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Sample records for hollow glass microsphere

  1. Porous-wall hollow glass microspheres as carriers for biomolecules

    Science.gov (United States)

    Li, Shuyi; Dynan, William S; Wicks, George; Serkiz, Steven

    2013-09-17

    The present invention includes compositions of porous-wall hollow glass microspheres and one or more biomolecules, wherein the one or more biomolecules are positioned within a void location within the hollow glass microsphere, and the use of such compositions for the diagnostic and/or therapeutic delivery of biomolecules.

  2. Hollow porous-wall glass microspheres for hydrogen storage

    Science.gov (United States)

    Heung, Leung K.; Schumacher, Ray F.; Wicks, George G.

    2010-02-23

    A porous wall hollow glass microsphere is provided having a diameter range of between 1 to 200 microns, a density of between 1.0 to 2.0 gm/cc, a porous-wall structure having wall openings defining an average pore size of between 10 to 1000 angstroms, and which contains therein a hydrogen storage material. The porous-wall structure facilitates the introduction of a hydrogen storage material into the interior of the porous wall hollow glass microsphere. In this manner, the resulting hollow glass microsphere can provide a membrane for the selective transport of hydrogen through the porous walls of the microsphere, the small pore size preventing gaseous or liquid contaminants from entering the interior of the hollow glass microsphere.

  3. Innovative hydrogen storage in hollow glass-microspheres

    Energy Technology Data Exchange (ETDEWEB)

    Keding, M.; Schmid, G.; Tajmar, M. [Austrian Research Centers, Vienna (Austria)

    2009-07-01

    Hydrogen storage technologies are becoming increasingly important for a number of future applications. The Austrian Research Centers (ARC) are developing a unique hydrogen storage system that combines the advantages of both hollow glass microsphere and chemical compound hydrogen storage, but eliminates their respective drawbacks. Water is utilized as a functional liquid to carry the hollow glass microspheres that are loaded with up to 700 bar of hydrogen gas. Sodium borohydride (NaBH{sub 4}) is then injected together with the glass microspheres into a reaction chamber where the water reacts catalytically with the NaBH{sub 4} producing hydrogen and heat. The heat is then utilized to release the hydrogen from the hollow glass microspheres providing a double hydrogen generation process without any external energy or heat during storage or gas release. The paper described this hydrogen storage system with particular reference to microspheres, the coating process, the experimental facility and NaBH{sub 4} test results. It was concluded that hydrogen storage and production on demand is possible with microspheres and sodium borohydride solution. 9 refs., 16 figs.

  4. PREPARATION AND CHARACTERIZATION OF POROUS WALLED HOLLOW GLASS MICROSPHERES

    Energy Technology Data Exchange (ETDEWEB)

    Raszewski, F; Erich Hansen, E; Ray Schumacher, R; David Peeler, D

    2008-04-21

    Porous-walled hollow glass microspheres (PWHGMs) of a modified alkali borosilicate composition have been successfully fabricated by combining the technology of producing hollow glass microspheres (HGMs) with the knowledge associated with porous glasses. HGMs are first formed by a powder glass--flame process, which are then transformed to PWHGMs by heat treatment and subsequent treatment in acid. Pore diameter and pore volume are most influenced by heat treatment temperature. Pore diameter is increased by a factor of 10 when samples are heat treated prior to acid leaching; 100 {angstrom} in non-heat treated samples to 1000 {angstrom} in samples heat treated at 600 C for 8 hours. As heat treatment time is increased from 8 hours to 24 hours there is a slight shift increase in pore diameter and little or no change in pore volume.

  5. Preparation of hollow hydroxyapatite microspheres by the conversion of borate glass at near room temperature

    International Nuclear Information System (INIS)

    Yao, Aihua; Ai, Fanrong; Liu, Xin; Wang, Deping; Huang, Wenhai; Xu, Wei

    2010-01-01

    Hollow hydroxyapatite microspheres, consisting of a hollow core and a porous shell, were prepared by converting Li 2 O-CaO-B 2 O 3 glass microspheres in dilute phosphate solution at 37 o C. The results confirmed that Li 2 O-CaO-B 2 O 3 glass was transformed to hydroxyapatite without changing the external shape and dimension of the original glass object. Scanning electron microscopy images showed the shell wall of the microsphere was built from hydroxyapatite particles, and these particles spontaneously align with one another to form a porous sphere with an interior cavity. Increase in phosphate concentration resulted in an increase in the reaction rate, which in turn had an effect on shell wall structure of the hollow hydroxyapatite microsphere. For the Li 2 O-CaO-B 2 O 3 glass microspheres reacted in low-concentration K 2 HPO 4 solution, lower reaction rate and a multilayered microstructure were observed. On the other hand, the glass microspheres reacted in higher phosphate solution converted more rapidly and produced a single hydroxyapatite layer. Furthermore, the mechanism of forming hydroxyapatite hollow microsphere was described.

  6. Preparation and properties of hollow glass microspheres for use in laser fusion experiments

    Energy Technology Data Exchange (ETDEWEB)

    Campbell, J.H.; Grens, J.Z.; Poco, J.F.

    1983-11-01

    We review the preparation of high quality, hollow-glass microspheres for use in laser driven fusion experiments at LLNL. The primary focus of this paper is on the liquid-droplet method for making glass spheres, which has been in use at LLNL for over six years. We have combined the results from previous studies with our current results to present a detailed description of the preparation and the composition and physical properties of the glass microspheres. We also present a mathematical model that simulates the microsphere formation process. Examples are given of the application of the model to study the effects of various process parameters.

  7. Preparation and properties of hollow glass microspheres for use in laser fusion experiments

    International Nuclear Information System (INIS)

    Campbell, J.H.; Grens, J.Z.; Poco, J.F.

    1983-01-01

    We review the preparation of high quality, hollow-glass microspheres for use in laser driven fusion experiments at LLNL. The primary focus of this paper is on the liquid-droplet method for making glass spheres, which has been in use at LLNL for over six years. We have combined the results from previous studies with our current results to present a detailed description of the preparation and the composition and physical properties of the glass microspheres. We also present a mathematical model that simulates the microsphere formation process. Examples are given of the application of the model to study the effects of various process parameters

  8. Potential of Hollow Glass Microsphere as Cement Replacement for Lightweight Foam Concrete on Thermal Insulation Performance

    Directory of Open Access Journals (Sweden)

    Shahidan Shahiron

    2017-01-01

    Full Text Available Global warming can be defined as a gradual increase in the overall temperature of the earth’s atmosphere. A lot of research work has been carried out to reduce that heat inside the residence such as the used of low density products which can reduce the self-weight, foundation size and construction costs. Foamed concrete it possesses high flow ability, low self-weight, minimal consumption of aggregate, controlled low strength and excellent thermal insulation properties. This study investigate the characteristics of lightweight foamed concrete where Portland cement (OPC was replaced by hollow glass microsphere (HGMs at 0%, 3%, 6%, 9% by weight. The density of wet concrete is 1000 kg/m3 were tested with a ratio of 0.55 for all water binder mixture. Lightweight foamed concrete hollow glass microsphere (HGMs produced were cured by air curing and water curing in tank for 7, 14 and 28 days. A total of 52 concrete cubes of size 100mm × 100mm × 100mm and 215mm × 102.5mm × 65mm were produced. Furthermore, Scanning Electron Microscope (SEM and X-ray fluorescence (XRF were carried out to study the chemical composition and physical properties of crystalline materials in hollow glass microspheres. The experiments involved in this study are compression strength, water absorption test, density and thermal insulation test. The results show that the compressive strength of foamed concrete has reached the highest in 3% of hollow glass microsphere with less water absorption and less of thermal insulation. As a conclusion, the quantity of hollow glass microsphere plays an important role in determining the strength and water absorption and also thermal insulation in foamed concrete and 3% hollow glass microspheres as a replacement for Portland cement (OPC showed an optimum value in this study as it presents a significant effect than other percentage.

  9. Improvements in processing characteristics and engineering properties of wood flour-filled high density polyethylene composite sheeting in the presence of hollow glass microspheres

    Science.gov (United States)

    Baris Yalcin; Steve E Amos; Andrew S D Souza; Craig M Clemons; I Sedat Gunes; Troy K Ista

    2012-01-01

    Hollow glass microspheres were introduced into wood flour/high density polyethylene composites by melt compounding in a twin-screw extruder. The prepared composites were subsequently converted to extruded profiles in order to obtain composite sheeting. The presence of hollow glass microspheres highly reduced the density of the extruded sheets down to 0.9 g/cc, while...

  10. Factors influencing the deposition of hydroxyapatite coating onto hollow glass microspheres

    International Nuclear Information System (INIS)

    Jiao, Yan; Xiao, Gui-Yong; Xu, Wen-Hua; Zhu, Rui-Fu; Lu, Yu-Peng

    2013-01-01

    Hydroxyapatite (HA) and HA coated microcarriers for cell culture and delivery have attracted more attention recently, owing to the rapid progress in the field of tissue engineering. In this research, a dense and uniform HA coating with the thickness of about 2 μm was successfully deposited on hollow glass microspheres (HGM) by biomimetic process. The influences of SBF concentration, immersion time, solid/liquid ratio and activation of HGM on the deposition rate and coating characteristics were discussed. X-ray diffraction (XRD) and Fourier transform infrared spectrum (FTIR) analyses revealed that the deposited HA is poorly crystalline. The thickness of HA coating showed almost no increase after immersion in 1.5SBF for more than 15 days with the solid/liquid ratio of 1:150. At the same time, SBF concentration, solid/liquid ratio and activation treatment played vital roles in the formation of HA coating on HGM. This poorly crystallized HA coated HGM could have potential use as microcarrier for cell culture. Highlights: • HA coatings were deposited on hollow glass microspheres by biomimetic process. • The obtained HA coating was poorly crystalline and carbonated. • The influencing factors of deposition rate and coating characteristics were studied. • The thickness of HA coating showed almost no increase after immersion for 15 days

  11. Optimization of the contents of hollow glass microsphere and sodium hexametaphosphate for glass fiber vacuum insulation panel

    Science.gov (United States)

    Li, C. D.; Chen, Z. F.; Zhou, J. M.

    2016-07-01

    In this paper, various additive amounts of hollow glass microspheres (HGMs) and sodium hexametaphosphate (SHMP) powders were blended with flame attenuated glass wool (FAGW) to form hybrid core materials (HCMs) through the wet method. Among them, the SHMP was dissolved in the glass fiber suspension and coated on the surface of glass fibers while the HGMs were insoluble in the glass fiber suspension and filled in the fiber-fiber pores. The average pore diameter of the FAGW/HGM HCMs was 8-11 μm which was near the same as that of flame attenuated glass fiber mats (FAGMs, i.e., 10.5 µm). The tensile strength of the SHMP coated FAGMs was enhanced from 160 N/m to 370 N/m when SHMP content increased from 0 wt.% to 0.2 wt.%. By contrast, the tensile strength of the FAGW/HGM HCMs decreased from 160 N/m to 40 N/m when HGM content increased from 0 wt.% to 50 wt.%. Both the FAGW/HGM HCMs and SHMP coated FAGMs were vacuumed completely to form vacuum insulation panels (VIPs). The results showed that both the addition of SHMP and HGM led a slight increase in the thermal conductivity of the corresponding VIPs. To obtain a high-quality VIP, the optimal SHMP content and HGM content in glass fiber suspension was 0.12-0.2 wt.% and 0 wt.%.

  12. Modelling and Characterization of Effective Thermal Conductivity of Single Hollow Glass Microsphere and Its Powder.

    Science.gov (United States)

    Liu, Bing; Wang, Hui; Qin, Qing-Hua

    2018-01-14

    Tiny hollow glass microsphere (HGM) can be applied for designing new light-weighted and thermal-insulated composites as high strength core, owing to its hollow structure. However, little work has been found for studying its own overall thermal conductivity independent of any matrix, which generally cannot be measured or evaluated directly. In this study, the overall thermal conductivity of HGM is investigated experimentally and numerically. The experimental investigation of thermal conductivity of HGM powder is performed by the transient plane source (TPS) technique to provide a reference to numerical results, which are obtained by a developed three-dimensional two-step hierarchical computational method. In the present method, three heterogeneous HGM stacking elements representing different distributions of HGMs in the powder are assumed. Each stacking element and its equivalent homogeneous solid counterpart are, respectively, embedded into a fictitious matrix material as fillers to form two equivalent composite systems at different levels, and then the overall thermal conductivity of each stacking element can be numerically determined through the equivalence of the two systems. The comparison of experimental and computational results indicates the present computational modeling can be used for effectively predicting the overall thermal conductivity of single HGM and its powder in a flexible way. Besides, it is necessary to note that the influence of thermal interfacial resistance cannot be removed from the experimental results in the TPS measurement.

  13. Method for sizing hollow microspheres

    Science.gov (United States)

    Farnum, E.H.; Fries, R.J.

    1975-10-29

    Hollow Microspheres may be effectively sized by placing them beneath a screen stack completely immersed in an ultrasonic bath containing a liquid having a density at which the microspheres float and ultrasonically agitating the bath.

  14. Glass microspheres for brachytherapy

    International Nuclear Information System (INIS)

    Prado, Miguel O.; Prastalo, Simon; Blaumann, Herman; Longhino, Juan M.; Repetto Llamazares, A.H.V.

    2007-01-01

    We developed the capacity to produce glass microspheres containing in their structure one or more radioactive isotopes useful for brachytherapy. We studied the various facts related with their production: (Rare earth) alumino silicate glass making, glass characterization, microspheres production, nuclear activation through (n,γ) nuclear reactions, mechanical characterization before and after irradiation. Corrosion tests in simulated human plasma and mechanical properties characterization were done before and after irradiation. (author) [es

  15. Preparation and microwave absorbing property of Ni–Zn ferrite-coated hollow glass microspheres with polythiophene

    Energy Technology Data Exchange (ETDEWEB)

    Li, Lindong; Chen, Xingliang; Qi, Shuhua, E-mail: qishuhuanwpu@163.com

    2016-11-01

    The composite of hollow glass microspheres (HMG) coated by Ni{sub 0.7}Zn{sub 0.3}Fe{sub 2}O{sub 4} particles was fabricated via sol–gel method, and then the ternary composite (HMG/Ni{sub 0.7}Zn{sub 0.3}Fe{sub 2}O{sub 4}/PT) was synthesized by in situ polymerization. The electrical property, magnetic performance and reflection loss of the composites were measured, and the results suggest that the conductivity and the saturation magnetization (Ms) of HMG/Ni{sub 0.7}Zn{sub 0.3}Fe{sub 2}O{sub 4}/PT reach 6.87×10{sup −5} S/cm and 11.627 emu/g, respectively. The ternary composite has good microwave absorbing properties (R{sub min}=−13.79 dB at 10.51 GHz) and the bandwidth less than −10 dB can reach 2.6 GHz (from 9.4 to 12.0 GHz) in X band (8.2–12.4 GHz). The morphology and chemical structure of the samples were measured through scanning electron microscopy (SEM), X-Ray diffraction (XRD) and Fourier transform infrared spectroscopy (FTIR). This paper also analyzes the relationship between the reflection loss of the absorber and its thickness. - Highlights: • This manuscript synthesized HMG/Ni{sub 0.7}Zn{sub 0.3}Fe{sub 2}O{sub 4}/PT composites. • The surface morphology, electrical property, magnetic performance and reflection loss of the composites were measured. • This paper also analyzed the relationship between the reflection loss of the absorber and its thickness.

  16. Hydrogen transport and storage in engineered glass microspheres

    Energy Technology Data Exchange (ETDEWEB)

    Rambach, G.D.

    1994-04-20

    New, high-strength, hollow, glass microspheres filled with pressurized hydrogen exhibit storage densities which make them attractive for bulk hydrogen storage and transport. The hoop stress at failure of our engineered glass microspheres is about 150,000 psi, permitting a three-fold increase in pressure limit and storage capacity above commercial microspheres, which fail at wall stresses of 50,000 psi. For this project, microsphere material and structure will be optimized for storage capacity and charge/discharge kinetics to improve their commercial practicality. Microsphere production scale up will be performed, directed towards large-scale commercial use. Our analysis relating glass microspheres for hydrogen transport with infrastructure and economics` indicate that pressurized microspheres can be economically competitive with other forms of bulk rail and truck transport such as hydride beds, cryocarbons and pressurized tube transports. For microspheres made from advanced materials and processes, analysis will also be performed to identify the appropriate applications of the microspheres considering property variables, and different hydrogen infrastructure, end use, production and market scenarios. This report presents some of the recent modelling results for large beds of glass microspheres in hydrogen storage applications. It includes plans for experiments to identify the properties relevant to large-bed hydrogen transport and storage applications, of the best, currently producible, glass microspheres. This work began in March, 1994. Project successes will be manifest in the matching of cur-rent glass microspheres with a useful application in hydrogen bulk transport and storage, and in developing microsphere materials and processes that increase the storage density and reduce the storage energy requirement.

  17. Glass microspheres for medical applications

    Science.gov (United States)

    Conzone, Samuel David

    Radioactive dysprosium lithium borate glass microspheres have been developed as biodegradable radiation delivery vehicles for the radiation synovectomy treatment of rheumatoid arthritis. Once injected into a diseased joint, the microspheres deliver a potent dose of radiation to the diseased tissue, while a non-uniform chemical reaction converts the glass into an amorphous, porous, hydrated dysprosium phosphate reaction product. The non-radioactive, lithium-borate component is dissolved from the glass (up to 94% weight loss), while the radioactive 165Dy reacts with phosphate anions in the body fluids, and becomes "chemically" trapped in a solid, dysprosium phosphate reaction product that has the same size as the un-reacted glass microsphere. Ethylene diamine tetraacetate (EDTA) chelation therapy can be used to dissolve the dysprosium phosphate reaction product after the radiation delivery has subsided. The dysprosium phosphate reaction product, which formed in vivo in the joint of a Sprague-Dawley rat, was dissolved by EDTA chelation therapy in 100 Gy) of localized beta radiation to a treatment site within the body, followed by complete biodegradability. The non-uniform reaction process is a desirable characteristic for a biodegradable radiation delivery vehicle, but it is also a novel material synthesis technique that can convert a glass to a highly porous materials with widely varying chemical composition by simple, low-temperature, glass/solution reaction. The reaction product formed by nonuniform reaction occupies the same volume as the un-reacted glass, and after drying for 1 h at 300°C, has a specific surface area of ≈200 m2/g, a pore size of ≈30 nm, and a nominal crushing strength of ≈10 MPa. Finally, rhenium glass microspheres, composed of micron-sized, metallic rhenium particles dispersed within a magnesium alumino borate glass matrix were produced by sintering ReO2 powder and glass frit at 1050°C. A 50 mg injection of radioactive rhenium glass

  18. TiO2-coated Hollow Glass Microspheres with Superhydrophobic and High IR-reflective Properties Synthesized by a Soft-chemistry Method.

    Science.gov (United States)

    Wong, Yinting; Zhong, Dan; Song, Aotian; Hu, Yan

    2017-04-26

    This manuscript proposes a soft-chemistry method to develop superhydrophobic and highly IR-reflective hollow glass microspheres (HGM). The anatase TiO2 and a superhydrophobic agent were coated on the HGM surface in one step. TBT and PFOTES were selected as the Ti source and the superhydrophobic agent, respectively. They were both coated on the HGM, and after the hydrothermal process, the TBT turned to anatase TiO2. In this way, a PFOTES/TiO2-coated HGM (MCHGM) was prepared. For comparison, PFOTES single-coated HGM (F-SCHGM) and TiO2 single-coated HGM (Ti-SCHGM) were synthesized as well. The PFOTES and TiO2 coatings on the HGM surface were demonstrated through X-ray diffraction (XRD), scanning electron microscopy (SEM), and energy-dispersive detector (EDS) characterizations. The MCHGM showed a higher contact angle (153°) but a lower sliding angle (16°) than F-SCHGM, with a contact angle of 141.2° and a sliding angle of 67°. In addition, both Ti-SCHGM and MCHGM displayed similar IR reflectivity values, which were about 5.8% higher than the original HGM and F-SCHGM. Also, the PFOTES coating barely changed the thermal conductivity. Therefore, F-SCHGM, with a thermal conductivity of 0.0479 W/(m·K), was quite like the original HGM, which was 0.0475 W/(m·K). MCHGM and Ti-SCHGM were also similar. Their thermal conductivity values were 0.0543 W/(m·K) and 0.0543 W/(m·K), respectively. The TiO2 coating slightly increased the thermal conductivity, but with the increase in reflectivity, the overall heat-insulation property was enhanced. Finally, since the IR-reflecting property is provided by the HGM coating, if the coating is fouled, the reflectivity decreases. Therefore, with the superhydrophobic coating, the surface is protected from fouling, and its lifetime is also prolonged.

  19. BMP2-loaded hollow hydroxyapatite microspheres exhibit enhanced osteoinduction and osteogenicity in large bone defects.

    Science.gov (United States)

    Xiong, Long; Zeng, Jianhua; Yao, Aihua; Tu, Qiquan; Li, Jingtang; Yan, Liang; Tang, Zhiming

    2015-01-01

    The regeneration of large bone defects is an osteoinductive, osteoconductive, and osteogenic process that often requires a bone graft for support. Limitations associated with naturally autogenic or allogenic bone grafts have demonstrated the need for synthetic substitutes. The present study investigates the feasibility of using novel hollow hydroxyapatite microspheres as an osteoconductive matrix and a carrier for controlled local delivery of bone morphogenetic protein 2 (BMP2), a potent osteogenic inducer of bone regeneration. Hollow hydroxyapatite microspheres (100±25 μm) with a core (60±18 μm) and a mesoporous shell (180±42 m(2)/g surface area) were prepared by a glass conversion technique and loaded with recombinant human BMP2 (1 μg/mg). There was a gentle burst release of BMP2 from microspheres into the surrounding phosphate-buffered saline in vitro within the initial 48 hours, and continued at a low rate for over 40 days. In comparison with hollow hydroxyapatite microspheres without BMP2 or soluble BMP2 without a carrier, BMP2-loaded hollow hydroxyapatite microspheres had a significantly enhanced capacity to reconstitute radial bone defects in rabbit, as shown by increased serum alkaline phosphatase; quick and complete new bone formation within 12 weeks; and great biomechanical flexural strength. These results indicate that BMP2-loaded hollow hydroxyapatite microspheres could be a potential new option for bone graft substitutes in bone regeneration.

  20. A Comparative Study of Production of Glass Microspheres by using Thermal Process

    Science.gov (United States)

    Lee, May Yan; Tan, Jully; Heng, Jerry YY; Cheeseman, Christopher

    2017-06-01

    Microspheres are spherical particles that can be distinguished into two categories; solid or hollow. Microspheres typical ranges from 1 to 200 μm in diameter. Microsphere are made from glass, ceramic, carbon or plastic depending on applications. Solid glass microsphere is manufactured by direct burning of glass powders while hollow glass microspheres is produced by adding blowing agent to glass powder. This paper presented the production of glass microspheres by using the vertical thermal flame (VTF) process. Pre-treated soda lime glass powder with particle sized range from 90 to 125μm was used in this work. The results showed that glass microspheres produced by two passes through the flame have a more spherical shape as compared with the single pass. Under the Scanning Electron Microscope (SEM), it is observed that there is a morphology changed from uneven surface of glass powders to smooth spherical surface particles. Qualitative analysis for density of the pre-burned and burned particles was performed. Burned particles floats in water while pre-burned particles sank indicated the change of density of the particles. Further improvements of the VTF process in terms of the VTF set-up are required to increase the transformation of glass powders to glass microspheres.

  1. Investigation of concrete mixtures incorporating hollow plastic microspheres.

    Science.gov (United States)

    1981-01-01

    This study investigated the potential of hollow plastic microspheres, HPM, for providing non-air-entrained portland cement concrete resistance to damage from cycles of freezing and thawing. In the study, a mixture with an air-entraining agent (vinsol...

  2. Biotemplate synthesis of monodispersed iron phosphate hollow microspheres

    International Nuclear Information System (INIS)

    Cao Feng; Li Dongxu

    2010-01-01

    Monodispersed iron phosphate hollow microspheres with a high degree of crystallization were prepared through a facile in situ deposition method using rape pollen grains as a biotemplate. The functional group on the surface of the pollen grains could adsorb Fe 3+ , which provided the nucleation sites for growth of iron phosphate nanoparticles. After being sintered at 600 deg. C for 10 h, the pollen grains were removed and iron phosphate hollow microspheres were obtained. A scanning electron microscope and x-ray diffraction were applied to characterize the morphology and crystalline structure of the pollen grains, iron phosphate-coated pollen grains and iron phosphate hollow microspheres. Differential scanning calorimetry and thermogravity analyses were performed to investigate the thermal behavior of the iron phosphate-coated pollen grains during the calcinations. Energy dispersive spectroscopy and Fourier transform infrared spectroscopy were utilized to investigate the interaction between the pollen grains and iron phosphate. The effect of the pollen wall on the surface morphology of these iron phosphate hollow microspheres was also proven in this work.

  3. Biotemplate synthesis of monodispersed iron phosphate hollow microspheres

    Energy Technology Data Exchange (ETDEWEB)

    Cao Feng; Li Dongxu, E-mail: dongxuli@njut.edu.c [College of Materials Science and Engineering, Nanjing University of Technology, Jiangsu Nanjing 210009 (China)

    2010-03-15

    Monodispersed iron phosphate hollow microspheres with a high degree of crystallization were prepared through a facile in situ deposition method using rape pollen grains as a biotemplate. The functional group on the surface of the pollen grains could adsorb Fe{sup 3+}, which provided the nucleation sites for growth of iron phosphate nanoparticles. After being sintered at 600 deg. C for 10 h, the pollen grains were removed and iron phosphate hollow microspheres were obtained. A scanning electron microscope and x-ray diffraction were applied to characterize the morphology and crystalline structure of the pollen grains, iron phosphate-coated pollen grains and iron phosphate hollow microspheres. Differential scanning calorimetry and thermogravity analyses were performed to investigate the thermal behavior of the iron phosphate-coated pollen grains during the calcinations. Energy dispersive spectroscopy and Fourier transform infrared spectroscopy were utilized to investigate the interaction between the pollen grains and iron phosphate. The effect of the pollen wall on the surface morphology of these iron phosphate hollow microspheres was also proven in this work.

  4. Electrodepositing of Au on hollow PS micro-spheres

    International Nuclear Information System (INIS)

    Sun Jingyuan; Zhang Yunwang; Du Kai; Wan Xiaobo; Xiao Jiang; Zhang Wei; Zhang Lin; Chen Jing

    2010-01-01

    Using the self-regulating new micro-sphere electrodepositing device, the techniques of electrodepositing gold on hollow PS micro-spheres were established. The experiment was carried out under the following conditions: voltage was about 0.7 ∼ 0.8 V, current density was 2.0 mA · cm -2 , the temperature was 45 degree C, cathode rotating rate was 250 r · min -1 , flow rate of the solution was 7 mL · min -1 · cm -2 . Hollow gold-plated micro-spheres were prepared with well spherical symmetry, uniform thickness and surface smoothness under 500 nm. The speed of the gold depositing was 6 μm · h -1 . (authors)

  5. Nanomechanics of biocompatible hollow thin-shell polymer microspheres.

    Science.gov (United States)

    Glynos, Emmanouil; Koutsos, Vasileios; McDicken, W Norman; Moran, Carmel M; Pye, Stephen D; Ross, James A; Sboros, Vassilis

    2009-07-07

    The nanomechanical properties of biocompatible thin-shell hollow polymer microspheres with approximately constant ratio of shell thickness to microsphere diameter were measured by nanocompression tests in aqueous conditions. These microspheres encapsulate an inert gas and are used as ultrasound contrast agents by releasing free microbubbles in the presence of an ultrasound field as a result of free gas leakage from the shell. The tests were performed using an atomic force microscope (AFM) employing the force-distance curve technique. An optical microscope, on which the AFM was mounted, was used to guide the positioning of tipless cantilevers on top of individual microspheres. We performed a systematic study using several cantilevers with spring constants varying from 0.08 to 2.3 N/m on a population of microspheres with diameters from about 2 to 6 microm. The use of several cantilevers with various spring constants allowed a systematic study of the mechanical properties of the microsphere thin shell at different regimes of force and deformation. Using thin-shell mechanics theory for small deformations, the Young's modulus of the thin wall material was estimated and was shown to exhibit a strong size effect: it increased as the shell became thinner. The Young's modulus of thicker microsphere shells converged to the expected value for the macroscopic bulk material. For high applied forces, the force-deformation profiles showed a reversible and/or irreversible nonlinear behavior including "steps" and "jumps" which were attributed to mechanical instabilities such as buckling events.

  6. [Synthesis of hollow titania microspheres by using microfluidic droplet-template].

    Science.gov (United States)

    Ma, Jingyun; Jiang, Lei; Qin, Jianhu

    2011-09-01

    Droplet-based microfluidics is of great interest due to its particular characteristics compared with the conventional methods, such as reduced reagent consumption, rapid mixing, high-throughput, shape controlled, etc. A novel method using microfluidic droplet as soft template for the synthesis of hollow titania microspheres was developed. A typical polydimethylsiloxane (PDMS) microfluidic device containing "flow-focusing" geometry was used to generate water/oil (W/O) droplet. The mechanism for the hollow structure formation was based on the interfacial hydrolysis reaction between the continuous phase containing titanium butoxide precursor and the dispersed containing water. The continuous phase mixed with butanol was added in the downstream of the channel after the hydrolysis reaction. This step was used for drawing the water out of the microgels for further hydrolysis. The microgels obtained through a glass pipe integrated were washed, dried under vacuum and calcined after aging for a certain time. The fluorescence and scanning electron microscope (SEM) image of the microspheres indicated the hollow structure and the thickness of the shell. In addition, these microspheres with thin shell (about 2 microm) were apt to rupture and collapse. Droplet-based microfluidic offered a gentle and size-controllable manner to moderate this problem. Moreover, it has potential applications in photocatalysis combined with some modification realized on the chip simultaneously.

  7. Method for selecting hollow microspheres for use in laser fusion targets

    Science.gov (United States)

    Farnum, Eugene H.; Fries, R. Jay; Havenhill, Jerry W.; Smith, Maurice Lee; Stoltz, Daniel L.

    1976-01-01

    Hollow microspheres having thin and very uniform wall thickness are useful as containers for the deuterium and tritium gas mixture used as a fuel in laser fusion targets. Hollow microspheres are commercially available; however, in commercial lots only a very small number meet the rigid requirements for use in laser fusion targets. Those meeting these requirements may be separated from the unsuitable ones by subjecting the commercial lot to size and density separations and then by subjecting those hollow microspheres thus separated to an external pressurization at which those which are aspherical or which have nonuniform walls are broken and separating the sound hollow microspheres from the broken ones.

  8. Recent progress on the fabrication of hollow microspheres

    International Nuclear Information System (INIS)

    Wang Aijuan; Lu Yupeng; Sun Ruixue

    2007-01-01

    Hollow microspheres represent a special class of materials, on which intense interest has been paid in the fields of material science, medicine, chemistry and chromatography. Several methods, including templating method, emulsion processing, high temperature smelting and layer-by-layer self-assembly technique, have been used to produce this kind of materials. However, most of the current needs for hollow microspheres are limited because of the disadvantages of these fabricating methods, such as time-consuming and relatively complex fabricating process. Spray drying method, as a simple and feasible technology, has also been used to fabricate this kind of materials. This method can improve the efficiency and save the time to some extent, and thus gains more and more interest recently. The factors of influencing the product morphology, including inlet air temperature, atomized pressure, feed rate, initial slurry concentration, primary powders size and additives, are reviewed in this paper. In addition, several kinds of typical hollow microspheres fabricated by this method are also listed particularly

  9. Hollow mesoporous titania microspheres: New technology and enhanced photocatalytic activity

    Energy Technology Data Exchange (ETDEWEB)

    Feng, Zhenliang; Wei, Wenrui; Wang, Litong [School of Chemical Engineering, Fuzhou University, Fuzhou 350108 (China); Hong, Ruoyu, E-mail: rhong@suda.edu.cn [School of Chemical Engineering, Fuzhou University, Fuzhou 350108 (China); College of Chemistry, Chemical Engineering and Materials Science & Key Laboratory of Organic Synthesis of Jiangsu Province, Soochow University, SIP, Suzhou 215123 (China)

    2015-12-01

    Graphical abstract: Schematic of the formation process of HTS. - Highlights: • Amino modified porous PS-DVB microspheres were used as templates to coat TiO{sub 2.} • The coating of TiO{sub 2} was conducted under regular changing atmospheric pressure. • The PS-DVB@TiO{sub 2} was calcinated first under nitrogen and then under air to get HTS. • The resultant products were provided with high surface area and excellent photocatalytic activity under UV irradiation. - Abstract: Hollow titania microspheres (HTS) were fabricated via a sol–gel process by coating the hydrolysis product of titanium tetrabutoxide (TBOT) onto the amino (–NH{sub 2}) modified porous polystyrene cross-linked divinyl benzene (PS-DVB) microspheres under changing atmospheric pressure, followed by calcination in nitrogen and air atmosphere. Particularly, the atmospheric pressure was continuously and regularly changed during the formation process of PS-DVB@TiO{sub 2} microspheres. Then the TiO{sub 2} particles were absorbed into the pores and onto the surface of PS-DVB as well. The resultant HTS (around 2 μm in diameter) featured a high specific surface area (84.37 m{sup 2}/g), anatase crystal and stable hollow microsphere structure, which led to high photocatalysis activity. The photocatalytic degradation of malachite green (MG) organic dye solution was conducted under ultraviolet (UV) light irradiation, which showed a high photocatalytic ability (81% of MG was degraded after UV irradiation for 88 min). Therefore, it could be potentially applied for the treatment of wastewater contaminated by organic pollutants.

  10. Hydrogen transport and storage in engineered glass microspheres

    Energy Technology Data Exchange (ETDEWEB)

    Rambach, G.D.

    1995-04-18

    New, high strength glass microspheres filled with pressurized hydrogen exhibit densities which make them attractive for bulk hydrogen storage and transport. The membrane tensile stress at failure for our engineered glass microspheres is about 150,000 psi, permitting a threefold increase in pressure limit and storage capacity above commercial microspheres, which have been studied a decade ago and have been shown to fail at membrane stresses of 50,000 psi. Our analysis relating glass microspheres for hydrogen transport with infrastructure and economics, indicate that pressurized microspheres can be economically competitive with other forms of bulk rail and truck transport such as pressurized tube transports and liquid hydrogen trailers.

  11. Glass microspheres covering film: first field evaluations

    International Nuclear Information System (INIS)

    Magnani, G.; Filippi, F.

    2006-01-01

    A trial was carried out to evaluate, in the North-Centre of Italy, the behaviour in field of a new plastic covering film, prepared with the inclusion of empty glass microspheres (Solex). The trial was conducted on tomato (Lycopersicon esculentum L.) and eggplant (Solanum melongena L.). The new film was compared to a covering film with the same optical (diffuse light) and constitutional (co-extruded three layers EVA-WPE) characteristics. Since the first results, the innovative film showed a better behaviour than the control one. It presented light and thermal conditions (lower temperature during the day and slightly higher temperature in the night, compared to the control film) that allowed a better growth and yield than the control film. The growth analysis of tomato showed that plants grown under glass microsphere film had an higher growth rate (dry weight/days) and thickness of leaves compared to the control one. The yield of tomato and eggplant presented an increase in plants cultivated under the innovative film, especially for number and weight of fruits. The commercial quality did not show any differences between the films, except for the flesh hardness of tomato: this could be explained with the fact that the glass microspheres film provides environmental conditions avoiding plant stress during some stages of its cycle [it

  12. Polymer blends used to develop felodipine-loaded hollow microspheres for improved oral bioavailability.

    Science.gov (United States)

    Pi, Chao; Feng, Ting; Liang, Jing; Liu, Hao; Huang, Dongmei; Zhan, Chenglin; Yuan, Jiyuan; Lee, Robert J; Zhao, Ling; Wei, Yumeng

    2018-06-01

    Felodipine (FD) has been widely used in anti-hypertensive treatment. However, it has extremely low aqueous solubility and poor bioavailability. To address these problems, FD hollow microspheres as multiple-unit dosage forms were synthesized by a solvent diffusion evaporation method. Particle size of the hollow microspheres, types of ethylcellulose (EC), amounts of EC, polyvinyl pyrrolidone (PVP) and FD were investigated based on an orthogonal experiment of three factors and three levels. In addition, the release kinetics in vitro and pharmacokinetics in beagle dogs of the optimized FD hollow microspheres was investigated and compared with Plendil (commercial FD sustained-release tablets) as a single-unit dosage form. Results showed that the optimal formulation was composed of EC 10 cp :PVP:FD (0.9:0.16:0.36, w/w). The FD hollow microspheres were globular with a hollow structure and have high drug loading (17.69±0.44%) and floating rate (93.82±4.05%) in simulated human gastric fluid after 24h. Pharmacokinetic data showed that FD hollow microspheres exhibited sustained-release behavior and significantly improved relative bioavailability of FD compared with the control. Pharmacodynamic study showed that the FD hollow microspheres could effectively lower blood pressure. Therefore, these findings demonstrated that the hollow microspheres were an effective sustained-release delivery system for FD. Copyright © 2018 Elsevier B.V. All rights reserved.

  13. Properties of dry masonry mixtures based on hollow aluminosilicate microspheres

    Directory of Open Access Journals (Sweden)

    Semenov Vyacheslav

    2017-01-01

    Full Text Available At present, there is a steady increase in the volume of housing construction in the Russian Federation. The modern trends in the field of energy and resource saving determine the need of the use of efficient building materials that ensure the safety, comfort and minimum cost of housing construction. Among the materials, often used for erecting of fencing structures, it is possible to note effective small-piece elements (ceramic and light-weight concrete units, etc.. To ensure the solidity of such structures, it is necessary to use the masonry mortars whose properties correspond to those of the main wall material. The existing dry mixes for obtaining of such mortars are expensive and often do not meet the minimum physical-and-mechanical and exploitation requirements. The solution of this problem is the usage of the hollow ceramics (aluminosilicate microspheres as a filler for such mixes. The article presents the results of studies of the main physical-and-mechanical and exploitation characteristics of dry masonry mixes with hollow ceramics microspheres modified with various chemical additives. The effect of the compounding factors on the average density and strength of dry masonry mixes was studied. The compositions have been optimized by the methods of mathematical planning.

  14. Hydrogen transport and storage in engineered glass microspheres

    Energy Technology Data Exchange (ETDEWEB)

    Rambach, G.D.

    1995-02-28

    New, high strength glass microspheres filled with pressurized hydrogen exhibit densities which make them attractive for bulk hydrogen storage and transport. The membrane tensile stress at failure for engineered glass microspheres is about 150,000 psi, permitting a three-fold increase in pressure limit and storage capacity above commercial microspheres, which have been studied a decade ago and have been shown to fail at membrane stresses of 50,000 psi. This analysis relating glass microspheres for hydrogen transport with infrastructure and economics, indicate that pressurized microspheres can be economically competitive with other forms of bulk rail and truck transport such as pressurized tube transports and liquid hydrogen trailers. This paper will describe the matching of current glass microspheres with the useful application in commercial hydrogen bulk transport and storage.

  15. Photoluminescence and lasing in whispering gallery mode glass microspherical resonators

    Energy Technology Data Exchange (ETDEWEB)

    Ristić, D. [Ruđer Bošković Institute, Division of Materials Physics, Laboratory for Molecular Physics, Bijenička c. 54, Zagreb (Croatia); Center of Excellence for Advanced Materials and Sensing Devices, Research unit New Functional Materials, Bijenička c. 54, Zagreb (Croatia); Berneschi, S.; Camerini, M. [IFAC-CNR Istituto di Fisica Applicata, Via Madonna del Piano 10, 50019 Sesto Fiorentino (Italy); Farnesi, D.; Pelli, S. [IFAC-CNR Istituto di Fisica Applicata, Via Madonna del Piano 10, 50019 Sesto Fiorentino (Italy); Centro Studi e Ricerche ' E. Fermi' , Piazza del Viminale 2, 00184 Roma (Italy); Trono, C. [IFAC-CNR Istituto di Fisica Applicata, Via Madonna del Piano 10, 50019 Sesto Fiorentino (Italy); Chiappini, A.; Chiasera, A.; Ferrari, M. [CSMFO Group, Istituto di Fotonica e Nanotecnologie, IFN-CNR, Via alla Cascata 56/C, 38050 Povo-Trento (Italy); Lukowiak, A. [Institute of Low Temperature and Structure Research, PAS, ul. Okolna 2, Wroclaw 50-950 (Poland); Dumeige, Y.; Féron, P. [Laboratoire d' Optronique, (CNRS-UMR 6082-Foton), ENSSAT, 6 rue de Kérampont, 22300 Lannion (France); Righini, G.C. [IFAC-CNR Istituto di Fisica Applicata, Via Madonna del Piano 10, 50019 Sesto Fiorentino (Italy); Centro Studi e Ricerche ' E. Fermi' , Piazza del Viminale 2, 00184 Roma (Italy); Soria, S., E-mail: s.soria@ifac.cnr.it [IFAC-CNR Istituto di Fisica Applicata, Via Madonna del Piano 10, 50019 Sesto Fiorentino (Italy); Conti, G. Nunzi [IFAC-CNR Istituto di Fisica Applicata, Via Madonna del Piano 10, 50019 Sesto Fiorentino (Italy); Centro Studi e Ricerche ' E. Fermi' , Piazza del Viminale 2, 00184 Roma (Italy)

    2016-02-15

    We report experimental results regarding the development of Er{sup 3+}-doped glass microspherical cavities for the fabrication of compact sources at 1.55 μm. We investigate several different approaches in order to fabricate the microspheres including direct melting of Er{sup 3+}-doped glass powders, synthesis of Er{sup 3+}-doped monolithic microspheres by drawing Er{sup 3+}-doped glass, and coating of silica microspheres with an Er{sup 3+}-doped sol–gel layer. Details of the different fabrication processes are presented together with the photoluminescence characterization in free space configuration of the microspheres and of the glass precursor. We have analyzed the photoluminescence spectra of the whispering gallery modes of the microspheres excited using evanescent coupling and we demonstrate tunable laser action in a wide range of wavelengths around 1.55 μm. As much as 90 μW of laser output power was measured in Er{sup 3+}-doped glass microspheres. - Highlights: • Different approaches in microsphere fabrication and various types of post-processing. • Trimming of photorefractive glass microsphere lasers with UV light. • Peak power record of 90 μW by pumping at 1480 nm.

