcumin-loaded nano emulsion using B16F10 and leukemic cell lines showed IC 50 values ranging from 3.5 to 30.1 and 22.2 to 53.7μM, respectively. These results demonstrated the successful incorporation of curcumin into lipid nano emulsion particles with small particle size, high loading capacity, good physical stability, and preserved cytotoxicity

  9. Control of the Nano-Particle Weight Ratio in Stainless Steel Micro and Nano Powders by Radio Frequency Plasma Treatment

    Directory of Open Access Journals (Sweden)

    Dong-Yeol Yang

    2015-11-01

    Full Text Available This study describes how to make stainless steel hybrid micro-nano-powders (a mixture of micro-powder and nano-powder using an in situ one-step process via radio frequency (RF thermal plasma treatment. Nano-particles attached to micro-powders were successfully prepared by RF thermal plasma treatment of stainless steel powder with an average size of 35 μm. The ratio of nano-powders is estimated with a two-dimensional fluid simulation that calculates the temperature profile influencing the rate of surface evaporation. The simulation is conducted to determine the variation of the input power and the distance from the plasma torch to the feeding nozzle. It was demonstrated experimentally that the nano-powder ratio in the micro-nano-powder mixture can be controlled by adjusting the feeding rate, plasma power, feeding position and quenching effect during plasma treatment. The ratio of nano-particles in the micro-nano-powder mixture was controlled in a range from 0.1 (wt. % to 30.7 (wt. %.

  10. Chemical composition shape form and size of suspended solids in the atmosphere carried by rain water

    International Nuclear Information System (INIS)

    Iturbe G, J.L.; Lopez M, B.E.; Torre O, J. De la

    2001-01-01

    The interest of this work is to know about shape form, size and chemical composition of the suspended solids in the atmosphere of Toluca city and which are carried by the rains. The harvest of the samples was carried out during january to november 1999. The separation of the particulate matter from the rain water was realized through centrifugation. The solids were analysed by Scanning Electron Microscopy to know the shape form and size and the chemical composition was determined by X-ray dispersive energy in general form and of some particles individually analysed. The p H was measured to the solutions and the quantification of some dissolved ions by the Icp technique was realized. The results of the solids showed C, O, Na, Mg, Al, Si, S, P, K, Ca, Ti and Fe. Moreover they present sizes which varying from a ten of nanometers until some tens of microns. (Author)

  11. Synthesis of Si, N co-Doped Nano-Sized TiO2 with High Thermal Stability and Photocatalytic Activity by Mechanochemical Method

    Directory of Open Access Journals (Sweden)

    Peisan Wang

    2018-05-01

    Full Text Available Τhe photocatalytic activity in the range of visible light wavelengths and the thermal stability of the structure were significantly enhanced in Si, N co-doped nano-sized TiO2, and synthesized through high-energy mechanical milling of TiO2 and SiO2 powders, which was followed by calcination at 600 °C in an ammonia atmosphere. High-energy mechanical milling had a pronounced effect on the mixing and the reaction between the starting powders and greatly favored the transformation of the resultant powder mixture into an amorphous phase that contained a large number of evenly-dispersed nanocrystalline TiO2 particles as anatase seeds. The experimental results suggest that the elements were homogeneously dispersed at an atomic level in this amorphous phase. After calcination, most of the amorphous phase was crystallized, which resulted in a unique nano-sized crystalline-core/disordered-shell morphology. This novel experimental process is simple, template-free, and provides features of high reproducibility in large-scale industrial production.

  12. Size-controlled fabrication of zein nano/microparticles by modified anti-solvent precipitation with/without sodium caseinate.