  16. Chalcogenide glass hollow core microstructured optical fibers

    Directory of Open Access Journals (Sweden)

    Vladimir S. eShiryaev

    2015-03-01

    Full Text Available The recent developments on chalcogenide glass hollow core microstructured optical fibers (HC-MOFs are presented. The comparative analysis of simulated optical properties for chalcogenide HC-MOFs of negative-curvature with different size and number of capillaries is given. The technique for the manufacture of microstructured chalcogenide preforms, which includes the assembly of the substrate glass tube and 8-10 capillaries, is described. Further trends to improve the optical transmission in chalcogenide NCHCFs are considered.

  17. Strain-tuned optoelectronic properties of hollow gallium sulphide microspheres

    Science.gov (United States)

    Zhang, Yin; Chen, Chen; Liang, C. Y.; Liu, Z. W.; Li, Y. S.; Che, Renchao

    2015-10-01

    Sulfide semiconductors have attracted considerable attention. The main challenge is to prepare materials with a designable morphology, a controllable band structure and optoelectronic properties. Herein, we report a facile chemical transportation reaction for the synthesis of Ga2S3 microspheres with novel hollow morphologies and partially filled volumes. Even without any extrinsic dopant, photoluminescence (PL) emission wavelength could be facilely tuned from 635 to 665 nm, depending on its intrinsic inhomogeneous strain distribution. Geometric phase analysis (GPA) based on high-resolution transmission electron microscopy (HRTEM) imaging reveals that the strain distribution and the associated PL properties can be accurately controlled by changing the growth temperature gradient, which depends on the distance between the boats used for raw material evaporation and microsphere deposition. The stacking-fault density, lattice distortion degree and strain distribution at the shell interfacial region of the Ga2S3 microspheres could be readily adjusted. Ab initio first-principles calculations confirm that the lowest conductive band (LCB) is dominated by S-3s and Ga-4p states, which shift to the low-energy band as a result of the introduction of tensile strain, well in accordance with the observed PL evolution. Therefore, based on our strain driving strategy, novel guidelines toward the reasonable design of sulfide semiconductors with tunable photoluminescence properties are proposed.Sulfide semiconductors have attracted considerable attention. The main challenge is to prepare materials with a designable morphology, a controllable band structure and optoelectronic properties. Herein, we report a facile chemical transportation reaction for the synthesis of Ga2S3 microspheres with novel hollow morphologies and partially filled volumes. Even without any extrinsic dopant, photoluminescence (PL) emission wavelength could be facilely tuned from 635 to 665 nm, depending on its

  18. Simple Synthesis of Molybdenum Disulfide/Reduced Graphene Oxide Composite Hollow Microspheres as Supercapacitor Electrode Material.

    Science.gov (United States)

    Xiao, Wei; Zhou, Wenjie; Feng, Tong; Zhang, Yanhua; Liu, Hongdong; Tian, Liangliang

    2016-09-20

    MoS₂/RGO composite hollow microspheres were hydrothermally synthesized by using SiO₂/GO microspheres as a template, which were obtained via the sonication-assisted interfacial self-assembly of tiny GO sheets on positively charged SiO₂ microspheres. The structure, morphology, phase, and chemical composition of MoS₂/RGO hollow microspheres were systematically investigated by a series of techniques such as FE-SEM, TEM, XRD, TGA, BET, and Raman characterizations, meanwhile, their electrochemical properties were carefully evaluated by CV, GCD, and EIS measurements. It was found that MoS₂/RGO hollow microspheres possessed unique porous hollow architecture with high-level hierarchy and large specific surface area up to 63.7 m²·g -1 . When used as supercapacitor electrode material, MoS₂/RGO hollow microspheres delivered a maximum specific capacitance of 218.1 F·g -1 at the current density of 1 A·g -1 , which was much higher than that of contrastive bare MoS₂ microspheres developed in the present work and most of other reported MoS₂-based materials. The enhancement of supercapacitive behaviors of MoS₂/RGO hollow microspheres was likely due to the improved conductivity together with their distinct structure and morphology, which not only promoted the charge transport but also facilitated the electrolyte diffusion. Moreover, MoS₂/RGO hollow microsphere electrode displayed satisfactory long-term stability with 91.8% retention of the initial capacitance after 1000 charge/discharge cycles at the current density of 3 A·g -1 , showing excellent application potential.

  19. Simple Synthesis of Molybdenum Disulfide/Reduced Graphene Oxide Composite Hollow Microspheres as Supercapacitor Electrode Material

    Directory of Open Access Journals (Sweden)

    Wei Xiao

    2016-09-01

    Full Text Available MoS2/RGO composite hollow microspheres were hydrothermally synthesized by using SiO2/GO microspheres as a template, which were obtained via the sonication-assisted interfacial self-assembly of tiny GO sheets on positively charged SiO2 microspheres. The structure, morphology, phase, and chemical composition of MoS2/RGO hollow microspheres were systematically investigated by a series of techniques such as FE-SEM, TEM, XRD, TGA, BET, and Raman characterizations, meanwhile, their electrochemical properties were carefully evaluated by CV, GCD, and EIS measurements. It was found that MoS2/RGO hollow microspheres possessed unique porous hollow architecture with high-level hierarchy and large specific surface area up to 63.7 m2·g−1. When used as supercapacitor electrode material, MoS2/RGO hollow microspheres delivered a maximum specific capacitance of 218.1 F·g−1 at the current density of 1 A·g−1, which was much higher than that of contrastive bare MoS2 microspheres developed in the present work and most of other reported MoS2-based materials. The enhancement of supercapacitive behaviors of MoS2/RGO hollow microspheres was likely due to the improved conductivity together with their distinct structure and morphology, which not only promoted the charge transport but also facilitated the electrolyte diffusion. Moreover, MoS2/RGO hollow microsphere electrode displayed satisfactory long-term stability with 91.8% retention of the initial capacitance after 1000 charge/discharge cycles at the current density of 3 A·g−1, showing excellent application potential.

  20. Hierarchical CuO hollow microspheres: Controlled synthesis for enhanced lithium storage performance

    International Nuclear Information System (INIS)

    Guan Xiangfeng; Li Liping; Li Guangshe; Fu Zhengwei; Zheng Jing; Yan Tingjiang

    2011-01-01

    Graphical abstract: Hierarchical CuO microspheres with hollow interiors were formed through self-wrapping of a single layer of radically oriented CuO nanorods, and these microspheres showed excellent cycle performance and enhanced lithium storage capacity. Display Omitted Research highlights: → Hierarchical CuO hollow microspheres were prepared by a hydrothermal method. → The CuO hollow microspheres were assembled from radically oriented nanorods. → The growth mechanism was proposed to proceed via self-assembly and Ostwald's ripening. → The microspheres showed good cycle performance and enhanced lithium storage capacity. → Hierarchical microstructures with hollow interiors promote electrochemical property. - Abstract: In this work, hierarchical CuO hollow microspheres were hydrothermally prepared without use of any surfactants or templates. By controlling the formation reaction conditions and monitoring the relevant reaction processes using time-dependent experiments, it is demonstrated that hierarchical CuO microspheres with hollow interiors were formed through self-wrapping of a single layer of radically oriented CuO nanorods, and that hierarchical spheres could be tuned to show different morphologies and microstructures. As a consequence, the formation mechanism was proposed to proceed via a combined process of self-assembly and Ostwald's ripening. Further, these hollow microspheres were initiated as the anode material in lithium ion batteries, which showed excellent cycle performance and enhanced lithium storage capacity, most likely because of the synergetic effect of small diffusion lengths in building blocks of nanorods and proper void space that buffers the volume expansion. The strategy reported in this work is reproducible, which may help to significantly improve the electrochemical performance of transition metal oxide-based anode materials via designing the hollow structures necessary for developing lithium ion batteries and the relevant

  1. Preparation and photocatalytic activity of hollow ZnSe microspheres via Ostwald ripening

    International Nuclear Information System (INIS)

    Zhang Lihui; Yang Heqing; Xie Xiaoli; Zhang Fenghua; Li Li

    2009-01-01

    Hollow ZnSe microspheres were prepared via a facile hydrothermal reaction of Zn(AC) 2 .2H 2 O with Na 2 SeO 3 and ethylene glycol in NaOH solution at 180 deg. C for 12 h. The products were characterized by means of X-ray diffraction, scanning electron microscopy, transmission electron microscopy and Raman spectrum. The hollow microspheres with the diameters of about 2 μm are constructed from ZnSe nanoparticles with the cubic zinc blende structure, the size of hollow interiors and constituent ZnSe nanodots can be tuned by changing the reaction time. The hollow microspheres are formed via an Ostwald ripening process. Photoluminescence and photocatalytic activity of the hollow ZnSe microspheres were studied at room temperature. The results indicate that the hollow microspheres constructed from ZnSe nanoparticles display a strong near-band edge emission at 479 nm and a very weak deep defect (DD) related emission at 556 nm and a high photocatalytic activity in the photodegradation of methyl orange. The photodegradation of methyl orange catalyzed by the ZnSe microspheres is a pseudo first-order reaction

  2. Biocompatible magnetic and molecular dual-targeting polyelectrolyte hybrid hollow microspheres for controlled drug release.

    Science.gov (United States)

    Du, Pengcheng; Zeng, Jin; Mu, Bin; Liu, Peng

    2013-05-06

    Well-defined biocompatible magnetic and molecular dual-targeting polyelectrolyte hybrid hollow microspheres have been accomplished via the layer-by-layer (LbL) self-assembly technique. The hybrid shell was fabricated by the electrostatic interaction between the polyelectrolyte cation, chitosan (CS), and the hybrid anion, citrate modified ferroferric oxide nanoparticles (Fe3O4-CA), onto the uniform polystyrene sulfonate microsphere templates. Then the magnetic hybrid core/shell composite particles were modified with a linear, functional poly(ethylene glycol) (PEG) monoterminated with a biotargeting molecule (folic acid (FA)). Afterward the dual targeting hybrid hollow microspheres were obtained after etching the templates by dialysis. The dual targeting hybrid hollow microspheres exhibit exciting pH response and stability in high salt-concentration media. Their pH-dependent controlled release of the drug molecule (anticancer drug, doxorubicin (DOX)) was also investigated in different human body fluids. As expected, the cell viability of the HepG2 cells which decreased more rapidly was treated by the FA modified hybrid hollow microspheres rather than the unmodified one in the in vitro study. The dual-targeting hybrid hollow microspheres demonstrate selective killing of the tumor cells. The precise magnetic and molecular targeting properties and pH-dependent controlled release offers promise for cancer treatment.

  3. Three-dimensional assembly structure of anatase TiO2 hollow microspheres with enhanced photocatalytic performance

    Science.gov (United States)

    Tang, Yihao; Zhan, Shuai; Wang, Li; Zhang, Bin; Ding, Minghui

    The pure anatase TiO2 hollow microspheres are synthesized by a one-step template-free hydrothermal route. By defining temperature and time limits, we produce TiO2 hollow microspheres with a fluoride-mediated self-transformation. The surface morphology of TiO2 hollow microspheres was studied by SEM. The hollow microspheres have diameters of about 800 nm and are remarkably uniform. The UV-light photocatalytic activity and the stability/multifunction of TiO2 hollow microspheres structure were evaluated by photocatalytic degradation of methylene blue and photocatalytic hydrogen evolution. The excellent photocatalytic activity is attributed to large specific surface area, more active sites, unique hollow structures, and improved light scattering.

  4. Sustained release of simvastatin from hollow carbonated hydroxyapatite microspheres prepared by aspartic acid and sodium dodecyl sulfate.

    Science.gov (United States)

    Wang, Ke; Wang, Yinjing; Zhao, Xu; Li, Yi; Yang, Tao; Zhang, Xue; Wu, Xiaoguang

    2017-06-01

    Hollow carbonated hydroxyapatite (HCHAp) microspheres as simvastatin (SV) sustained-release vehicles were fabricated through a novel and simple one-step biomimetic strategy. Firstly, hollow CaCO 3 microspheres were precipitated through the reaction of CaCl 2 with Na 2 CO 3 in the presence of aspartic acid and sodium dodecyl sulfate. Then, the as-prepared hollow CaCO 3 microspheres were transformed into HCHAp microspheres with a controlled anion-exchange method. The HCHAp microspheres were 3-5μm with a shell thickness of 0.5-1μm and were constructed of short needle nanoparticles. The HCHAp microspheres were then loaded with SV, exhibiting excellent drug-loading capacity and sustained release properties. These results present a new material synthesis strategy for HCHAp microspheres and suggest that the as-prepared HCHAp microspheres are promising for applications in drug delivery. Copyright © 2017 Elsevier B.V. All rights reserved.

  5. Template-directed synthesis of MS (M=Cd, Zn) hollow microsphere via hydrothermal method

    Science.gov (United States)

    Wang, Shi-Ming; Wang, Qiong-Sheng; Wan, Qing-Li

    2008-05-01

    CdS, ZnS hollow microspheres were prepared with chitosan as the synthesis template at 140 and 150 °C, respectively, by hydrothermal method. The resultant products were characterized by X-ray diffraction (XRD) measurements in order to determine the crystalline phase of the products. The structural and morphological features of the nanoparticles were investigated by transmission electron microscopy (TEM) and ultraviolet-visible diffuse reflection spectroscopy (DRS). The experimental results indicated that all the nanoparticles aggregated into hollow microspheres and chitosan as a template played an important role in the formation of hollow microspheres. In addition, an intermediate complex structure-controlling possible reaction mechanism was proposed in this paper.

  6. Synthesis, characterization, and photocatalytic properties of Ni12P5 hollow microspheres

    Science.gov (United States)

    Liu, Shuling; Han, Xiaoli; Zhang, Hongzhe; Liu, Hui

    2017-05-01

    Ni12P5 hollow microspheres were prepared by a simple mixed cetyltrimethyl ammonium bromide/sodium dodecyl sulfate surfactant-assisted hydrothermal route. The as-prepared Ni12P5 microstructures were characterized by X-ray powder diffraction (XRD), field emission scanning electron microscopy (FE-SEM), and transmission electron microscopy (TEM). It was interesting to find that cetyltrimethyl ammonium bromide/sodium dodecyl sulfate could form a micro-reactor by the mixed micelles in the aqueous solution, which served as a soft template for Ni12P5 hollow microspheres with a diameter of 2 6 μm. Moreover, the as-prepared Ni12P5 hollow microspheres exhibited a good photocatalytic degradation activity for some organic dyes (such as Rhodamine B, Methylene Blue, Pyronine B, and Safranine T), and the degradation ratio could achieve more than 80%.

  7. Synthesis and Characterization of Gd2O3 Hollow Microspheres Using a Template-Directed Method

    Directory of Open Access Journals (Sweden)

    Xueliang Jiang

    2016-04-01

    Full Text Available Uniform rare-earth gadolinium oxide (Gd2O3 hollow microspheres, as formed through a urea-assisted homogenous precipitation process using carbon spheres as a template and a subsequent heat treatment, were characterized by using X-ray diffraction, Fourier transformed infared spectroscopy, thermogravimetry, X-ray photoelectron spectroscopy, scanning electron microscopy, transmission electron microscopy and Brunauer-Emmett-Tellet surface area measurement. The results indicate that the final products can be indexed to a cubic Gd2O3 phase with high purity and have a uniform morphology at 500 nm in diameter and 20 nm in shell thickness. The as-synthesized Gd2O3 hollow microspheres exhibited a superior photooxidation activity to that of Gd2O3 powder and an effect similar to P25, significantly broadening the potential of Gd2O3 hollow microspheres for many practical applications.

  8. Facile Synthesis of Magnetic Mesoporous Hollow Carbon Microspheres for Rapid Capture of Low-Concentration Peptides

    OpenAIRE

    Cheng, Gong; Zhou, Ming-Da; Zheng, Si-Yang

    2014-01-01

    Mesoporous and hollow carbon microspheres embedded with magnetic nanoparticles (denoted as MHM) were prepared via a facile self-sacrificial method for rapid capture of low-abundant peptides from complex biological samples. The morphology, structure, surface property, and magnetism were well-characterized. The hollow magnetic carbon microspheres have a saturation magnetization value of 130.2 emu g?1 at room temperature and a Brunauer?Emmett?Teller specific surface area of 48.8 m2 g?1 with an a...

  9. Phase transformation, morphology evolution and luminescence property variation in Y2O3: Eu hollow microspheres

    International Nuclear Information System (INIS)

    Wang, Qin; Guo, Jing; Jia, Wenjing; Liu, Baocang; Zhang, Jun

    2012-01-01

    Highlights: ► We report a general and facile method for the synthesis of Y 2 O 3 : Eu hollow microspheres. ► This method may be of great significance in the synthesis of many other hollow spherical materials. ► Phase, morphology and luminescence property were found to be strongly dependent on temperature and pH. ► The evolution process under various temperatures and pH values were discussed. ► The sample shows a strong red emission under short UV irradiation, and the lifetime is determined to be 7.0 ms. - Abstract: Y 2 O 3 : Eu hollow microspheres with average size of 500–600 nm have been successfully synthesized via a solvothermal method in the presence of sodium citrate as surfactant followed by a subsequent heat treatment process. High polymer F127(EO 106 PO 70 EO 106 ) served as a soft template in the formation of as prepared hollow microspheres. It is found that the pH values and the reaction temperature are two crucial factors in determining the phase, morphology and luminescence properties of the Y 2 O 3 : Eu hollow microspheres. Morphology evolution can be achieved by changing the pH and the reaction temperature. The properties of the Eu 3+ -doped Y 2 O 3 : Eu nanocrystals were characterized by XRD, FE-SEM, HR-TEM and UV–vis spectroscopy.

  10. Automated characterization of glass microspheres used for laser fusion experiments

    International Nuclear Information System (INIS)

    Tajima, Tsuyoshi; Norimatsu, Takayoshi; Izawa, Yasukazu; Yamanaka, Chiyoe.

    1985-01-01

    In laser fusion experiments glass microspheres of 100 to 1000 μm in diameter and 1 to 20 μm in wall thickness are most commonly used as fuel containers. The glass microspheres should be characterized precisely to meet stringent experimental requirements. Much time is consumed to characterize and select good quality spheres among thousands of spheres. We have developed an automated system to characterize and select glass microspheres. The system consists of charger, quadrupole rail, image processing and X-Y stage control with micro-computer. Total processing time primarily depends on the time required for image analysis, which should be compromised with the accuracy of characterization. The time for simple characterization requires about 10 sec. at present. (author)

  11. Synthesis of Hollow CdS-TiO2 Microspheres with Enhanced Visible-Light Photocatalytic Activity

    Directory of Open Access Journals (Sweden)

    Yuning Huo

    2012-01-01

    Full Text Available CdS-TiO2 composite photocatalyst in the shape of hollow microsphere was successfully synthesized via the hard-template preparation with polystyrene microspheres followed by ion-exchange approach. The hollow CdS-TiO2 microspheres significantly extended the light adsorption into visible light region, comparing to TiO2 microspheres. It led to much higher photocatalytic activities of hollow CdS-TiO2 microspheres than that of TiO2 during the photodegradation of rhodamine B under visible light irradiations. Furthermore, the well-remained hollow structure could achieve light multireflection within the interior cavities and the separation of photo-induced electrons and holes is efficient in CdS-TiO2, which were facilitated to improving the photoactivity.

  12. Properties and shaping of lightweight ceramics based on phosphate-bonded hollow silica microspheres

    NARCIS (Netherlands)

    With, de G.; Verweij, H.

    1986-01-01

    The values for the Young's modulus, strength, fracture toughness and thermal conductivity of lightweight ceramics based on phosphate-bonded hollow silica microspheres are reported as a function of the processing conditions. They are compared with the relevant data for other lightweight ceramic

  13. One-pot template-free synthesis of monodisperse hollow hydrogel microspheres and their resulting properties.

    Science.gov (United States)

    Lim, Hyung-Seok; Kwon, Eunji; Lee, Moonjoo; Moo Lee, Young; Suh, Kyung-Do

    2013-08-01

    Monodisperse poly(methacrylic acid/ethyleneglycoldimethacrylate) (MAA/EGDMA) hollow microcapsules, which exhibit pH-responsive behavior, are prepared by diffusion of cationic surfactants and hydrophobic interaction. During the association of the negatively charged hydrogel microspheres and an oppositely charged surfactant (cetyltrimethylammonium bromide, CTA(+)B), the hydrophobic polymer-surfactant complexes that form are separated from the internal water; consequently, a hollow structure can be formed. Confocal laser scanning microscopy, UV spectro-scopy and zeta potential are employed to study the formation of the hollow structure during the diffusion of the cationic surfactant. The controlled release behavior of methylene blue as a model drug from the as-prepared poly(MAA/EGDMA) microcapsules with a hollow structure is investigated under different pH conditions. The hollow structure can be retained, even during repetitive pH changes. © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  14. Catalyst-free combined synthesis of Zn/ZnO core/shell hollow microspheres and metallic Zn microparticles by thermal evaporation and condensation route

    Energy Technology Data Exchange (ETDEWEB)

    Khan, Waheed S. [Research Centre of Materials Science, Beijing Institute of Technology, Beijing 100081 (China); Cao Chuanbao, E-mail: cbcao@bit.edu.c [Research Centre of Materials Science, Beijing Institute of Technology, Beijing 100081 (China); Nabi, Ghulam; Yao Ruimin; Bhatti, Sajjad H. [Research Centre of Materials Science, Beijing Institute of Technology, Beijing 100081 (China)

    2010-09-17

    Research highlights: {yields} Catalyst-free combined synthesis of metal/semiconductor Zn/ZnO core/shell microspheres with hollow interiors on Si substrate and metallic Zn polygonal microparticles on glass substrate in a single experiment via thermal evaporation and condensation technique was reported. The Zn/ZnO hollow microspheres were observed to have dimensions in the range of 70-80 {mu}m whereas metallic Zn microparticles with polygonal cross section and oblate spherical shape were found to be of 8-10 {mu}m. Some of the Zn/ZnO core/shell hollow spheres were also observed to have single crystalline ZnO pointed rods in extremely low density grown on the outer shell. A vapor-liquid-solid (VLS) process based growth mechanism was proposed for the formation of Zn/ZnO core/shell microspheres with hollow interior. The optical properties of Zn/ZnO core/shell microspheres were investigated by measuring the photoluminescence (PL) spectra at room temperature (RT). Two very strong emission bands were observed at 373 and 469 nm in the ultraviolet and visible regions respectively under excitation wavelength of 325 nm. Also the effect of the various excitation wavelengths on the PL behaviour was studied at room temperature. PL studies of Zn/ZnO core/shell microspheres show the promise of the material for applications in UV and blue light optical devices. - Abstract: Here we report catalyst-free combined synthesis of metal/semiconductor Zn/ZnO core/shell microspheres with hollow interiors on Si substrate and metallic Zn polygonal microparticles on glass substrate in a single experiment via thermal evaporation and condensation technique using nitrogen (N{sub 2}) as carrier agent at 800 {sup o}C for 120 min. The Zn/ZnO hollow microspheres were observed to have dimensions in the range of 70-80 {mu}m whereas metallic Zn microparticles with polygonal cross section and oblate spherical shape were found to be of 8-10 {mu}m. Some of the Zn/ZnO core/shell hollow spheres were also

  15. A template-free method for stable CuO hollow microspheres fabricated from a metal organic framework (HKUST-1).

    Science.gov (United States)

    Zhang, Suoying; Liu, Hong; Liu, Pengfei; Yang, Zhuhong; Feng, Xin; Huo, Fengwei; Lu, Xiaohua

    2015-06-07

    Uniform CuO hollow microspheres were successfully achieved from a non-uniform metal organic framework by using a template-free method. The process mechanism has been revealed to be spherical aggregation and Ostwald ripening. When tested in CO oxidation and heat treatment, these assembled microspheres exhibited an excellent catalytic performance and show a much better stability than the inherited hollow structure from MOFs.

  16. Statistical analysis on hollow and core-shell structured vanadium oxide microspheres as cathode materials for Lithium ion batteries

    Directory of Open Access Journals (Sweden)

    Xing Liang

    2018-06-01

    Full Text Available In this data, the statistical analyses of vanadium oxide microspheres cathode materials are presented for the research article entitled “Statistical analyses on hollow and core-shell structured vanadium oxides microspheres as cathode materials for Lithium ion batteries” (Liang et al., 2017 [1]. This article shows the statistical analyses on N2 adsorption-desorption isotherm and morphology vanadium oxide microspheres as cathode materials for LIBs. Keywords: Adsorption-desorption isotherm, Pore size distribution, SEM images, TEM images

  17. Hollow microspheres with a tungsten carbide kernel for PEMFC application.

    Science.gov (United States)

    d'Arbigny, Julien Bernard; Taillades, Gilles; Marrony, Mathieu; Jones, Deborah J; Rozière, Jacques

    2011-07-28

    Tungsten carbide microspheres comprising an outer shell and a compact kernel prepared by a simple hydrothermal method exhibit very high surface area promoting a high dispersion of platinum nanoparticles, and an exceptionally high electrochemically active surface area (EAS) stability compared to the usual Pt/C electrocatalysts used for PEMFC application.

  18. Fabrication of polystyrene hollow microspheres as laser fusion ...

    Indian Academy of Sciences (India)

    free from preheating problems and have emerged as good alternative to .... carry a system over the energy barrier comes from the Brownian motion of the ... This increase implies an increase in the electrical contribution to the free energy of the .... microsphere is mainly determined by rotational speed of the magnetic stirrer.

  19. Effects of hepatic arterial yttrium 90 glass microspheres in dogs.

    Science.gov (United States)

    Wollner, I; Knutsen, C; Smith, P; Prieskorn, D; Chrisp, C; Andrews, J; Juni, J; Warber, S; Klevering, J; Crudup, J

    1988-04-01

    A 22-micron glass microsphere called TheraSphere (Theragenics Corp., Atlanta, GA) has been developed in which yttrium 89 oxide is incorporated into the glass matrix and is activated by neutron bombardment to form the beta-emitting isotope yttrium 90 (Y 90) before using the spheres as radiotherapeutic vehicles. The injection of up to 12 times (on a liver weight basis) the anticipated human dose of nonradioactive TheraSphere into the hepatic arteries of dogs was well tolerated and produced clinically silent alterations within centrolobular areas. The hepatic arterial (HA) injection of radioactive TheraSphere also produced portal changes similar to those observed in humans after external beam therapy. While the extent of damage increased with the delivered dose, radiation exposures in excess of 30,000 cGy did not cause total hepatic necrosis and were compatible with survival. No microspheres distributed to the bone marrow and absolutely no myelosuppression was encountered in any animal. Proposed hepatic exposures to humans of 5000 to 10,000 cGy by means of these microspheres, therefore, would appear to be feasible and tolerable. Radiotherapeutic microsphere administration preceded by regional infusion of a radiosensitizing agent and/or immediately following the redistribution of blood flow toward intrahepatic tumor by vasoactive agents can potentially yield a synergistic, highly selective attack on tumors confined to the liver.

  20. Trapping of microwave radiation in hollow polypyrrole microsphere through enhanced internal reflection: A novel approach

    OpenAIRE

    Ritwik Panigrahi; Suneel K. Srivastava

    2015-01-01

    In present work, spherical core (polystyrene, PS)/shell (polypyrrole, PPy) has been synthesized via in situ chemical oxidative copolymerization of pyrrole (Py) on the surface of sulfonated PS microsphere followed by the formation of hollow polypyrrole (HPPy) shell by dissolving PS inner core in THF. Thereafter, we first time established that such fabricated novel art of morphology acts as a conducting trap in absorbing electromagnetic (EM) wave by internal reflection. Further studies have bee...

  1. Synthesis and photoluminescence properties of self-assembled Eu-doped ZnO hollow microspheres

    Energy Technology Data Exchange (ETDEWEB)

    Xu, Jin [Department of Materials Science and Engineering, College of Materials, Xiamen University, Siming South Road 422, 361005 Xiamen (China); Key Laboratory for Fire Retardant Materials of Fujian Province, Xiamen University, Siming South Road 422, 361005 Xiamen (China); Wang, Nating; Wang, Weiqiang [Department of Materials Science and Engineering, College of Materials, Xiamen University, Siming South Road 422, 361005 Xiamen (China)

    2011-12-15

    ZnO hollow microspheres with a shell wall consisting of crystalline ZnO nanosheets were synthesized by using Zn{sub 5}(CO{sub 3}){sub 2}(OH){sub 6} microspheres as spherical templates. Zn{sub 5}(CO{sub 3}){sub 2}(OH){sub 6} microspheres were first fabricated by a solvothermal procedure in an ethylene glycol (EG)-water solution. ZnO microspheres with a hexagonal structure were identified by means of X-ray diffraction (XRD) and selected-area electron diffraction (SAED). On the basis of the results, a possible self-assembly growth mechanism was proposed. It reveals that the EG played an important role in determining the hollow morphologies of Zn{sub 5}(CO{sub 3}){sub 2}(OH){sub 6} structures. In addition, photoluminescence (PL) investigation of ZnO:Eu{sup 3+} suggested that a direct energy transfer occurred, which was ascribed to the energy transfer from ZnO host to Eu{sup 3+} ions. (Copyright copyright 2011 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

  2. Hollow reduced graphene oxide microspheres as a high-performance anode material for Li-ion batteries

    International Nuclear Information System (INIS)

    Mei, Riguo; Song, Xiaorui; Hu, Yan; Yang, Yanfeng; Zhang, Jingjie

    2015-01-01

    Hollow reduced graphene oxide (RGO) microspheres are successfully synthesized in large quantities through spray-drying suspension of graphene oxide (GO) nanosheets and subsequent carbothermal reduction. With this new procedure, blighted-microspherical GO precursor is synthesized through the process of spray drying, afterwards the GO precursor is subsequently calcined at 800 °C for 5 h to obtain hollow RGO microspheres. A series of analyses, such as X-ray diffraction (XRD), scanning electron microscopy (SEM), high-resolution transmission electron microscopy (HRTEM) and Fourier transform infrared spectroscopy (FTIR) are performed to characterize the structure and morphology of intermediates and as-obtained product. The as-obtained hollow RGO microspheres provide a high specific surface area (175.5 m 2 g −1 ) and excellent electronic conductivity (6.3 S cm −1 ), and facilitated high electrochemical performance as anode material for Li-ion batteries (LIBs). Compared with the RGO nanosheets, the as-obtained hollow RGO microspheres exhibit superior specific capacity and outstanding cyclability. In addition, this spray drying and carbothermal reduction (SDCTR) method provided a facile route to prepare hollow RGO microspheres in large quantities

  3. Hollow TiO2 modified reduced graphene oxide microspheres encapsulating hemoglobin for a mediator-free biosensor.

    Science.gov (United States)

    Liu, Hui; Guo, Kai; Duan, Congyue; Dong, Xiaonan; Gao, Jiaojiao

    2017-01-15

    Hollow TiO 2 modified reduced graphene oxide microspheres (hollow TiO 2 -rGO microspheres or H-TiO 2 -rGO MS) have been synthesized and then be used to immobilize hemoglobin (Hb) to fabricate a mediator-free biosensor. The morphology and structure of hollow TiO 2 -rGO microspheres were characterized by scanning electron microscopy, transmission electronic microscopy and X-ray diffraction. Results of spectroscopy and electrochemistry tests revealed that hollow TiO 2 -rGO microsphere is an excellent immobilization matrix with biocompatibility for redox protein, affording good protein bioactivity and stability. The hollow TiO 2 -rGO microspheres with special structure and component enhance the immobilization efficiency of proteins and facilitate the direct electron transfer, which result in the better H 2 O 2 detection performance-the wide linear range of 0.1-360μM for H 2 O 2 (sensitivity of 417.6 μA mM -1 cm -2 ) and the extremely low detection limit of 10nM for H 2 O 2 . Moreover, the hollow microsphere can provide a protective microenvironment for Hb to make the as-prepared biosensor improve long-term stability. The as-prepared biosensor retains 95.4% of the initial response to H 2 O 2 after 60-d storage. Hence, this work suggests that if can be fabricated a mediator-free biosensor, hollow TiO 2 -rGO microspheres will find wide potential applications in environmental analysis and biomedical detection. Copyright © 2016 Elsevier B.V. All rights reserved.

  4. A method and apparatus for the manufacture of glass microspheres adapted to contain a thermonuclear fuel

    International Nuclear Information System (INIS)

    Budrick, R.G.; Nolen, R.L. Jr.; Solomon, D.E.; King, F.T.

    1975-01-01

    The invention relates to the manufacture of glass microspheres. It refers to a method according to which a sintered glass-powder, whose particles are calibrated, is introduced into a blow-pipe adapted to project said glass-powder particles into a heated flue, said sintered glass-powder containing a pore-forming agent adapted to expand the glass particles into microspheres which are collected in a chamber situated abode said flue. The method can be applied to the manufacture of microspheres adapted to contain a thermonuclear fuel [fr

  5. Rambutan-like FeCO3 hollow microspheres: facile preparation and superior lithium storage performances.

    Science.gov (United States)

    Zhong, Yiren; Su, Liwei; Yang, Mei; Wei, Jinping; Zhou, Zhen

    2013-11-13

    Rambutan-like FeCO3 hollow microspheres were prepared via a facile and economic one-step hydrothermal method. The structure and morphology evolution mechanism was disclosed through time-dependent experiments. After undergoing the symmetric inside-out Ostwald ripening, the resultants formed microporous/nanoporous constructions composed of numerous one-dimensional (1D) nanofiber building blocks. Tested as anode materials of Li-ion batteries, FeCO3 hollow microspheres presented attractive electrochemical performances. The capacities were over 1000 mAh g(-1) for initial charge, ~880 mAh g(-1) after 100 cycles at 50 mA g(-1), and ~710 mAh g(-1) after 200 cycles at 200 mA g(-1). The 1D nanofiber assembly and hollow interior endow this material efficient contact with electrolyte, short Li(+) diffusion paths, and sufficient void spaces to accommodate large volume variation. The cost-efficient FeCO3 with rationally designed nanostructures is a promising anode candidate for Li-ion batteries.

  6. Novel syntactic foams made of ceramic hollow micro-spheres and starch: theory, structure and properties

    Energy Technology Data Exchange (ETDEWEB)

    Islam, M.M.; Kim, H.S. [University of Newcastle, Callaghan, NSW (Australia). Faculty of Engineering & Built Environments

    2007-08-15

    Novel syntactic foams for potential building material applications were developed using starch as binder and ceramic hollow micro-spheres available as waste from coal-fired power stations. Foams of four different micro-sphere size groups were manufactured with either pre- or post-mould gelatinization process. They were of ternary system including voids with a foam density range of approximately 0.33-0.44 g/cc. Compressive failure behaviour and mechanical properties of the manufactured foams were evaluated. Not much difference in failure behaviour or in mechanical properties between the two different processes (pre- and post-mould gels) was found for a given binder content. Compressive failure of all syntactic foams was of shear on plane inclined 45 degrees to compressive loading direction. Failure surfaces of most syntactic foams were characterized by debonded micro-spheres. Compressive strength and modulus of syntactic foams were found to be dependant mainly on binder content but mostly independent of micro-sphere size. Some conditions of relativity arising from properties of constituents leading to the rule of mixtures relationships for compressive strength and to understanding of compressive/transitional failure behaviour were developed. The developed relationships based on the rule of mixtures were partially verified. Some formation of starch webs on failure surfaces was discussed.

  7. Effect of Synthesis Time on Morphology of Hollow Porous Silica Microspheres

    Directory of Open Access Journals (Sweden)

    Qian CHEN

    2012-03-01

    Full Text Available Hollow porous silica microspheres may be applicable as containers for the controlled release in drug delivery systems (DDS, foods, cosmetics, agrochemical, textile industry, and in other technological encapsulation use. In order to control the surface morphological properties of the silica microspheres, the effect of synthesis time on their formation was studied by a method of water-in-oil (W/O emulsion mediated sol-gel techniques. An aqueous phase of water, ammonium hydroxide and a surfactant Tween 20 was emulsified in an oil phase of 1-octanol with a stabilizer, hydroxypropyl cellulose (HPC, and a surfactant, sorbitan monooleate (Span 80 with low hydrophile-lipophile balance (HLB value. Tetraethyl orthosilicate (TEOS as a silica precursor was added to the emulsion. The resulting silica particles at different synthesis time 24, 48, and 72 hours were air-dried at room temperature and calcinated at 773 K for 3 hours. The morphology of the particles was characterized by scanning electron microscopy and the particle size distribution was measured by laser diffraction. The specific surface areas were studied by 1-point BET method, and pore sizes were measured by Image Tool Software. Both dense and porous silica microspheres were observed after all three syntheses. Hollow porous silica microspheres were formed at 24 and 48 hours synthesis time. Under base catalyzed sol-gel solution, the size of silica particles was in the range of 5.4 μm to 8.2 μm, and the particles had surface area of 111 m2/g – 380 m2/g. The longer synthesis time produced denser silica spheres with decreased pore sizes.DOI: http://dx.doi.org/10.5755/j01.ms.18.1.1344

  8. Facile Synthesis of Rambutan-Like ZnO Hierarchical Hollow Microspheres with Highly Photocatalytic Activity

    Directory of Open Access Journals (Sweden)

    Ke-Jian Ju

    2015-01-01

    Full Text Available Rambutan-like ZnO hierarchical hollow microspheres (ZnO HHMs were constructed under hydrothermal conditions, using carboxyl methyl starch (CMS as a soft template. The resulting products were characterized by using X-ray diffraction (XRD, scanning electron microscopy (SEM, and transmission electron microscopy (TEM. The experimental parameters and growth mechanism of rambutan-like ZnO HHMs were discussed in some detail. The as-prepared samples displayed improved photocatalytic activity for the degradation of rhodamine B under ultraviolet (UV irradiation.

  9. Lead recovery and glass microspheres synthesis from waste CRT funnel glasses through carbon thermal reduction enhanced acid leaching process.

    Science.gov (United States)

    Mingfei, Xing; Yaping, Wang; Jun, Li; Hua, Xu

    2016-03-15

    In this study, a novel process for detoxification and reutilization of waste cathode ray tube (CRT) funnel glass was developed by carbon thermal reduction enhanced acid leaching process. The key to this process is removal of lead from the CRT funnel glass and synchronous preparation of glass microspheres. Carbon powder was used as an isolation agent and a reducing agent. Under the isolation of the carbon powder, the funnel glass powder was sintered into glass microspheres. In thermal reduction, PbO in the funnel glass was first reduced to elemental Pb by carbon monoxide and then located on the surface of glass microspheres which can be removed easily by acid leaching. Experimental results showed that temperature, carbon adding amount and holding time were the major parameters that controlled lead removal rate. The maximum lead removal rate was 94.80% and glass microspheres that measured 0.73-14.74μm were obtained successfully by setting the temperature, carbon adding amount and holding time at 1200°C, 10% and 30min, respectively. The prepared glass microspheres may be used as fillers in polymer materials and abrasive materials, among others. Accordingly, this study proposed a practical and economical process for detoxification and recycling of waste lead-containing glass. Copyright © 2015 Elsevier B.V. All rights reserved.

  10. Facile synthesis of nanorod-assembled multi-shelled Co3O4 hollow microspheres for high-performance supercapacitors

    Science.gov (United States)

    Wang, Yaping; Pan, Anqiang; Zhu, Qinyu; Nie, Zhiwei; Zhang, Yifang; Tang, Yan; Liang, Shuquan; Cao, Guozhong

    2014-12-01

    In this work, we report a novel strategy for the controlled synthesis of nanorod assembled multi-shelled cobalt oxide (Co3O4) hollow microspheres (HSs). The Co2CO3(OH)2 NRs are first vertically grown on the carbon microspheres (CS) to form the core-shelled composites by a low-temperature solution route. The multi-shelled hollow interiors within the Co3O4 microspheres are unconventionally obtained by annealing the as-prepared core-shell structured CS@Co2CO3(OH)2 composite in air. When evaluated for supercapacitive performance, the multi-shelled Co3O4 hollow microspheres exhibit high capacitance of 394.4 and 360 F g-1 at the current densities of 2 A g-1 and 10 A g-1, respectively. The superior electrochemical performance can be attributed to the multi-shelled hollow structures, which facilitate the electrolyte penetration and provide more active sites for the electrochemical reactions.

  11. Morphology-controlled synthesis of SiO{sub 2} hollow microspheres using pollen grain as a biotemplate

    Energy Technology Data Exchange (ETDEWEB)

    Cao Feng; Li Dongxu, E-mail: caofeng.cn@gmail.co, E-mail: dongxuli@njut.edu.c [College of Materials Science and Engineering, Nanjing University of Technology, Jiangsu Nanjing 210009 (China)

    2009-04-15

    Hollow surface-structured silica microspheres, a potential candidate for drug delivery systems, were synthesized using the rape pollen grain as a biotemplate via a facile sol-gel coating followed by a calcination process. Different surface morphologies relating to the controllable release property were also achieved on the as-prepared silica hollow microspheres by changing the ratio of the tetraethyl orthosilicate (TEOS) and water in sols. Differential scanning calorimetry (DSC) and thermogravity (TG), scanning electron microscopy (SEM), energy dispersive spectroscopy (EDS), as well as Fourier transform infrared spectroscopy (FT-IR) were utilized to characterize the original pollen grain, the silica sols-coated pollen grain and the as-prepared hollow silica microspheres, respectively. Results indicated that the pollen grain would be removed at around 500 deg. C, and the sol coating was kept to form hollow microspheres. Physical adsorption was proved to be the main effect in the sol coating. A speculation on the formation mechanism of different morphologies is also given.

  12. Morphology-controlled synthesis of SiO2 hollow microspheres using pollen grain as a biotemplate

    International Nuclear Information System (INIS)

    Cao Feng; Li Dongxu

    2009-01-01

    Hollow surface-structured silica microspheres, a potential candidate for drug delivery systems, were synthesized using the rape pollen grain as a biotemplate via a facile sol-gel coating followed by a calcination process. Different surface morphologies relating to the controllable release property were also achieved on the as-prepared silica hollow microspheres by changing the ratio of the tetraethyl orthosilicate (TEOS) and water in sols. Differential scanning calorimetry (DSC) and thermogravity (TG), scanning electron microscopy (SEM), energy dispersive spectroscopy (EDS), as well as Fourier transform infrared spectroscopy (FT-IR) were utilized to characterize the original pollen grain, the silica sols-coated pollen grain and the as-prepared hollow silica microspheres, respectively. Results indicated that the pollen grain would be removed at around 500 deg. C, and the sol coating was kept to form hollow microspheres. Physical adsorption was proved to be the main effect in the sol coating. A speculation on the formation mechanism of different morphologies is also given.

  13. Ag-doped TiO2 hollow microspheres with visible light response by template-free route for removal of tetracycline hydrochloride from aqueous solution

    Science.gov (United States)

    Zhang, Jian; Li, Xuanhua; Peng, Meiling; Tang, Yuanyuan; Ke, Anqi; Gan, Wei; Fu, Xucheng; Hao, Hequn

    2018-06-01

    In this study, Ag-doped TiO2 hollow microspheres were synthesized by a template-free route, and their photocatalytic performance and catalytic mechanism were investigated. The hollow microspheres were characterized by x-ray diffraction, scanning electron microscopy, transmission electron microscopy, x-ray photoelectron spectroscopy and UV–vis spectroscopy. Ag-doped hollow TiO2 microspheres exhibited excellent photocatalytic performance for tetracycline hydrochloride (TC) in water. TC degradation follows pseudo first-order kinetics, and hydroxyl radical (OH·) and holes (h+) were active substances in the photocatalytic reaction.

  14. Preparation and crystallization of hollow α-Fe2O3 microspheres following the gas-bubble template method

    International Nuclear Information System (INIS)

    Valladares, L. de los Santos; León Félix, L.; Espinoza Suarez, S.M.; Bustamante Dominguez, A.G.; Mitrelias, T.; Holmes, S.; Moreno, N.O.; Albino Aguiar, J.; Barnes, C.H.W.

    2016-01-01

    In this work we report the formation of hollow α-Fe 2 O 3 (hematite) microspheres by the gas-bubble template method. This technique is simple and it does not require hard templates, surfactants, special conditions of atmosphere or complex steps. After reacting Fe(NO 3 ) 3 .9H 2 O and citric acid in water by sol–gel, the precursor was annealed in air at different temperatures between 180 and 600 °C. Annealing at 550 and 600 °C generates bubbles on the melt which crystallize and oxidizes to form hematite hollow spheres after quenching. The morphology and crystal evolution are studied by means of X-ray diffraction and scanning electron microscopy. We found that after annealing at 250–400 °C, the sample consist of a mixture of magnetite, maghemite and hematite. Single hematite phase in the form of hollow microspheres is obtained after annealing at 550 and 600 °C. The crystallization and crystal size of the hematite shells increase with annealing temperature. A possible mechanism for hollow sphere formation is presented. - Highlights: • Formation of hollow hematite microspheres by the gas-bubble template method. • This technique does not require hard templates or special conditions of atmosphere. • Annealing promotes the transition magnetite to maghemite to hematite. • Crystallization of the hematite shells increase with annealing temperature.

  15. Chemical Modifications of Hollow Silica Microspheres for the Removal of Organic Pollutants in Simulated Wastewater

    KAUST Repository

    Torano, Aniela Zarzar

    2017-05-01

    Aqueous industrial effluents containing organic pollutants, such as textile dyes and crude oil, represent environmental and human health concerns due to their toxicity and possible carcinogenic effects. Adsorption is the most promising wastewater treatment method due to its efficiency, ease of operation, and low cost. However, currently used adsorbents have either high regeneration costs or low adsorption capacities. In this work, new organic/inorganic hybrids based on hollow silica microspheres were successfully synthesized, and their ability to remove Methylene Blue from wastewater and crude oil from simulated produced water was evaluated. By employing four different silanes, namely triethoxy (octyl) silane, triethoxy (dodecyl) silane, trichloro (octadecyl) silane, and triethoxy (pentafluorophenyl) silane, hydro and fluorocarbons were grafted onto the surface of commercially available silica microspheres. These silica derivatives were tested as adsorbents by exposing them to Methylene Blue aqueous solutions and synthetic produced water. Absorbance and oil concentration were measured via a UV/Vis Spectrophotometer and an HD-1000 Oil-in-Water Analyzer respectively. Methylene Blue uptake experiments showed that increasing the adsorbent dosage and decreasing initial dye concentration might increase adsorption percentage. On the other hand, adsorption capacities were improved with lower adsorbent dosages and higher initial dye concentrations. Varying the initial solution pH, from pH 5 to pH 9, and increasing ionic strength did not seem to have a significant impact on the extent of adsorption of Methylene Blue. Overall, the silica derivative containing aromatic functional groups, Caro, was proven to be the most effective adsorbent due to the presence of π-π and cation-π interactions in addition to the van der Waals and hydrophobic interactions occurring with all four adsorbents. Although the Langmuir Model did not accurately represent the equilibrium data, it

  16. Enhanced microwave absorption properties of MnO{sub 2} hollow microspheres consisted of MnO{sub 2} nanoribbons synthesized by a facile hydrothermal method

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Yan; Han, Bingqian; Chen, Nan; Deng, Dongyang; Guan, Hongtao [Department of Materials Science and Engineering, Yunnan University, 650091, Kunming (China); Wang, Yude, E-mail: ydwang@ynu.edu.cn [Department of Materials Science and Engineering, Yunnan University, 650091, Kunming (China); Yunnan Province Key Lab of Micro-Nano Materials and Technology, Yunnan University, 650091, Kunming (China)

    2016-08-15

    MnO{sub 2} hollow microspheres consisted of nanoribbons were successfully fabricated via a facile hydrothermal method with SiO{sub 2} sphere templates. The crystal structure, morphology and microwave absorption properties in X and Ku band of the as-synthesized samples were characterized by powder X-ray diffraction (XRD), transmission electron microscopy (TEM) and a vector network analyzer. The results show that the three-dimensional (3D) hollow microspheres are assembled by ultra thin and narrow one-dimensional (1D) nanoribbons. A rational process for the formation of hollow microspheres is proposed. The 3D MnO{sub 2} hollow microspheres possess improved dielectric and magnetic properties than the 1D nanoribbons prepared by the same procedures with the absence of SiO{sub 2} hard templates, which are closely related to their special nanostructures. The MnO{sub 2} microspheres also show much better microwave absorption properties in X (8–12 GHz) and Ku (12–18 GHz) microwave band compared with 1D MnO{sub 2} nanoribbons. The minimum reflection loss of −40 dB for hollow microsphere can be observed at 14.2 GHz and reflection loss below −10 dB is 3.5 GHz with a thickness of only 4 mm. The possible mechanism for the enhanced microwave absorption properties is also discussed. - Graphical abstract: MnO{sub 2} hollow microspheres composed of nanoribbons show the excellent microwave absorption properties in X and Ku band. - Highlights: • MnO{sub 2} hollow microspheres consisted of MnO{sub 2} nanoribbons were successfully prepared. • MnO{sub 2} hollow microspheres possess good microwave absorption performances. • The excellent microwave absorption properties are in X and Ku microwave band. • Electromagnetic impedance matching is great contribution to absorption properties.

  17. TiO_2 hierarchical hollow microspheres with different size for application as anodes in high-performance lithium storage

    International Nuclear Information System (INIS)

    Wang, Xiaobing; Meng, Qiuxia; Wang, Yuanyuan; Liang, Huijun; Bai, Zhengyu; Wang, Kui; Lou, Xiangdong; Cai, Bibo; Yang, Lin

    2016-01-01

    Graphical abstract: In the application of lithium-ion batteries, the influences of microsphere sizes are more significant than the secondary nanoparticles size and crystallinity of TiO_2-HSs for their transfer resistance and cycling performance, so that the bigger sizes of TiO_2-HSs can retain high reversible capacities after 30 recycles. - Highlights: • Hierarchical hollow microspheres have size-effect in the application of lithium ion battery. • The microsphere sizes can significantly affect the cycling capacities of TiO_2. • The nanoparticles size affect the initial discharge capacity and lithium ion diffusion. • Controlled microsphere size is more significant for improving TiO_2 cycling capacities. - Abstract: Nowadays, the safety issue has greatly hindered the development of large capacity lithium-ion batteries (LIBs), especially in electric vehicles applications. TiO_2 is a kind of potential anode candidate for improving the safety of LIBs. However, it still needs to understand how to improve the performance of TiO_2 anode in the practical applications. Herein, we design a contrast experiment by using three sizes of TiO_2 hierarchical hollow microspheres (TiO_2-HSs). The research results indicated that the cycling performance of TiO_2-HSs anode can be affected by the size of microspheres, and the nanoparticles size of microspheres and crystallinity of TiO_2 can affect their initial discharge capacity and lithium ion diffusion. And, the influence of microspheres size is more significant. This may provide a new strategy for improving the lithium-ion storage property of TiO_2 anode material in the practical applications.

  18. Phase transformation, morphology evolution and luminescence property variation in Y{sub 2}O{sub 3}: Eu hollow microspheres

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Qin; Guo, Jing; Jia, Wenjing; Liu, Baocang [College of Chemistry and Chemical Engineering, Inner Mongolia University, Hohhot (China); Zhang, Jun, E-mail: cejzhang@sina.com [College of Chemistry and Chemical Engineering, Inner Mongolia University, Hohhot (China)

    2012-11-25

    Highlights: Black-Right-Pointing-Pointer We report a general and facile method for the synthesis of Y{sub 2}O{sub 3}: Eu hollow microspheres. Black-Right-Pointing-Pointer This method may be of great significance in the synthesis of many other hollow spherical materials. Black-Right-Pointing-Pointer Phase, morphology and luminescence property were found to be strongly dependent on temperature and pH. Black-Right-Pointing-Pointer The evolution process under various temperatures and pH values were discussed. Black-Right-Pointing-Pointer The sample shows a strong red emission under short UV irradiation, and the lifetime is determined to be 7.0 ms. - Abstract: Y{sub 2}O{sub 3}: Eu hollow microspheres with average size of 500-600 nm have been successfully synthesized via a solvothermal method in the presence of sodium citrate as surfactant followed by a subsequent heat treatment process. High polymer F127(EO{sub 106}PO{sub 70}EO{sub 106}) served as a soft template in the formation of as prepared hollow microspheres. It is found that the pH values and the reaction temperature are two crucial factors in determining the phase, morphology and luminescence properties of the Y{sub 2}O{sub 3}: Eu hollow microspheres. Morphology evolution can be achieved by changing the pH and the reaction temperature. The properties of the Eu{sup 3+}-doped Y{sub 2}O{sub 3}: Eu nanocrystals were characterized by XRD, FE-SEM, HR-TEM and UV-vis spectroscopy.

  19. Controlled synthesis of ZnO hollow microspheres via precursor-template method and its gas sensing property

    International Nuclear Information System (INIS)

    Tian, Yu; Li, Jinchai; Xiong, Hui; Dai, Jiangnan

    2012-01-01

    Highlights: ► Zn powder as precursor template for synthesis ZnO hollow spheres. ► Different precursor templates result in different ZnO nanostructures. ► Different experimental conditions enable growth of different surface morphologies of ZnO sphere. ► ZnO hollow sphere materials have good gas sensing performance for detecting ethanol gas. - Abstract: Using Zn powder as precursor templates, ZnO hollow microspheres were successfully prepared by thermal evaporation method and characterized by X-ray diffraction analysis, scanning electron microscope and transmission electron microscope. It was found that different size and shape of precursor resulted in different ZnO nanostructures. When varying experimental conditions, such as air flow rate and working pressure, ZnO hollow spheres with different surface morphologies could be obtained. The advantages of the present synthetic technology are simple, relatively low cost, and high reproducibility. A gas sensor was fabricated from the as-prepared ZnO hollow microspheres and tested to the ethanol gas at different operating temperatures.

  20. Hierarchical NiO-SiO2 composite hollow microspheres with enhanced adsorption affinity towards Congo red in water.

    Science.gov (United States)

    Lei, Chunsheng; Zhu, Xiaofeng; Zhu, Bicheng; Yu, Jiaguo; Ho, Wingkei

    2016-03-15

    Hollow microspheres and hierarchical porous nanostructured materials with desired morphologies have gained remarkable attention for their potential applications in environmental technology. In this study, NiO-SiO2 hollow microspheres were prepared by co-precipitation with SiO2 and nickel salt as precursors, followed by dipping in alkaline solution and calcination. The samples were characterized by X-ray diffraction, field-emission scanning electron microscopy, transmission electron microscopy, Fourier transform infrared spectroscopy, nitrogen adsorption, and X-ray photoelectron spectroscopy. The synthesized hollow spheres were composed of a SiO2 shell and hierarchical porous NiO nanosheets on the surface. Adsorption experiments suggested that NiO-SiO2 composite particles were powerful adsorbents for removal of Congo red from water, with a maximum adsorption capacity of 204.1 mg/g. The high specific surface areas, hollow structures, and hierarchical porous surfaces of the hollow composite particles are suitable for various applications, including adsorption of pollutants, chemical separation, and water purification. Copyright © 2015 Elsevier Inc. All rights reserved.

  1. Novel hollow microspheres of hierarchical zinc-aluminum layered double hydroxides and their enhanced adsorption capacity for phosphate in water

    International Nuclear Information System (INIS)

    Zhou, Jiabin; Yang, Siliang; Yu, Jiaguo; Shu, Zhan

    2011-01-01

    Highlights: → Hierarchical Zn-Al LDHs hollow microspheres were first synthesized by a simple hydrothermal method using urea as precipitating agent. → The morphology of Zn-Al LDHs can be tailored from irregular platelet to hollow microspheres by simply varying concentrations of urea. → The as-prepared samples exhibit high adsorption capacity (54.1-232 mg/g) for phosphate from aqueous solution. - Abstract: Hollow microspheres of hierarchical Zn-Al layered double hydroxides (LDHs) were synthesized by a simple hydrothermal method using urea as precipitating agent. The morphology and microstructure of the as-prepared samples were characterized by X-ray diffraction (XRD), field-emission scanning electron microscopy (FE-SEM), nitrogen adsorption-desorption isotherms and fourier transform infrared (FTIR) spectroscopy. It was found that the morphology of hierarchical Zn-Al LDHs can be tuned from irregular platelets to hollow microspheres by simply varying concentrations of urea. The effects of initial phosphate concentration and contact time on phosphate adsorption using various Zn-Al LDHs and their calcined products (LDOs) were investigated from batch tests. Our results indicate that the equilibrium adsorption data were best fitted by Langmuir isothermal model, with the maximum adsorption capacity of 54.1-232 mg/g; adsorption kinetics follows the pseudo-second-order kinetic equation and intra-particle diffusion model. In addition, Zn-Al LDOs are shown to be effective adsorbents for removing phosphate from aqueous solutions due to their hierarchical porous structures and high specific surface areas.

  2. Facile dicyandiamide-mediated fabrication of well-defined CuO hollow microspheres and their catalytic application

    International Nuclear Information System (INIS)

    Yang Shengyang; Wang Caifeng; Chen Li; Chen Su

    2010-01-01

    Nearly monodisperse CuO hollow microspheres were successfully synthesized by a straightforward one-pot hydrothermal approach using dicyandiamide (DDA) as structure-guiding agent. The composition, structure and morphology of the products were investigated in detail, via a set of characterizations including X-ray diffraction (XRD) pattern, energy dispersive X-ray (EDX), scanning electron microscope (SEM), and transmission electron microscope (TEM). The results demonstrated that different copper sources and experimental procedures would significantly affect the shape or size of CuO products. A possible formation mechanism of CuO microspheres in this process was thoroughly discussed. Also, some other novel CuO microstructures were fabricated based on DDA-mediated synthetic route. DSC/TGA analysis revealed that as-prepared CuO microspheres can be explored as a promising additive to accelerate the thermal decomposition of ammonium perchlorate, a key oxidizer in composite solid propellants.

  3. Upconversion channels in Er3+ ZBLALiP fluoride glass microspheres

    NARCIS (Netherlands)

    O'Shea, D. G.; Ward, J. M.; Shortt, B. J.; Mortier, M.; Feron, P.; Chormaic, S. Nic

    We present results on the realization of a multicolour microspherical glass light source fabricated from the erbium doped fluoride glass ZBLALiP. Whispering gallery mode lasing and upconversion processes give rise to laser and fluorescent emissions at multiple wavelengths from the ultraviolet to the

  4. Pilot trial of Y-90 glass microspheres in the treatment of primary hepatocellular carcinoma

    International Nuclear Information System (INIS)

    Houle, S.; Yip, T.C.K.; Shepherd, F.A.; Rotstein, L.E.; Theis, B.; Cawthorn, R.; Barnes, K.

    1987-01-01

    A pilot trial is currently under way at our institution to determine the potential of new Y-90 glass microspheres (Theraspheres, Theragenics Corp., Atlanta) for the treatment of primary hepatocellular carcinoma. The Y-90 microspheres are injected through a percutaneous hepatic artery catheter positioned angiographically. The injection is facilitated by a new delivery system. Prior to the injection of the Y-90 microspheres, the presence of shunting is assessed by injecting Tc-99m human albumin microspheres (HAM) via the hepatic artery catheter. Bremsstrahlung scans done after injection demonstrate the distribution the Y-90 microspheres within the liver and the lack of extrahepatic activity. In the first group of patients treated, no significant toxicity was demonstrated for absorbed doses between 5,000 and 10,000 rad to the liver, and up to 20,000 rad to the tumor itself

  5. Development of phosphate glass microspheres containing holmium for selective internal radiotherapy

    International Nuclear Information System (INIS)

    Barros Filho, Eraldo Cordeiro

    2016-01-01

    The selective internal radiotherapy is an alternative for some kinds of cancer as the hepatocellular carcinoma (HCC) or primary liver cancer treatment. In this treatment, glass or polymer microspheres containing radionuclides inside their structure are introduced in the liver through hepatic artery and trapped at the arterioles that feed the tumor. In this work, the development of phosphate glasses containing holmium for production of microspheres and their application in Brazil are proposed. The developed glasses presented suitable chemical durability, density of 2,7(3) g/cm 3 , high thermal stability and the impurities contained therein do not preclude the treatment. The microspheres were produced by the flame method and the gravitational fall method, and were characterized by means of several techniques to evaluate shape, average particle size, activity and biocompatibility suitable for selective internal radiotherapy. Based in the main results, the submission to in vivo tests is proposed. (author)

  6. Trapping of microwave radiation in hollow polypyrrole microsphere through enhanced internal reflection: A novel approach

    Science.gov (United States)

    Panigrahi, Ritwik; Srivastava, Suneel K.

    2015-01-01

    In present work, spherical core (polystyrene, PS)/shell (polypyrrole, PPy) has been synthesized via in situ chemical oxidative copolymerization of pyrrole (Py) on the surface of sulfonated PS microsphere followed by the formation of hollow polypyrrole (HPPy) shell by dissolving PS inner core in THF. Thereafter, we first time established that such fabricated novel art of morphology acts as a conducting trap in absorbing electromagnetic (EM) wave by internal reflection. Further studies have been extended on the formation of its silver nanocomposites HPPy/Ag to strengthen our contention on this novel approach. Our investigations showed that electromagnetic interference (EMI) shielding efficiency (SE) of HPPy (34.5-6 dB) is significantly higher compared to PPy (20-5 dB) in the frequency range of 0.5-8 GHz due to the trapping of EM wave by internal reflection. We also observed that EMI shielding is further enhanced to 59-23 in 10 wt% Ag loaded HPPy/Ag-10. This is attributed to the simultaneous contribution of internal reflection as well as reflection from outer surface. Such high EMI shielding capacity using conducting polymers are rarely reported.

  7. Synthesis and characterization of hollow V2O5 microspheres for supercapacitor electrode with pseudocapacitance

    Directory of Open Access Journals (Sweden)

    Zhang Yifu

    2017-02-01

    Full Text Available Hollow V2O5 microspheres (HVOM were fabricated using NH4VO3, ethylene glycol and carbon spheres as the starting materials by a template solvothermal approach and subsequent calcination. The morphology and composition were characterized by field emission scanning electron microscopy (FE-SEM, X-ray powder diffraction (XRD, Fourier transform infrared spectroscopy (FT-IR and Brunauer-Emmet-Teller (BET. The results showed that the obtained HVOM were constructed from nanoparticles with rough surface. The electrochemical properties of HVOM as a supercapacitor electrode were investigated by cyclic voltammetry (CV and galvanostatic charge-discharge (GCD. HVOM displayed excellent pseudocapacitance property and their specific capacitances were 488 F·g–1, 455 F·g–1, 434 F·g–1 and 396 F·g–1 at the current density of 0.5 A·g–1, 1 A·g–1, 2 A·g–1 and 5 A·g–1, respectively. They also exhibited an excellent energy density of 8.784 × 105 J·kg–1 at a power density of 900 W·kg–1 . The good electrochemical properties of the as-synthesized HVOM make them a promising candidate as a cathode material for supercapacitors.

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

    Science.gov (United States)

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

    2016-09-01

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

  9. Development and evaluation of holmium doped phosphate glass microspheres for selective internal radiotherapy

    International Nuclear Information System (INIS)

    Barros Filho, Eraldo C.; Martinelli, Jose Roberto; Squair, Peterson L; Osso Junior, Joao A.; Sene, Frank Ferrer

    2013-01-01

    Selective Internal Radiotherapy is used to treat hepatocellular carcinoma. In this treatment 90 Y -doped aluminosilicate glass microspheres are introduced in the hepatic artery and they migrate to the liver near to the tumor where they are trapped in the arterioles. The radiation β- emitted by the decay of 90 Y annihilates the cancer cells. A macroaggregate of albumin containing technetium is previously used to monitor the lung shunt and to prevent the spreading of 90 Y during the treatment. In the present work, 165 Ho- doped phosphate glass microspheres were developed aiming that application. 165 Ho has high cross section for neutron capture (64 bars) and 166 Ho decays emitting β- radiation with appropriate energy for killing cancer cells, and gamma rays with low energy which can be used to obtain images of the microspheres location and to check possible occurrence of lung shunt. Holmium also is highly paramagnetic and can be used to obtain images whereby NMR. The glass matrix consists of (P 2 O 5 ) tetrahedrons and can be produced by a relatively lower melting temperature of chemical compounds. The 31 P decays by emitting β- radiation and contributes to the absorbed dose, helping to annihilate the cancer cells. The microspheres were produced by using two methods: the flame and the gravitation falling methods to obtain microspheres with appropriate properties. (author)

  10. Synthesis of Y2O2S:Eu3+, Mg2+, Ti4+ hollow microspheres via homogeneous precipitation route

    Directory of Open Access Journals (Sweden)

    Peng-Fei Ai, Ying-Liang Liu, Li-Yuan Xiao, Hou-Jin Wang and Jian-Xin Meng

    2010-01-01

    Full Text Available A phosphorescent material in the form of Y2O2S:Eu3+, Mg2+, Ti4+ hollow microspheres was prepared by homogeneous precipitation using monodispersed carbon spheres as hard templates. Y2O3:Eu3+ hollow microspheres were first synthesized to serve as the precursor. Y2O2S:Eu3+, Mg2+, Ti4+ powders were obtained by calcinating the precursor in a CS2 atmosphere. The crystal structure, morphology and optical properties of the composites were characterized. X-ray diffraction measurements confirmed the purity of the Y2O2S phase. Electron microscopy observations revealed that the Y2O2S:Eu3+, Mg2+, Ti4+ particles inherited the hollow spherical shape from the precursor after being calcined in a CS2 atmosphere and that they had a diameter of 350–450 nm and a wall thickness of about 50–80 nm. After ultraviolet radiation at 265 or 325 nm for 5 min, the particles emitted strong red long-lifetime phosphorescence originating from Eu3+ ions. This phosphorescence is associated with the trapping of charge carriers by Ti4+ and Mg2+ ions.

  11. Magnetic propulsion of microspheres at liquid-glass interfaces

    Science.gov (United States)

    Helgesen, Geir

    2018-02-01

    Bio-coated, magnetic microspheres have many applications in biotechnology and medical technology as a tool to separate and extract cells or molecules in a water solution by applying external strong magnetic field gradients. However, magnetic microspheres with or without attached cargo can also be separated in the liquid solution if they are exposed to alternating or rotating, relatively weak magnetic fields. Microspheres that have a higher density than the liquid will approach the bottom surface of the sample cell, and then a combination of viscous and surface frictional forces can propel the magnetic microspheres along the surface in a direction perpendicular to the axis of field rotation. Experiments demonstrating this type of magnetic propulsion are shown, and the forces active in the process are discussed. The motion of particles inside sample cells that were tilted relative to the horizontal direction was studied, and the variation of propulsion velocity as a function of tilt angle was used to find the values of different viscous and mechanical parameters of motion. Propulsion speeds of up to 5 μm/s were observed and were found to be caused by a partly rolling and partly slipping motion of rotating microspheres with a slipping coefficient near 0.6.

  12. Preparation of carbon nanotubes/epoxy resin composites by using hollow glass beads as the carrier

    International Nuclear Information System (INIS)

    Wu, X.F.; Zhao, Y.K.; Zhang, D.; Chen, T.B.; Ma, L.Y.

    2012-01-01

    Hollow glass beads had been utilized as the carrier to assist dispersion of carbon nanotubes in epoxy resin. Hollow glass beads were firstly aminated with gamma-aminopropyl-triethoxysilane, sencondly reacted with carboxyl-functionalized carbon nanotubes via an amidation reaction and susequently mixed with epoxy resin and hardener. The experimental results showed that carbon nanotubes could be loaded on the surfaces of hollow glass beads and approximately a monolayer of carbon nanotubes was formed when the weight ratio of hollow glass beads to carbon nanotubes was 100:5. Moreover, the dispersity of carbon nanotubes in the matrix was improved as compared to the control samples prepared by using a conventional mixing method. (author)

  13. Hierarchical assembly of urchin-like alpha-iron oxide hollow microspheres and molybdenum disulphide nanosheets for ethanol gas sensing.

    Science.gov (United States)

    Zhang, Dongzhi; Fan, Xin; Yang, Aijun; Zong, Xiaoqi

    2018-08-01

    In this paper, we fabricated a high-performance ethanol sensor using layer-by-layer self-assembled urchin-like alpha-iron oxide (α-Fe 2 O 3 ) hollow microspheres/molybdenum disulphide (MoS 2 ) nanosheets heterostructure as sensitive materials. The nanostructural, morphological, and compositional properties of the as-prepared α-Fe 2 O 3 /MoS 2 heterostructure were characterized by X-ray diffraction (XRD), energy dispersive spectrometer (EDS), scanning electron microscopy (SEM), transmission electron microscope (TEM) and X-ray photoelectron spectroscopy (XPS), which confirmed its successful preparation and rationality. The α-Fe 2 O 3 /MoS 2 nanocomposite sensor shows good selectivity, excellent reproducibility, fast response/recovery time and low detection limit towards ethanol gas at room temperature, which is superior to the single component of α-Fe 2 O 3 hollow microspheres and MoS 2 nanosheets. Furthermore, the response of the α-Fe 2 O 3 /MoS 2 nanocomposite sensor as a function of ethanol gas concentration was also demonstrated. The enhanced ethanol sensing properties of the α-Fe 2 O 3 /MoS 2 nanocomposite sensor were ascribed to the synergistic effect and heterojunction between the urchin-Like α-Fe 2 O 3 hollow microspheres and MoS 2 nanosheets. This work verifies that the hierarchical α-Fe 2 O 3 /MoS 2 nanoheterostructure is a potential candidate for fabricating room-temperature ethanol gas sensor. Copyright © 2018 Elsevier Inc. All rights reserved.

  14. Self-templated Synthesis of Nickel Silicate Hydroxide/Reduced Graphene Oxide Composite Hollow Microspheres as Highly Stable Supercapacitor Electrode Material.

    Science.gov (United States)

    Zhang, Yanhua; Zhou, Wenjie; Yu, Hong; Feng, Tong; Pu, Yong; Liu, Hongdong; Xiao, Wei; Tian, Liangliang

    2017-12-01

    Nickel silicate hydroxide/reduced graphene oxide (Ni 3 Si 2 O 5 (OH) 4 /RGO) composite hollow microspheres were one-pot hydrothermally synthesized by employing graphene oxide (GO)-wrapped SiO 2 microspheres as the template and silicon source, which were prepared through sonication-assisted interfacial self-assembly of tiny GO sheets on positively charged SiO 2 substrate microspheres. The composition, morphology, structure, and phase of Ni 3 Si 2 O 5 (OH) 4 /RGO microspheres as well as their electrochemical properties were carefully studied. It was found that Ni 3 Si 2 O 5 (OH) 4 /RGO microspheres featured distinct hierarchical porous morphology with hollow architecture and a large specific surface area as high as 67.6 m 2  g -1 . When utilized as a supercapacitor electrode material, Ni 3 Si 2 O 5 (OH) 4 /RGO hollow microspheres released a maximum specific capacitance of 178.9 F g -1 at the current density of 1 A g -1 , which was much higher than that of the contrastive bare Ni 3 Si 2 O 5 (OH) 4 hollow microspheres and bare RGO material developed in this work, displaying enhanced supercapacitive behavior. Impressively, the Ni 3 Si 2 O 5 (OH) 4 /RGO microsphere electrode exhibited outstanding rate capability and long-term cycling stability and durability with 97.6% retention of the initial capacitance after continuous charging/discharging for up to 5000 cycles at the current density of 6 A g -1 , which is superior or comparable to that of most of other reported nickel-based electrode materials, hence showing promising application potential in the energy storage area.

  15. Optical bistability in Er-Yb codoped phosphate glass microspheres at room temperature

    NARCIS (Netherlands)

    Warda, Jonathan M.; O'Shea, Danny G.; Shortt, Brian J.; Chormaic, Sile Nic

    2007-01-01

    We experimentally demonstrate optical bistability in Er(3+)-Yb(3+) phosphate glass microspheres at 295 K. Bistability is associated with both Er(3+) fluorescence and lasing behavior, and chromatic switching. The chromatic switching results from an intrinsic mechanism exploiting the thermal coupling

  16. Synthesis, characterization and photocatalytic activity of porous WO3/TiO2 hollow microspheres

    International Nuclear Information System (INIS)

    Yang, Liuyang; Si, Zhichun; Weng, Duan; Yao, Youwei

    2014-01-01

    Porous WO 3 /TiO 2 hollow microspheres were prepared by a spray drying method for photodegradation of methylene blue and phenol. The catalysts were characterized by X-ray diffraction, Field Emission Scanning Electron Microscope, High Resolution Transmission Electron Microscope, N 2 adsorption–desorption measurements, Raman spectrometer, UV–Vis Diffuse Reflectance Spectroscopy and Zeta-Meter measurements. The results showed that the tungsten oxides mainly existed in highly dispersed amorphous form on anatase when the loading amount of tungsten oxide was below 3 mol%. The improved photocatalytic activity under UV light irradiation of the WO 3 /TiO 2 catalyst mainly arises from the enhanced charge separation efficiency rather than the improved light absorbance by highly dispersed amorphous tungsten oxides. Highly dispersed amorphous WO x can form a shallowly trapped site due to its similar band structure with TiO 2 . The strongly electron-withdrawing of tungsten oxide in highly dispersed state facilitates the electron transition between titanium and WO x , and consequently improves the charge separation. The enhanced acidity of catalyst by WO x in reactant environment also improved the charge separation efficiency due to the timely transition of holes and electrons accumulated on TiO 2 and WO x , respectively. However, the improved photocatalytic activity under visible light irradiation of the WO 3 /TiO 2 catalyst mainly arises from light harvest. TiO 2 containing 3 mol% WO 3 displayed the highest photocatalytic activity under UV light irradiation while that containing 4 mol% WO 3 present highest activity under visible light irradiation

  17. A method for preparing a sintered glass powder for manufacturing microspheres

    International Nuclear Information System (INIS)

    Budrick, R.G.; King, F.T.; Nolen, R.L. Jr.; Solomon, D.E.

    1975-01-01

    The invention relates to the manufacture of sintered glass-powder. It relates to a method comprising the step of forming a vitreous gel so that it contains an occluded substance adapted to expand when heated, said gel being subsequently dried, then crushed and sorted prior to being washed and dried again. Application to the manufacture of sintered glass-powder for forming microspheres adapted to contain a thermonuclear fuel [fr

  18. Microstructure and magnetic properties of yttrium alumina silicate glass microspheres containing iron oxide

    International Nuclear Information System (INIS)

    Sharma, K.; Basak, C.B.; Prajapat, C.L.; Singh, M.R.

    2015-01-01

    Yttrium alumino-silicate glass microspheres have been used for localized delivery of high radiation dose to tissues in the treatment of hepatocellular carcinoma (BCC) and synovitis. 90 Y is a pure beta emitter with beta emission energy of 0.9367 MeV, average penetration range in tissue 2.5 mm, physical half-life of 64.2 h, thus an effective radioisotope for delivering high radiation dose to the tumor. The efficacy of radiotherapy can further be improved if the glass microspheres are doped with magnetic particles for targeted delivery of high radiation dose. Magnetic glass microspheres can also be utilized for cancer treatment using the magnetic heating of tumor cell. The magnetic glass microspheres are obtained from the glasses with nominal composition (64-x) SiO 2 -17Y 2 O 3 -19 Al 2 O 3 -xFe 2 O 3 (x=4-16 mol %). Density of glasses increases from 3.5g/cc to 3.8g/cc as iron oxide content is increased from 4 to 16 mol %. The glass transition temperature and peak crystallization temperature decreases as the iron oxide content increases. T g values of glass samples decreases with increase of Fe 2 O 3 , while SiO 2 content is decreased. SiO 2 is a network forming oxide and a decrease in the network former in glass lead to decrease in thermo-physical properties like T g . The development of ferrimagnetic crystallites in glasses arise from the conversion of iron oxide into magnetite, magnemite and hematite, which is influenced by the structural and ordering of magnetic particles. The microstructure of glass-ceramic exhibited the formation of 50-100 nm size particles. The magnetite and hematite are formed as major crystalline phases. The magnetization values increased with an increase of iron oxide content and attributed to formation of magnetite phase. Results have shown that the glass microspheres with magnetic properties can be used as potential materials for cancer treatment. (author)

  19. The behaviour of selected yttrium containing bioactive glass microspheres in simulated body environments.

    Science.gov (United States)

    Cacaina, D; Ylänen, H; Simon, S; Hupa, M

    2008-03-01

    The study aims at the manufacture and investigation of biodegradable glass microspheres incorporated with yttrium potentially useful for radionuclide therapy of cancer. The glass microspheres in the SiO2-Na2O-P2O5-CaO-K2O-MgO system containing yttrium were prepared by conventional melting and flame spheroidization. The behaviour of the yttrium silicate glass microspheres was investigated under in vitro conditions using simulated body fluid (SBF) and Tris buffer solution (TBS), for different periods of time, according to half-life time of the Y-90. The local structure of the glasses and the effect of yttrium on the biodegradability process were evaluated by Fourier Transform Infrared (FT-IR) spectroscopy and Back Scattered Electron Imaging of Scanning Electron Microscopy (BEI-SEM) equipped with Energy Dispersive X-ray (EDX) analysis. UV-VIS spectrometry and Inductively Coupled Plasma Mass Spectrometry (ICP-MS) was used for analyzing the release behaviour of silica and yttrium in the two used solutions. The results indicate that the addition of yttrium to a bioactive glass increases its structural stability which therefore, induced a different behaviour of the glasses in simulated body environments.

  20. Synthesis and electrochemical properties of porous double-shelled Mn2O3 hollow microspheres as a superior anode material for lithium ion batteries

    International Nuclear Information System (INIS)

    Qiao, Yu; Yu, Yan; Jin, Yi; Guan, Yi-Biao; Chen, Chun-Hua

    2014-01-01

    Highlights: • Double-shelled Mn 2 O 3 hollow microspheres are prepared by a multi-step. • synthesis procedure. • Solid, hollow and yolk-structured Mn 2 O 3 spheres are prepared for comparison. • The double-shelled hollow Mn 2 O 3 is superior in electrochemical properties. - Abstract: By means of a specially designed multi-step synthesis procedure involving steps of precipitation, controlled oxidation, selective etching and calcination, porous double-shelled Mn 2 O 3 hollow microspheres are synthesized. Solid, hollow and yolk-structured Mn 2 O 3 are also similarly synthesized for comparison. X-ray diffraction, scanning and transmission electron microscopies, IR spectroscopy, thermogravimetry, and Brunauer-Emmett-Teller measurements are employed to investigate their structures and compositions. Galvanostatic cell cycling and impedance spectroscopy are used to characterize the electrochemical properties of Mn 2 O 3 /Li cells. The results show that the hierarchical hollow structured (double-shelled, hollow and yolk-structured) Mn 2 O 3 anode materials deliver higher reversible capacities and excellent cycling stabilities than the solid Mn 2 O 3 . Moreover, among the three hierarchical hollow structured samples, the double shelled sample possesses the best cycling performance, especially at a high current density

  1. Li and Na storage behavior of bowl-like hollow Co3O4 microspheres as an anode material for lithium-ion and sodium-ion batteries

    International Nuclear Information System (INIS)

    Wen, Jian-Wu; Zhang, Da-Wei; Zang, Yong; Sun, Xin; Cheng, Bin; Ding, Chu-Xiong; Yu, Yan; Chen, Chun-Hua

    2014-01-01

    Highlights: • A unique bowl-like hollow spherical Co 3 O 4 structure is prepared through a simple, low-cost and mass-yield method. • Such a bowl-like hollow Co 3 O 4 microsphere demonstrates extraordinary rate and cycling performance for Li-storage. • The sodium-storage behavior of Co 3 O 4 is investigated for the first time. - Abstract: Bowl-like hollow Co 3 O 4 microspheres are prepared via a simple and low-cost route by thermally treating Co-containing resorcinol-formaldehyde composites gel in air. Scanning electron microscopy, transmission electron microscope and N 2 adsorption-desorption measurements demonstrate that these bowl-like hollow Co 3 O 4 microspheres are composed of hollow inner cavities and outer shell walls (70 nm thickness), on which a considerable amount of mesopores centered around 5-17 nm size are distributed. When employed as the anode material for lithium-ion batteries, these bowl-like hollow Co 3 O 4 microspheres exhibit extraordinary cycling performance (111% retention after 50 cycles owing to capacity rise), fairly high rate capacity (650 mAh g −1 at 5 C) and enhanced lithium storage capacity. Meanwhile, the Na-storage behavior of Co 3 O 4 as an anode material of Na-ion batteries is initially investigated based on such a hollow structure and it exhibits similar feature of discharge/charge profiles and a high initial discharge capacity but relatively moderate capacity retention compared with the Li-storage performance

  2. One-pot hydrothermal synthesis of hollow Fe3O4 microspheres assembled with nanoparticles for lithium-ion battery anodes

    DEFF Research Database (Denmark)

    Liu, Yanguo; Wang, Xiaoliang; Ma, Wuming

    2016-01-01

    Hollow Fe3O4 microspheres assembled with nanoparticles were successfully synthesized without the addition of any templates or subsequent treatments. When used as the anode materials for lithium-ion battery (LIB), the products showed good lithium storage properties, demonstrating their promising...