    Science.gov (United States)

    Li, Feng; Chen, Yan; Liu, Shubo; Qi, Jian; Wang, Weiying; Wang, Chenhua; Zhong, Ruiyue; Chen, Zhijun; Li, Xiaoming; Guan, Yuanzhou; Kong, Wei; Zhang, Yong

    2017-01-01

    Zein-based nano/microparticles have been demonstrated to be promising carrier systems for both the food industry and biomedical applications. However, the fabrication of size-controlled zein particles has been a challenging issue. In this study, a modified anti-solvent precipitation method was developed, and the effects of various factors, such as mixing method, solvent/anti-solvent ratio, temperature, zein concentrations and the presence of sodium caseinate (SC) on properties of zein particles were investigated. Evidence is presented that, among the previously mentioned factors, the mixing method, especially mixing rate, could be used as an effective parameter to control the size of zein particles without changing other parameters. Moreover, through fine-tuning the mixing rate together with zein concentration, particles with sizes ranging from nanometers to micrometers and low polydispersity index values could be easily obtained. Based on the size-controlled fabrication method, SC-coated zein nanoparticles could also be obtained in a size-controlled manner by incubation of the coating material with the already-formed zein particles. The resultant nanoparticles showed better performance in both drug loading and controlled release, compared with zein/SC hybrid nanoparticles fabricated by adding aqueous ethanol solution to SC solution. The possible mechanisms of the nanoprecipitation process and self-assembly formation of these nanoparticles are discussed.

  13. Synthesis and characterization of nano-hydroxyapatite using Sapindus Mukorossi extract

    Science.gov (United States)

    Subha, B.; Prasath, P. Varun; Abinaya, R.; Kavitha, R. J.; Ravichandran, K.

    2015-06-01

    Nano-Hydroxyapatite (HAP) powders were successfully synthesised by hydrothermal method using Sapindus Mukorossi extract as an additive. The structural and morphological analyses of thus synthesised powders were carried out using FT-IR, XRD and FESEM/EDX. The FT-IR spectra confirm the presence of phosphate and hydroxyl groups corresponding to HAP. The XRD analysis reveals the formation of HAP phase and found to reduce the crystallite size with addition of Sapindus Mukorossi extract. The morphology changes from sphere to flake shape by the influence of extract.

  14. Nano copper ferrite: A reusable catalyst for the synthesis of β, γ ...

    Indian Academy of Sciences (India)

    aCatalyst recovered by membrane filtration and washed with diethyl ether and then by distilled water. bYields compared to isolated products. From table 3, it is noticed that in some reactions the catalyst needs co-catalysts/additives. Some reac- tions need the acidic/basic workup to get the product. But here in this nano sized ...

  15. Fluorine-18-labeling of polymerized nano-micelles for in vivo PET imaging

    International Nuclear Information System (INIS)

    Kuhnast, B.; Hinnen, F.; Mackiewicz, N.; Tavitian, B.; Duconge, F.; Dolle, F.; Gravel, E.; Doris, E.

    2011-01-01

    Complete text of publication follows: Objectives: One of the key issues in nano-medicine, and in particular in the field of cancer treatment and follow up, is the development of nano-particles able to improve the delivery of drugs or contrast agents. It is well established that passive targeting by nano-particles is favoured by specific features of tumors, a phenomena usually defined as the enhanced permeability and retention (EPR) effect. While several nano-particulate systems in the 70- 200 nm size range have been explored for cancer targeting by the EPR effect (liposomes, dendrimers, ceramic or metallic nano-particles, carbon nano-tubes...), recent studies suggested that particles of smaller sizes (≤ 30 nm) might better diffuse through blood vessel walls and reach deeper tumor tissues. Recently, a novel series of small-sized (diameter of ca. 10 nm) and highly stable (polymerized) micelles were designed as drug nano-carriers. For in vivo 3D-imaging purposes, these micelles were provided with a sulfhydryl function permitting prosthetic conjugation with maleimide-based reagents such as AlexaFluor680 R (AF680) for optical fluorescence imaging and [ 18 F]FPyME (1-[3-(2-[ 18 F]fluoropyridin-3-yloxy)propyl]pyrrole-2, 5-dione), a prosthetic reagent labeled with the positron-emitter fluorine-18 for PET imaging, which latter work is presented herein. Methods: nano-micelles were synthesized using standard already reported procedures and comprise a defined molar ratio of functionalized diacetylene-containing poly(ethyleneglycol) (PEG-2000) lipids (pentacosa-10, 12- diyn-1-oxy-penta-tetraconta-ethylene-glycols). Preparation includes polymerization of the diacetylene functions borne by the C-25 lipophilic chains upon UV-irradiation at 254 nm via a topochemical 1, 4-addition mechanism. [ 18 F]FPyME was conjugated with the micelles in a 1/9 (v:v) mixture (1 mL) of DMSO and 0.1 M aq. PBS (pH 7.5) at room temperature for 15 min. The conjugated micelles were then separated from