  3. Preparation of hollow microspheres of Ce{sup 3+} doped NiCo ferrite with high microwave absorbing performance

    Energy Technology Data Exchange (ETDEWEB)

    Duan, Hong-zhen, E-mail: duanhz2000@163.com; Zhou, Fang-ling; Cheng, Xia; Chen, Guo-hong; Li, Qiao-ling

    2017-02-15

    Hollow microspheres of Ce{sup 3+} doped NiCo-ferrites were synthesized by template-based-deposition and surface reaction method with carbon sphere as the template. The phase structure, morphology, magnetic properties and wave absorbing properties of the sample were characterized by X-ray powder diffraction(XRD), Scanning electronic microscopy(SEM), Vibration sample magnetometer (VSM) and a network vector analyzer (NVA), respectively. The results indicated that the particle size of the carbon sphere sample prepared by hydrothermal method was about 0.5 µm and the particle size of the Ni{sub 0.5}Co{sub 0.5}Fe{sub 2}O{sub 4} sample prepared by template-based method was about 300 nm. The influence of the amount of rare earth element on the magnetic and absorbing properties of sample was studied. The saturation magnetization and coercivity decreased gradually with the increase of the content of Ce. When the content of Ce was 0.02, the maximal saturation magnetization value and coercivity was 75.72 emu• g{sup −1} and 789.88 Oe, respectively. The associated ferrite hollow spheres have good absorbing performance, and the return loss value was −18.8 dB at 5500 MHz. - Highlights: • Hollow microspheres of Ce{sup 3+} doped NiCo-ferrites were synthesized by template-based-deposition and surface reaction method. • The influence of rare earth Ce{sup 3+} on the magnetic and absorbing properties of sample was studied. • When the content of Ce was 0.02, the maximal saturation magnetization value and coercivity was 75.72 emu• g{sup −1} and 789.88 Oe, respectively.

  4. Green and facile fabrication of hollow porous MnO/C microspheres from microalgaes for lithium-ion batteries.

    Science.gov (United States)

    Xia, Yang; Xiao, Zhen; Dou, Xiao; Huang, Hui; Lu, Xianghong; Yan, Rongjun; Gan, Yongping; Zhu, Wenjun; Tu, Jiangping; Zhang, Wenkui; Tao, Xinyong

    2013-08-27

    Hollow porous micro/nanostructures with high surface area and shell permeability have attracted tremendous attention. Particularly, the synthesis and structural tailoring of diverse hollow porous materials is regarded as a crucial step toward the realization of high-performance electrode materials, which has several advantages including a large contact area with electrolyte, a superior structural stability, and a short transport path for Li(+) ions. Meanwhile, owing to the inexpensive, abundant, environmentally benign, and renewable biological resources provided by nature, great efforts have been devoted to understand and practice the biotemplating technology, which has been considered as an effective strategy to achieve morphology-controllable materials with structural specialty, complexity, and related unique properties. Herein, we are inspired by the natural microalgae with its special features (easy availability, biological activity, and carbon sources) to develop a green and facile biotemplating method to fabricate monodisperse MnO/C microspheres for lithium-ion batteries. Due to the unique hollow porous structure in which MnO nanoparticles were tightly embedded into a porous carbon matrix and form a penetrative shell, MnO/C microspheres exhibited high reversible specific capacity of 700 mAh g(-1) at 0.1 A g(-1), excellent cycling stability with 94% capacity retention, and enhanced rate performance of 230 mAh g(-1) at 3 A g(-1). This green, sustainable, and economical strategy will extend the scope of biotemplating synthesis for exploring other functional materials in various structure-dependent applications such as catalysis, gas sensing, and energy storage.

  5. Investigation of emulsified, acid and acid-alkali catalyzed mesoporous bioactive glass microspheres for bone regeneration and drug delivery

    Energy Technology Data Exchange (ETDEWEB)

    Miao, Guohou [School of Materials Science and Engineering, South China University of Technology, Guangzhou 510641 China (China); National Engineering Research Center for Tissue Restoration and Reconstruction, Guangzhou 510006 China (China); Guangdong Province Key Laboratory of Biomedical Engineering, South China University of Technology, Guangzhou 510006 China (China); Chen, Xiaofeng, E-mail: chenxf@scut.edu.cn [School of Materials Science and Engineering, South China University of Technology, Guangzhou 510641 China (China); National Engineering Research Center for Tissue Restoration and Reconstruction, Guangzhou 510006 China (China); Guangdong Province Key Laboratory of Biomedical Engineering, South China University of Technology, Guangzhou 510006 China (China); Dong, Hua [National Engineering Research Center for Tissue Restoration and Reconstruction, Guangzhou 510006 China (China); Guangdong Province Key Laboratory of Biomedical Engineering, South China University of Technology, Guangzhou 510006 China (China); School of Biological Science and Engineering, South China University of Technology, Guangzhou 510006 (China); Fang, Liming; Mao, Cong; Li, Yuli; Li, Zhengmao; Hu, Qing [School of Materials Science and Engineering, South China University of Technology, Guangzhou 510641 China (China); National Engineering Research Center for Tissue Restoration and Reconstruction, Guangzhou 510006 China (China); Guangdong Province Key Laboratory of Biomedical Engineering, South China University of Technology, Guangzhou 510006 China (China)

    2013-10-15

    Acid-catalyzed mesoporous bioactive glass microspheres (MBGMs-A) and acid-alkali co-catalyzed mesoporous bioactive glass microspheres (MBGMs-B) were successfully synthesized via combination of sol-gel and water-in-oil (W/O) micro-emulsion methods. The structural, morphological and textural properties of mesoporous bioactive glass microspheres (MBGMs) were characterized by various techniques. Results show that both MBGMs-A and MBGMs-B exhibit regularly spherical shape but with different internal porous structures, i.e., a dense microstructure for MBGMs-A and internally porous structure for MBGMs-B. {sup 29}Si NMR data reveal that MGBMs have low polymerization degree of silica network. The in vitro bioactivity tests indicate that the apatite formation rate of MBGMs-B was faster than that of MBGMs-A after soaking in simulated body fluid (SBF) solution. Furthermore, the two kinds of MBGMs have similar storage capacity of alendronate (AL), and the release behaviors of AL could be controlled due to their unique porous structure. In conclusion, the microspheres are shown to be promising candidates as bone-related drug carriers and filling materials of composite scaffold for bone repair. - Graphical abstract: The morphologies and microstructures of acid-catalyzed mesoporous bioactive glass microspheres (MBGMs-A) and acid-alkali co-catalyzed mesoporous bioactive glass microspheres (MBGMs-B) were observed by scanning electron microscope and transmission electron microscope. MBGMs-A exhibits a dense structure and a porous can be observed in MBGMs-B. The microspheres have a quick inducing-apatite formation ability and show a sustained release of alendronate (AL). Highlights: • A rapid method was reported to prepare mesoporous bioactive glass microspheres. • The addition of ammonia significantly shortens the preparation time. • Acid and acid-alkali co-catalyzed microspheres were studied for the first time. • The materials exhibited excellent in vitro bioactivity and

  6. Production and Characterization of Glass Microspheres for Hepatic Cancer Treatment

    OpenAIRE

    Bortot, M. B.; Prastalo, S.; Prado, Miguel Oscar

    2017-01-01

    A simple theoretical mathematical model was developed to assess the process of glass particles spheroidization in a propane-butane-oxygen flame. The model has been designed to gain a better understanding of the dependency amongst the variables that come into play during glass spheroidization. Using the model and theoretical values of: glass viscosity, density, shear modulus, thermal conductivity as well as measured values of the temperature of the flame at different positions, particle size a...

  7. Controlled Synthesis of Heterostructured SnO2-CuO Composite Hollow Microspheres as Efficient Cu-Based Catalysts for the Rochow Reaction

    Directory of Open Access Journals (Sweden)

    Hezhi Liu

    2018-04-01

    Full Text Available In this work, we report the design and synthesis of a series of heterostructured SnO2-CuO hollow microspherical catalysts (H-SnO2(x-CuO, x is the weight ratio of Sn/Cu for the Rochow reaction. The microspherical catalysts with nanosheets and nanoparticles as building blocks were prepared by a facile one-pot hydrothermal method coupled with calcination. When tested for the Rochow reaction, the prepared H-SnO2(0.2-CuO composite exhibited higher dimethyldichlorosilane selectivity (88.2% and Si conversion (36.7% than the solid CuO, hollow CuO and other H-SnO2(x-CuO microspherical samples, because in the former there is a stronger synergistic interaction between CuO and SnO2.

  8. Embedding of Hollow Polymer Microspheres with Hydrophilic Shell in Nafion Matrix as Proton and Water Micro-Reservoir

    Directory of Open Access Journals (Sweden)

    Zhaolin Liu

    2012-08-01

    Full Text Available Assimilating hydrophilic hollow polymer spheres (HPS into Nafion matrix by a loading of 0.5 wt % led to a restructured hydrophilic channel, composed of the pendant sulfonic acid groups (–SO3H and the imbedded hydrophilic hollow spheres. The tiny hydrophilic hollow chamber was critical to retaining moisture and facilitating proton transfer in the composite membranes. To obtain such a tiny cavity structure, the synthesis included selective generation of a hydrophilic polymer shell on silica microsphere template and the subsequent removal of the template by etching. The hydrophilic HPS (100–200 nm possessed two different spherical shells, the styrenic network with pendant sulfonic acid groups and with methacrylic acid groups, respectively. By behaving as microreservoirs of water, the hydrophilic HPS promoted the Grotthus mechanism and, hence, enhanced proton transport efficiency through the inter-sphere path. In addition, the HPS with the –SO3H borne shell played a more effective role than those with the –CO2H borne shell in augmenting proton transport, in particular under low humidity or at medium temperatures. Single H2-PEMFC test at 70 °C using dry H2/O2 further verified the impactful role of hydrophilic HPS in sustaining higher proton flux as compared to pristine Nafion membrane.

  9. Preparation and crystallization of hollow α-Fe{sub 2}O{sub 3} microspheres following the gas-bubble template method

    Energy Technology Data Exchange (ETDEWEB)

    Valladares, L. de los Santos, E-mail: ld301@cam.ac.uk [Cavendish Laboratory, Department of Physics, University of Cambridge, J.J Thomson Av., Cambridge, CB3 0HE (United Kingdom); León Félix, L. [Laboratorio de Cerámicos y Nanomateriales, Facultad de Ciencias Físicas, Universidad Nacional Mayor de San Marcos, Ap. Postal 14-0149, Lima (Peru); Laboratory of Magnetic Characterization, Instituto de Física, Universidade de Brasília, DF 70910-900, Brasilia (Brazil); Espinoza Suarez, S.M.; Bustamante Dominguez, A.G. [Laboratorio de Cerámicos y Nanomateriales, Facultad de Ciencias Físicas, Universidad Nacional Mayor de San Marcos, Ap. Postal 14-0149, Lima (Peru); Mitrelias, T.; Holmes, S. [Cavendish Laboratory, Department of Physics, University of Cambridge, J.J Thomson Av., Cambridge, CB3 0HE (United Kingdom); Moreno, N.O. [Departamento de Física, Universidade Federal de Sergipe, 49100-000, Sao Cristóvao, Sergipe (Brazil); Albino Aguiar, J. [Laboratório de Supercondutividade e Materiais Avançados, Departamento de Física, Universidade Federal de Pernambuco, 50670-901, Recife (Brazil); Barnes, C.H.W. [Cavendish Laboratory, Department of Physics, University of Cambridge, J.J Thomson Av., Cambridge, CB3 0HE (United Kingdom)

    2016-02-01

    In this work we report the formation of hollow α-Fe{sub 2}O{sub 3} (hematite) microspheres by the gas-bubble template method. This technique is simple and it does not require hard templates, surfactants, special conditions of atmosphere or complex steps. After reacting Fe(NO{sub 3}){sub 3}.9H{sub 2}O and citric acid in water by sol–gel, the precursor was annealed in air at different temperatures between 180 and 600 °C. Annealing at 550 and 600 °C generates bubbles on the melt which crystallize and oxidizes to form hematite hollow spheres after quenching. The morphology and crystal evolution are studied by means of X-ray diffraction and scanning electron microscopy. We found that after annealing at 250–400 °C, the sample consist of a mixture of magnetite, maghemite and hematite. Single hematite phase in the form of hollow microspheres is obtained after annealing at 550 and 600 °C. The crystallization and crystal size of the hematite shells increase with annealing temperature. A possible mechanism for hollow sphere formation is presented. - Highlights: • Formation of hollow hematite microspheres by the gas-bubble template method. • This technique does not require hard templates or special conditions of atmosphere. • Annealing promotes the transition magnetite to maghemite to hematite. • Crystallization of the hematite shells increase with annealing temperature.

  10. Rational design of anatase TiO2 architecture with hierarchical nanotubes and hollow microspheres for high-performance dye-sensitized solar cells

    Science.gov (United States)

    Gu, Jiuwang; Khan, Javid; Chai, Zhisheng; Yuan, Yufei; Yu, Xiang; Liu, Pengyi; Wu, Mingmei; Mai, Wenjie

    2016-01-01

    Large surface area, sufficient light-harvesting and superior electron transport property are the major factors for an ideal photoanode of dye-sensitized solar cells (DSSCs), which requires rational design of the nanoarchitectures and smart integration of state-of-the-art technologies. In this work, a 3D anatase TiO2 architecture consisting of vertically aligned 1D hierarchical TiO2 nanotubes (NTs) with ultra-dense branches (HTNTs, bottom layer) and 0D hollow TiO2 microspheres with rough surface (HTS, top layer) is first successfully constructed on transparent conductive fluorine-doped tin oxide glass through a series of facile processes. When used as photoanodes, the DSSCs achieve a very large short-current density of 19.46 mA cm-2 and a high overall power conversion efficiency of 8.38%. The remarkable photovoltaic performance is predominantly ascribed to the enhanced charge transport capacity of the NTs (function as the electron highway), the large surface area of the branches (act as the electron branch lines), the pronounced light harvesting efficiency of the HTS (serve as the light scattering centers), and the engineered intimate interfaces between all of them (minimize the recombination effect). Our work demonstrates a possibility of fabricating superior photoanodes for high-performance DSSCs by rational design of nanoarchitectures and smart integration of multi-functional components.

  11. A hierarchically assembled mesoporous ZnO hemisphere array and hollow microspheres for photocatalytic membrane water filtration.

    Science.gov (United States)

    Pan, Jia Hong; Zhang, Xiwang; Du, Alan J; Bai, Hongwei; Ng, Jiawei; Sun, Darren

    2012-05-28

    A mesoporous ZnO hemisphere array has been prepared via a topotactic transition of Zn(4)(OH)(6)CO(3)·H(2)O (ZCHH) by chemical bath deposition. Each hemisphere is comprised of a radially oriented nanoflake shell grown on the hemispherical interior. Reaction time-dependent SEM analysis shows that the morphological formation of ZCHH involves a deposition-growth-secondary growth-redeposition procedure. Upon calcination, ZCHH readily decomposes to nanocrystalline wurtzite-phase ZnO without significant change in morphology, and the release of CO(2) and H(2)O from ZCHH creates an additional mesoporous structure in both hemispherical interior and nanoflake shell. A similar process but without using a substrate has been developed for synthesis of mesoporous ZnO hollow microspheres in powder form. Both the elaborated superstructured photocatalysts consisting of mesoporous nanoflakes have been demonstrated to exhibit excellent performances in the photocatalytic membrane filtration.

  12. Facile synthesis of α-Fe{sub 2}O{sub 3}@ porous hollow yeast-based carbonaceous microspheres for fluorescent whitening agent-VBL wastewater treatment

    Energy Technology Data Exchange (ETDEWEB)

    Zheng, Pei; Tong, Zhiqing [College of Environmental Science and Engineering, Chang' an University, Xi' an 710054 (China); Bai, Bo, E-mail: baibochina@163.com [Key Laboratory of Tibetan Medicine Research, Northwest Plateau Institute of Biology, Chinese Academy of Sciences, Xining 810001 (China)

    2016-03-15

    Porous hollow carbonaceous microspheres (PHCMs) fabricated from yeast cells by hydrothermal treatment have stimulated interest because of their outstanding chemical and physical properties. Herein, the functionalizations of PHCMs by further coating of α-Fe{sub 2}O{sub 3} nanoparticles onto the surface were carried out. The structure of resulted α-Fe{sub 2}O{sub 3}@PHCMs products were characterized by field emission scanning electron microscopy (FE-SEM), energy dispersive spectrometry (EDS), X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR), and BET specific surface area measurements (BET), respectively. Its promising application was evaluated by the Fenton-like degradation of fluorescent whitening agent-VBL from aqueous solutions. - Graphical abstract: In this work, novel α-Fe{sub 2}O{sub 3}@porous hollow carbonaceous microspheres (α-Fe{sub 2}O{sub 3}@PHCMs) were synthesized through a combination of hydrothermal method and calcinations route and achieved excellent removal efficiency for fluorescent whitening Agent-VBL. - Highlights: • The hybrid α-Fe{sub 2}O{sub 3}@ porous hollow microspheres (PHCMs) were firstly fabricated. • The formation mechanism of α-Fe{sub 2}O{sub 3}@PHCMs microspheres was proposed and verified. • Dithizone played a key role in the synthesis of α-Fe{sub 2}O{sub 3}@PHCMs composites. • A favorable removal for the fluorescent whitening agent-VBL were achieved.

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

    Science.gov (United States)

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

    2013-07-01

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

  14. Ag/α-Fe2O3 hollow microspheres: Preparation and application for hydrogen peroxide detection

    Science.gov (United States)

    Kang, Xinyuan; Wu, Zhiping; Liao, Fang; Zhang, Tingting; Guo, Tingting

    2015-09-01

    In this paper, we demonstrated a simple approach for preparing α-Fe2O3 hollow spheres by mixing ferric nitrate aqueous and glucose in 180 °C. The glucose was found to act as a soft template in the process of α-Fe2O3 hollow spheres formation. Ag/α-Fe2O3 hollow nanocomposite was obtained under UV irradiation without additional reducing agents or initiators. Synthesized Ag/α-Fe2O3 hollow composites exhibited remarkable catalytic performance toward H2O2 reduction. The electrocatalytic activity mechanism of Ag/α-Fe2O3/GCE were discussed toward the reduction of H2O2 in this paper.

  15. Investigating the effect of silver coating on the solubility, antibacterial properties, and cytocompatibility of glass microspheres.

    Science.gov (United States)

    Haas, L M; Smith, C M; Placek, L M; Hall, M M; Gong, Y; Mellott, N P; Wren, Anthony W

    2015-10-01

    Silver (Ag) coatings have been incorporated into many medical materials due to its ability to eradicate harmful microbes. In this study, glass microspheres (SiO2-Na2O-CaO-Al2O3) were synthesized and employed as substrates to investigate the effect Ag coating has on glass solubility and the subsequent biological effects. Initially, glasses were amorphous with a glass transition point (T(g)) of 605℃ and microspheres were spherical with a mean particle diameter of 120 µm (±27). The Ag coating was determined to be crystalline in nature and its presence was confirmed using scanning electron microscopy and X-ray photoelectron spectroscopy. Ion release determined that Ag-coated (Ag-S) microspheres increased the Na(+) release rate but slightly reduced the Ca(2+) and Si(4+) release compared to an uncoated control (UC-S). Additionally, the Ag-S reduced the pH to just above neutral (7.3-8.5) compared to the UC-S (7.7-9.1). Antibacterial testing determined significant reductions in planktonic Escherichia coli (p = 0.000), Staphylococcus epidermidis (p = 0.000) and Staphylococcus aureus (p = 0.000) growth as a function of the presence of Ag and with respect to maturation (1, 7, and 30 days). Testing for toxicity levels using L929 Fibroblasts determined higher cell viability for the Ag-S at lower concentrations (5 µg/ml); in addition, no significant reduction in cell viability was observed with higher concentrations (15, 30 µg/ml). © The Author(s) 2015.

  16. Yttrium-90 Selective Internal Radiation Therapy with Glass Microspheres for Hepatocellular Carcinoma: Current and Updated Literature Review

    International Nuclear Information System (INIS)

    Lee, Edward Wolfgang; Alanis, Lourdes; Cho, Sung-Ki; Saab, Sammy

    2016-01-01

    Hepatocellular carcinoma is the most common primary liver cancer and it represents the majority of cancer-related deaths in the world. More than 70% of patients present at an advanced stage, beyond potentially curative options. Ytrrium-90 selective internal radiation therapy (Y90-SIRT) with glass microspheres is rapidly gaining acceptance as a potential therapy for intermediate and advanced stage primary hepatocellular carcinoma and liver metastases. The technique involves delivery of Y90 infused glass microspheres via the hepatic arterial blood flow to the appropriate tumor. The liver tumor receives a highly concentrated radiation dose while sparing the healthy liver parenchyma due to its preferential blood supply from portal venous blood. There are two commercially available devices: TheraSphere® and SIR-Spheres®. Although, Y90-SIRT with glass microspheres improves median survival in patients with intermediate and advanced hepatocellular carcinoma and has the potential to downstage hepatocellular carcinoma so that the selected candidates meet the transplantable criteria, it has not gained widespread acceptance due to the lack of large randomized controlled trials. Currently, there are various clinical trials investigating the use of Y90-SIRT with glass microspheres for treatment of hepatocellular carcinoma and the outcomes of these trials may result in the incorporation of Y90-SIRT with glass microspheres into the treatment guidelines as a standard therapy option for patients with intermediate and advanced stage hepatocellular carcinoma

  17. Yttrium-90 selective internal radiation therapy with glass microspheres for hepatocellular carcinoma: Current and updated literature review

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Edward Wolfgang; Alanic, Lourdes [Div. of Interventional Radiology, Dept. of Radiology, UCLA Medical Center, David Geffen School of Medicine at UCLA, Los Angeles (United States); Cho, Sung Ki [Div. of Interventional Radiology, Dept. of Radiology, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul (Korea, Republic of); Saab, Sammy [Div. of Hepatology, Dept. of Medicine, Pfleger Liver Institute, University of California at Los Angeles, Los Angeles (United States)

    2016-07-15

    Hepatocellular carcinoma is the most common primary liver cancer and it represents the majority of cancer-related deaths in the world. More than 70% of patients present at an advanced stage, beyond potentially curative options. Ytrrium-90 selective internal radiation therapy (Y90-SIRT) with glass microspheres is rapidly gaining acceptance as a potential therapy for intermediate and advanced stage primary hepatocellular carcinoma and liver metastases. The technique involves delivery of Y90 infused glass microspheres via the hepatic arterial blood flow to the appropriate tumor. The liver tumor receives a highly concentrated radiation dose while sparing the healthy liver parenchyma due to its preferential blood supply from portal venous blood. There are two commercially available devices: TheraSphere® and SIR-Spheres®. Although, Y90-SIRT with glass microspheres improves median survival in patients with intermediate and advanced hepatocellular carcinoma and has the potential to downstage hepatocellular carcinoma so that the selected candidates meet the transplantable criteria, it has not gained widespread acceptance due to the lack of large randomized controlled trials. Currently, there are various clinical trials investigating the use of Y90-SIRT with glass microspheres for treatment of hepatocellular carcinoma and the outcomes of these trials may result in the incorporation of Y90-SIRT with glass microspheres into the treatment guidelines as a standard therapy option for patients with intermediate and advanced stage hepatocellular carcinoma.

  18. Yttrium-90 Selective Internal Radiation Therapy with Glass Microspheres for Hepatocellular Carcinoma: Current and Updated Literature Review

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Edward Wolfgang; Alanis, Lourdes [Division of Interventional Radiology, Department of Radiology, UCLA Medical Center, David Geffen School of Medicine at UCLA, Los Angeles, CA 90095 (United States); Cho, Sung-Ki [Division of Interventional Radiology, Department of Radiology, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul 06351 (Korea, Republic of); Saab, Sammy [Division of Hepatology, Department of Medicine, Pfleger Liver Institute, University of California at Los Angeles, Los Angeles, CA 90024 (United States)

    2016-11-01

    Hepatocellular carcinoma is the most common primary liver cancer and it represents the majority of cancer-related deaths in the world. More than 70% of patients present at an advanced stage, beyond potentially curative options. Ytrrium-90 selective internal radiation therapy (Y90-SIRT) with glass microspheres is rapidly gaining acceptance as a potential therapy for intermediate and advanced stage primary hepatocellular carcinoma and liver metastases. The technique involves delivery of Y90 infused glass microspheres via the hepatic arterial blood flow to the appropriate tumor. The liver tumor receives a highly concentrated radiation dose while sparing the healthy liver parenchyma due to its preferential blood supply from portal venous blood. There are two commercially available devices: TheraSphere® and SIR-Spheres®. Although, Y90-SIRT with glass microspheres improves median survival in patients with intermediate and advanced hepatocellular carcinoma and has the potential to downstage hepatocellular carcinoma so that the selected candidates meet the transplantable criteria, it has not gained widespread acceptance due to the lack of large randomized controlled trials. Currently, there are various clinical trials investigating the use of Y90-SIRT with glass microspheres for treatment of hepatocellular carcinoma and the outcomes of these trials may result in the incorporation of Y90-SIRT with glass microspheres into the treatment guidelines as a standard therapy option for patients with intermediate and advanced stage hepatocellular carcinoma.

  19. Yttrium-90 selective internal radiation therapy with glass microspheres for hepatocellular carcinoma: Current and updated literature review

    International Nuclear Information System (INIS)

    Lee, Edward Wolfgang; Alanic, Lourdes; Cho, Sung Ki; Saab, Sammy

    2016-01-01

    Hepatocellular carcinoma is the most common primary liver cancer and it represents the majority of cancer-related deaths in the world. More than 70% of patients present at an advanced stage, beyond potentially curative options. Ytrrium-90 selective internal radiation therapy (Y90-SIRT) with glass microspheres is rapidly gaining acceptance as a potential therapy for intermediate and advanced stage primary hepatocellular carcinoma and liver metastases. The technique involves delivery of Y90 infused glass microspheres via the hepatic arterial blood flow to the appropriate tumor. The liver tumor receives a highly concentrated radiation dose while sparing the healthy liver parenchyma due to its preferential blood supply from portal venous blood. There are two commercially available devices: TheraSphere® and SIR-Spheres®. Although, Y90-SIRT with glass microspheres improves median survival in patients with intermediate and advanced hepatocellular carcinoma and has the potential to downstage hepatocellular carcinoma so that the selected candidates meet the transplantable criteria, it has not gained widespread acceptance due to the lack of large randomized controlled trials. Currently, there are various clinical trials investigating the use of Y90-SIRT with glass microspheres for treatment of hepatocellular carcinoma and the outcomes of these trials may result in the incorporation of Y90-SIRT with glass microspheres into the treatment guidelines as a standard therapy option for patients with intermediate and advanced stage hepatocellular carcinoma

  20. Yttrium-90 Selective Internal Radiation Therapy with Glass Microspheres for Hepatocellular Carcinoma: Current and Updated Literature Review.

    Science.gov (United States)

    Lee, Edward Wolfgang; Alanis, Lourdes; Cho, Sung-Ki; Saab, Sammy

    2016-01-01

    Hepatocellular carcinoma is the most common primary liver cancer and it represents the majority of cancer-related deaths in the world. More than 70% of patients present at an advanced stage, beyond potentially curative options. Ytrrium-90 selective internal radiation therapy (Y90-SIRT) with glass microspheres is rapidly gaining acceptance as a potential therapy for intermediate and advanced stage primary hepatocellular carcinoma and liver metastases. The technique involves delivery of Y90 infused glass microspheres via the hepatic arterial blood flow to the appropriate tumor. The liver tumor receives a highly concentrated radiation dose while sparing the healthy liver parenchyma due to its preferential blood supply from portal venous blood. There are two commercially available devices: TheraSphere® and SIR-Spheres®. Although, Y90-SIRT with glass microspheres improves median survival in patients with intermediate and advanced hepatocellular carcinoma and has the potential to downstage hepatocellular carcinoma so that the selected candidates meet the transplantable criteria, it has not gained widespread acceptance due to the lack of large randomized controlled trials. Currently, there are various clinical trials investigating the use of Y90-SIRT with glass microspheres for treatment of hepatocellular carcinoma and the outcomes of these trials may result in the incorporation of Y90-SIRT with glass microspheres into the treatment guidelines as a standard therapy option for patients with intermediate and advanced stage hepatocellular carcinoma.

  1. NUMERICAL ESTIMATION OF EFFECTIVE ELASTIC MODULI OF SYNTACTIC FOAMS REINFORCED BY SHORT GLASS FIBERS

    Directory of Open Access Journals (Sweden)

    Wei Yu

    2016-03-01

    Full Text Available The mechanical properties of hollow glass microsphere/epoxy resin syntactic foams reinforced by short glass fibers are studied using representative volume elements. Both the glass fibers and the hollow glass microspheres exhibit random arrangement in the epoxy resin. The volume fraction and wall thickness of hollow glass microspheres and the volume fraction of glass fibers are considered as parameters. It is observed that the elastic modulus values of syntactic foams decrease with the increase of microsphere volume fraction when the microsphere relative wall thickness is lower. However, it increases with the increase of microsphere volume fraction when the relative wall thickness exceeds a critical value. The elastic modulus value goes through a maximum when the relative wall thickness is around 0.06 at 25 % volume fraction of microspheres. The addition of glass fibers reduces the critical wall thickness values of the microspheres and increases the mechanical properties of the composites. The highest stress lies on the equatorial plane perpendicular to the loading direction. Adding fibers reduces the large stress distribution areas on the microspheres, and the fibers aligned with the loading direction play an important load-bearing role.

  2. Ag/α-Fe2O3 hollow microspheres: Preparation and application for hydrogen peroxide detection

    International Nuclear Information System (INIS)

    Kang, Xinyuan; Wu, Zhiping; Liao, Fang; Zhang, Tingting; Guo, Tingting

    2015-01-01

    In this paper, we demonstrated a simple approach for preparing α-Fe 2 O 3 hollow spheres by mixing ferric nitrate aqueous and glucose in 180 °C. The glucose was found to act as a soft template in the process of α-Fe 2 O 3 hollow spheres formation. Ag/α-Fe 2 O 3 hollow nanocomposite was obtained under UV irradiation without additional reducing agents or initiators. Synthesized Ag/α-Fe 2 O 3 hollow composites exhibited remarkable catalytic performance toward H 2 O 2 reduction. The electrocatalytic activity mechanism of Ag/α-Fe 2 O 3 /GCE were discussed toward the reduction of H 2 O 2 in this paper. - Graphical abstract: Glucose is carbonized as carbon balls in the 180 °C hydrothermal carbonization process, which plays a role of a soft template. Carbon spherical shell is rich in many hydroxyls, which have good hydrophilicity and surface reactivity. When Fe(NO 3 ) 3 is added to the aqueous solution of Glucose, the hydrophilic -OH will adsorb Fe 3+ to form coordination compound by coordination bond. α-FeOOH is formed on the surface of carbon balls by hydrothermal reaction. After calcination at 500 °C, carbon spheres react with oxygen to form carbon dioxide, which disappears in the air. Meanwhile α-FeOOH is calcined to form α-Fe 2 O 3 hollow spheres.

  3. Hollow magnetic nano-CO3O4/polystyrene microspheres synthesized through radiation induced interfacial polymerization

    International Nuclear Information System (INIS)

    Zhang Wei; Wang Mozhen; Wang Shufeng; Zhang Zhicheng

    2010-01-01

    Co 3 O 4 nanoparticles (around 8 nm) were synthesized hydrothermally by dissolving Co 2+ in the mixture of ethanol and water, and then decorated with oleic acid to endow them with hydrophobic surface nature. After that, nano-particles were added into emulsion which consisted by sodium dodecyl sulfate, water, styrene and cetyl alcohol. Hollow magnetic composite spheres were prepared by irradiated the emulsion with γ-rays. The final products are thoroughly characterized by X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR), thermogravimetric analysis (TGA), field-emission scanning electron microscopy (SEM), transmission electron microscopy (TEM), and X-ray photoelectron spectroscopy (XPS) techniques, which showed the formation of hollow magnetic composite spheres. The influence of addition dosage of nano-particles, sodium dodecyl sulfate and the types of nano-particles on the average size and shape of hollow composites were studied. The effects of nano-particles to the polymerization of styrene were studied by kinetics. Nano-particles are capsulated by polystyrene to form hollow composites, which confirmed by XPS results. Finally, magnetic property of hollow composites is compared with pure nano-Co 3 O 4 . (authors)

  4. Hydroxyapatite hierarchically nanostructured porous hollow microspheres: rapid, sustainable microwave-hydrothermal synthesis by using creatine phosphate as an organic phosphorus source and application in drug delivery and protein adsorption.

    Science.gov (United States)

    Qi, Chao; Zhu, Ying-Jie; Lu, Bing-Qiang; Zhao, Xin-Yu; Zhao, Jing; Chen, Feng; Wu, Jin

    2013-04-22

    Hierarchically nanostructured porous hollow microspheres of hydroxyapatite (HAP) are a promising biomaterial, owing to their excellent biocompatibility and porous hollow structure. Traditionally, synthetic hydroxyapatite is prepared by using an inorganic phosphorus source. Herein, we report a new strategy for the rapid, sustainable synthesis of HAP hierarchically nanostructured porous hollow microspheres by using creatine phosphate disodium salt as an organic phosphorus source in aqueous solution through a microwave-assisted hydrothermal method. The as-obtained products are characterized by powder X-ray diffraction (XRD), Fourier-transform IR (FTIR) spectroscopy, SEM, TEM, Brunauer-Emmett-Teller (BET) nitrogen sorptometry, dynamic light scattering (DLS), and thermogravimetric analysis (TGA). SEM and TEM micrographs show that HAP hierarchically nanostructured porous hollow microspheres consist of HAP nanosheets or nanorods as the building blocks and DLS measurements show that the diameters of HAP hollow microspheres are within the range 0.8-1.5 μm. The specific surface area and average pore size of the HAP porous hollow microspheres are 87.3 m(2) g(-1) and 20.6 nm, respectively. The important role of creatine phosphate disodium salt and the influence of the experimental conditions on the products were systematically investigated. This method is facile, rapid, surfactant-free and environmentally friendly. The as-prepared HAP porous hollow microspheres show a relatively high drug-loading capacity and protein-adsorption ability, as well as sustained drug and protein release, by using ibuprofen as a model drug and hemoglobin (Hb) as a model protein, respectively. These experiments indicate that the as-prepared HAP porous hollow microspheres are promising for applications in biomedical fields, such as drug delivery and protein adsorption. Copyright © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  5. Microradiographic microsphere manipulator

    International Nuclear Information System (INIS)

    Singleton, R.M.

    1980-01-01

    A method and apparatus are provided for radiographic characterization of small hollow spherical members (microspheres), constructed of either optically transparent or opaque materials. The apparatus involves a microsphere manipulator which holds a batch of microspheres between two parallel thin plastic films for contact microradiographic characterization or projection microradiography thereof. One plastic film is translated to relative to and parallel to the other to roll the microspheres through any desired angle to allow different views of the microspheres

  6. Breaking the glass ceiling: hollow OmniGuide fibers

    Science.gov (United States)

    Johnson, Steven G.; Ibanescu, Mihai; Skorobogatiy, Maksim A.; Weisberg, Ori; Engeness, Torkel D.; Soljacic, Marin; Jacobs, Steven A.; Joannopoulos, John D.; Fink, Yoel

    2002-04-01

    We argue that OmniGuide fibers, which guide light within a hollow core by concentric multilayer films having the property of omnidirectional reflection, have the potential to lift several physical limitations of silica fibers. We show how the strong confinement in OmniGuide fibers greatly suppresses the properties of the cladding materials: even if highly lossy and nonlinear materials are employed, both the intrinsic losses and nonlinearities of silica fibers can be surpassed by orders of magnitude. This feat, impossible to duplicate in an index-guided fiber with existing materials, would open up new regimes for long-distance propagation and dense wavelength-division multiplexing (DWDM). The OmniGuide-fiber modes bear a strong analogy to those of hollow metallic waveguides; from this analogy, we are able to derive several general scaling laws with core radius. Moreover, there is strong loss discrimination between guided modes, depending upon their degree of confinement in the hollow core: this allows large, ostensibly multi-mode cores to be used, with the lowest-loss TE01 mode propagating in an effectively single-mode fashion. Finally, because this TE01 mode is a cylindrically symmetrical ('azimuthally' polarized) singlet state, it is immune to polarization-mode dispersion (PMD), unlike the doubly-degenerate linearly-polarized modes in silica fibers that are vulnerable to birefringence.

  7. Template-Free Synthesis of Sb2S3 Hollow Microspheres as Anode Materials for Lithium-Ion and Sodium-Ion Batteries

    Science.gov (United States)

    Xie, Jianjun; Liu, Li; Xia, Jing; Zhang, Yue; Li, Min; Ouyang, Yan; Nie, Su; Wang, Xianyou

    2018-03-01

    Hierarchical Sb2S3 hollow microspheres assembled by nanowires have been successfully synthesized by a simple and practical hydrothermal reaction. The possible formation process of this architecture was investigated by X-ray diffraction, focused-ion beam-scanning electron microscopy dual-beam system, and transmission electron microscopy. When used as the anode material for lithium-ion batteries, Sb2S3 hollow microspheres manifest excellent rate property and enhanced lithium-storage capability and can deliver a discharge capacity of 674 mAh g-1 at a current density of 200 mA g-1 after 50 cycles. Even at a high current density of 5000 mA g-1, a discharge capacity of 541 mAh g-1 is achieved. Sb2S3 hollow microspheres also display a prominent sodium-storage capacity and maintain a reversible discharge capacity of 384 mAh g-1 at a current density of 200 mA g-1 after 50 cycles. The remarkable lithium/sodium-storage property may be attributed to the synergetic effect of its nanometer size and three-dimensional hierarchical architecture, and the outstanding stability property is attributed to the sufficient interior void space, which can buffer the volume expansion. [Figure not available: see fulltext.

  8. An assessment of glass microspheres for use as number-based aerodynamic size standards

    International Nuclear Information System (INIS)

    Ball, M.H.E.; Marshall, I.A.; Mitchell, J.P.; Rideal, G.

    1989-08-01

    Polydisperse, non-porous microspheres are required with well-defined aerodynamic properties to determine if enhanced settling of micron-sized aerosol particles occurs in the presence of larger particles (gravitational agglomeration). Glass spheres with claimed unimodal narrow distributions were evaluated using a TSI Aerodynamic Particle Sizer (APS33B). The size fractions containing particles in the range from 1 to 5 μm aerodynamic diameter were truly unimodal, but the fractions which were supposed to consist solely of particles larger than 5 μm aerodynamic diameter contained a significant proportion of submicron particles. (author)

  9. Biodistribution And Preclinical Test Of P-32 Glass Microspheres For Cancer Therapy

    International Nuclear Information System (INIS)

    A, Laksmi; C, Djoharly; P, Ratlan; W, Widyastuti; Purwoko; Bagiwati, Sri; Setiyowati, Sri; Abidin; Sri, Aguswarini

    2003-01-01

    The superiority of radiopharmaceutical compare to the other techniques of medical services, especially for diagnosis and therapy of several deadly diseases such as cancer, shows that this technique is more specific and accurate. P-32-Glass microsphere (P-32 GMS) is one of the radiopharmaceuticals developed recently for therapy using internal radiation method for several malignant cancers, such as hepatic cancer. The P-32 GMS was prepared by irradiating P-31 GMS with neutron at a nuclear reactor, then the preparation was injected to the cancerous infected area. To make easy injection, it needs suspension agent that was including PVP, dextrose and saline with a composition of 16% PVP - 50% dextrose - saline as 2 : 3 : 3 (v/v/v). As microsphere size should be maintained at 40-60 μm, the injection needle was selected properly in order to remain the particle size of P-32 GMS unchanged when the friction occurs between microspheres and the inside surfaces of the needle. The injection needle used was needle produced by BD with a typical size of 20 G1 Tw. Biodistribution studies were carried out after 1, 3, 5 and 24 hour of injection. Experimental results for 1, 3 and 24 hour post-injection studies showed that 100% activity of P-32 GMS was accumulated at the injected area. For 5 hour post-injection study, accumulation of P-32 GMS activity was also found at stomach besides the injected area, but it was presumed as working error

  10. Etched glass self-assembles into micron-size hollow platonic solids

    KAUST Repository

    Boukhalfa, Sofiane

    2012-10-03

    The interaction between the spreading of a hydrofluoric acid-based drop on a glass surface and its etching rate gives rise to hollow crystals of various shapes, including cubes, triangles, and icosahedra. These geometries are dependent on their position with respect to the contact line, where a rim forms by agglutination, similar to the formation of a coffee stain. Atomic force microscopy indentation and transmission electron microscopy observations revealed that these crystals are hollow ammonium-fluosilicate-based cryptohalite shells. © 2012 American Chemical Society.

  11. Etched glass self-assembles into micron-size hollow platonic solids

    KAUST Repository

    Boukhalfa, Sofiane; Chaieb, Saharoui

    2012-01-01

    The interaction between the spreading of a hydrofluoric acid-based drop on a glass surface and its etching rate gives rise to hollow crystals of various shapes, including cubes, triangles, and icosahedra. These geometries are dependent on their position with respect to the contact line, where a rim forms by agglutination, similar to the formation of a coffee stain. Atomic force microscopy indentation and transmission electron microscopy observations revealed that these crystals are hollow ammonium-fluosilicate-based cryptohalite shells. © 2012 American Chemical Society.

  12. Nickel/cobalt layered double hydroxide hollow microspheres with hydrangea-like morphology for high-performance supercapacitors

    International Nuclear Information System (INIS)

    Tao, Yan; Ruiyi, Li; Tingting, Yang; Zaijun, Li

    2015-01-01

    Graphical abstract: We report a new template synthesis of nickel/cobalt layered double hydroxides (Ni/Co-LDH) without any adscititious alkali source, oxidant and step for removal of the template. The perfect match between generation rate of Ni/Co-LDH nanoflakes and removal rate of template creates elaborate three-dimensional architecture with well-defined hollow interior and hydrangea-like exterior. The unique structure improves faradaic redox reaction and mass transfer during the redox process, thus the Ni/Co-LDH electrode provides excellent electrochemical performance for supercapacitors. - Highlights: • The study demonstrated a new strategy for template synthesis of Ni/Co-LDH without any adscititious alkali source, oxidant and step for removal of the template. • The perfect match between generation rate of Ni/Co-LDH nanoflakes and removal rate of SiO 2 template create hollow microspheres with hydrangea-like morphology. • The unique structure of Ni/Co-LDH will greatly improve faradaic redox reaction and mass transfer during the redox process. • The Ni/Co-LDH electrode displays high specific capacitance, good charge/discharge capability, large energy density and superior cycle stability. • The study provides a prominent approach to fabricate various hollow nanomaterials for supercapacitors, Li-ion batteries, catalyst and sensors. - Abstract: Electroactive materials with hollow nanostructures received great attractiveness due to large surface area, low density and superior structure permeablity. The paper reported a new template synthesis of nickel/cobalt layered double hydroxides (Ni/Co-LDH) without any adscititious alkali source, oxidant and step for removal of the template. Nickel nitrate, cobalt nitrate and SiO 2 nanosphere were dispersed in an ethanol solution. Then, the mixed soution was heated at 160 °C for 6 h to obtain Ni/Co-LDH product. During the process, ethanol and nitrate underwent a redox reaction releasing hydroxide ions, which will react

  13. Controlling X-ray beam trajectory with a flexible hollow glass fibre

    Energy Technology Data Exchange (ETDEWEB)

    Tanaka, Yoshihito, E-mail: yotanaka@riken.jp [RIKEN, 1-1-1 Kouto, Sayo-cho, Hyogo 679-5148 (Japan); Kwansei Gakuin University, Gakuen, Sanda, Hyogo 669-1337 (Japan); Nakatani, Takashi; Onitsuka, Rena [Kwansei Gakuin University, Gakuen, Sanda, Hyogo 669-1337 (Japan); Sawada, Kei [RIKEN, 1-1-1 Kouto, Sayo-cho, Hyogo 679-5148 (Japan); Takahashi, Isao [Kwansei Gakuin University, Gakuen, Sanda, Hyogo 669-1337 (Japan)

    2014-01-01

    X-ray beam trajectory control has been performed by using a 1.5 m-long flexible hollow glass fibre. A two-dimensional scan of a synchrotron radiation beam was demonstrated for X-ray absorption mapping. A metre-length flexible hollow glass fibre with 20 µm-bore and 1.5 mm-cladding diameters for transporting a synchrotron X-ray beam and controlling the trajectory has been examined. The large cladding diameter maintains a moderate curvature to satisfy the shallow glancing angle of total reflection. The observed transmission efficiency was more than 20% at 12.4 keV. As a demonstration, a wide-area scan of a synchrotron radiation beam was performed to identify the elements for a fixed metal film through its absorption spectra.

  14. Long-term conversion of 45S5 bioactive glass-ceramic microspheres in aqueous phosphate solution.

    Science.gov (United States)

    Fu, Hailuo; Rahaman, Mohamed N; Day, Delbert E; Huang, Wenhai

    2012-05-01

    The conversion of 45S5 glass and glass-ceramics to a hydroxyapatite (HA)-like material in vitro has been studied extensively, but only for short reaction times (typically glass-ceramic microspheres (designated 45S5c) in an aqueous phosphate solution. Microspheres of 45S5c (75-150 μm) were immersed for 10 years at room temperature (~25 °C) in K(2)HPO(4) solution with a concentration of 0.01 M or 1.0 M, and with a starting pH of 7.0 or 9.5. The reacted 45S5c microspheres and solutions were analyzed using structural and analytical techniques. Only 25-45 vol% of the 45S5c microspheres were converted to an HA-like material after the 10 year reaction. In solutions with a starting pH of 9.5, an increase in the K(2)HPO(4) concentration from 0.01 to 1.0 M resulted in a doubling of the volume of the microspheres converted to an HA-like material but had little effect on the composition of the HA-like product. In comparison, reaction of the 45S5c microspheres in the solution with a starting pH of 7.0 resulted in an HA-like product in the 0.01 M K(2)HPO(4) solution but a calcium pyrophosphate product, Ca(10)K(4)(P(2)O(7))(6).9H(2)O, in the 1.0 M solution. The consequences of these results for the long-term use of 45S5 glass-ceramics in biomedical applications are discussed.

  15. An investigation into the effects of residual water on the glass transition temperature of polylactide microspheres using modulated temperature DSC.

    Science.gov (United States)

    Passerini, N; Craig, D Q

    2001-05-18

    The objective of the study was to ascertain residual water levels in polylactide and polylactide-co-glycolide microspheres prepared using the solvent evaporation technique and to investigate the effects of that water on the glass transitional behaviour of the microspheres. Microspheres were prepared from polylactic acid (PLA) and polylactide-co-glycolide (PLGA) 50:50 and 75:25 using a standard solvent evaporation technique. The glass transition was measured as a function of drying conditions using modulated temperature DSC. The microspheres were found to contain very low levels of dichloromethane, while residual water levels of up to circa 3% w/w were noted after freeze or oven drying, these levels being higher for microspheres containing higher glycolic acid levels. The residual water was found to lower the T(g) following the Gordon-Taylor relationship. The data indicate that the microparticles may retain significant water levels following standard preparation and drying protocols and that this drying may markedly lower the T(g) of the spheres.

  16. Solvothermal Synthesis of a Hollow Micro-Sphere LiFePO4/C Composite with a Porous Interior Structure as a Cathode Material for Lithium Ion Batteries

    Science.gov (United States)

    Liu, Yang; Zhang, Jieyu; Li, Ying; Hu, Yemin; Li, Wenxian; Zhu, Mingyuan; Hu, Pengfei; Chou, Shulei; Wang, Guoxiu

    2017-01-01

    To overcome the low lithium ion diffusion and slow electron transfer, a hollow micro sphere LiFePO4/C cathode material with a porous interior structure was synthesized via a solvothermal method by using ethylene glycol (EG) as the solvent medium and cetyltrimethylammonium bromide (CTAB) as the surfactant. In this strategy, the EG solvent inhibits the growth of the crystals and the CTAB surfactant boots the self-assembly of the primary nanoparticles to form hollow spheres. The resultant carbon-coat LiFePO4/C hollow micro-spheres have a ~300 nm thick shell/wall consisting of aggregated nanoparticles and a porous interior. When used as materials for lithium-ion batteries, the hollow micro spherical LiFePO4/C composite exhibits superior discharge capacity (163 mAh g−1 at 0.1 C), good high-rate discharge capacity (118 mAh g−1 at 10 C), and fine cycling stability (99.2% after 200 cycles at 0.1 C). The good electrochemical performances are attributed to a high rate of ionic/electronic conduction and the high structural stability arising from the nanosized primary particles and the micro-sized hollow spherical structure. PMID:29099814

  17. Solvothermal Synthesis of a Hollow Micro-Sphere LiFePO4/C Composite with a Porous Interior Structure as a Cathode Material for Lithium Ion Batteries

    Directory of Open Access Journals (Sweden)

    Yang Liu

    2017-11-01

    Full Text Available To overcome the low lithium ion diffusion and slow electron transfer, a hollow micro sphere LiFePO4/C cathode material with a porous interior structure was synthesized via a solvothermal method by using ethylene glycol (EG as the solvent medium and cetyltrimethylammonium bromide (CTAB as the surfactant. In this strategy, the EG solvent inhibits the growth of the crystals and the CTAB surfactant boots the self-assembly of the primary nanoparticles to form hollow spheres. The resultant carbon-coat LiFePO4/C hollow micro-spheres have a ~300 nm thick shell/wall consisting of aggregated nanoparticles and a porous interior. When used as materials for lithium-ion batteries, the hollow micro spherical LiFePO4/C composite exhibits superior discharge capacity (163 mAh g−1 at 0.1 C, good high-rate discharge capacity (118 mAh g−1 at 10 C, and fine cycling stability (99.2% after 200 cycles at 0.1 C. The good electrochemical performances are attributed to a high rate of ionic/electronic conduction and the high structural stability arising from the nanosized primary particles and the micro-sized hollow spherical structure.

  18. Cauliflower-like SnO2 hollow microspheres as anode and carbon fiber as cathode for high performance quantum dot and dye-sensitized solar cells

    Science.gov (United States)

    Ganapathy, Veerappan; Kong, Eui-Hyun; Park, Yoon-Cheol; Jang, Hyun Myung; Rhee, Shi-Woo

    2014-02-01

    Cauliflower-like tin oxide (SnO2) hollow microspheres (HMS) sensitized with multilayer quantum dots (QDs) as photoanode and alternative stable, low-cost counter electrode are employed for the first time in QD-sensitized solar cells (QDSCs). Cauliflower-like SnO2 hollow spheres mainly consist of 50 nm-sized agglomerated nanoparticles; they possess a high internal surface area and light scattering in between the microspheres and shell layers. This makes them promising photoanode material for both QDSCs and dye-sensitized solar cells (DSCs). Successive ionic layer adsorption and reaction (SILAR) method and chemical bath deposition (CBD) are used for QD-sensitizing the SnO2 microspheres. Additionally, carbon-nanofiber (CNF) with a unique structure is used as an alternative counter electrode (CE) and compared with the standard platinum (Pt) CE. Their electrocatalytic properties are measured using electrochemical impedance spectroscopy (EIS), cyclic voltammetry (CV), and Tafel-polarization. Under 1 sun illumination, solar cells made with hollow SnO2 photoanode sandwiched with the stable CNF CE showed a power conversion efficiency of 2.5% in QDSCs and 3.0% for DSCs, which is quite promising with the standard Pt CE (QDSCs: 2.1%, and DSCs: 3.6%).Cauliflower-like tin oxide (SnO2) hollow microspheres (HMS) sensitized with multilayer quantum dots (QDs) as photoanode and alternative stable, low-cost counter electrode are employed for the first time in QD-sensitized solar cells (QDSCs). Cauliflower-like SnO2 hollow spheres mainly consist of 50 nm-sized agglomerated nanoparticles; they possess a high internal surface area and light scattering in between the microspheres and shell layers. This makes them promising photoanode material for both QDSCs and dye-sensitized solar cells (DSCs). Successive ionic layer adsorption and reaction (SILAR) method and chemical bath deposition (CBD) are used for QD-sensitizing the SnO2 microspheres. Additionally, carbon-nanofiber (CNF) with a

  19. Hollow nanogold microsphere-signalized lateral flow immuno dipstick for the sensitive determination of the neurotoxin brevetoxin B

    International Nuclear Information System (INIS)

    Zhang, Kangyao; Wu, Jiachang; Li, Yineng; Wu, Yarong; Huang, Tianfu; Tang, Dianping

    2014-01-01

    We report on a new membrane-based lateral-flow assay for the rapid determination of the algal biotoxin brevetoxin B (BrevTox) that can be found in fish. Hollow nanogold microspheres (HGMS) with an average size of 45 nm were synthesized by using the reverse micelle method, followed by functionalization with monoclonal mouse anti-BrevTox antibody (mAb-HGMS). They served as the signalling reagent. Bovine serum albumin-BrevTox conjugate and rabbit anti-mouse IgG antibody were manually spotted on the nitrocellulose membrane and served as reagents for the test line and control line, respectively. Both spherical gold nanoparticle-labeled anti-BrevTox antibody (mAb-AuNP) and mAb-HGMS conjugate were investigated with respect to their suitability as signal-transduction tags, and the latter was found to give improved analytical features. The HGMS-based labeling method was then also studied in terms of performance in the immuno dipstick assay. Under optimal conditions, the visual detection limit (cut-off value) of the mAb-AuNP based assay is 1.5 ng mL −1 , while the sensitivity of the mAb-HGMS based assay is as low as 0.1 ng mL −1 . Yes/no decisions can be made within 10 min without the need for expensive instrumentation. The results for the analysis of target BrevTox in spiked fish samples showed a good correlation with data obtained with the commercial ELISA. Importantly, the assay gave no false negative results. (author)

  20. Synthesis, characterization and photocatalytic activity of porous WO{sub 3}/TiO{sub 2} hollow microspheres

    Energy Technology Data Exchange (ETDEWEB)

    Yang, Liuyang [Graduate School at Shenzhen, Tsinghua University, Shenzhen 518055 (China); Si, Zhichun, E-mail: emsztsinghua@126.com [Graduate School at Shenzhen, Tsinghua University, Shenzhen 518055 (China); Weng, Duan [Graduate School at Shenzhen, Tsinghua University, Shenzhen 518055 (China); State Key Laboratory of New Ceramics and Fine Process, School of Materials Science and Engineering, Tsinghua University, Beijing 100084 (China); Yao, Youwei [Graduate School at Shenzhen, Tsinghua University, Shenzhen 518055 (China)

    2014-09-15

    Porous WO{sub 3}/TiO{sub 2} hollow microspheres were prepared by a spray drying method for photodegradation of methylene blue and phenol. The catalysts were characterized by X-ray diffraction, Field Emission Scanning Electron Microscope, High Resolution Transmission Electron Microscope, N{sub 2} adsorption–desorption measurements, Raman spectrometer, UV–Vis Diffuse Reflectance Spectroscopy and Zeta-Meter measurements. The results showed that the tungsten oxides mainly existed in highly dispersed amorphous form on anatase when the loading amount of tungsten oxide was below 3 mol%. The improved photocatalytic activity under UV light irradiation of the WO{sub 3}/TiO{sub 2} catalyst mainly arises from the enhanced charge separation efficiency rather than the improved light absorbance by highly dispersed amorphous tungsten oxides. Highly dispersed amorphous WO{sub x} can form a shallowly trapped site due to its similar band structure with TiO{sub 2}. The strongly electron-withdrawing of tungsten oxide in highly dispersed state facilitates the electron transition between titanium and WO{sub x}, and consequently improves the charge separation. The enhanced acidity of catalyst by WO{sub x} in reactant environment also improved the charge separation efficiency due to the timely transition of holes and electrons accumulated on TiO{sub 2} and WO{sub x}, respectively. However, the improved photocatalytic activity under visible light irradiation of the WO{sub 3}/TiO{sub 2} catalyst mainly arises from light harvest. TiO{sub 2} containing 3 mol% WO{sub 3} displayed the highest photocatalytic activity under UV light irradiation while that containing 4 mol% WO{sub 3} present highest activity under visible light irradiation.

  1. A Quasi-Solid-State Li-Ion Capacitor Based on Porous TiO2 Hollow Microspheres Wrapped with Graphene Nanosheets.

    Science.gov (United States)

    Wang, Faxing; Wang, Chun; Zhao, Yujuan; Liu, Zaichun; Chang, Zheng; Fu, Lijun; Zhu, Yusong; Wu, Yuping; Zhao, Dongyuan

    2016-12-01

    The quasi-solid-state Li-ion capacitor is demonstrated with graphene nanosheets prepared by an electrochemical exfoliation as the positive electrode and the porous TiO 2 hollow microspheres wrapped with the same graphene nanosheets as the negative electrode, using a Li-ion conducting gel polymer electrolyte. This device may be the key to bridging the gap between conventional lithium-ion batteries and supercapacitors, meanwhile meeting the safety demands of electronic devices. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  2. Enhanced Raman scattering and nonlinear conductivity in Ag-doped hollow ZnO microspheres

    Energy Technology Data Exchange (ETDEWEB)

    Tringe, Joseph W.; Levie, Harold W.; McCall, Scott K.; Teslich, Nick E.; Wall, Mark A.; Orme, Christine A.; Matthews, Manyalibo J. [Lawrence Livermore National Laboratory, Livermore, CA (United States)

    2012-10-15

    Hollow spherical ZnO particles doped with Ag were synthesized with a two-step oxidation and sublimation furnace annealing process. Ag nanoparticle precipitates, as observed by transmission electron microscopy, were present in the polycrystalline ZnO matrix at Ag concentrations below 0.02 mol%, significantly below the 0.8 mol% solubility limit for Ag in ZnO. Enhanced Raman scattering of ZnO phonon modes is observed, increasing with Ag nanoparticle concentration. A further enhancement in Raman scattering due to resonance effects was observed for LO phonons excited by 2.33-eV photons as compared with Raman scattering under 1.96-eV excitation. Room-temperature photoluminescence spectra showed both a near-band-edge emission due to free exciton transitions and a mid-gap transition due to the presence of singly ionized oxygen vacancies. ZnO:Ag particles were measured electrically in a packed column and in monolithic form, and in both cases displayed nonlinear current-voltage characteristics similar to those previously observed in sintered ZnO:Ag monoliths where Ag-enhanced disorder at grain boundaries is thought to control current transport. We demonstrate therefore that Ag simultaneously modifies the electrical and optical properties of ZnO particles through the introduction of vacancies and other defects. (orig.)

  3. Sustained safety and efficacy of extended-shelf-life {sup 90}Y glass microspheres: long-term follow-up in a 134-patient cohort

    Energy Technology Data Exchange (ETDEWEB)

    Lewandowski, Robert J.; Minocha, Jeet; Memon, Khairuddin; Riaz, Ahsun; Gates, Vanessa L.; Ryu, Robert K.; Sato, Kent T.; Omary, Reed; Salem, Riad [Northwestern University, Department of Radiology, Chicago, IL (United States)

    2014-03-15

    To validate our initial pilot study and confirm sustained safety and tumor response of extended-shelf-life {sup 90}Y glass microspheres. We hypothesized that for the same planned tissue dose, the increase in number of glass microspheres (decayed to the second week of their allowable shelf-life) administered for the same absorbed dose would result in better tumor distribution of the microspheres without causing additional adverse events. Between June 2007 and January 2010, 134 patients underwent radioembolization with extended-shelf-life {sup 90}Y glass microspheres; data from 84 new patients were combined with data from our 50-patient pilot study cohort. Baseline and follow-up imaging and laboratory data were obtained 1 and 3 months after therapy and every 3 months thereafter. Clinical and biochemical toxicities were prospectively captured and categorized according to the Common Terminology Criteria. Response in the index lesion was assessed using WHO and EASL guidelines. The mean delivered radiation dose was 123 Gy to the target liver tissue. The mean increase in number of microspheres with this approach compared to standard {sup 90}Y glass microsphere dosimetry was 103 %, corresponding to an increase from 3.84 to 7.78 million microspheres. Clinical toxicities included fatigue (89 patients, 66 %), abdominal pain (49 patients, 36.6 %), and nausea/vomiting (25 patients, 18.7 %). Grade 3/4 bilirubin toxicity was seen in three patients (2 %). Two (1 %) of the initial 50-patient cohort showed gastroduodenal ulcers; gastroduodenal ulcers were not seen in any of the subsequent 84 patients. According to WHO and EASL guidelines, response rates were 48 % and 57 %, respectively, and 21 % demonstrated a complete EASL response. This study showed sustained safety and efficacy of extended-shelf-life {sup 90}Y glass microspheres in a larger, 134-patient cohort. The increase in number of microspheres administered theoretically resulted in better tumor distribution of the

  4. Estimated refractive index and solid density of DT, with application to hollow-microsphere laser targets

    International Nuclear Information System (INIS)

    Briggs, C.K.; Tsugawa, R.T.; Hendricks, C.D.; Souers, P.C.

    1975-01-01

    The literature values for the 0.55-μm refractive index N of liquid and gaseous H 2 and D 2 are combined to yield the equation (N - 1) = [(3.15 +- 0.12) x 10 -6 ]rho, where rho is the density in moles per cubic meter. This equation can be extrapolated to 300 0 K for use on DT in solid, liquid, and gas phases. The equation is based on a review of solid-hydrogen densities measured in bulk and also by diffraction methods. By extrapolation, the estimated densities and 0.55-μm refractive indices for DT are given. Radiation-induced point defects could possibly cause optical absorption and a resulting increased refractive index in solid DT and T 2 . The effect of the DT refractive index in measuring glass and cryogenic DT laser targets is also described

  5. Stressed waveguides with tubular depressed-cladding inscribed in phosphate glasses by femtosecond hollow laser beams.

    Science.gov (United States)

    Long, Xuewen; Bai, Jing; Zhao, Wei; Stoian, Razvan; Hui, Rongqing; Cheng, Guanghua

    2012-08-01

    We report on the single-step fabrication of stressed optical waveguides with tubular depressed-refractive-index cladding in phosphate glasses by the use of focused femtosecond hollow laser beams. Tubelike low index regions appear under direct exposure due to material rarefaction following expansion. Strained compacted zones emerged in domains neighboring the tubular track of lower refractive index, and waveguiding occurs mainly within the tube core fabricated by the engineered femtosecond laser beam. The refractive index profile of the optical waveguide was reconstructed from the measured transmitted near-field intensity.

  6. Sonochemically assisted hollow/solid BaTiO3:Dy3+ microspheres and their applications in effective detection of latent fingerprints and lip prints

    Directory of Open Access Journals (Sweden)

    M. Dhanalakshmi

    2017-03-01

    Full Text Available Nanostructured materials find potential benefits for surface-based science such as latent fingerprints (LFPs and lip print detection on porous and non-porous surfaces. To encounter the drawbacks viz. low sensitivity, high background hindrance, complicated procedure and high toxicity associated with traditional fluorescent powders were resolved by using hollow/solid BaTiO3:Dy3+ (1–5 mol % microspheres. The visualization of LFPs stained by the optimized BaTiO3:Dy3+ (2 mol % hollow/solid microspheres exhibits well-defined ridge patterns with high sensitivity, low background hindrance, high efficiency and low toxicity on various surfaces. The powder X-ray diffraction results revealed the body centered cubic phase of the prepared samples. The emission spectra exhibit intensive peaks at ∼480, 575, and 637 nm, which were attributed to transitions 4F9/2→6HJ (J = 15/2, 13/2, 11/2 of Dy3+ ions, respectively. Surface morphologies were extensively studied with different sonication times and concentrations of the used barbituric acid. The Commission International De I-Eclairage (CIE and Correlated Color Temperature (CCT analyses revealed that the present phosphor is highly useful for the fabrication of white light emitting diodes.

  7. Construct 3D porous hollow Co3O4 micro-sphere: A potential oxidizer of nano-energetic materials with superior reactivity

    Science.gov (United States)

    Wang, Jun; Zheng, Bo; Qiao, Zhiqiang; Chen, Jin; Zhang, Liyuan; Zhang, Long; Li, Zhaoqian; Zhang, Xingquan; Yang, Guangcheng

    2018-06-01

    High energy density and rapid reactivity are the future trend for nano-energetic materials. Energetic performance of nano-energetic materials depends on the interfacial diffusion and mass transfer during the reacted process. However, the development of desired structure to significantly enhance reactivity still remains challenging. Here we focused on the design and preparation of 3D porous hollow Co3O4 micro-spheres, in which gas-blowing agents (air) and maximize interfacial interactions were introduced to enhance mass transport and reduce the diffusion distance between the oxidizer and fuel (Aluminum). The 3D hierarchical Co3O4/Al based nano-energetic materials show a low-onset decomposition temperature (423 °C), and high heat output (3118 J g-1) resulting from porous and hollow nano-structure of Co3O4 micro-spheres. Furthermore, 3D hierarchical Co3O4/Al arrays were directly fabricated on the silicon substrate, which was fully compatible with silicon-based microelectromechanical systems to achieve functional nanoenergetics-on-a-chip. This approach provides a simple and efficient way to fabricate 3D ordered nano-energetic arrays with superior reactivity and the potential on the application in micro-energetic devices.

  8. radio embolization of yttrium 90 glass microspheres in treatment of hepatocellular carcinoma

    International Nuclear Information System (INIS)

    El Fouly, A.H.A.

    2010-01-01

    Hepatocellular carcinoma (HCC) is a common cancer that typically occurs in the setting of cirrhosis and chronic hepatitis virus infections. HCC is considered currently as global problem; its incidence is expected to increase dramatically by the next few decades. More than 90 % of the accidentally diagnosed patients have non resectable tumor. Portal vein thrombosis, diffuse multifocal liver infiltration and large tumor burden are considered to be a great obstacle in front of the modern lines of treatment, even with Child A liver cirrhosis. Transarterial intrahepatic application of Yttrium-90 glass microspheres may allow effective local ablative treatment of patients with intrahepatic advanced hepatocellular carcinoma (HCC) with or without portal vein thrombosis. The aim of this open-label phase II study was to validate evidence on the safety and efficacy of this treatment in an European cohort of patients with locally advanced HCC such as (large tumor burden, multifocal distribution, portal vein thrombosis). And to assess the response rate according to different approved response assessment guidelines (WHO, RECIST and EASL). Patients and Methods Starting from November 2006 till March 2009, one hundred and eight advanced unresectable HCC patients with and without portal vein thrombosis were included in this prospective study. Yttrium-90 microspheres radiotherapy was performed in a lobar fashion through the right or left hepatic artery. In bilobar disease, right and left liver lobe were treated with 4-6 weeks intervals in between. Response rate was assessed according to different international response assessment criteria (WHO, RECIST and EASL) with sequential computed tomography scans till the last clinical visit or death. The safety of this technique was assessed according to the Common Toxicity Criteria version 3

  9. Synthesis and luminescence of CePO4 and CePO4:Tb hollow and core-shell microspheres composed of single-crystal nanorods

    International Nuclear Information System (INIS)

    Guan Mingyun; Sun Jianhua; Han Min; Xu Zheng; Tao Feifei; Yin Gui; Wei Xianwen; Zhu Jianmin; Jiang Xiqun

    2007-01-01

    Lanthanide phosphate microspheres composed of single-crystal CePO 4 and CePO 4 :Tb nanorods were successfully synthesized, respectively, using the functionalized composite aggregate as a template, which is composed of P123, H 6 P 4 O 13 and Ce 3+ , and also as a resource of reaction species with high chemical potential. The shape and the phase structure of the CePO 4 nanocrystal can be easily controlled via adjusting reaction temperature, monomer concentration and annealing temperature. SEM images show the spherical superstructure composed of nanorods. HRTEM and SAED images reveal the single-crystalline nature of nanorod and TEM images show the hollow interiors of the superstructure. XRD patterns indicate that the crystal structure of the nanorods is hexagonal before and monoclinic after annealing. The formation mechanism was proposed. Strong UV and green luminescence were observed for the CePO 4 and CePO 4 :Tb microspheres, respectively. The synthesis method can be extended to the fabrication of NRHS and core-shell microspheres of other rare-earth or doped LnPO 4 materials for wide applications

  10. Three-dimensional MnO{sub 2} porous hollow microspheres for enhanced activity as ozonation catalysts in degradation of bisphenol A

    Energy Technology Data Exchange (ETDEWEB)

    Tan, Xiuqin; Wan, Yifeng; Huang, Yajing [School of Environmental Science and Engineering, Sun Yat-sen University, Guangzhou, 510275 (China); He, Chun, E-mail: hechun@mail.sysu.edu.cn [School of Environmental Science and Engineering, Sun Yat-sen University, Guangzhou, 510275 (China); Guangdong Provincial Key Laboratory of Environmental Pollution Control and Remediation Technology, Guangzhou, 510275 (China); Zhang, Zaili; He, Zhuoyan; Hu, Lingling; Zeng, Jiawei [School of Environmental Science and Engineering, Sun Yat-sen University, Guangzhou, 510275 (China); Shu, Dong, E-mail: dshu@scnu.edu.cn [Key Lab of Technology on Electrochemical Energy Storage and Power Generation in Guangdong Universities, School of Chemistry and Environment, South China Normal University, Guangzhou, 510006 (China)

    2017-01-05

    Highlights: • 3D MnO{sub 2} porous hollow microspheres (PHMSs) are prepared by a self-template process. • MnO{sub 2} PHMSs with excellent adsorption and catalytic ozonation performance for BPA. • MnO{sub 2} PHMSs show enhanced activity due to hollow-mesoporous shell spherical structure. • O{sub 2}{sup −} and ·OH are reactive species to induce effective catalytic ozonation of BPA. - Abstract: Three-dimensional (3D) MnO{sub 2} porous hollow microspheres (δ- and α- MnO{sub 2} PHMSs), with high adsorption and catalytic ozonation performance, were synthesized by a self-template (MnCO{sub 3} microspheres) process at room temperature. The synthesized MnO{sub 2} PHMSs were characterized by X-ray diffraction (XRD), scanning electronic microscopy (SEM), transmission electron microscopy (TEM), X-ray photoelectron spectroscopy (XPS) and Brunauer-Emmett-Teller (BET) surface area. The results showed that PHMSs exhibit the excellent adsorption ability and catalytic activity owning to their hollow spherical structure, mesoporous shell and well-defined interior voids, leading to the strong adsorption for bisphenol A (BPA) and the retention of O{sub 3} molecules on catalyst. Moreover, the catalytic performance of α-MnO{sub 2} PHMSs was better than that of δ-MnO{sub 2} PHMSs which was attributed to the richer lattice oxygen of α-MnO{sub 2} PHMSs to accelerate O{sub 3} decomposition by producing more reactive oxidative species. The degradation efficiency of BPA using 3D α-MnO{sub 2} PHMSs was more than 90% in the presence of ozone within 30 min reaction time. The probe tests for reactive oxidative species (ROSs) displayed that BPA degradation by catalytic ozonation is dominated by ·O{sub 2}{sup −} and ·OH in our present study. Furthermore, the organic compounds as intermediates of the degradation process were identified by LC/MS.

  11. In situ grown hierarchical 50%BiOCl/BiOI hollow flowerlike microspheres on reduced graphene oxide nanosheets for enhanced visible-light photocatalytic degradation of rhodamine B

    Science.gov (United States)

    Su, Xiangde; Yang, Jinjin; Yu, Xiang; Zhu, Yi; Zhang, Yuanming

    2018-03-01

    50%BiOCl/BiOI/reduced graphene oxide (50%BiOCl/BiOI/rGO) composite photocatalyst was synthesized successfully by a facile one-step solvothermal route in this work. Reduction of graphene oxide (GO) took place in the process of solvothermal reaction and a new Bi-C bond between rGO and 50%BiOCl/BiOI was formed. The introduction of rGO affected the morphology of 50%BiOCl/BiOI, resulting in the transformation of 50%BiOCl/BiOI from solid microspheres to hollow microspheres. Both the introduction of rGO and formation of 50%BiOCl/BiOI hollow microspheres can facilitate the light absorption. The strong interaction between 50%BiOCl/BiOI and rGO and the electrical conductivity of rGO greatly improved the effective separation of photogenerated carriers. Hence, GOB-5 demonstrated the highest photocatalytic activity which was over twice of the pristine 50%BiOCl/BiOI in the presence of visible light. Mechanism study revealed that 50%BiOCl/BiOI generated electrons and holes in the presence of visible light, and holes together with rad O2- generated from reduction of O2 by electrons degraded the pollutant directly. Overall, this work provides an excellent reference to the synthesis of chemically bonded BiOX/BiOY (X, Y = Cl, Br, I)/rGO nanocomposite and helps to promote their applications in environmental protection and photoelectric conversion.

  12. Synthesis of morphology-controlled carbon hollow particles by carbonization of resorcinol-formaldehyde precursor microspheres and applications in lithium-ion batteries

    Energy Technology Data Exchange (ETDEWEB)

    Zhang Haijiao, E-mail: seaboyfang@163.com [Modern Manufacture Engineering Center, Heilongjiang Institute of Science and Technology, 150027 (China); Xu Huifang, E-mail: xuhf@hit.edu.cn [School of Chemical Engineering and Technology, Harbin Institute of Technology, 150001 (China); Zhao Can [Modern Manufacture Engineering Center, Heilongjiang Institute of Science and Technology, 150027 (China)

    2012-03-15

    Highlights: Black-Right-Pointing-Pointer Resorcinol-formaldehyde hollow particles could be obtained by inverse suspension method. Black-Right-Pointing-Pointer The morphologies of RF carbon precursor particles could be controlled by adjusting the pH values of the RF precursor. Black-Right-Pointing-Pointer The prepared carbon hollow particles, which derived from resorcinol-formaldehyde, exhibited microporous properties. Black-Right-Pointing-Pointer The RF carbon microcapsules displayed excellent power property and cycle durability. - Abstract: The morphology-controlled carbon hollow particles, derived from resorcinol-formaldehyde (RF) particles, were prepared by using an (oil phase) O/(water phase) W/(oil phase) O inverse-emulsion system which was formed by adding RF precursor (water phase) to n-hexane (oil phase) with Span-80 as surfactant and the following carbonization. This simple method led to the formation of various morphologies of RF carbon precursor particles such as hollow spheres, bowl-like hollow structures, microcapsules, or solid microspheres by adjusting the pH values of the RF precursor. The synthesized carbon particles exhibited porous characters with the surface area of 659 m{sup 2} g{sup -1} and the total pore volume of 0.44 cm{sup 3} g{sup -1}. Additionally, the electrochemical behavior of the typical RF carbon particles in lithium-ion batteries revealed that the RF carbon microcapsules displayed a high initial discharge capacity of 1059 mAh g{sup -1} and stabilized at about 330 mAh g{sup -1}, indicating its excellent power property and cycle durability.

  13. Facile synthesis of hollow Co3O4 microspheres and its use as a rapid responsive CL sensor of combustible gases.

    Science.gov (United States)

    Teng, Fei; Yao, Wenqing; Zheng, Youfei; Ma, Yutao; Xu, Tongguang; Gao, Guizhi; Liang, Shuhui; Teng, Yang; Zhu, Yongfa

    2008-09-15

    The hollow Co(3)O(4) microspheres (HCMs) were prepared by the carbonaceous templates, which did not need the surface pretreatment. The chemiluminescence (CL) and catalytic properties for CO oxidation over these hollow samples were evaluated. The samples were characterized by scanning electron microscopy (SEM), energy disperse spectra (EDS), transmission electron microscopy (TEM), selected area electron diffraction (ED), X-ray diffraction (XRD), temperature-programmed desorption (TPD) and N(2) adsorption. The influences of filter' band length, flow rate of gas, test temperature, and particle structure on CL intensities were mainly investigated. It was found that compared with the solid Co(3)O(4) particles (SCPs), HCMs had a stronger CL intensity, which was ascribed to its hollow structure; and that CL properties of the catalysts were well correlated with their reaction activities. Moreover, HCMs were used to fabricate a highly sensitive gas detector, which is a rapid and effective method for the selection of catalysts or the detection of environmental deleterious gases.

  14. Multifunctional hollow superhydrophobic SiO2 microspheres with robust and self-cleaning and separation of oil/water emulsions properties.

    Science.gov (United States)

    Guo, Fei; Wen, Qiuying; Peng, Yubing; Guo, Zhiguang

    2017-05-15

    Superhydrophobic materials have drawn great attention due to its' remarkable non-wetting properties and applications in many fields. In this paper, we synthesize a hollow superhydrophobic SiO 2 powder by typical template method and self-assembly functionalization. Robustness of many superhydrophobic surfaces has become the development bottleneck for industrial applications. Aiming at this problem, the adhesive epoxy resin is specially taken to use as the binding layer between superhydrophobic SiO 2 powder and substrates to create robust superhydrophobic coating. The mechanical durability of the obtained superhydrophobic coating is evaluated by a cyclic sandpaper abrasion. Also, the chemical stability of this superhydrophobic coating is assessed by exposuring it to different pH conditions and UV irradiation, respectively. Significantly, because of the special structure and superhydrophobicity/superoleophilicity of the hollow microspheres, these hollow superhydrophobic SiO 2 powders manifest great oil-adsorbing capacity, which thus can be used to separate oil/water mixtures and remove oil from oil-in-water emulsions. Copyright © 2017 Elsevier Inc. All rights reserved.

  15. The high surface energy of NiO {110} facets incorporated into TiO{sub 2} hollow microspheres by etching Ti plate for enhanced photocatalytic and photoelectrochemical activity

    Energy Technology Data Exchange (ETDEWEB)

    Li, Jian; Cui, Hongzhi, E-mail: cuihongzhi1965@163.com; Song, Xiaojie; Wei, Na; Tian, Jian, E-mail: jiantian@sdust.edu.cn

    2017-02-28

    Highlights: • NiO/TiO{sub 2} hollow microspheres were fabricated by etching Ti plate. • The incorporated NiO nanoparticles exposed high surface energy {110} facets. • The p–n junction catalysts improved photoelectrochemical and photocatalytic activity. • Using this synthesis strategy, other mixed semiconducting metal oxide microspheres. - Abstract: We present a rational design for the controllable synthesis of NiO/TiO{sub 2} hollow microspheres (NTHMs) with Ti plate via a one-pot template-free synthesis strategy. Specifically, to enhance the formation of hollow microspheres, part of the titanium source is provided by the Ti plate. The hollow spherical NiO/TiO{sub 2} particles possess unique microstructural characteristics, namely, a higher specific surface area (∼65.82 m{sup 2} g{sup −1}), a larger mesoporous structure (∼7.79 nm), and hierarchical nanoarchitectures connected with mesopores within the shell (monodispersed size of ∼1 μm and shell thickness of ∼80 nm). In addition, as a cocatalyst for improved catalytic activity, the incorporated NiO nanoparticles with exposed high surface energy {110} facets displayed an outstanding performance. It has been proven that this facile nanostructure possesses remarkably high photoelectrochemical and photocatalytic activities. The main mechanism for enhancement of photocatalytic activity is attributed to the construction of p-n junctions with an inner electric field between TiO{sub 2} and NiO, which can dramatically enhance the separation efficiency of the photogenerated electron-hole pairs. This strategy could be applied to fabricate mixed metal oxide hollow microspheres toward the photoelectrochemical catalysis.

  16. Laser fusion experiments at 2 TW. [Argus system; implosion of D-T filled glass microspheres

    Energy Technology Data Exchange (ETDEWEB)

    Storm, E.K.; Ahlstrom, H.G.; Boyle, M.J.

    1976-10-01

    The Lawrence Livermore Laboratory Solid State Laser System, Arqus, has successfully performed laser implosion experiments at power levels exceeding 2 TW. D-T filled glass microspheres have been imploded to yield thermonuclear reaction products in excess of 5 x 10/sup 8/ per event. Neutron and ..cap alpha.. time-of-flight measurements indicate that D-T ion temperatures of approximately 5-6 keV and a density confinement time product (n tau) of approximately 1 x 10/sup 12/ were obtained in these experiments. Typically two 40J, 40 psec pulses of 1.06 ..mu..m light were focused on targets using 20 cm aperture f/1 lenses, producing intensities at the target in excess of 10/sup 16/ W/cm/sup 2/. An extensive array of diagnostics routinely monitored the laser performance and the laser target interaction process. Measurements of absorption and asymmetry in both the scattered light distribution and the ion blow off is evidence for non-classical absorption mechanisms and density scale heights of the order of 2 ..mu..m or less. The symmetry of the thermonuclear burn region is investigated by monitoring the ..cap alpha..-particle flux in several directions, and an experiment to image the thermonuclear burn region is in process. These experiments significantly extend our data base and our understanding of laser induced thermonuclear implosions and the basic laser plasma interaction physics from the 0.4 to 0.7 TW level of previous experiments.

  17. Radioisotope generators for nuclear medicine based on Fajans adsorption on glass microspheres

    International Nuclear Information System (INIS)

    Ehrhardt, G.J.; Symes, S.; Guimon, R.K.; Zinn, K.R.

    1992-01-01

    Several radioisotope generator systems exist in which the carrier-free daughter product would precipitate if present in macro amounts at pH levels at which the parent is soluble. Included among these are the 68 Ge/ 68 Ga, 90 Sr/ 90 Y, and 47 Ca/ 47 Sc pairs. This paper reveals that in these systems, chemical separation can be achieved by Fajans adsorption of the radiocolloidal daughter products onto surfaces such as activated glass microspheres at an appropriate pH. This is followed by washing to remove the parent solution and desorption of the daughter crop by acid washes. Investigation of the Ge/Ga and Sr/Y systems demonstrated that this solid-phase extraction method is erratic, but can give daughter yields as high at 89% with separation factors up to ∼ 10,000 form parent isotope. This method has the potential for producing daughter isotopes with a minimum of metal and organic impurities for labeling cells, receptor binding ligands, and antibodies for diagnostic and radiotherapeutic purposes

  18. Absorbed dose kernel and self-shielding calculations for a novel radiopaque glass microsphere for transarterial radioembolization.