  16. Combustion synthesis of CaSc2O4:Ce3+ nano-phosphors in a closed system

    International Nuclear Information System (INIS)

    Peng Wenfang; Zou Shaoyu; Liu Guanxi; Xiao Quanlan; Zhang Rui; Xie Lijuan; Cao Liwei; Meng Jianxin; Liu Yingliang

    2011-01-01

    Highlights: → CaSc 2 O 4 :Ce 3+ nano-phosphors can be prepared by a single-step combustion method. → The ignition temperature is the lowest in the combustion synthesis of Ce 3+ /Eu 2+ doped phosphors. → The as-prepared nano-phosphors give a uniform particle size in the range of 15-20 nm and have highly dispersity and fluorescence intensity. → It is a convenient method for preparation of monodispersed oxide nano-phosphors, especially those being sensitive to air at high temperature. - Abstract: The CaSc 2 O 4 :Ce 3+ nano-phosphors were successfully prepared by a single-step combustion method at an ignition temperature as low as 200 deg. C in a closed autoclave using glycine as a fuel and PEG4000 as a dispersant. The samples were characterized by X-ray diffraction (XRD), photoluminescence (PL) spectroscopy, scanning electron microscopy (SEM) and transmission electron microscope (TEM). The results revealed that CaSc 2 O 4 :Ce 3+ nano-phosphors can be conveniently prepared at an ignition temperature as low as 200 deg. C, which was much lower than that in the ordinary combustion methods. The optimized ignition temperature was 220 deg. C. The CaSc 2 O 4 :Ce 3+ nano-phosphors give a uniform particle size in the range of 15-20 nm. The low ignition temperature and the addition of PEG4000 dispersant play important roles in the formation of small sized nanoparticles. The as-prepared nano-phosphors were incompact aggregates, but highly dispersed nano-phosphors can be obtained after further ultrasonic treatment. The CaSc 2 O 4 :Ce 3+ nano-phosphors give satisfactory luminescence characteristic benefiting from the closed circumstance, in which cerium atoms can be isolated from the oxidizing atmosphere and non-fluorescent Ce 4+ ions can be ruled out. The present highly dispersed CaSc 2 O 4 :Ce 3+ nano-phosphors with efficient fluorescence are promising in the field of biological labeling, and the present low temperature combustion method is facile and convenient and can

  17. Effect of Iron Oxides (Ordinary and Nano and Municipal Solid Waste Compost (MSWC Coated Sulfur on Wheat (Triticum aestivum L. Plant Iron Concentration and Growth

    Directory of Open Access Journals (Sweden)

    S Mazaherinia

    2011-02-01

    Full Text Available Abstract A greenhouse study was conducted to compare the effects of ordinary iron oxide (0.02-0.06 mm and nano iron oxide (25-250 nm and five levels of both iron oxides (0, 0.05, 0.1, 0.5, and 1.0 %w/w and two levels of sulfurous granular compost (MSW (0 and 2% w/w on plant height, spike length, grain weight per spike, total plant dry matter weight and thousands grain weight of wheat. The experimental factors were combined in factorial arrangement in a completely randomized design with 3 replications. Results showed that nano iron oxide was superior over ordinary iron oxide in all parameters studied. Fe concentration, spike length, plant height, grain weight per spike, total plant dry weight and thousands grain weight showed increasing trend per increase in both of iron oxides levels. Also, all parameters studied in sulfurous granular compost (MSW treatment were superior over granular compost without sulfurous (MSW. This increase in all parameters were significantly higher when urban solid waste compost coated with sulfur coupled with nano iron oxide compared to urban sulfurous granular compost (MSW along with ordinary iron oxide. Keywords: Sulfurous granular compost (MSW, Nano and ordinary iron oxides, Wheat

  18. Parametric investigations on the influence of nano-second Nd{sup 3+}:YAG laser wavelength and fluence in synthesizing NiTi nano-particles using liquid assisted laser ablation technique