    Science.gov (United States)

    Church, Cody; Mawko, George; Archambault, John Paul; Lewandowski, Robert; Liu, David; Kehoe, Sharon; Boyd, Daniel; Abraham, Robert; Syme, Alasdair

    2018-02-01

    Radiopaque microspheres may provide intraprocedural and postprocedural feedback during transarterial radioembolization (TARE). Furthermore, the potential to use higher resolution x-ray imaging techniques as opposed to nuclear medicine imaging suggests that significant improvements in the accuracy and precision of radiation dosimetry calculations could be realized for this type of therapy. This study investigates the absorbed dose kernel for novel radiopaque microspheres including contributions of both short and long-lived contaminant radionuclides while concurrently quantifying the self-shielding of the glass network. Monte Carlo simulations using EGSnrc were performed to determine the dose kernels for all monoenergetic electron emissions and all beta spectra for radionuclides reported in a neutron activation study of the microspheres. Simulations were benchmarked against an accepted 90 Y dose point kernel. Self-shielding was quantified for the microspheres by simulating an isotropically emitting, uniformly distributed source, in glass and in water. The ratio of the absorbed doses was scored as a function of distance from a microsphere. The absorbed dose kernel for the microspheres was calculated for (a) two bead formulations following (b) two different durations of neutron activation, at (c) various time points following activation. Self-shielding varies with time postremoval from the reactor. At early time points, it is less pronounced due to the higher energies of the emissions. It is on the order of 0.4-2.8% at a radial distance of 5.43 mm with increased size from 10 to 50 μm in diameter during the time that the microspheres would be administered to a patient. At long time points, self-shielding is more pronounced and can reach values in excess of 20% near the end of the range of the emissions. Absorbed dose kernels for 90 Y, 90m Y, 85m Sr, 85 Sr, 87m Sr, 89 Sr, 70 Ga, 72 Ga, and 31 Si are presented and used to determine an overall kernel for the

  19. Synthesis of hollow titania microspheres by using microfluidic droplet-template%微流控液滴软模板制备二氧化钛中空微球

    Institute of Scientific and Technical Information of China (English)

    马静云; 姜雷; 秦建华

    2011-01-01

    Droplet-based microfluidics is of great interest due to its particular characteristics compared with the conventional methods, such as reduced reagent consumption, rapid mixing, high-throughput, shape controlled, etc. A novel method using microfluidic droplet as soft template for the synthesis of hollow titania microspheres was developed. A typical polydimethylsi-loxane (PDMS) microfluidic device containing "flow-focusing" geometry was used to generate water/oil (W/O) droplet. The mechanism for the hollow structure formation was based on the interfacial hydrolysis reaction between the continuous phase containing titanium butoxide precursor and the dispersed containing water. The continuous phase mixed with butanol was added in the downstream of the channel after the hydrolysis reaction. This step was used for drawing the water out of the microgels for further hydrolysis. The microgels obtained through a glass pipe integrated were washed, dried under vacuum and calcined after aging for a certain time. The fluorescence and scanning electron microscope ( SEM) image of the microspheres indicated the hollow structure and the thickness of the shell. In addition, these microspheres with thin shell (about 2 u.m) were apt to rupture and collapse. Droplet-based microfluidic offered a gentle and size-controllable manner to moderate this problem. Moreover, it has potential applications in photocatalysis combined with some modification realized on the chip simultaneously.%应用微流控液滴技术合成功能材料已发展成为一个新兴领域.本文以夹流结构微流控芯片产生的微液滴作为软模板,以液滴模板界面处发生的水解反应生成二氧化钛球壳,并经后续脱核处理,制备二氧化钛中空微球.采用激光诱导荧光成像、扫描电镜等手段对微球形貌结构进行了分析表征.结果表明,通过控制微流控芯片液滴合成条件,可以得到壁厚约2 μm的二氧化钛中空微球.这种以微流控液滴为

  20. Li3V2(PO4)3/LiFePO4 composite hollow microspheres for wide voltage lithium ion batteries

    International Nuclear Information System (INIS)

    He, Wen; Wei, Chuanliang; Zhang, Xudong; Wang, Yaoyao; Liu, Qinze; Shen, Jianxing; Wang, Lianzhou; Yue, Yuanzheng

    2016-01-01

    Highlights: • Using yeast cells to control the in-situ growth of crystal particle. • Heterogeneous isomorphism nanocomposite hollow microspheres are synthesized. • The cathode exhibits a higher discharge capacity and energy density. - Abstract: Li 3 V 2 (PO 4 ) 3 (LVP)/LiFePO 4 (LVP) composite hollow microspheres (LVP/LFP-CHMs) for lithium-ion batteries have been synthesized by a combination method, using yeast cells as both structure templates and biocarbon source. The stable heterogeneous isomorphism solid solution with superlattice structure is formed in the joint of LVP and LFP particles. A detailed analysis of the formation mechanism of solid solution with superlattice structure and the influences of different Fe:V mole ratios on the structure and electrochemical properties of composites are presented. When the LVP/LFP-CHMs with a Fe:V mole ratio of 1:3 were used as cathode material in coin cells with metallic Li as anode, the cell exhibits a discharge capacity of 221.5 mAh g −1 for 5 cycles and discharge specific energy of 682 Wh kg −1 at 0.1C in a wide voltage range (1.5–4.3 V). Its capacity is far higher than the capacity of unsubstituted LFP and LVP in the same wide voltage range. The energy density of this cell is about 4 times higher than that of modern commercial lithium-ion batteries (157 Wh kg −1 ). The wide voltage range not only increases the discharge capacity and energy density of cathode materials, but also could expand the range of its applications in electronic equipment.

  1. Tollen’s reagent assisted synthesis of hollow polyaniline microsphere/Ag nanocomposite and its applications in sugar sensing and electromagnetic shielding

    Energy Technology Data Exchange (ETDEWEB)

    Panigrahi, R.; Srivastava, S.K., E-mail: sunit@chem.iitkgp.ernet.in

    2015-04-15

    Graphical abstract: Probable scheme to demonstrate the mechanism of PnHMAg showing enhanced EMI shielding compared to PnHM. - Highlights: • Hollow polyaniline microsphere (PnHM) exhibits superior properties due to its enhanced surface to volume ratio. • PnHMAg has been used in developing efficient sensor for the detection of sugar. • Presence of Ag nanoparticles enhances the electrical conductivity of PnHMAg resulting in the improvement of electromagnetic interference shielding in both X- and S-band regions. • Such properties could be harnessed effectively for development of devices for commercial as well as national purposes. - Abstract: The present study is focused on synthesis of polyaniline hollow microspheres (PnHM) nanocomposites of silver (Ag) i.e., PnHMAg by emulsion polymerization of aniline and Tollen’s reagent as a source for Ag nanoparticles. X-ray diffraction (XRD) and transmission electron microscopy (TEM) analysis of PnHMAg indicated presence of silver nanoparticles dispersed on polyaniline surface. The electrical conductivity of PnHMAg is increased by ∼6 times compared to PnHM. Cyclic voltammogram of PnHM in sugar sensing exhibits characteristics redox peaks at ∼0.09 (sugar) and ∼0.53 V (polyaniline). Interestingly, PnHMAg showed a single peak at ∼−0.18 V with increased intensity (∼5 times) indicating its high sugar sensing ability. PnHMAg also exhibits high shielding efficiency of 19.5 dB (11.2 GHz) due to the presence of highly conducting Ag nanoparticles. TEM studies confirmed that Ag nanoparticles are well distributed on PnHM. As a result, a continuous electronic path is developed due to enhanced interconnectivity of PnHM.

  2. 氧化亚铜空心球制备及其在海洋污损材料中的应用%Synthesis of Cu2O Hollow Microspheres and Its Application in Antifouling Materials

    Institute of Scientific and Technical Information of China (English)

    熊杨凯; 汪国庆; 谢卓琳; 李玉; 王爱明; 姜宏

    2017-01-01

    采用软模板法和自模板法分别制备了Cu2O空心球,探索了不同制备方法下反应条件对Cu2O空心球形貌及性能的影响,研究了以其作为防污剂制备的涂层防海洋污损生物的防污性能.通过X射线衍射(XRD)、扫描电子显微镜(SEM)、透射电子显微镜(TEM)和抑菌测试等手段表征和探讨了Cu2O空心球的抑菌性能.结果表明:用软模板法得到表面光滑、结晶度高的Cu2O空心球;用自模板法制备得到由纳米粒子组成的开口空心微球.在抑菌试验中,2种空心球浊液浓度为50 μg/mL时,抑菌作用均可以达到95%以上,抑菌效果好.将2种Cu2O空心球作为防污剂与含氟嵌段共聚树脂SBF改性树脂混合,得到2种杂化防污涂层.通过SEM进行表征,在抗藻类附着试验中,表面基本没有藻类附着,具有良好的防污性能.在浸泡过程中,2种杂化涂层的表面形成了不同的特殊纳米结构表面形貌,这应是少量Cu2O空心球即可使杂化涂层具有好的防污效果的原因.%Two kinds of Cu2O hollow microspheres were prepared by soft-templating method and self-templating method.The effects of different reaction conditions on the morphology and performance of Cu2O hollow spheres were studied.XRD,SEM and TEM were utilized to characterize the antibacterial property of Cu2O hollow spheres.The results showed that the hollow microsphere with perfect ball-shape could be successfully prepared by soft-templating method,at mean time,the hollow Cu2O microsphere with open-mouth was prepared through self-templating method.The antibacterial experiment results showed when the turbid liquid concentration of two hollow microspheres reached 50 μg/mL,the antibacterial effect could reach more than 95%,indicating that the two hollow microspheres had good antibacterial properties.Using SBF as the film-forming agent,two kinds of synthesized Cu2O hollow microspheres as anti-fouling agent respectively,two kinds of hybrid coatings were

  3. Aluminum-Doped SnO2 Hollow Microspheres as Photoanode Materials for Dye-Sensitized Solar Cells

    Directory of Open Access Journals (Sweden)

    Binghua Xu

    2016-01-01

    Full Text Available Al doped SnO2 microspheres were prepared through hydrothermal method. As-prepared SnO2 microspheres were applied as photoanode materials in dye-sensitized solar cells (DSCs. The properties of the assembled DSCs were significantly improved, especially the open-circuit voltage. The reason for the enhancement was explored through the investigation of dark current curves and electrochemistry impedance spectra. These results showed that the Al doping significantly increased the reaction resistance of recombination reactions and restrained the dark current. The efficient lifetime of photoexcited electrons was also obviously lengthened.

  4. Neutron transmission measurements on hydrogen filled microspheres

    International Nuclear Information System (INIS)

    Dyrnjaja, Eva; Hummel, Stefan; Keding, Marcus; Smolle, Marie-Theres; Gerger, Joachim; Zawisky, Michael

    2014-01-01

    Hollow microspheres are promising candidates for future hydrogen storage technologies. Although the physical process for hydrogen diffusion through glass is well understood, measurements of static quantities (e.q. hydrogen pressure inside the spheres) as well as dynamic properties (e.g. diffusion rate of hydrogen through glass) are still difficult to handle due to the small size of the spheres (d≈15μm). For diffusion rate measurements, the long-term stability of the experiment is also mandatory due to the relatively slow diffusion rate. In this work, we present an accurate and long-term stable measurement technique for static and dynamic properties, using neutron radiography. Furthermore, possible applications for hydrogen filled microspheres within the scope of radiation issues are discussed

  5. Development of phosphate glass microspheres containing holmium for selective internal radiotherapy; Desenvolvimento de microesferas de vidro fosfato contendo holmio para uso em radioterapia interna seletiva

    Energy Technology Data Exchange (ETDEWEB)

    Barros Filho, Eraldo Cordeiro

    2016-11-01

    The selective internal radiotherapy is an alternative for some kinds of cancer as the hepatocellular carcinoma (HCC) or primary liver cancer treatment. In this treatment, glass or polymer microspheres containing radionuclides inside their structure are introduced in the liver through hepatic artery and trapped at the arterioles that feed the tumor. In this work, the development of phosphate glasses containing holmium for production of microspheres and their application in Brazil are proposed. The developed glasses presented suitable chemical durability, density of 2,7(3) g/cm{sup 3}, high thermal stability and the impurities contained therein do not preclude the treatment. The microspheres were produced by the flame method and the gravitational fall method, and were characterized by means of several techniques to evaluate shape, average particle size, activity and biocompatibility suitable for selective internal radiotherapy. Based in the main results, the submission to in vivo tests is proposed. (author)

  6. Fabry-Perot interferometer fiber tip sensor based on a glass microsphere glued at the etched end of multimode fiber

    Science.gov (United States)

    Chen, Weiping P.; Wang, Dongning N.; Xu, Ben; Wang, Zhaokun K.; Zhao, Chun-Liu

    2017-05-01

    We demonstrate an optical Fabry-Perot interferometer fiber tip sensor based on a glass microsphere glued at the etched end of a multimode fiber. The fiber device is miniature and robust, with a convenient reflection mode of operation, a high temperature sensitivity of 202.6 pm/°C within the range from 5°C to 90°C, a good refractive index sensitivity of ˜119 nm/RIU within the range from 1.331 to 1.38, and a gas pressure sensitivity of 0.19 dB/MPa.

  7. Building Honeycomb-Like Hollow Microsphere Architecture in a Bubble Template Reaction for High-Performance Lithium-Rich Layered Oxide Cathode Materials.

    Science.gov (United States)

    Chen, Zhaoyong; Yan, Xiaoyan; Xu, Ming; Cao, Kaifeng; Zhu, Huali; Li, Lingjun; Duan, Junfei

    2017-09-13

    In the family of high-performance cathode materials for lithium-ion batteries, lithium-rich layered oxides come out in front because of a high reversible capacity exceeding 250 mAh g -1 . However, the long-term energy retention and high energy densities for lithium-rich layered oxide cathode materials require a stable structure with large surface areas. Here we propose a "bubble template" reaction to build "honeycomb-like" hollow microsphere architecture for a Li 1.2 Mn 0.52 Ni 0.2 Co 0.08 O 2 cathode material. Our material is designed with ca. 8-μm-sized secondary particles with hollow and highly exposed porous structures that promise a large flexible volume to achieve superior structure stability and high rate capability. Our preliminary electrochemical experiments show a high capacity of 287 mAh g -1 at 0.1 C and a capacity retention of 96% after 100 cycles at 1.0 C. Furthermore, the rate capability is superior without any other modifications, reaching 197 mAh g -1 at 3.0 C with a capacity retention of 94% after 100 cycles. This approach may shed light on a new material engineering for high-performance cathode materials.

  8. Core-shell composite of hierarchical MoS2 nanosheets supported on graphitized hollow carbon microspheres for high performance lithium-ion batteries

    International Nuclear Information System (INIS)

    Xia, Yuan; Wang, Beibei; Zhao, Xiaojun; Wang, Gang; Wang, Hui

    2016-01-01

    In this work, a core-shell composite composed of MoS 2 nanosheets grown on hollow carbon microspheres is synthesized by a hydrothermal and a subsequent annealing route. The result shows that well-graphitized hollow-carbon@highlycrystallineMoS 2 (HC@MoS 2 ) was obtained after the four-step reaction. And it is found that the synthesized MoS 2 is consist of 2H and 1T phases. The lithium storage property of the composite is investigated as an anode material for lithium-ion batteries. Benefited from the special morphology and structure, a stable capacity of 970 mAh g −1 for over 100 cycles at a current density of 0.25 A g −1 is realized on the material. Even at a high current density of 4 A g −1 , a reversible capacity as high as 560 mAh g −1 is delivered. Moreover, the reasons for the excellent electrochemical performance of the material are explored and discussed in detail.

  9. Spectral Optical Readout of Rectangular-Miniature Hollow Glass Tubing for Refractive Index Sensing.

    Science.gov (United States)

    Rigamonti, Giulia; Bello, Valentina; Merlo, Sabina

    2018-02-16

    For answering the growing demand of innovative micro-fluidic devices able to measure the refractive index of samples in extremely low volumes, this paper presents an overview of the performances of a micro-opto-fluidic sensing platform that employs rectangular, miniature hollow glass tubings. The operating principle is described by showing the analytical model of the tubing, obtained as superposition of different optical cavities, and the optical readout method based on spectral reflectivity detection. We have analyzed, in particular, the theoretical and experimental optical features of rectangular tubings with asymmetrical geometry, thus with channel depth larger than the thickness of the glass walls, though all of them in the range of a few tens of micrometers. The origins of the complex line-shape of the spectral response in reflection, due to the different cavities formed by the tubing flat walls and channel, have been investigated using a Fourier transform analysis. The implemented instrumental configuration, based on standard telecom fiberoptic components and a semiconductor broadband optical source emitting in the near infrared wavelength region centered at 1.55 µm, has allowed acquisition of reflectivity spectra for experimental verification of the expected theoretical behavior. We have achieved detection of refractive index variations related to the change of concentration of glucose-water solutions flowing through the tubing by monitoring the spectral shift of the optical resonances.

  10. Spectral Optical Readout of Rectangular–Miniature Hollow Glass Tubing for Refractive Index Sensing

    Science.gov (United States)

    Rigamonti, Giulia; Bello, Valentina

    2018-01-01

    For answering the growing demand of innovative micro-fluidic devices able to measure the refractive index of samples in extremely low volumes, this paper presents an overview of the performances of a micro-opto-fluidic sensing platform that employs rectangular, miniature hollow glass tubings. The operating principle is described by showing the analytical model of the tubing, obtained as superposition of different optical cavities, and the optical readout method based on spectral reflectivity detection. We have analyzed, in particular, the theoretical and experimental optical features of rectangular tubings with asymmetrical geometry, thus with channel depth larger than the thickness of the glass walls, though all of them in the range of a few tens of micrometers. The origins of the complex line-shape of the spectral response in reflection, due to the different cavities formed by the tubing flat walls and channel, have been investigated using a Fourier transform analysis. The implemented instrumental configuration, based on standard telecom fiberoptic components and a semiconductor broadband optical source emitting in the near infrared wavelength region centered at 1.55 µm, has allowed acquisition of reflectivity spectra for experimental verification of the expected theoretical behavior. We have achieved detection of refractive index variations related to the change of concentration of glucose-water solutions flowing through the tubing by monitoring the spectral shift of the optical resonances. PMID:29462907

  11. Study of the focusing effect of silica microspheres on the upconversion of Er{sup 3+}–Yb{sup 3+} codoped glass ceramics

    Energy Technology Data Exchange (ETDEWEB)

    Pérez-Rodríguez, C., E-mail: cjperez@ull.edu.es [Dpto. Física Fundamental y Experimental, Electrónica y Sistemas, Universidad de La Laguna, Av. Astrofísico Francisco Sánchez, s/n E-38206 La Laguna, Tenerife (Spain); Imanieh, M.H. [Department of Chemical and Environmental Engineering, University of Toledo, Toledo, OH (United States); Department of Materials, Ceramic Division, Iran University of Science and Technology, Tehran (Iran, Islamic Republic of); Martín, L.L [Dpto. Física Fundamental y Experimental, Electrónica y Sistemas, Universidad de La Laguna, Av. Astrofísico Francisco Sánchez, s/n E-38206 La Laguna, Tenerife (Spain); Ríos, S. [Dpto. de Física Básica, Universidad de La Laguna, Av. Astrofísico Francisco Sánchez, s/n E-38206 La Laguna, Tenerife (Spain); Martín, I.R. [Dpto. Física Fundamental y Experimental, Electrónica y Sistemas, Universidad de La Laguna, Av. Astrofísico Francisco Sánchez, s/n E-38206 La Laguna, Tenerife (Spain); MALTA Consolider Team, Av. Astrofísico Francisco Sánchez, s/n E-38206 La Laguna, Tenerife (Spain); Yekta, Bijan Eftekhari [Department of Materials, Ceramic Division, Iran University of Science and Technology, Tehran (Iran, Islamic Republic of)

    2013-11-05

    Highlights: •Silica microspheres have been located on the surface of glass and glass ceramics samples codoped with Er and Yb. •Microspheres act as microlens of the 950 nm excitation light resulting in focalized excited regions in the samples with sizes under the micron. •Intense red upconversion is achieved in the focalized areas. •Microspheres collect the upconversion emission light, scoping with the together microlensing properties an enhancement of the detected signal in a 3x factor. •Performed Finite-Difference Time-Domain simulations predict the size of the focalized regions in good agreement with the experimental measurements. -- Abstract: The upconversion emission properties of Er{sup 3+}–Yb{sup 3+} codoped glass and glass ceramic samples with different Si/Al ratios and thermal treatments were analyzed by covering their surfaces with silica microspheres (3.8 μm diameter). A 950 nm laser beam is focused by the microspheres producing a set of photonic nanojets near the surface of the samples. After the upconversion processes of the Er{sup 3+} ions located in each microsphere focus area, these ions emit light in the green and red regions. The red emission from each sample was measured, yielding an upconversion intensity in the focal areas three times higher than the emission from the bare substrate. To estimate the real size of the red emission area under a single microsphere, a deconvolution of the measured focal spots with the Point Spread Function of the experimental setup was performed, resulting in a Full Width at Half Maximum of 330 nm. The results obtained by Finite-Difference Time-Domain simulations are in good agreement with the experimental values.

  12. Study of the focusing effect of silica microspheres on the upconversion of Er3+–Yb3+ codoped glass ceramics

    International Nuclear Information System (INIS)

    Pérez-Rodríguez, C.; Imanieh, M.H.; Martín, L.L; Ríos, S.; Martín, I.R.; Yekta, Bijan Eftekhari

    2013-01-01

    Highlights: •Silica microspheres have been located on the surface of glass and glass ceramics samples codoped with Er and Yb. •Microspheres act as microlens of the 950 nm excitation light resulting in focalized excited regions in the samples with sizes under the micron. •Intense red upconversion is achieved in the focalized areas. •Microspheres collect the upconversion emission light, scoping with the together microlensing properties an enhancement of the detected signal in a 3x factor. •Performed Finite-Difference Time-Domain simulations predict the size of the focalized regions in good agreement with the experimental measurements. -- Abstract: The upconversion emission properties of Er 3+ –Yb 3+ codoped glass and glass ceramic samples with different Si/Al ratios and thermal treatments were analyzed by covering their surfaces with silica microspheres (3.8 μm diameter). A 950 nm laser beam is focused by the microspheres producing a set of photonic nanojets near the surface of the samples. After the upconversion processes of the Er 3+ ions located in each microsphere focus area, these ions emit light in the green and red regions. The red emission from each sample was measured, yielding an upconversion intensity in the focal areas three times higher than the emission from the bare substrate. To estimate the real size of the red emission area under a single microsphere, a deconvolution of the measured focal spots with the Point Spread Function of the experimental setup was performed, resulting in a Full Width at Half Maximum of 330 nm. The results obtained by Finite-Difference Time-Domain simulations are in good agreement with the experimental values

  13. Method for the production of fabricated hollow microspheroids

    Science.gov (United States)

    Wickramanayake, Shan; Luebke, David R.

    2015-06-09

    The method relates to the fabrication of a polymer microspheres comprised of an asymmetric layer surrounding a hollow interior. The fabricated hollow microsphere is generated from a nascent hollow microsphere comprised of an inner core of core fluid surrounded by a dope layer of polymer dope, where the thickness of the dope layer is at least 10% and less than 50% of the diameter of the inner core. The nascent hollow microsphere is exposed to a gaseous environment, generating a vitrified hollow microsphere, which is subsequently immersed in a coagulation bath. Solvent exchange produces a fabricated hollow microsphere comprised of a densified outer skin surrounding a macroporous inner layer, which surrounds a hollow interior. In an embodiment, the polymer is a polyimide or a polyamide-imide, and the non-solvent in the core fluid and the coagulation bath is water. The fabricated hollow microspheres are particularly suited as solvent supports for gas separation processes.

  14. Facile synthesis of aluminum-doped LiNi{sub 0.5}Mn{sub 1.5}O{sub 4} hollow microspheres and their electrochemical performance for high-voltage Li-ion batteries

    Energy Technology Data Exchange (ETDEWEB)

    Liu, Xiaolin, E-mail: liu_x_l@sina.cn [College of Material Science and Engineering, Jiangxi University of Science and Technology, Ganzhou 341000, Jiangxi (China); Li, Dan; Mo, Qiaoling; Guo, Xiaoyu; Yang, Xiaoxiao [College of Material Science and Engineering, Jiangxi University of Science and Technology, Ganzhou 341000, Jiangxi (China); Chen, Guoxin, E-mail: gxchen@nimte.ac.cn [Ningbo Institute of Material Technology and Engineering, Chinese Academy of Sciences, Ningbo 315201, Zhejiang (China); Zhong, Shengwen [College of Material Science and Engineering, Jiangxi University of Science and Technology, Ganzhou 341000, Jiangxi (China)

    2014-10-01

    Graphical abstract: LiNi{sub 0.5}Mn{sub 1.5}O{sub 4} and Al doped LiNi{sub 0.5}Mn{sub 1.5}O{sub 4} hollow microspheres as 5 V cathodes are prepared by templated transformation method using monodisperse MnCO{sub 3} microspheres as precursor. As a cathodic material for high voltage lithium ion batteries, the as-synthesized LiNi{sub 0.5}Mn{sub 1.5}O{sub 4} and Al doped LiNi{sub 0.5}Mn{sub 1.5}O{sub 4} hollow microspheres are investigated by galvanostatic cycling (GC) approach to evaluate their electrochemical properties in the range of 2.7–4.8 V vs. Li/Li{sup +} at the current rate 1 C. - Highlights: • LNMO and LANMO hollow microspheres are synthesized by template method. • The as-synthesized hollow microspheres have particle-size of 2 μm. • The hollow structure is responsible for improved electrochemical performance. - Abstract: This paper presents the preparation of LiNi{sub 0.5}Mn{sub 1.5}O{sub 4} and aluminum (Al) doped LiNi{sub 0.5}Mn{sub 1.5}O{sub 4} hollow microspheres as 5 V cathodes using monodisperse MnCO{sub 3} microspheres as precursor and template, which were synthesized using MnSO{sub 4}·H{sub 2}O, NaHCO{sub 3} and ethanol in water at room temperature. XRD and morphology characterization results indicated that the as-prepared LiNi{sub 0.5}Mn{sub 1.5}O{sub 4} and Al doped LiNi{sub 0.5}Mn{sub 1.5}O{sub 4} were both spinel structure, and have particle sizes of 2–3 μm. The cathode electrochemical properties of LiNi{sub 0.5}Mn{sub 1.5}O{sub 4} and Al doped LiNi{sub 0.5}Mn{sub 1.5}O{sub 4} hollow microspheres (as 5 V cathodes) were evaluated and compared by galvanostatic cycling (GC) vs. Li/Li{sup +} at the current rate 1 C in 2.7–4.8 V. The specific initial capacities of all samples were in the range of 70–120 mA h g{sup −1}. Compared to undoped LiNi{sub 0.5}Mn{sub 1.5}O{sub 4}, Al doped LiNi{sub 0.5}Mn{sub 1.5}O{sub 4} hollow structures can effectively improve discharge capacity (up to 140 (±5) mA h g{sup −1}) and cycling stability (70

  15. Studies on the preparation and plasma spherodization of yttrium aluminosilicate glass microspheres for their potential application in liver brachytherapy

    Science.gov (United States)

    Sreekumar, K. P.; Saxena, S. K.; Kumar, Yogendra; Thiyagarajan, T. K.; Dash, Ashutosh; Ananthapadmanabhan, P. V.; Venkatesh, Meera

    2010-02-01

    Plasma spheroidization exploits the high temperature and high enthalpy available in the thermal plasma jet to melt irregularly shaped powder particles and quench them to get dense spherical particles. Plasma spheroidization is a versatile process and can be applied to metals, ceramics, alloys and composites to obtain fine spherical powders. Radioactive microspheres incorporated with high energetic beta emitting radioisotopes have been reported to be useful in the palliative treatment of liver cancer. These powders are to be prepared in closer range of near spherical morphology in the size range 20-35 microns. Inactive glass samples were prepared by heating the pre-calculated amount of glass forming ingredients in a recrystallized alumina crucible. The glass was formed by keeping the glass forming ingredients at 1700°C for a period of three hours to form a homogeneous melt. After cooling, the glass was recovered from the crucible by crushing and was subsequently powdered mechanically with the help of mortar and pestle. This powder was used as the feed stock for plasma spheroidization using an indigenously developed 40 kW plasma spray system. Experiments were carried out at various operating parameters. The operating parameters were optimised to get spheroidised particles. The powder was sieved to get the required size range before irradiation.

  16. Studies on the preparation and plasma spherodization of yttrium aluminosilicate glass microspheres for their potential application in liver brachytherapy

    Energy Technology Data Exchange (ETDEWEB)

    Sreekumar, K P; Saxena, S K; Kumar, Yogendra; Thiyagarajan, T K; Dash, Ashutosh; Ananthapadmanabhan, P V; Venkatesh, Meera, E-mail: nair.sreekumar@gmail.co [Laser and Plasma Technology Division, Radiopharmaceuticals Division, Bhabha Atomic Research Centre, Trombay, Mumbai - 400 085 (India)

    2010-02-01

    Plasma spheroidization exploits the high temperature and high enthalpy available in the thermal plasma jet to melt irregularly shaped powder particles and quench them to get dense spherical particles. Plasma spheroidization is a versatile process and can be applied to metals, ceramics, alloys and composites to obtain fine spherical powders. Radioactive microspheres incorporated with high energetic beta emitting radioisotopes have been reported to be useful in the palliative treatment of liver cancer. These powders are to be prepared in closer range of near spherical morphology in the size range 20-35 microns. Inactive glass samples were prepared by heating the pre-calculated amount of glass forming ingredients in a recrystallized alumina crucible. The glass was formed by keeping the glass forming ingredients at 1700{sup 0}C for a period of three hours to form a homogeneous melt. After cooling, the glass was recovered from the crucible by crushing and was subsequently powdered mechanically with the help of mortar and pestle. This powder was used as the feed stock for plasma spheroidization using an indigenously developed 40 kW plasma spray system. Experiments were carried out at various operating parameters. The operating parameters were optimised to get spheroidised particles. The powder was sieved to get the required size range before irradiation.

  17. Studies on the preparation and plasma spherodization of yttrium aluminosilicate glass microspheres for their potential application in liver brachytherapy

    International Nuclear Information System (INIS)

    Sreekumar, K P; Saxena, S K; Kumar, Yogendra; Thiyagarajan, T K; Dash, Ashutosh; Ananthapadmanabhan, P V; Venkatesh, Meera

    2010-01-01

    Plasma spheroidization exploits the high temperature and high enthalpy available in the thermal plasma jet to melt irregularly shaped powder particles and quench them to get dense spherical particles. Plasma spheroidization is a versatile process and can be applied to metals, ceramics, alloys and composites to obtain fine spherical powders. Radioactive microspheres incorporated with high energetic beta emitting radioisotopes have been reported to be useful in the palliative treatment of liver cancer. These powders are to be prepared in closer range of near spherical morphology in the size range 20-35 microns. Inactive glass samples were prepared by heating the pre-calculated amount of glass forming ingredients in a recrystallized alumina crucible. The glass was formed by keeping the glass forming ingredients at 1700 0 C for a period of three hours to form a homogeneous melt. After cooling, the glass was recovered from the crucible by crushing and was subsequently powdered mechanically with the help of mortar and pestle. This powder was used as the feed stock for plasma spheroidization using an indigenously developed 40 kW plasma spray system. Experiments were carried out at various operating parameters. The operating parameters were optimised to get spheroidised particles. The powder was sieved to get the required size range before irradiation.

  18. Towards modular bone tissue engineering using Ti-Co-doped phosphate glass microspheres: cytocompatibility and dynamic culture studies.

    Science.gov (United States)

    Peticone, Carlotta; De Silva Thompson, David; Owens, Gareth J; Kim, Hae-Won; Micheletti, Martina; Knowles, Jonathan C; Wall, Ivan

    2017-09-01

    The production of large quantities of functional vascularized bone tissue ex vivo still represent an unmet clinical challenge. Microcarriers offer a potential solution to scalable manufacture of bone tissue due to their high surface area-to-volume ratio and the capacity to be assembled using a modular approach. Microcarriers made of phosphate bioactive glass doped with titanium dioxide have been previously shown to enhance proliferation of osteoblast progenitors and maturation towards functional osteoblasts. Furthemore, doping with cobalt appears to mimic hypoxic conditions that have a key role in promoting angiogenesis. This characteristic could be exploited to meet the clinical requirement of producing vascularized units of bone tissue. In the current study, the human osteosarcoma cell line MG-63 was cultured on phosphate glass microspheres doped with 5% mol titanium dioxide and different concentrations of cobalt oxide (0%, 2% and 5% mol), under static and dynamic conditions (150 and 300 rpm on an orbital shaker). Cell proliferation and the formation of aggregates of cells and microspheres were observed over a period of two weeks in all glass compositions, thus confirming the biocompatibility of the substrate and the suitability of this system for the formation of compact micro-units of tissue. At the concentrations tested, cobalt was not found to be cytotoxic and did not alter cell metabolism. On the other hand, the dynamic environment played a key role, with moderate agitation having a positive effect on cell proliferation while higher agitation resulting in impaired cell growth. Finally, in static culture assays, the capacity of cobalt doping to induce vascular endothelial growth factor (VEGF) upregulation by osteoblastic cells was observed, but was not found to increase linearly with cobalt oxide content. In conclusion, Ti-Co phosphate glasses were found to support osteoblastic cell growth and aggregate formation that is a necessary precursor to tissue

  19. Template-free synthesis and luminescent properties of hollow Ln:YOF (Ln = Eu or Er + Yb) microspheres

    Energy Technology Data Exchange (ETDEWEB)

    Martinez-Castro, E. [Instituto de Ciencia de Materiales de Sevilla (CSIC-US), Americo Vespucio 49, Isla de La Cartuja, 41092 Sevilla (Spain); García-Sevillano, J.; Cussó, F. [Dpto. Física de Materiales, C-04, Universidad Autónoma de Madrid, Avda. Francisco Tomás y Valiente, 7, 28049 Madrid (Spain); Ocaña, M., E-mail: mjurado@icmse.csic.es [Instituto de Ciencia de Materiales de Sevilla (CSIC-US), Americo Vespucio 49, Isla de La Cartuja, 41092 Sevilla (Spain)

    2015-01-15

    Highlights: • Hollow lanthanide doped YOF spheres have been synthesised through a template-free procedure. • Strong red emissions are observed for Eu-doped spheres under UV illumination. • Concentration quenching of luminescence takes place in the spheres at very high Eu doping levels. • Bright red emission is observed for Er, Yb codoped spheres, making this matrix advantageous for biomedical imaging. - Abstract: A method for the synthesis of hollow lanthanide doped yttrium oxyfluoride (YOF) spheres in the micrometer size range with cubic structure based on the pyrolysis at 600 °C of liquid aerosols generated from aqueous solutions containing the corresponding rare earth chlorides and trifluoroacetic acid has been developed. This procedure, which has been used for the first time for the synthesis of YFO based materials, is simpler and advantageous when compared with other methods usually employed for the production of hollow spheres since it does not require the use of sacrificial templates. In addition, it is continuous, which is desirable because of practical reasons. The procedure is also suitable for doping the YOF spheres with europium cations resulting in down converting red phosphors when activated with UV light, or for co-doping with both Er{sup 3+} and Yb{sup 3+} giving rise to up-converting phosphors, which emit intense red light under near infrared (NIR) irradiation. Because of their optical properties and hollow architecture, the developed materials may find applications in optoelectronic devices and biotechnology.

  20. Ag/α-Fe{sub 2}O{sub 3} hollow microspheres: Preparation and application for hydrogen peroxide detection

    Energy Technology Data Exchange (ETDEWEB)

    Kang, Xinyuan; Wu, Zhiping; Liao, Fang, E-mail: liaozhang2003@163.com; Zhang, Tingting; Guo, Tingting

    2015-09-15

    In this paper, we demonstrated a simple approach for preparing α-Fe{sub 2}O{sub 3} hollow spheres by mixing ferric nitrate aqueous and glucose in 180 °C. The glucose was found to act as a soft template in the process of α-Fe{sub 2}O{sub 3} hollow spheres formation. Ag/α-Fe{sub 2}O{sub 3} hollow nanocomposite was obtained under UV irradiation without additional reducing agents or initiators. Synthesized Ag/α-Fe{sub 2}O{sub 3} hollow composites exhibited remarkable catalytic performance toward H{sub 2}O{sub 2} reduction. The electrocatalytic activity mechanism of Ag/α-Fe{sub 2}O{sub 3}/GCE were discussed toward the reduction of H{sub 2}O{sub 2} in this paper. - Graphical abstract: Glucose is carbonized as carbon balls in the 180 °C hydrothermal carbonization process, which plays a role of a soft template. Carbon spherical shell is rich in many hydroxyls, which have good hydrophilicity and surface reactivity. When Fe(NO{sub 3}){sub 3} is added to the aqueous solution of Glucose, the hydrophilic -OH will adsorb Fe{sup 3+} to form coordination compound by coordination bond. α-FeOOH is formed on the surface of carbon balls by hydrothermal reaction. After calcination at 500 °C, carbon spheres react with oxygen to form carbon dioxide, which disappears in the air. Meanwhile α-FeOOH is calcined to form α-Fe{sub 2}O{sub 3} hollow spheres.

  1. A self-template and self-activation co-coupling green strategy to synthesize high surface area ternary-doped hollow carbon microspheres for high performance supercapacitors.

    Science.gov (United States)

    Gao, Meng; Fu, Jianwei; Wang, Minghuan; Wang, Kai; Wang, Shaomin; Wang, Zhiwei; Chen, Zhimin; Xu, Qun

    2018-04-06

    Development of facile and cost-effective routes to achieve hierarchical porous and heteroatoms-doped carbon architectures is urgently needed for high-performance supercapacitor application. In our study, ternary-doped (nitrogen, phosphorus and oxygen) hollow carbon microspheres (NPO-HCSs) are fabricated by one-step pyrolysis of single poly(cyclotriphosphazene-co-phloroglucinol) (PCPP) microsphere, which is generated through a facile polymerization between hexachlorocyclotriphosphazene and phloroglucinol at mild conditions. The whole preparation process is not used any additional template or activating agent. The obtained NPO-HCS-950 with average diameter of 580 nm and shell thickness of about 80 nm have a high specific surface area (2390 m 2  g -1 ), a large pore volume (1.35 cm 3  g -1 ), hierarchically interconnected pore texture, and uniform ternary heteroatom doping (O: 3.04 at%; N: 1.33 at% and P: 0.67 at%). As an electrode material for supercapacitors, the specific capacitance of the NPO-HCS-950 reaches 253 F g -1 of 1 A g - 1 and 176 F g -1 at 20 A g -1 , revealing superior rate performance. The capacity retention after 10,000 consecutive charge-discharge cycles at 20 A g -1 is up to 98.9%, demonstrating excellent cycling stability. Moreover, the assembled symmetric supercapacitor using NPO-HCS-950 exhibits a relatively high energy density of 17.6 W h kg -1 at a power density of 800 W kg -1 . Thus, a promising electrode material for high-performance supercapacitors is obtained through a facile, green and scalable synthesis route. Copyright © 2018 Elsevier Inc. All rights reserved.

  2. Low threshold lasing of bubble-containing glass microspheres by non-whispering gallery mode excitation over a wide wavelength range

    Energy Technology Data Exchange (ETDEWEB)

    Kumagai, Tsutaru, E-mail: kumagai.t.af@m.titech.ac.jp; Kishi, Tetsuo; Yano, Tetsuji [Department of Chemistry and Materials Science, Tokyo Institute of Technology, 2-12-1 Ookayama, Meguro-ku, Tokyo 152-8550 (Japan)

    2015-03-21

    Bubble-containing Nd{sup 3+}-doped tellurite glass microspheres were fabricated by localized laser heating technique to investigate their optical properties for use as microresonators. Fluorescence and excitation spectra measurements were performed by pumping with a tunable CW-Ti:Sapphire laser. The excitation spectra manifested several sharp peaks due to the conventional whispering gallery mode (WGM) when the pumping laser was irradiated to the edge part of the microsphere. However, when the excitation light was irradiated on the bubble position inside the microsphere, “non-WGM excitation” was induced, giving rise to numerous peaks at a broad wavelength range in the excitation spectra. Thus, efficient excitation was achieved over a wide wavelength range. Lasing threshold excited at the bubble position was much lower than that for the excitation at the edges of the microsphere. The lowest value of the laser threshold was 34 μW for a 4 μm sphere containing a 0.5 μm bubble. Efficiency of the excitation at the bubble position with broadband light was calculated to be 5 times higher than that for the edge of the microsphere. The bubble-containing microsphere enables efficient utilization of broadband light excitation from light-emitting diodes and solar light.