    Energy Technology Data Exchange (ETDEWEB)

    Patra, Nandini, E-mail: nandinipatra2007@gmail.com [Centre for Material Science and Engineering, Indian Institute of Technology, Indore, Madhya Pradesh, Pin-453441 (India); Akash, K.; Shiva, S.; Gagrani, Rohit; Rao, H. Sai Pranesh; Anirudh, V.R. [Mechatronics and Instrumentation lab, Discipline of Mechanical Engineering, Indian Institute of Technology, Indore, Madhya Pradesh, Pin-453441 (India); Palani, I.A., E-mail: palaniia@iiti.ac.in [Centre for Material Science and Engineering, Indian Institute of Technology, Indore, Madhya Pradesh, Pin-453441 (India); Mechatronics and Instrumentation lab, Discipline of Mechanical Engineering, Indian Institute of Technology, Indore, Madhya Pradesh, Pin-453441 (India); Singh, Vipul [Centre for Material Science and Engineering, Indian Institute of Technology, Indore, Madhya Pradesh, Pin-453441 (India)

    2016-03-15

    Graphical abstract: - Highlights: • Influence of laser wavelengths (1064 nm, 532 nm and 355 nm) and fluences (40 J/cm{sup 2}, 30 J/cm{sup 2} and 20 J/cm{sup 2}) on generation of underwater laser ablated NiTi nanoparticles. • Particle size range of 140–10 nm was generated at varying laser wavelengths. • The alloy formation of NiTi nanoparticles was confirmed from XRD and TEM analysis where the crystalline peaks of NiTi, Ni{sub 4}Ti{sub 3} and Ni{sub 3}Ti were observed from XRD. • Formation efficiency of NiTi nanoparticles was maximum at 1064 nm wavelength and 40 J/cm{sup 2} fluence. - Abstract: This paper investigates the influence of laser wavelengths and laser fluences on the size and quality of the NiTi nanoparticles, generated through underwater solid state Nd:YAG laser ablation technique. The experiments were performed on Ni55%–Ti45% sheet to synthesize NiTi nano-particles at three different wavelengths (1064 nm, 532 nm and 355 nm) with varying laser fluences ranging from 20 to 40 J/cm{sup 2}. Synthesized NiTi nano-particles were characterized through SEM, DLS, XRD, FT-IR, TEM and UV–vis spectrum. It was observed that, maximum particle size of 140 nm and minimum particle size of 10 nm were generated at varying laser wavelengths. The crystallinity and lattice spacing of NiTi alloy nanoparticles were confirmed from the XRD analysis and TEM images, respectively.

  19. The flexoelectric effect associated size dependent pyroelectricity in solid dielectrics

    Science.gov (United States)

    Bai, Gang; Liu, Zhiguo; Xie, Qiyun; Guo, Yanyan; Li, Wei; Yan, Xiaobing

    2015-09-01

    A phenomenological thermodynamic theory is used to investigate the effect of strain gradient on the pyroelectric effect in centrosymmetric dielectric solids. Direct pyroelectricity can exist as external mechanical stress is applied to non-pyroelectric dielectrics with shapes such as truncated pyramids, due to elastic strain gradient induced flexoelectric polarization. Effective pyroelectric coefficient was analyzed in truncated pyramids. It is found to be controlled by size, ambient temperature, stress, and aspect ratio and depends mainly on temperature sensitivity of flexoelectric coefficient (TSFC) and strain gradient of the truncated pyramids dielectric solids. These results show that the pyroelectric property of Ba0.67Sr0.33TiO3 above Tc similar to PZT and other lead-based ferroelectrics can be obtained. This feature might widely broaden the selection of materials for infrared detectors with preferable properties.

  20. Multiplex PCR, amplicon size and hybridization efficiency on the NanoChip electronic microarray

    DEFF Research Database (Denmark)

    Børsting, Claus; Sanchez, Juan J; Morling, Niels

    2004-01-01

    We tested the SNP typing protocol developed for the NanoChip electronic microarray by analyzing the four Y chromosome loci SRY1532, SRY8299, TAT, and 92R7. Amplicons of different lengths containing the same locus were purified and addressed to the NanoChip array and fluorescently labelled reporte...