  3. Facile synthesis of Co3O4 nanowires grown on hollow NiO microspheres with superior electrochemical performance

    International Nuclear Information System (INIS)

    Fan, Meiqing; Ren, Bo; Yu, Lei; Song, Dalei; Liu, Qi; Liu, Jingyuan; Wang, Jun; Jing, Xiaoyan; Liu, Lianhe

    2015-01-01

    Graphical abstract: Display Omitted - Highlights: • The NiO hollow spheres were decorated by Co 3 O 4 nanowires. • The NiO hollow spheres were comprised of many NiO particles. • The Co 3 O 4 nanowires were composed of nanoparticles. • The NiO/Co 3 O 4 core/shell nanocomposites have good electrochemical properties. - Abstract: The NiO/Co 3 O 4 core/shell composites as a promising supercapacitor material have been fabricated by facile hydrothermal process. The structure and morphology of the NiO/Co 3 O 4 core/shell composites were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM) and transmission electron microscopy (TEM). The results indicated that the NiO hollow spheres were decorated by Co 3 O 4 nanowires, and the nanowires were composed of nanoparticles. Electrochemical properties were characterized by cyclic voltammetry, galvanostatic charge/discharge measurements, and electrochemical impedance spectroscopy. The results suggested that the NiO/Co 3 O 4 core/shell composites had good electrochemical reversibility and displayed superior capacitive performance with large capacitance (510 F g −1 ). Moreover, NiO/Co 3 O 4 core/shell composites showed excellent cyclic performanceafter 1000 cycles

  4. Rose-like monodisperse bismuth subcarbonate hierarchical hollow microspheres: One-pot template-free fabrication and excellent visible light photocatalytic activity and photochemical stability for NO removal in indoor air

    International Nuclear Information System (INIS)

    Dong, Fan; Lee, S.C.; Wu, Zhongbiao; Huang, Yu; Fu, Min; Ho, Wing-Kei; Zou, Shichun; Wang, Bo

    2011-01-01

    Graphical abstract: Rose-like monodisperse hierarchical nitrogen doped (BiO) 2 CO 3 hollow microspheres fabricated by a one-pot template-free method exhibit excellent visible light photocatalytic activity and photochemical stability in the removal of NO in indoor air. The special hierarchical microstructure, the high charge separation efficiency and two-band-gap structure in all contribute to the outstanding photocatalytic performance. Highlights: → Rose-like monodisperse hierarchical (BiO) 2 CO 3 hollow microspheres are fabricated. → The (BiO) 2 CO 3 microspheres are self-assembled of single-crystalline nanosheets. → Nitrogen is in situ doped into the lattice of hierarchical (BiO) 2 CO 3 microspheres. → The (BiO) 2 CO 3 microspheres exhibit outstanding visible light activity for NO removal. → The (BiO) 2 CO 3 microspheres also exhibit high photochemical stability. - Abstract: Rose-like monodisperse hierarchical (BiO) 2 CO 3 hollow microspheres are fabricated by a one-pot template-free method for the first time based on hydrothermal treatment of ammonia bismuth citrate and urea in water. The microstructure and band structure of the as-prepared (BiO) 2 CO 3 superstructure are characterized in detail by X-ray diffraction, Raman spectroscopy, Fourier transform-infrared spectroscopy, transmission electron microscopy, scanning electron microscopy, N 2 adsorption-desorption isotherms, X-ray photoelectron spectroscopy and UV-vis diffuse reflectance spectroscopy. The monodisperse hierarchical (BiO) 2 CO 3 microspheres are constructed by the self-assembly of single-crystalline nanosheets. The aggregation of nanosheets result in the formation of three dimensional hierarchical framework containing mesopores and macropores, which is favorable for efficient transport of reaction molecules and harvesting of photo-energy. The result reveals the existence of special two-band-gap structure (3.25 and 2.0 eV) for (BiO) 2 CO 3 . The band gap of 3.25 eV is intrinsic and the

  5. One-step synthesis of in situ reduced metal Bi decorated bismuth molybdate hollow microspheres with enhancing photocatalytic activity

    Energy Technology Data Exchange (ETDEWEB)

    Jin, Meng [College of Chemistry & Chemical Engineering, Chongqing University, Chongqing 400044 (China); Lu, Shiyu [Institute for Clean Energy & Advanced Materials, Faculty of Materials and Energy, Southwest University, Chongqing, 400715 (China); Ma, Li, E-mail: mlsys607@126.com [College of Chemistry & Chemical Engineering, Chongqing University, Chongqing 400044 (China); Gan, Mengyu [College of Chemistry & Chemical Engineering, Chongqing University, Chongqing 400044 (China)

    2017-02-28

    Highlights: • Metal Bi decorated Bi{sub 2-x}MoOy was synthesised by a simple and one-step. • Bi{sup 3+} could be in situ reduced to Bi{sup 0} gradually and dispersed uniform in Bi{sub 2-x}MoOy. • It shows excellent photocatalytic activity due to special structure and composition. - Abstract: In this feature work, in situ metal Bi are successfully modified bismuth molybdate hollow spheres using an effective one-pot solvthermal reduction without any temple. In order to deeply understand the influence of reduction conditions on the texture, surface state, and photocatalytic performance of the resulting samples, a series of products were synthesized by tuning the temperatures. The similar morphology, surface area of photocatalysis (BMO-160 and BMO-170) were synthesized, only with the different composition. The detailed characterization and analysis distinctly suggested that increasing solvothermal reduction temperature led to Bi{sup 3+} was in situ reduced to elementary substance Bi{sup 0} by ethylene glycol gradually and dispersed very uniform in bismuth molybdate. Benefiting from the enhanced charge separation, transfer, and donor density resulting from the formation of Bi decorated bismuth molybdate where Bi as cocatalyst, the photocatalytic performance of the reductive Bi/Bi{sub 2-x}MoO{sub y} hollow spheres (BMO-170) is higher than that of the untreated Bi{sub 2-x}MoO{sub y} hollow spheres (BMO-160) for Rh6G degradation under visible light irradiation. Additionally, the reductive BMO-170 has a superior stability after five cycles.

  6. General Approach to Prepare 0.33Li₂MnO₃ · 0.67LiNi1/3Co1/3Mn1/3O₂ Hollow Microspheres for High Performance Lithium Ion Batteries.

    Science.gov (United States)

    Li, Jingfa; Xu, Wenjin; Zhang, Lei; Li, Min

    2018-06-01

    Li-excess manganese-based oxide layered structures, have drawn increasing interests as the promising cathodes to succeed the conventional LiCoO2 in lithium ion batteries (LIBs). It could deliver a higher energy density and output potential, as well as the nature of environment benign and low cost. Pristine Li-excess manganese-based oxides however suffer from poor rate capacity and voltage fading after cycling, and their inherent capacity limits of bulk size in performance. Micro-/Nanostructured electrode materials are considered to hold the key to overcome these thresholds. This paper reports a general approach to prepare 0.33Li2MnO3 · 0.67LiNi1/3Co1/3Mn1/3O2 microspheres with pores and void space, which benefits improving both the capacity and cyclability. The electrode made of hollow 0.33Li2MnO3 · 0.67LiNi1/3Co1/3Mn1/3O2 microspheres exhibits a 224 mAh g-1 discharge capacity over 200 cycles at 0.25 C rate, and 195 mAh g-1 at 5.0 C rate. These results indicated good perspective of hollow microspheres for practical battery applications.

  7. Metallic coating of microspheres

    International Nuclear Information System (INIS)

    Meyer, S.F.

    1980-01-01

    Extremely smooth, uniform metal coatings of micrometer thicknesses on microscopic glass spheres (microspheres) are often needed as targets for inertial confinement fusion (ICF) experiments. The first part of this paper reviews those methods used successfully to provide metal coated microspheres for ICF targets, including magnetron sputtering, electro- and electroless plating, and chemical vapor pyrolysis. The second part of this paper discusses some of the critical aspects of magnetron sputter coating of microspheres, including substrate requirements, the sticking of microspheres during coating (preventing a uniform coating), and the difficulties in growing the desired dense, smooth, uniform microstructure on continuously moving spherical substrates

  8. DNA-assisted binding of microspheres on glass substrates and their laser-induced release

    International Nuclear Information System (INIS)

    Kim, Sejong; Geiss, Erik; Yu, Phillip; Papadimitrakopoulos, Fotios; Marcus, Harris L.

    2006-01-01

    DNA hybridization has been increasingly adopted in materials sciences due to its complementary nature of single stranded DNAs. This unique property could be potentially used in the realization of 2 dimensional (2D) arrays of colloidal microspheres as a precursor to further build more complicated superstructures. In order to precisely understand this DNA-assisted assembly of colloidal particles, we quantitatively assessed the surface density of grafted and hybridizing accessible DNA oligomers on both substrate and colloidal particles. The DNA grafting densities were determined by UV-Vis of dye-functionalized complementary DNA oligomers, in conjunction with theoretical models. The variations of the concentration of hybridized DNA as a function of parameters such as the number of DNA base pairs (bp), the length of spacer and the size of sphere were also investigated to determine the immobilization strength of colloidal microspheres on the substrate. Dehybridization of the particle was conducted by utilizing a focused laser beam. These results were also compared with the particle hybridization energies and modeled according to the sum of DNA bindings as a function of the number of hybridized bases

  9. Retrofit of hollow concrete masonry infilled steel frames using glass fiber reinforced plastic laminates

    Science.gov (United States)

    Hakam, Zeyad Hamed-Ramzy

    2000-11-01

    This study focuses on the retrofit of hollow concrete masonry infilled steel frames subjected to in-plane lateral loads using glass fiber reinforced plastic (GFRP) laminates that are epoxy-bonded to the exterior faces of the infill walls. An extensive experimental investigation using one-third scale modeling was conducted and consisted of two phases. In the first phase, 64 assemblages, half of which were retrofitted, were tested under various combined in-plane loading conditions similar to those which different regions of a typical infill wall are subjected to. In the second phase, one bare and four masonry-infilled steel frames representative of a typical single-story, single-bay panel were tested under diagonal loading to study the overall behavior and the infill-frame interaction. The relative infill-to-frame stiffness was varied as a test parameter by using two different steel frame sections. The laminates altered the failure modes of the masonry assemblages and reduced the variability and anisotropic nature of the masonry. For the prisms which failed due to shear and/or mortar joint slip, significant strength increases were observed. For those exhibiting compression failure modes, a marginal increase in strength resulted. Retrofitting the infilled frames resulted in an average increase in initial stiffness of two-fold compared to the unretrofitted infilled frames, and seemed independent of the relative infill-to-frame stiffness. However, the increase in the load-carrying capacity of the retrofitted frames compared to the unretrofitted counterparts was higher for those with the larger relative infill-to-frame stiffness parameter. Unlike the unretrofitted infill walls, the retrofitted panels demonstrated almost identical failure modes that were characterized as "strictly comer crushing" in the vicinity of the loaded comers whereas no signs of distress were evident throughout the remainder of the infill. The laminates also maintained the structural integrity of

  10. In Situ Synthesis of MnS Hollow Microspheres on Reduced Graphene Oxide Sheets as High-Capacity and Long-Life Anodes for Li- and Na-Ion Batteries.

    Science.gov (United States)

    Xu, Xijun; Ji, Shaomin; Gu, Mingzhe; Liu, Jun

    2015-09-23

    Uniform MnS hollow microspheres in situ crystallized on reduced graphene oxide (RGO) nanosheets via a facile hydrothermal method. The MnS/RGO composite material was used as the anode for Na-ion batteries for the first time and exhibited excellent cycling performance, superior specific capacity, and great cycle stability and rate capability for both Li- and Na-ion batteries. Compared with nonencapsulated pure MnS hollow microspheres, these MnS/RGO nanocomposites demonstrated excellent charge-discharge stability and long cycle life. Li-ion storage testing revealed that these MnS/RGO nanocomposites deliver high discharge-charge capacities of 640 mAh g(-1) at 1.0 A g(-1) after 400 cycles and 830 mAh g(-1) at 0.5 A g(-1) after 100 cycles. The MnS/RGO nanocomposites even retained a specific capacity of 308 mAh g(-1) at a current density of 0.1 A g(-1) after 125 cycles as the anode for Na-ion batteries. The outstanding electrochemical performance of the MnS/RGO composite attributed to the RGO nanosheets greatly improved the electronic conductivity and efficiently mitigated the stupendous volume expansion during the progress of charge and discharge.

  11. Hollow mesoporous CuCo2O4 microspheres derived from metal organic framework: A novel functional materials for simultaneous H2O2 biosensing and glucose biofuel cell.

    Science.gov (United States)

    Cui, Shiqiang; Gu, Shuqing; Ding, Yaping; Zhang, Jiangjiang; Zhang, Zhen; Hu, Zongqian

    2018-02-01

    Hollow mesoporous CuCo 2 O 4 (meso-CuCo 2 O 4 ) microspheres were successfully synthesized by decomposing metal-organic frameworks (MOFs) as the template. The as-prepared CuCo 2 O 4 microspheres were first simultaneously used for H 2 O 2 biosensing and glucose biofuel cell (GFC) as the enzyme mimic. The resulting of meso-CuCo 2 O 4 displayed not only excellent catalytic performances to H 2 O 2 including a super-fast response time (within 2s), a super-high sensitivity (654.23 μA mM -1 cm -2 ) and a super-low detection limit (3nM at S/N = 3) on the sensor, but also great values in GFC as anode material with an open circuit voltage of 0.85V, a maximum power density of 0.33 mWcm -2 and a limiting current density of 1.27 mAcm -2 , respectively. The preeminent catalytic abilities to H 2 O 2 and glucose may be attributed to the surpassing intrinsic catalytic activity of CuCo 2 O 4 and large specific area of mesoporous structure. These significant findings deriving from this work not only provided a novel exploration for the fabrication of hollow spherical mesoporous bimetallic oxides, but also promoted the development of the supersensitive detection of H 2 O 2 and non-enzymatic biofuel cell. Copyright © 2017. Published by Elsevier B.V.

  12. A dosimetric treatment planning strategy in radioembolization of hepatocarcinoma with 90Y glass microspheres.

    Science.gov (United States)

    Chiesa, C; Mira, M; Maccauro, M; Romito, R; Spreafico, C; Sposito, C; Bhoori, S; Morosi, C; Pellizzari, S; Negri, A; Civelli, E; Lanocita, R; Camerini, T; Bampo, C; Carrara, M; Seregni, E; Marchianò, A; Mazzaferro, V; Bombardieri, E

    2012-12-01

    Our goal was to limit liver toxicity and to obtain good efficacy by developing a dosimetric treatment planning strategy. While several dosimetric evaluations are reported in literature, the main problem of the safety of the treatment is rarely addressed. Our work is the first proposal of a treatment planning method for glass spheres, including both liver toxicity and efficacy issues. Fifty-two patients (series 1) had been treated for intermediated/advanced hepatocellular carcinoma (HCC) with glass spheres, according to the Therasphere® prescription of 120 Gy averaged on the injected lobe. They were retrospectively evaluated with voxel dosimetry, adopting the local deposition hypothesis. Regions of interest on tumor and non tumor parenchyma were drawn to determine the parenchyma absorbed dose, averaged also on non irradiated voxels, excluding tumor voxels. The relationship between the mean non tumoral parenchyma absorbed dose D and observed liver decompensation was analyzed. Basal Child-Pugh strongly affected the toxicity incidence, which was 22% for A5, 57% for A6, 89% for B7 patients. Restricting the analysis to our numerically richest class (basal Child-Pugh A5 patients), D median values were significantly different between toxic (median 90 Gy) and non toxic treatments (median 58 Gy) at a Mann-Withney test, (P=0.033). Using D as a marker for toxicity, the separation of the two populations in terms of area under ROC curve was 0.75, with 95% C.I. of [0.55-0.95]. The experimental Normal Tissue Complication Probability (NTCP) curve as a function of D resulted in the following values: 0%, 14%, 40%, 67% for D interval of [0-35] Gy, [35-70] Gy, [70-105] Gy, [105-140] Gy. A limit of about 70 Gy for the mean absorbed dose to parenchyma was assumed for A5 patients, corresponding to a 14% risk of liver decompensation. This result is applicable only to our administration conditions: glass spheres after a decay interval of 3.75 days. Different safety limit (40 Gy) are

  13. Boosted selective internal radiation therapy with 90Y-loaded glass microspheres (B-SIRT) for hepatocellular carcinoma patients: a new personalized promising concept

    International Nuclear Information System (INIS)

    Garin, E.; Lenoir, L.; Edeline, J.; Laffont, S.; Mesbah, H.; Poree, P.; Sulpice, L.; Boudjema, K.; Mesbah, M.; Guillygomarc'h, A.; Quehen, E.; Pracht, M.; Raoul, J.L.; Clement, B.; Rolland, Y.; Boucher, E.

    2013-01-01

    To evaluate the impact of dosimetry based on MAA SPECT/CT for the prediction of response, toxicity and survival, and for treatment planning in patients with hepatocellular carcinoma (HCC) treated with 90 Y-loaded glass microspheres (TheraSphere registered). TheraSphere registered was administered to 71 patients with inoperable HCC. MAA SPECT/CT quantitative analysis was used for the calculation of the tumour dose (TD), healthy injected liver dose (HILD), and total injected liver dose. Response was evaluated at 3 months using EASL criteria. Time to progression (TTP) and overall survival (OS) were evaluated using the Kaplan-Meier method. Factors potentially associated with liver toxicity were combined to construct a liver toxicity score (LTS). The response rate was 78.8 %. Median TD were 342 Gy for responding lesions and 191 Gy for nonresponding lesions (p 205 Gy (p = 0.0015 and not significant). Among patients with portal vein thrombosis (PVT) (n = 33), the median TTP and OS were 4.5 months (2-7 months) and 5 months (2-8 months), respectively, in patients with TD 205 Gy (p = 0.039 and 0.005). The median OS was 24.5 months (18-28.5 months) in PVT patients with TD >205 Gy and good PVT targeting on MAA SPECT/CT. The LTS was able to detect severe liver toxicity (n = 6) with a sensitivity of 83 % and overall accuracy of 97 %. Dosimetry based on MAA SPECT/CT was able to accurately predict response and survival in patients treated with glass microspheres. This method can be used to adapt the injected activity without increasing liver toxicity, thus defining a new concept of boosted selective internal radiation therapy (B-SIRT). This new concept and LTS enable fully personalized treatment planning with glass microspheres to be achieved. (orig.)

  14. Boosted selective internal radiation therapy with 90Y-loaded glass microspheres (B-SIRT) for hepatocellular carcinoma patients: a new personalized promising concept.

    Science.gov (United States)

    Garin, E; Lenoir, L; Edeline, J; Laffont, S; Mesbah, H; Porée, P; Sulpice, L; Boudjema, K; Mesbah, M; Guillygomarc'h, A; Quehen, E; Pracht, M; Raoul, J L; Clement, B; Rolland, Y; Boucher, E

    2013-07-01

    To evaluate the impact of dosimetry based on MAA SPECT/CT for the prediction of response, toxicity and survival, and for treatment planning in patients with hepatocellular carcinoma (HCC) treated with (90)Y-loaded glass microspheres (TheraSphere®). TheraSphere® was administered to 71 patients with inoperable HCC. MAA SPECT/CT quantitative analysis was used for the calculation of the tumour dose (TD), healthy injected liver dose (HILD), and total injected liver dose. Response was evaluated at 3 months using EASL criteria. Time to progression (TTP) and overall survival (OS) were evaluated using the Kaplan-Meier method. Factors potentially associated with liver toxicity were combined to construct a liver toxicity score (LTS). The response rate was 78.8%. Median TD were 342 Gy for responding lesions and 191 Gy for nonresponding lesions (p 205 Gy (p = 0.0015 and not significant). Among patients with portal vein thrombosis (PVT) (n = 33), the median TTP and OS were 4.5 months (2-7 months) and 5 months (2-8 months), respectively, in patients with TD 205 Gy (p = 0.039 and 0.005). The median OS was 24.5 months (18-28.5 months) in PVT patients with TD >205 Gy and good PVT targeting on MAA SPECT/CT. The LTS was able to detect severe liver toxicity (n = 6) with a sensitivity of 83% and overall accuracy of 97%. Dosimetry based on MAA SPECT/CT was able to accurately predict response and survival in patients treated with glass microspheres. This method can be used to adapt the injected activity without increasing liver toxicity, thus defining a new concept of boosted selective internal radiation therapy (B-SIRT). This new concept and LTS enable fully personalized treatment planning with glass microspheres to be achieved.

  15. Absorption Spectroscopy in Hollow-Glass Waveguides Using Infrared Diode Lasers[4817-25

    International Nuclear Information System (INIS)

    Blake, Thomas A.; Kelly, James F.; Stewart, Timothy L.; Hartman, John S.; Sharpe, Steven W.; Sams, Robert L.; Alan Fried

    2002-01-01

    Near- and mid-infrared diode lasers combined with flexible, hollow waveguides hold the promise of light weight, field portable, fast response gas sensors. The advantages of using the waveguides compared to White or Herriott multireflection cells include a small gas volume, a high photon fill factor in the waveguide, which increases molecule-light interactions, and reduction or elimination of optical fringing, which usually sets the practical limit of detectivity in absorption spectroscopy. Though hollow waveguides have been commercially available for several years, relatively few results have been reported in the literature. We present here results from our laboratory where we have injected infrared laser light into straight and coiled lengths of hollow waveguides and performed direct and wavelength modulated absorption spectroscopy on nitrous oxide, ethylene, and nitric oxide. Using a 1 mm bore, 3 meter long coiled waveguide coated for the near infrared, nitrous oxide transitions near 6595 cm-1 were observed under flowing conditions. Signal-to-noise ratios on the order of 1500:1 with RMS noise equal to 2 X 10-5 were measured. In the mid-infrared light from either a 10.1 or 5.3 micron lead salt diode laser was injected into a three meter length of 1 mm bore hollow waveguide coated for the mid-infrared. The waveguide was coiled with one loop at a diameter of 52 cm. Ethylene transitions were observed in the vicinity of 985 cm-1 with a static fill of 0.2 Torr of pure ethylene in the waveguide and nitric oxide transitions were observed in the vicinity of 1906 cm-1 using either a flow or a static fill of 1 ppm NO in nitrogen. In direct absorption the NO transitions are observed to have a signal-to-noise of approximately 5:1 for transitions with absorbances on the order of 10-3. Using wavelength modulated techniques the signal-to-noise ratio improves at least an order of magnitude. These encouraging results indicate that waveguides can be used for in situ gas monitoring

  16. Radiotherapy fiber dosimeter probes based on silver-only coated hollow glass waveguides

    Science.gov (United States)

    Darafsheh, Arash; Melzer, Jeffrey E.; Harrington, James A.; Kassaee, Alireza; Finlay, Jarod C.

    2018-01-01

    Manifestation of Čerenkov radiation as a contaminating signal is a significant issue in radiation therapy dose measurement by fiber-coupled scintillator dosimeters. To enhance the scintillation signal transmission while minimizing Čerenkov radiation contamination, we designed a fiber probe using a silver-only coated hollow waveguide (HWG). The HWG with scintillator inserted in its tip, embedded in tissue-mimicking phantoms, was irradiated with clinical electron and photon beams generated by a medical linear accelerator. Optical spectra of the irradiated tip were taken using a fiber spectrometer, and the signal was deconvolved with a linear fitting algorithm. The resultant decomposed spectra of the scintillator with and without Čerenkov correction were in agreement with measurements performed by a standard electron diode and ion chamber for electron and photon beam dosimetry, respectively, indicating the minimal effect of Čerenkov contamination in the HWG-based dosimeter. Furthermore, compared with a silver/dielectric-coated HWG fiber dosimeter design, we observed higher signal transmission in the design based on the use of silver-only HWG.

  17. Review: microspheres for radioembolization therapy

    International Nuclear Information System (INIS)

    Zhao Mingqiang; Xu Shuhe

    2007-12-01

    Radioembolization of liver cancer has been proven to be an effective therapy in nuclear medicine. The yttrium-90 glass microspheres has been used to treat both primary and metastatic liver tumors in clinic which shown encouraging results. The preparation, stability, degradation and application for medical purpose of radioactive microspheres are reviewed. At first, the theory of radioem- bolization treating cancer is discussed; and then three major radiolabled micro- sphere materials are expounded: viz. glass, resin-based and polymer-based; Future improvements in the preparation and use of radioactive microspheres are prospected at last. (authors)

  18. Review: microspheres for radioembolization therapy

    Energy Technology Data Exchange (ETDEWEB)

    Mingqiang, Zhao; Shuhe, Xu [China Inst. of Atomic Energy, Beijing (China)

    2007-12-15

    Radioembolization of liver cancer has been proven to be an effective therapy in nuclear medicine. The yttrium-90 glass microspheres has been used to treat both primary and metastatic liver tumors in clinic which shown encouraging results. The preparation, stability, degradation and application for medical purpose of radioactive microspheres are reviewed. At first, the theory of radioem- bolization treating cancer is discussed; and then three major radiolabled micro- sphere materials are expounded: viz. glass, resin-based and polymer-based; Future improvements in the preparation and use of radioactive microspheres are prospected at last. (authors)

  19. Boosted selective internal radiation therapy with {sup 90}Y-loaded glass microspheres (B-SIRT) for hepatocellular carcinoma patients: a new personalized promising concept

    Energy Technology Data Exchange (ETDEWEB)

    Garin, E.; Lenoir, L. [Comprehensive Cancer Center, Institute Eugene Marquis, Department of Nuclear Medicine, CS 44229, Rennes (France); University of Rennes 1, Rennes (France); INSERM, U-991, Liver Metabolisms and Cancer, Rennes (France); Edeline, J. [University of Rennes 1, Rennes (France); Comprehensive Cancer Center, Institute Eugene Marquis, Department of Medical Oncology, CS 44229, Rennes (France); Laffont, S. [Comprehensive Cancer Center, Institute Eugene Marquis, Department of Nuclear Medicine, CS 44229, Rennes (France); Mesbah, H.; Poree, P. [Comprehensive Cancer Center, Institute Eugene Marquis, Department of Medical Informatics, CS 44229, Rennes (France); Sulpice, L. [INSERM, U-991, Liver Metabolisms and Cancer, Rennes (France); Centre Hospitalier Universitaire Pontchaillou, Department of Digestive Surgery, Rennes (France); Boudjema, K. [University of Rennes 1, Rennes (France); INSERM, U-991, Liver Metabolisms and Cancer, Rennes (France); Centre Hospitalier Universitaire Pontchaillou, Department of Digestive Surgery, Rennes (France); Mesbah, M. [University of Pierre et Marie Curie, Paris (France); Guillygomarc' h, A. [Centre Hospitalier Universitaire Pontchaillou, Department of Hepatology, Rennes (France); Quehen, E. [Centre Hospitalier Universitaire Pontchaillou, Department of Radiology, Rennes (France); Pracht, M. [Comprehensive Cancer Center, Institute Eugene Marquis, Department of Medical Oncology, CS 44229, Rennes (France); Raoul, J.L. [Comprehensive Cancer Center, Institute Paoli Calmette, Department of Medical Oncology, Marseille (France); Clement, B. [INSERM, U-991, Liver Metabolisms and Cancer, Rennes (France); Rolland, Y. [Comprehensive Cancer Center, Institute Eugene Marquis, Department of Medical Imaging, CS 44229, Rennes (France); Boucher, E. [INSERM, U-991, Liver Metabolisms and Cancer, Rennes (France); Comprehensive Cancer Center, Institute Eugene Marquis, Department of Medical Oncology, CS 44229, Rennes (France)

    2013-07-15

    To evaluate the impact of dosimetry based on MAA SPECT/CT for the prediction of response, toxicity and survival, and for treatment planning in patients with hepatocellular carcinoma (HCC) treated with {sup 90}Y-loaded glass microspheres (TheraSphere registered). TheraSphere registered was administered to 71 patients with inoperable HCC. MAA SPECT/CT quantitative analysis was used for the calculation of the tumour dose (TD), healthy injected liver dose (HILD), and total injected liver dose. Response was evaluated at 3 months using EASL criteria. Time to progression (TTP) and overall survival (OS) were evaluated using the Kaplan-Meier method. Factors potentially associated with liver toxicity were combined to construct a liver toxicity score (LTS). The response rate was 78.8 %. Median TD were 342 Gy for responding lesions and 191 Gy for nonresponding lesions (p < 0.001). With a threshold TD of 205 Gy, MAA SPECT/CT predicted response with a sensitivity of 100 % and overall accuracy of 90 %. Based on TD and HILD, 17 patients underwent treatment intensification resulting in a good response rate (76.4 %), without increased grade III liver toxicity. The median TTP and OS were 5.5 months (2-9.5 months) and 11.5 months (2-31 months), respectively, in patients with TD <205 Gy and 13 months (10-16 months) and 23.2 months (17.5-28.5 months), respectively, in those with TD >205 Gy (p = 0.0015 and not significant). Among patients with portal vein thrombosis (PVT) (n = 33), the median TTP and OS were 4.5 months (2-7 months) and 5 months (2-8 months), respectively, in patients with TD <205 Gy and 10 months (6-15.2 months) and 21.5 months (12-28.5 months), respectively, in those with TD >205 Gy (p = 0.039 and 0.005). The median OS was 24.5 months (18-28.5 months) in PVT patients with TD >205 Gy and good PVT targeting on MAA SPECT/CT. The LTS was able to detect severe liver toxicity (n = 6) with a sensitivity of 83 % and overall accuracy of 97 %. Dosimetry based on MAA SPECT/CT was

  20. Preparation of polystyrene microsphere with emulsion microencapsulation method

    International Nuclear Information System (INIS)

    Li Bo Zhang Lin; Zhang Zhganwen; You Dan; Wei Yun; Wang Chaoyang; Lin Bo; Shi Tao; Chu Qiaomei

    2003-01-01

    The preparation of hollow polystyrene microspheres that are used as inner shell of multi-shell plastic microspheres in the ICF experiments is focused on. The effects of surfactants, water-soluble polymer and electrolyte on the properties of resultant microspheres are studied. Based on these experiments, a fabricating procedure was established with which hollow microspheres were prepared with diameter about 150-3000 μm, wall thickness 0.8-15 μm and toughness Ra less than 4 nm. (authors)

  1. Preparation and Application of Hollow Silica/magnetic Nanocomposite Particle

    Science.gov (United States)

    Wang, Cheng-Chien; Lin, Jing-Mo; Lin, Chun-Rong; Wang, Sheng-Chang

    The hollow silica/cobalt ferrite (CoFe2O4) magnetic microsphere with amino-groups were successfully prepared via several steps, including preparing the chelating copolymer microparticles as template by soap-free emulsion polymerization, manufacturing the hollow cobalt ferrite magnetic microsphere by in-situ chemical co-precipitation following calcinations, and surface modifying of the hollow magnetic microsphere by 3-aminopropyltrime- thoxysilane via the sol-gel method. The average diameter of polymer microspheres was ca. 200 nm from transmission electron microscope (TEM) measurement. The structure of the hollow magnetic microsphere was characterized by using TEM and scanning electron microscope (SEM). The spinel-type lattice of CoFe2O4 shell layer was identified by using XRD measurement. The diameter of CoFe2O4 crystalline grains ranged from 54.1 nm to 8.5 nm which was estimated by Scherrer's equation. Additionally, the hollow silica/cobalt ferrite microsphere possesses superparamagnetic property after VSM measurement. The result of BET measurement reveals the hollow magnetic microsphere which has large surface areas (123.4m2/g). After glutaraldehyde modified, the maximum value of BSA immobilization capacity of the hollow magnetic microsphere was 33.8 mg/g at pH 5.0 buffer solution. For microwave absorption, when the hollow magnetic microsphere was compounded within epoxy resin, the maximum reflection loss of epoxy resins could reach -35dB at 5.4 GHz with 1.9 mm thickness.

  2. Hepatic arterial 90Yttrium glass microspheres (Therasphere) for unresectable hepatocellular carcinoma: interim safety and survival data on 65 patients.

    Science.gov (United States)

    Carr, Brian I

    2004-02-01

    Hepatocellular carcinoma (HCC) generally arises in a cirrhotic liver and, in most cases, is multifocal and bilobar. Although trans-hepatic artery chemoembolization (TACE) can be highly affective in shrinking tumors, it is limited by virtue of the damage that it can cause to the liver that is already damaged by chronic disease. A high priority in HCC research, after primary prevention and early detection, is to find new treatment modalities that are both effective and non-toxic to the underlying cirrhotic liver. A cohort of 65 patients with biopsy-proven unresectable HCC have been treated with hepatic arterial 90Yttrium microspheres (Therasphere), and the interim results are reported here. Only 1 cycle of Therasphere treatment ever was performed on 46 patients, 17 patients had 2 cycles, and 2 patients had 3 cycles of therapy. The median dose delivered was 134 Gy, typically as either 5 or 10 GBq (2-4 million microspheres). Clinical toxicities include 9 episodes of abdominal pain and 2 episodes of acute cholecystitis, requiring cholecystectomy. A main lab toxicity was elevated bilirubin which increased by more than 200% in 25 patients (30.5%) during 6 months of therapy, although 18 of these patients had only transient elevation. A prominent finding was prolonged and profound (>70%) lymphopenia in more than 75% of the patients, but without clinical significance. Forty-two patients (64.6%) had a substantial decrease in tumor vascularity in response to therapy, and 25 patients (38.4%) had a partial response, by computed tomography scan. Median survival for Okuda stage I patients (n=42) was 649 days (historical comparison 244) and for Okuda stage II patients (n=23) was 302 days (historical comparison 64 days). All patients were followed after therapy for a minimum of 6 months. There were 42 deaths, 21 due to liver failure, 6 from HCC progression, and 3 from metastases. Therasphere appears to be a relatively safe and effective therapy for advanced-stage unresectable HCC.

  3. Ultrathin 1T-phase MoS2 nanosheets decorated hollow carbon microspheres as highly efficient catalysts for solar energy harvesting and storage

    KAUST Repository

    Hsiao, Min-Chien

    2017-02-08

    The composite of MoS2 and hollow carbon sphere (MoS2@HCS) is prepared via a glucose-assisted one pot synthesis. The composite consists of hierarchical spheres with a diameter of 0.5–4 μm and these hollow spheres are decorated with a number of curled and interlaced MoS2 nanosheets. After the composite is subject to the lithium intercalation, the MoS2 is converted from 2H to 1T phase. In this current work, the activities of 1T-MoS2@HCS toward photocatalytic hydrogen evolution and the reduction of I3− in dye-sensitized solar cells (DSCs) are systemically investigated. When evaluated as the photocatalyst for hydrogen evolution, the amount of evolved hydrogen over 1T-MoS2@HCS can reach 143 μmol in 2 h, being 3.6 times higher than as-synthesized 2H-MoS2@HCS. Additionally, the 1T-MoS2@HCS can be employed as the counter electrode (CE) material in DSCs. The DSCs based on 1T-MoS2@HCS CE possesses the power conversion efficiency of 8.94%, being higher than that with 2H-MoS2@HCS CE (8.16%) and comparable to that with Pt CE (8.87%). Our study demonstrates that 1T-MoS2@HCS has a great potential as an inexpensive alternative to Pt catalysts.

  4. Ultrathin 1T-phase MoS2 nanosheets decorated hollow carbon microspheres as highly efficient catalysts for solar energy harvesting and storage

    KAUST Repository

    Hsiao, Min-Chien; Chang, Chin-Yu; Niu, Li-Juan; Bai, Feng; Li, Lain-Jong; Shen, Hsin-Hui; Lin, Jeng-Yu; Lin, Tsung-Wu

    2017-01-01

    The composite of MoS2 and hollow carbon sphere (MoS2@HCS) is prepared via a glucose-assisted one pot synthesis. The composite consists of hierarchical spheres with a diameter of 0.5–4 μm and these hollow spheres are decorated with a number of curled and interlaced MoS2 nanosheets. After the composite is subject to the lithium intercalation, the MoS2 is converted from 2H to 1T phase. In this current work, the activities of 1T-MoS2@HCS toward photocatalytic hydrogen evolution and the reduction of I3− in dye-sensitized solar cells (DSCs) are systemically investigated. When evaluated as the photocatalyst for hydrogen evolution, the amount of evolved hydrogen over 1T-MoS2@HCS can reach 143 μmol in 2 h, being 3.6 times higher than as-synthesized 2H-MoS2@HCS. Additionally, the 1T-MoS2@HCS can be employed as the counter electrode (CE) material in DSCs. The DSCs based on 1T-MoS2@HCS CE possesses the power conversion efficiency of 8.94%, being higher than that with 2H-MoS2@HCS CE (8.16%) and comparable to that with Pt CE (8.87%). Our study demonstrates that 1T-MoS2@HCS has a great potential as an inexpensive alternative to Pt catalysts.

  5. Enhanced microwave absorption performance of lightweight absorber based on reduced graphene oxide and Ag-coated hollow glass spheres/epoxy composite

    International Nuclear Information System (INIS)

    Wang, Junpeng; Sun, Yu; Chen, Wei; Wang, Tao; Xu, Renxin; Wang, Jun

    2015-01-01

    Using a combination of Ag-coated hollow glass spheres (HGS@Ag) and a small quantity of graphene sheets within the epoxy matrix, we have prepared a novel lightweight high efficiency microwave absorption composite. Compared with pure HGS@Ag and graphene composite, the −10 dB absorption bandwidth and the minimum reflection loss of the novel composite are improved. Reflection loss exceeding −20 dB is obtained for composites in a wide frequency range and the minimum reflection loss reaches −46 dB while bandwidth less than −10 dB can reach up to 4.1 GHz when an appropriate absorber thickness between 2 and 3.5 mm is chosen. The enhanced microwave absorption performance of the novel composite is due to the enhanced dielectric response, enhanced conductivity, and the trap of electromagnetic radiation with increased propagation paths by multiple reflections

  6. Booted selective internal radiation therapy (B-SIRT) using 90Y-loaded glass microspheres induces prolonged overall survival for PVT patients

    International Nuclear Information System (INIS)

    Garin, E.; Lenoir, L.; Edeline, J.; Laffont, S.; Mesbah, H.; Poree, P.; Boucher, E.; Rolland, Y.

    2015-01-01

    Full text of publication follows. Goal: evaluation of the response rate and survival of hepatocellular carcinoma PVT patients treated with Therasphere using the boost concept. Material and methods: Therasphere was administered in 40 PVT hepatocellular carcinoma patients (main = 11, lobar = 23, segmental = 6). MAA SPECT/CT quantitative analysis was used for the calculation of the tumour dose (TD), the healthy injected liver dose (HLD) and the injected liver dose (LD). Response was evaluated at 3 months using EASL criterion. OS was evaluated using Kaplan and Meyer tests. Results: Mean 90 Y-loaded microspheres injected activity was 3.1 ± 1.5 GBq. Mean LD was 143 ± 49 Gy. Median TD was 316 Gy for responding lesions versus 133 Gy for non responding lesion (p<0.0001). With a threshold TD of 205 Gy, MAA-SPECT/CT was predictive of response with a sensibility of 100%, and an overall accuracy of 90% (0FN, 4FP). Knowing the TD and the HLD, 40% of the patients received an intensification of the treatment (increase of the injected activity with the goal to achieve a TD> 205 Gy with a LD > 150 Gy and a HLD<120 Gy) with a good response rate (81%) and without increased liver grade III toxicity (6.2% as against 12.5% in the non boosted patients, ns). 6 patients were put aside, 5 received a lobar hepatectomy. Median OS was 18.2 months [12-27]. It was 4 m [12-27] for patients with a TD < 205 Gy versus 21.5 m [12-28.5] for patients with a TD > 205 Gy. OS was 12 m [3-∞] for patients with main PVT versus 21.5 m [12-28.7] for patients segmental or lobar PVT (ns). Finally Os was 23.2 m for patients with a TD > 205 Gy and a good PVT targeting (n = 34). Conclusion: boosted selective internal radiation therapy using 90 Y-loaded glass microspheres induces prolonged overall survival for PVT patients without increasing liver toxicity. (authors)

  7. Low pressure gas filling of laser fusion microspheres

    International Nuclear Information System (INIS)

    Koo, J.C.; Dressler, J.L.; Hendricks, C.D.

    1979-01-01

    In our laser fusion microsphere production, large, thin gel-microspheres are formed before the chemicals are fused into glass. In this transient stage,, the gel-microspheres are found to be highly permeable to argon and many other inert gases. When the gel transforms to glass, the argon gas, for example, is trapped within to form argon filled, fusion target quality, glass microspheres. On the average, the partial pressure of the argon fills attained in this process is around 2 x 10 4 Pa at room temperature

  8. Radioembolization of hepatocarcinoma with 90Y glass microspheres: development of an individualized treatment planning strategy based on dosimetry and radiobiology

    International Nuclear Information System (INIS)

    Chiesa, C.; Maccauro, M.; Aliberti, G.; Padovano, B.; Seregni, E.; Crippa, F.; Mira, M.; Negri, A.; Spreafico, C.; Morosi, C.; Civelli, E.; Lanocita, R.; Marchiano, A.; Romito, R.; Sposito, C.; Bhoori, S.; Facciorusso, A.; Mazzaferro, V.; Camerini, T.; Carrara, M.; Pellizzari, S.; Migliorisi, M.; De Nile, M.C.

    2015-01-01

    The aim of this study was to optimize the dosimetric approach and to review the absorbed doses delivered, taking into account radiobiology, in order to identify the optimal methodology for an individualized treatment planning strategy based on 99m Tc-macroaggregated albumin (MAA) single photon emission computed tomography (SPECT) images. We performed retrospective dosimetry of the standard TheraSphere registered treatment on 52 intermediate (n = 17) and advanced (i.e. portal vein thrombosis, n = 35) hepatocarcinoma patients with tumour burden < 50 % and without obstruction of the main portal vein trunk. Response was monitored with the densitometric radiological criterion (European Association for the Study of the Liver) and treatment-related liver decompensation was defined ad hoc with a time cut-off of 6 months. Adverse events clearly attributable to disease progression or other causes were not attributed to treatment. Voxel dosimetry was performed with the local deposition method on 99m Tc-MAA SPECT images. The reconstruction protocol was optimized. Concordance of 99m Tc-MAA and 90 Y bremsstrahlung microsphere biodistributions was studied in 35 sequential patients. Two segmentation methods were used, based on SPECT alone (home-made code) or on coregistered SPECT/CT images (IMALYTICS trademark by Philips). STRATOS trademark absorbed dose calculation was validated for 90 Y with a single time point. Radiobiology was used introducing other dosimetric variables besides the mean absorbed dose D: equivalent uniform dose (EUD), biologically effective dose averaged over voxel values (BED ave ) and equivalent uniform biologically effective dose (EUBED). Two sets of radiobiological parameters, the first derived from microsphere irradiation and the second from external beam radiotherapy (EBRT), were used. A total of 16 possible methodologies were compared. Tumour control probability (TCP) and normal tissue complication probability (NTCP) were derived. The area under the

  9. Comparison of post-embolization syndrome in the treatment of patients with unresectable hepatocellular carcinoma: Trans-catheter arterial chemo-embolization versus Yttrium-90 glass microspheres

    International Nuclear Information System (INIS)

    Goin, J.E.; Roberts, C.A.; Dancey, J.E.; Sickles, C.J.; Leung, D.A.; Soulen, M.C.

    2004-01-01

    Post-embolization syndrome (PES) occurs in most patients who undergo trans-catheter arterial chemoembolization (TACE) for treatment of unresectable hepatocellular carcinoma (HCC). Intra-hepatic arterial administration of TheraSphere, yttrium-90 glass microspheres, is an alternative treatment for unresectable HCC that does not require embolization of major vessels and may have a more favorable toxicity profile than TACE. This paper compares the incidence of PES after TACE vs. TheraSphere treatment in unresectable HCC patients. Data for 29 TACE-treated and 34 TheraSphere-treated patients were evaluated for PES. PES toxicities (i.e., nausea, vomiting, fever in the absence of infection, and abdominal pain) were scored according to Southwest Oncology Group (SWOG) toxicity criteria. PES was defined as a total score for the four toxicities of 2 or greater. Survival was defined from the date of treatment to the date of death. TACE patients underwent one to seven treatment procedures; TheraSphere patients underwent one to two treatment procedures. The incidence of PES was 3.8-times (95% confidence interval 1.6-16.3) higher after TACE [20/29(69%)] than after TheraSphere [6/34 (18%)] treatment; this difference was statistically significant (p=.003). Median survival was similar for TheraSphere (N=20; 378 days, CI 209-719) and TACE (N=29; 343 days, CI 217-511) patients. It was concluded that treatment of unresectable HCC with TheraSphere results in a much lower incidence of PES compared to TACE. Since TheraSphere is a pure beta emitter; it can potentially be administered safely on an outpatient basis, and appears to be at least as efficacious as TACE on survival with fewer treatments per patient. (author)

  10. Influence of the apex angle of a hollow prism made from an ordinary commercial glass plate as a simple refractometer to the accuracy of the refractive index measurement of the edible oil

    Science.gov (United States)

    Idris, N.; Maswati; Yusibani, E.

    2018-05-01

    The influence of the apex angle of a hollow prism used as a simple refractometer to the accuracy of a refractive index measurement of the edible oil samples was studied. The hollow prism was made from an ordinary commercial glass plate with a thickness of 2 mm. The apex angle of the constructed hollow prism was varied. The edible oil sample used in this study was palm oil, namely the packaged, branded oil sample and the bulk oil sample. For measuring the refractive index, the oil sample was filled in the constructed hollow prism, and then a helium-neon laser beam was passed through the oil sample at a certain angle of incidence. The angle of minimum deviation of the transmitted laser He-Ne beam was measured and then was used for calculating the refractive index of the oil sample. The refractive index measurement was made using the hollow prism with different apex angles, ranging from 300 to 600. The measurement accuracy was estimated by comparing the refractive index measured using the hollow prisms to that of obtained using a standard Abbe refractometer. It was found that the refractive index of the edible oil can be measured accurately by using the hollow prism. It was also found that the accuracy of the refractive index measurement significantly changes with the apex angle of the hollow prism. The refractive index values measured using this simple refractometer deviate up to 3,49% from the refractive index value measured using the standard Abbe refractometer, especially when the apex angle of the prism is 30°. The measurement results with high accuracies obtained when using the hollow prisms with apex angles of 450 and 600. The optimum apex angle for the present constructed hollow prism is 450. The refractive index obtained using the hollow prism with the apex angle of 450 is 1,4623 and 1,4438 for the bulk oil and the packed, branded oil samples, respectively. This result suggests that the apex angle of the prism used affects largely the accuracy of the

  11. Method to fabricate hollow microneedle arrays

    Energy Technology Data Exchange (ETDEWEB)

    Kravitz, Stanley H [Placitas, NM; Ingersoll, David [Albuquerque, NM; Schmidt, Carrie [Los Lunas, NM; Flemming, Jeb [Albuquerque, NM

    2006-11-07

    An inexpensive and rapid method for fabricating arrays of hollow microneedles uses a photoetchable glass. Furthermore, the glass hollow microneedle array can be used to form a negative mold for replicating microneedles in biocompatible polymers or metals. These microneedle arrays can be used to extract fluids from plants or animals. Glucose transport through these hollow microneedles arrays has been found to be orders of magnitude more rapid than natural diffusion.

  12. Studies in the Use of Magnetic Microspheres for Immunoaffinity Extraction of Paralytic Shellfish Poisoning Toxins from Shellfish

    Directory of Open Access Journals (Sweden)

    Christopher Elliott

    2011-01-01

    Full Text Available Paralytic shellfish poisoning (PSP is a potentially fatal human health condition caused by the consumption of shellfish containing high levels of PSP toxins. Toxin extraction from shellfish and from algal cultures for use as standards and analysis by alternative analytical monitoring methods to the mouse bioassay is extensive and laborious. This study investigated whether a selected MAb antibody could be coupled to a novel form of magnetic microsphere (hollow glass magnetic microspheres, brand name Ferrospheres-N and whether these coated microspheres could be utilized in the extraction of low concentrations of the PSP toxin, STX, from potential extraction buffers and spiked mussel extracts. The feasibility of utilizing a mass of 25 mg of Ferrospheres-N, as a simple extraction procedure for STX from spiked sodium acetate buffer, spiked PBS buffer and spiked mussel extracts was determined. The effects of a range of toxin concentrations (20–300 ng/mL, incubation times and temperature on the capability of the immuno-capture of the STX from the spiked mussel extracts were investigated. Finally, the coated microspheres were tested to determine their efficiency at extracting PSP toxins from naturally contaminated mussel samples. Toxin recovery after each experiment was determined by HPLC analysis. This study on using a highly novel immunoaffinity based extraction procedure, using STX as a model, has indicated that it could be a convenient alternative to conventional extraction procedures used in toxin purification prior to sample analysis.

  13. A One-Square-Millimeter Compact Hollow Structure for Microfluidic Pumping on an All-Glass Chip

    Directory of Open Access Journals (Sweden)

    Xing Yue (Larry Peng

    2016-04-01

    Full Text Available A micro surface tension pump is a new type of low-cost, built-in, all-glass, microfluidic pump on a glass microchip fabricated by one-step glass etching. However, geometric minimization and optimization for practical use are challenging. Here, we report a one-square-millimeter, built-in, all-glass pump controlled by two-way digital gas pressure. The pump consists simply of two joint chambers and a piston between two gas control channels. It does not require pre-perfusion for initialization, and can immediately begin to run when a liquid enters its inlet channel. It is also more reliable than conventional micro pumps for practical use due to its ability to restart after the formation of a blocking bubble, which can serve as a valuable troubleshooting procedure. Its volumetric pump output was 0.5–0.7 nL·s−1 under a pump head pressure of 300 Pa.

  14. Use of Yttrium-90 glass microspheres (TheraSphere) for the treatment of unresectable hepatocellular carcinoma in patients with portal vein thrombosis.

    Science.gov (United States)

    Salem, Riad; Lewandowski, Robert; Roberts, Carol; Goin, James; Thurston, Kenneth; Abouljoud, Marwan; Courtney, Angi

    2004-04-01

    Intra-arterial injection of Yttrium-90 glass microspheres ((90)Y- microS; TheraSphere, MDS Nordion, Ottawa, Canada) is indicated for treatment of unresectable hepatocellular carcinoma (HCC) in the presence of acceptable liver function. This study presents hepatic toxicity results after unilobar and bilobar intra-arterial administration of (90)Y- microS in patients with unresectable HCC who had known portal vein thrombosis (PVT) without evidence of cavernous transformation. Fifteen patients with unresectable HCC and PVT of one or both first order and related segmental portal venous branches received a total of 29 infusions of (90)Y- microS for treatment of HCC. All patients had pretreatment evaluation including: computed tomography (CT) imaging, alpha-fetoprotein (AFP) levels, liver function tests, technetium-99m macroaggregated albumin ((99)Tc-MAA) scan for evaluation of lung and visceral shunting, and angiography with visualization into the portal venous phase. (90)Y- micro S dose was based on lobar hepatic volume with adjustment for lung shunt activity. Liver toxicity was assessed by serum total bilirubin graded for severity according to the NIH NCI Clinical Toxicity Criteria (CTC version 2.0). Other adverse events were reported according to the standards established by the Society of Interventional Radiology. There were no procedural complications with delivery of (90)Y- microS, and treatment was well tolerated by all patients. Increased post-treatment bilirubin levels were observed across all treatments in five patients, four of whom had CT or AFP evidence of intrahepatic disease progression. After initial treatment, two patients developed bilirubin toxicity (grades 1 and 2); one patient demonstrated an increment in bilirubin toxicity grade (grade 1 to grade 3) and one patient had an improvement in grade after initial treatment. There were no new treatment-related toxicities in nine patients after a second treatment. (90)Y- microS treatment was well tolerated

  15. Glasses

    DEFF Research Database (Denmark)

    Dyre, Jeppe

    2004-01-01

    The temperature dependence of the viscosity of most glassforming liquids is known to depart significantly from the classical Arrhenius behaviour of simple fluids. The discovery of an unexpected correlation between the extent of this departure and the Poisson ratio of the resulting glass could lead...... to new understanding of glass ageing and viscous liquid dynamics....

  16. Magnetic Ganoderma lucidum spore microspheres: A novel material to immobilize CotA multicopper oxidase for dye decolorization

    Energy Technology Data Exchange (ETDEWEB)

    Fan, Lili [School of Chemistry and Chemical Engineering, Harbin Institute of Technology, Harbin 150001 (China); Wang, Yan, E-mail: wangy_msn@hit.edu.cn [School of Chemistry and Chemical Engineering, Harbin Institute of Technology, Harbin 150001 (China); Zhao, Min [College of Life Science, Northeast Forestry University, Harbin 150040 (China); Song, Jinzhu [School of Life Science and Technology, Harbin Institute of Technology, Harbin 150001 (China); Wang, Jueyu; Jin, Zijing [College of Life Science, Northeast Forestry University, Harbin 150040 (China)

    2016-08-05

    Highlights: • Hollow microspheres were obtained from Ganoderma lucidum spores. • Novel magnetic microspheres were prepared by load hollow spore microspheres with Fe{sub 3}O{sub 4} nanoparticles. • CotA multicopper oxidase was immobilized on the magnetic spore microspheres for indigo carmine decolorization. • The immobilized CotA displayed higher decolorization capability and reusability. - Abstract: In this study, hollow microspheres were obtained from Ganoderma lucidum spores. Then the hollow microspheres were loaded with Fe{sub 3}O{sub 4} nanoparticles to prepare novel magnetic spore microspheres. TEM images and X-ray diffractometry demonstrated that the Fe{sub 3}O{sub 4} nanoparticles were incorporated throughout the spore microsphere. CotA multicopper oxidase was chosen as biomacromolecule to study the loading ability of the magnetic spore microspheres. The combination of the CotA enzyme with the microsphere was observed by laser scanning confocal microscope. The loaded amount of CotA on the microspheres was 75 mg/g when the CotA concentration was 1.2 mg/mL and the activity recovery of the immobilized CotA was 81%. The magnetic microspheres loaded with CotA, which can be easily and quickly recovered by an external magnetic field, were used for dye decolorization. After 1 h decolorization, 99% of the indigo carmine has been removed by 10 mg microspheres. In addition, the immobilized CotA retained 75% of activity after 10 consecutive cycles, which indicated that the magnetic spore microspheres are good support material for immobilization of the enzyme.

  17. Magnetic Ganoderma lucidum spore microspheres: A novel material to immobilize CotA multicopper oxidase for dye decolorization

    International Nuclear Information System (INIS)

    Fan, Lili; Wang, Yan; Zhao, Min; Song, Jinzhu; Wang, Jueyu; Jin, Zijing

    2016-01-01

    Highlights: • Hollow microspheres were obtained from Ganoderma lucidum spores. • Novel magnetic microspheres were prepared by load hollow spore microspheres with Fe_3O_4 nanoparticles. • CotA multicopper oxidase was immobilized on the magnetic spore microspheres for indigo carmine decolorization. • The immobilized CotA displayed higher decolorization capability and reusability. - Abstract: In this study, hollow microspheres were obtained from Ganoderma lucidum spores. Then the hollow microspheres were loaded with Fe_3O_4 nanoparticles to prepare novel magnetic spore microspheres. TEM images and X-ray diffractometry demonstrated that the Fe_3O_4 nanoparticles were incorporated throughout the spore microsphere. CotA multicopper oxidase was chosen as biomacromolecule to study the loading ability of the magnetic spore microspheres. The combination of the CotA enzyme with the microsphere was observed by laser scanning confocal microscope. The loaded amount of CotA on the microspheres was 75 mg/g when the CotA concentration was 1.2 mg/mL and the activity recovery of the immobilized CotA was 81%. The magnetic microspheres loaded with CotA, which can be easily and quickly recovered by an external magnetic field, were used for dye decolorization. After 1 h decolorization, 99% of the indigo carmine has been removed by 10 mg microspheres. In addition, the immobilized CotA retained 75% of activity after 10 consecutive cycles, which indicated that the magnetic spore microspheres are good support material for immobilization of the enzyme.

  18. Microsphere zeolite materials derived from coal fly ash cenospheres as precursors to mineral-like aluminosilicate hosts for 135,137Cs and 90Sr

    International Nuclear Information System (INIS)

    Vereshchagina, Tatiana A.; Vereshchagin, Sergei N.; Shishkina, Nina N.; Vasilieva, Nataly G.; Solovyov, Leonid A.; Anshits, Alexander G.

    2013-01-01

    Hollow microsphere zeolite materials with a bilayered zeolite/glass crystalline shell bearing NaP1 zeolite were synthesized by the hydrothermal treatment of coal fly ash cenospheres (Si/Al = 2.7) in an alkaline medium. Cs + and/or Sr 2+ forms of zeolitized cenospheres with the different Cs + and/or Sr 2+ loading were prepared by the ion exchange from nitrate solutions. The resulted (Cs,Na)P1, (Sr,Na)P1 and (Cs,Sr,Na)P1 bearing microsphere zeolites were converted to glass ceramics by heating at 900–1000 °C. The differential scanning calorimetry and quantitative phase analysis were used to monitor the solid-phase transformation of the initial and ion exchanged zeolite materials. It was established that the final solidified forms of Cs + and/or Sr 2+ are glass–crystalline ceramic materials based on pollucite–nepheline, Sr-feldspar–nepheline and Sr-feldspar–pollucite composites including ∼60 wt.% of the major host phases (pollucite, Sr-feldspar) and 10–20 wt.% of glass. The 137 Cs leaching rate of 4.1 × 10 −7 g cm −2 day −1 was determined for the pollucite glass–ceramic according to Russian State Standard (GOST) No. 52126 P-2003 (7 day, 25 °C, distilled water)

  19. Optimization of the quantitative direct solid total-reflection X-ray fluorescence analysis of glass microspheres functionalized with Zr organometallic compounds

    Energy Technology Data Exchange (ETDEWEB)

    Fernandez-Ruiz, Ramon, E-mail: ramon.fernandez@uam.e [Servicio Interdepartamental de Investigacion, Facultad de Ciencias, Universidad Autonoma de Madrid, Cantoblanco, E-28049, Madrid (Spain); Andres, Roman; Jesus, Ernesto de [Departamento de Quimica Inorganica, Universidad de Alcala, Campus Universitario, 28871, Alcala de Henares, Madrid (Spain); Terreros, Pilar [Instituto de Catalisis y Petroleo-Quimica, CSIC, Cantoblanco, 28049, Madrid (Spain)

    2010-06-15

    Quantitative determination of Zr in the system constituted by quartz microspheres functionalized with two kinds of organometallic compounds has been studied due to the importance of the correct quantization of the Zr from a catalytic point of view. Two parallel approximations were done, i.e. acid leaching and direct solid quantization. To validate the acid leaching TXRF measures, ICP-MS analysis were carried out. The results obtained by means of the optimization of the quantitative direct solid procedure show that, with a previous particle size distribution modification, TXRF obtain the same analytical results as ICP-MS and TXRF by acid leaching way but without previous chemical acid manipulation. This fact implies an important improvement for the analysis time, reagents costs and analysis facility and it proves again the versatility of TXRF to solve analytical problems in an easy, quick and accurate way. Additionally and for the direct solid TXRF measurements, a deeper study was done to evaluate the intrinsic analytical parameters of the Zr TXRF analysis of this material. So, the influence of the particle size distributions (modified by means of a high power ultrasound probe) with respect to uncertainty and detection limits for Zr were developed. The main analytical conclusion was the strong correlation between the average particle sizes and the TXRF analytical parameters of Zr measurements, i.e. concentration, accuracy, uncertainty and detection limits.

  20. Radioembolization of hepatocarcinoma with {sup 90}Y glass microspheres: development of an individualized treatment planning strategy based on dosimetry and radiobiology

    Energy Technology Data Exchange (ETDEWEB)

    Chiesa, C.; Maccauro, M.; Aliberti, G.; Padovano, B.; Seregni, E.; Crippa, F. [Foundation IRCCS Istituto Nazionale Tumori, Nuclear Medicine Division, Milan (Italy); Mira, M.; Negri, A. [University of Milan, Postgraduate Health Physics School, Milan (Italy); Spreafico, C.; Morosi, C.; Civelli, E.; Lanocita, R.; Marchiano, A. [Foundation IRCCS Istituto Nazionale Tumori, Radiology 2, Milan (Italy); Romito, R.; Sposito, C.; Bhoori, S.; Facciorusso, A.; Mazzaferro, V. [Foundation IRCCS Istituto Nazionale Tumori, Surgery 1, Milan (Italy); Camerini, T. [Foundation IRCCS Istituto Nazionale Tumori, Scientific Direction, Milan (Italy); Carrara, M. [Foundation IRCCS Istituto Nazionale Tumori, Health Physics, Milan (Italy); Pellizzari, S. [University La Sapienza, Engineering Faculty, Rome (Italy); Migliorisi, M. [Foundation IRCCS Istituto Nazionale Tumori, Nuclear Medicine Division, Milan (Italy); Foundation IRCCS Istituto Nazionale Tumori, Clinical Engineering, Milan (Italy); De Nile, M.C. [University of Pavia, Physics Faculty, Pavia, Lombardy (Italy)

    2015-10-15

    The aim of this study was to optimize the dosimetric approach and to review the absorbed doses delivered, taking into account radiobiology, in order to identify the optimal methodology for an individualized treatment planning strategy based on {sup 99m}Tc-macroaggregated albumin (MAA) single photon emission computed tomography (SPECT) images. We performed retrospective dosimetry of the standard TheraSphere registered treatment on 52 intermediate (n = 17) and advanced (i.e. portal vein thrombosis, n = 35) hepatocarcinoma patients with tumour burden < 50 % and without obstruction of the main portal vein trunk. Response was monitored with the densitometric radiological criterion (European Association for the Study of the Liver) and treatment-related liver decompensation was defined ad hoc with a time cut-off of 6 months. Adverse events clearly attributable to disease progression or other causes were not attributed to treatment. Voxel dosimetry was performed with the local deposition method on {sup 99m}Tc-MAA SPECT images. The reconstruction protocol was optimized. Concordance of {sup 99m}Tc-MAA and {sup 90}Y bremsstrahlung microsphere biodistributions was studied in 35 sequential patients. Two segmentation methods were used, based on SPECT alone (home-made code) or on coregistered SPECT/CT images (IMALYTICS trademark by Philips). STRATOS trademark absorbed dose calculation was validated for {sup 90}Y with a single time point. Radiobiology was used introducing other dosimetric variables besides the mean absorbed dose D: equivalent uniform dose (EUD), biologically effective dose averaged over voxel values (BED{sub ave}) and equivalent uniform biologically effective dose (EUBED). Two sets of radiobiological parameters, the first derived from microsphere irradiation and the second from external beam radiotherapy (EBRT), were used. A total of 16 possible methodologies were compared. Tumour control probability (TCP) and normal tissue complication probability (NTCP) were

  1. Minimizing resputtering of Pt-coated microspheres in a batch magnetron sputtering process

    International Nuclear Information System (INIS)

    Plake, A.L.

    1981-01-01

    Preventing DT loss from glass microspheres being smoothly coated with PT is needed during fabrication of laser fusion targets. Evidence indicates that the increase of substrate temperature due to resputtering will cause DT loss. Resputtering will prevent a smooth and uniform coating on these glass microspheres (140 μm in diameter). This paper reviews the method that was developed to find a set of coating conditions to minimize the DT loss, and still be able to produce thick smooth Pt coated glass microspheres

  2. Hollow spheres: crucial building blocks for novel nanostructures and nanophotonics

    Directory of Open Access Journals (Sweden)

    Zhong Kuo

    2018-03-01

    Full Text Available In this review, we summarize the latest developments in research specifically derived from the unique properties of hollow microspheres, in particular, hollow silica spheres with uniform shells. We focus on applications in nanosphere (colloidal lithography and nanophotonics. The lithography from a layer of hollow spheres can result in nanorings, from a multilayer in unique nano-architecture. In nanophotonics, disordered hollow spheres can result in antireflection coatings, while ordered colloidal crystals (CCs of hollow spheres exhibit unique refractive index enhancement upon infiltration, ideal for optical sensing. Furthermore, whispering gallery mode (WGM inside the shell of hollow spheres has also been demonstrated to enhance light absorption to improve the performance of solar cells. These applications differ from the classical applications of hollow spheres, based only on their low density and large surface area, such as catalysis and chemical sensing. We provide a brief overview of the synthesis and self-assembly approaches of the hollow spheres. We elaborate on their unique optical features leading to defect mode lasing, optomicrofluidics, and the existence of WGMs inside shell for light management. Finally, we provide a perspective on the direction towards which future research relevant to hollow spheres might be directed.

  3. Hollow spheres: crucial building blocks for novel nanostructures and nanophotonics

    Science.gov (United States)

    Zhong, Kuo; Song, Kai; Clays, Koen

    2018-03-01

    In this review, we summarize the latest developments in research specifically derived from the unique properties of hollow microspheres, in particular, hollow silica spheres with uniform shells. We focus on applications in nanosphere (colloidal) lithography and nanophotonics. The lithography from a layer of hollow spheres can result in nanorings, from a multilayer in unique nano-architecture. In nanophotonics, disordered hollow spheres can result in antireflection coatings, while ordered colloidal crystals (CCs) of hollow spheres exhibit unique refractive index enhancement upon infiltration, ideal for optical sensing. Furthermore, whispering gallery mode (WGM) inside the shell of hollow spheres has also been demonstrated to enhance light absorption to improve the performance of solar cells. These applications differ from the classical applications of hollow spheres, based only on their low density and large surface area, such as catalysis and chemical sensing. We provide a brief overview of the synthesis and self-assembly approaches of the hollow spheres. We elaborate on their unique optical features leading to defect mode lasing, optomicrofluidics, and the existence of WGMs inside shell for light management. Finally, we provide a perspective on the direction towards which future research relevant to hollow spheres might be directed.

  4. Method for producing small hollow spheres

    International Nuclear Information System (INIS)

    Hendricks, C.D.

    1979-01-01

    A method is described for producing small hollow spheres of glass, metal or plastic, wherein the sphere material is mixed with or contains as part of the composition a blowing agent which decomposes at high temperature (T >approx. 600 0 C). As the temperature is quickly raised, the blowing agent decomposes and the resulting gas expands from within, thus forming a hollow sphere of controllable thickness. The thus produced hollow spheres (20 to 10 3 μm) have a variety of application, and are particularly useful in the fabrication of targets for laser implosion such as neutron sources, laser fusion physics studies, and laser initiated fusion power plants

  5. Formation of Uniform Hollow Silica microcapsules

    Science.gov (United States)

    Yan, Huan; Kim, Chanjoong

    2013-03-01

    Microcapsules are small containers with diameters in the range of 0.1 - 100 μm. Mesoporous microcapsules with hollow morphologies possess unique properties such as low-density and high encapsulation capacity, while allowing controlled release by permeating substances with a specific size and chemistry. Our process is a one-step fabrication of monodisperse hollow silica capsules with a hierarchical pore structure and high size uniformity using double emulsion templates obtained by the glass-capillary microfluidic technique to encapsulate various active ingredients. These hollow silica microcapsules can be used as biomedical applications such as drug delivery and controlled release.

  6. Sputter coating of microspherical substrates by levitation

    Science.gov (United States)

    Lowe, A.T.; Hosford, C.D.

    Microspheres are substantially uniformly coated with metals or nonmetals by simltaneously levitating them and sputter coating them at total chamber pressures less than 1 torr. A collimated hole structure comprising a parallel array of upwardly projecting individual gas outlets is machined out to form a dimple. Glass microballoons,, which are particularly useful in laser fusion applications, can be substantially uniformly coated using the coating method and apparatus.

  7. Synthesis of V2O5 microspheres by spray pyrolysis as cathode material for supercapacitors

    Science.gov (United States)

    Yin, Zhendong; Xu, Jie; Ge, Yali; Jiang, Qiaoya; Zhang, Yaling; Yang, Yawei; Sun, Yuping; Hou, Siyu; Shang, Yuanyuan; Zhang, Yingjiu

    2018-03-01

    Vanadium oxide (V2O5) microspheres have attracted considerable attention in the energy field due to their unique properties such as high stability and electrochemical activity. Here, massive V2O5 microspheres with smooth surface, hollow cavity and uniform particle sizes (0.4–1.5 μm), were synthesized by a facile spray pyrolysis process. Post-treatment at predefined temperatures effectively turned the microsphere shell into stacked nanorods with widths of 100 nm and lengths of 500 nm when processed at 500 °C for 3 h under nitrogen atmosphere, with enhanced crystallinity. When applied as cathode materials for supercapacitors, the post-treated V2O5 microspheres at 500 °C exhibited improved specific capacitance and longer discharge time. This is an effective method to manufacture massive V2O5 microspheres with tailored structure and potential applications in high-performance energy storage materials.

  8. Review of Synthetic Methods to Form Hollow Polymer Nanocapsules

    Energy Technology Data Exchange (ETDEWEB)

    Barker, Madeline T. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    2014-03-13

    Syntactic foams have grown in interest due to the widened range of applications because of their mechanical strength and high damage tolerance. In the past, hollow glass or ceramic particles were used to create the pores. This paper reviews literature focused on the controlled synthesis of hollow polymer spheres with diameters ranging from 100 –200 nm. By using hollow polymer spheres, syntactic foams could reach ultra-low densities.

  9. Birefringent hollow core fibers

    DEFF Research Database (Denmark)

    Roberts, John

    2007-01-01

    Hollow core photonic crystal fiber (HC-PCF), fabricated according to a nominally non-birefringent design, shows a degree of un-controlled birefringence or polarization mode dispersion far in excess of conventional non polarization maintaining fibers. This can degrade the output pulse in many...... applications, and places emphasis on the development of polarization maintaining (PM) HC-PCF. The polarization cross-coupling characteristics of PM HC-PCF are very different from those of conventional PM fibers. The former fibers have the advantage of suffering far less from stress-field fluctuations...... and an increased overlap between the polarization modes at the glass interfaces. The interplay between these effects leads to a wavelength for optimum polarization maintenance, lambda(PM), which is detuned from the wavelength of highest birefringence. By a suitable fiber design involving antiresonance of the core...

  10. Recent advances in Pt coating of microspheres by a batch magnetron sputtering process

    International Nuclear Information System (INIS)

    Hsieh, E.J.; Meyer, S.F.

    1980-01-01

    Some proposed inertial confinement fusion targets require high-Z, high density metal coatings on glass microspheres. Platinum, which satisfies the high-Z and density requirements, can be coated onto microspheres with a batch magnetron sputtering process incorporating oxygen as a dopant gas to prevent the microspheres from sticking. This paper outlines recent progress in three areas: First, the coating process has been improved; second, the oxygen content and resistivity of the oxygen doped platinum films are analyzed; and third, the roles oxygen may play in reducing microsphere sticking during sputtering are discussed in regard to cold welding, Van der Waals bonding, electrostatic sticking, and sintering

  11. Hollow MEMS

    DEFF Research Database (Denmark)

    Larsen, Peter Emil

    Miniaturization of electro mechanical sensor systems to the micro range and beyond has shown impressive sensitivities measuring sample properties like mass, viscosity, acceleration, pressure and force just to name a few applications. In order to enable these kinds of measurements on liquid samples...... a hollow MEMS sensor has been designed, fabricated and tested. Combined density, viscosity, buoyant mass spectrometry and IR absorption spectroscopy are possible on liquid samples and micron sized suspended particles (e.g. single cells). Measurements are based on changes in the resonant behavior...... of these sensors. Optimization of the microfabrication process has led to a process yield of almost 100% .This is achieved despite the fact, that the process still offers a high degree of flexibility. By simple modifications the Sensor shape can be optimized for different size ranges and sensitivities...

  12. Fabrication of polymeric hollow nanospheres, hollow nanocubes and hollow plates

    Science.gov (United States)

    Cheng, Daming; Xia, Haibing; Chan, Hardy Sze On

    2006-03-01

    A facile strategy for fabricating polypyrrole-chitosan (PPy-CS) hollow nanostructures with different shapes (sphere, cube and plate) and a wide range of sizes (from 35 to 600 nm) is described. These hollow structures have been fabricated using silver bromide as a single template material for polymer nucleation and growth. PPy-CS hollow nanostructures are formed by reaction with an etching agent to remove the core. These hollow nanostructures have been extensively characterized using various techniques such as TEM, FT-IR, UV-vis, and XRD.

  13. Combined use of lightweight magnetic Fe{sub 3}O{sub 4}-coated hollow glass spheres and electrically conductive reduced graphene oxide in an epoxy matrix for microwave absorption

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Junpeng; Wang, Jun, E-mail: wgdfrp@whut.edu.cn; Zhang, Bin; Sun, Yu; Chen, Wei; Wang, Tao

    2016-03-01

    Epoxy resin based lightweight composites comprising Fe{sub 3}O{sub 4}-coated hollow glass spheres (HGS@Fe{sub 3}O{sub 4}) and reduced graphene oxide (RGO) were prepared. Impedance matching condition and electromagnetic wave attenuation characteristic are used for analysis of the reflection loss (RL) performance of the composites. Compared with pure HGS@Fe{sub 3}O{sub 4} and RGO composite, the −10 dB absorption bandwidth and the minimum RL of the hybrid composites are enhanced. RL values less than −10 dB are obtained in a wide frequency range and the corresponding bandwidth can reach up to 3.6 GHz when an appropriate absorber thickness is chosen. The density of the hybrid composite is in the range of 0.57–0.72 g/cm{sup 3}, which is attractive candidate for a new type of lightweight microwave absorber. - Highlights: • Lightweight composites comprising HGS@Fe{sub 3}O{sub 4} and RGO were prepared. • The RL less than −10 dB can reach up to 3.6 GHz with layer thickness of 2.5 mm. • The density of the composites is in the range of 0.57−0.72 g/cm{sup 3}.

  14. Preparation and characterization of composite microspheres for brachytherapy and hyperthermia treatment of cancer

    International Nuclear Information System (INIS)

    Zhao Di; Huang Wenhai; Rahaman, Mohamed N.; Day, Delbert E.; Wang Deping; Gu Yifei

    2012-01-01

    Composite microspheres were prepared by coating yttrium–aluminum–silicate (YAS) glass microspheres (20–30 μm) with a layer of Fe 3 O 4 nanoparticles and evaluated for potential use in brachytherapy and hyperthermia treatment of cancer. After neutron activation to form the β-emitting 90 Y radionuclide, the composite microspheres can be injected into a patient to destroy cancerous tumors; at the same time, the composite microspheres can generate heat upon application of a magnetic field to also destroy the tumors. The results showed that the composite microspheres were chemically durable when immersed in a simulated body fluid (SBF), with ∼ 0.25% weight loss and ∼ 3.2% yttrium dissolved into the SBF after 30 days at 37 °C. The composite microspheres also showed ferromagnetic properties as a result of the Fe 3 O 4 coating; when immersed in water at 20 °C (20 mg in 1 mL of water), the application of an alternating magnetic field produced a temperature increase from 20 °C to 38−46 °C depending on the thickness of the Fe 3 O 4 coating. The results indicate that these composite microspheres have promising potential in combined brachytherapy and hyperthermia treatment of cancerous tumors. - Highlights: ► Composite microspheres for brachytherapy and hyperthermia treatment of cancer. ► Fe 3 O 4 nanoparticles coated on the yttrium–aluminum–silicate glass microspheres. ► Microspheres are chemically stable in SBF. ► Microspheres can generate heat for hyperthermia under an alternating magnetic field. ► Microspheres can emit β-rays for brachytherapy after neutron activation.

  15. Facile Synthesis of V2O5 Hollow Spheres as Advanced Cathodes for High-Performance Lithium-Ion Batteries

    Directory of Open Access Journals (Sweden)

    Xingyuan Zhang

    2017-01-01

    Full Text Available Three-dimensional V2O5 hollow structures have been prepared through a simple synthesis strategy combining solvothermal treatment and a subsequent thermal annealing. The V2O5 materials are composed of microspheres 2–3 μm in diameter and with a distinct hollow interior. The as-synthesized V2O5 hollow microspheres, when evaluated as a cathode material for lithium-ion batteries, can deliver a specific capacity as high as 273 mAh·g−1 at 0.2 C. Benefiting from the hollow structures that afford fast electrolyte transport and volume accommodation, the V2O5 cathode also exhibits a superior rate capability and excellent cycling stability. The good Li-ion storage performance demonstrates the great potential of this unique V2O5 hollow material as a high-performance cathode for lithium-ion batteries.

  16. Crystallization of Yttrium and Samarium Aluminosilicate Glasses

    OpenAIRE

    Lago, Diana Carolina; Prado, Miguel Oscar

    2016-01-01

    Aluminosilicate glasses containing samarium and yttrium (SmAS and YAS glasses) exhibit high glass transition temperatures, corrosion resistance, and glass stability on heating which make them useful for technological applications. Yttrium aluminosilicate glass microspheres are currently being used for internal selective radiotherapy of liver cancer. During the preparation process, crystallization needs to be totally or partially avoided depending on the final application. Thus knowing the cry...

  17. Ceramic microspheres for cementing applications

    NARCIS (Netherlands)

    2011-01-01

    A method and apparatus for manufacturing ceramic microspheres from industrial slag. The microspheres have a particle size of about 38 microns to about 150 microns. The microspheres are used to create a cement slurry having a density of at least about 11 lbs/g. The resultant cement slurry may then be

  18. Ceramic microspheres for cementing applications

    NARCIS (Netherlands)

    2010-01-01

    A method and apparatus for manufacturing ceramic microspheres from industrial slag. The microspheres have a particle size of about 38 microns to about 150 microns. The microspheres are used to create a cement slurry having a density of at least about 11 lbs/g. The resultant cement slurry may then be

  19. Ceramic microspheres for cementing applications

    NARCIS (Netherlands)

    2012-01-01

    A method and apparatus for manufacturing ceramic microspheres from industrial slag. The microspheres have a particle size of about 38 microns to about 150 microns. The microspheres are used to create a cement slurry having a density of at least about 11 lbs/g. The resultant cement slurry may then be

  20. Preparation of alumina microspheres

    International Nuclear Information System (INIS)

    Santos, W.R. dos; Abrao, A.

    1980-01-01

    Inorganic exchangers are widely used for adsorption and column partition chromatography. The main difficulty of using commercial alumina (in powder) for column chromatography is related to its packing, and the operations through the column become diffcult and time-consuming; also it turns to be virtually impossible to use large dimension columns. In order to eliminate these problems, a process for the preparation of alumina micro-spheres was developed as an adaptation of a similar process used to prepare nuclear fuel microspheres (UO 2 , ThO 2 ). The flowsheet of this process is presented together with the analytical results of sphericity after calcination, granulometry, density and characterization by X-ray diffractometry. Solubility tests showed that the so-prepared microspheres are well resistant to strong acids and bases; retention tests showed their efficiency, mainly to copper. (C.L.B.) [pt

  1. Silicon Microspheres Photonics

    International Nuclear Information System (INIS)

    Serpenguzel, A.

    2008-01-01

    Electrophotonic integrated circuits (EPICs), or alternatively, optoelectronic integrated circuit (OEICs) are the natural evolution of the microelectronic integrated circuit (IC) with the addition of photonic capabilities. Traditionally, the IC industry has been based on group IV silicon, whereas the photonics industry on group III-V semiconductors. However, silicon based photonic microdevices have been making strands in siliconizing photonics. Silicon microspheres with their high quality factor whispering gallery modes (WGMs), are ideal candidates for wavelength division multiplexing (WDM) applications in the standard near-infrared communication bands. In this work, we will discuss the possibility of using silicon microspheres for photonics applications in the near-infrared

  2. Synergistic effects of hollow structure and surface fluorination on the photocatalytic activity of titania

    International Nuclear Information System (INIS)

    Lv Kangle; Yu Jiaguo; Deng Kejian; Sun Jie; Zhao Yanxi; Du Dongyun; Li Mei

    2010-01-01

    To study the synergistic effects of hollow structure and surface fluorination on the photoactivity of TiO 2 , TiO 2 hollow microspheres were synthesized by a hydrolysis-precipitate method using sulfonated polystyrene (PS) as templates and tetrabutylorthotitanate (TBOT) as precursor, and then calcined at 500 o C for 2 h. The calcined samples were characterized by X-ray diffraction, scanning electron microscopy, transmission electron microscopy and N 2 sorption. Photocatalytic activity was evaluated using reactive brilliant red X3B, an anionic organic dye, as a model pollutant in water. The results show that the photocatalytic activity of TiO 2 hollow microspheres is significantly higher than that of TiO 2 nanoparticles prepared in the same experimental conditions. At pH 7 and 3, the apparent rate constants of the former exceed that of the latter by a factor of 3.38 and 3.15, respectively. After surface fluorination at pH 3, the photoactivity of hollow microspheres and nanoparticles further increases for another 1.61 and 2.19 times, respectively. The synergistic effect of surface fluorination and hollow structure can also be used to prepare other highly efficient photocatalyst.

  3. Time reduction in well construction with the addition of glass microspheres and thixotropic agents in cement slurries in zonal isolation at Solimoes Basin; Reducao do tempo de construcao de pocos de petroelo na Bacia do Solimoes atraves da utilizacao de microsferas de vidro e agentes tixotropicos nas fases de cimentacao

    Energy Technology Data Exchange (ETDEWEB)

    Ferreira, Cledeilson R.L.; Duque, Luis H.; Steffan, Rodolfo H.P.; Guimaraes, Zacarias [Baker Hyghes, Houston, TX (United States); Corregio, Fabio; Augusto, Marcelo; Mendes, Sandro C. [Petroleo Brasileiro S.A. (PETROBRAS), Rio de Janeiro, RJ (Brazil)

    2012-07-01

    One of the problems faced by the oil industry during the well construction is the damage effect of the hydrostatic head of cement slurries on unconsolidated reservoirs, trending to a necessity of lightweight cementing slurries with high resistance for zonal isolation. This paper presents experiences with lightweight cementing slurries obtained by the addition of glass microspheres and thixotropic agents in oil and gas wells located at Solimoes Basin - Amazon Basin, Brazil, which led to 100% time reduction on well construction when compared with the standard cementing procedures, besides the benefit of no reservoir damage. It also includes lab tests, cement slurry designs, case histories and results that allow a complete evaluation of the technique that can be applied in other similar environments. (author)

  4. Preparation of porous hollow silica spheres via a layer-by-layer process and the chromatographic performance

    Science.gov (United States)

    Wei, Xiaobing; Gong, Cairong; Chen, Xujuan; Fan, Guoliang; Xu, Xinhua

    2017-03-01

    Hollow silica spheres possessing excellent mechanical properties were successfully prepared through a layer-by-layer process using uniform polystyrene (PS) latex fabricated by dispersion polymerization as template. The formation of hollow SiO2 micro-spheres, structures and properties were observed in detail by zeta potential, SEM, TEM, FTIR, TGA and nitrogen sorption porosimetry. The results indicated that the hollow spheres were uniform with particle diameter of 1.6 μm and shell thickness of 150 nm. The surface area was 511 m2/g and the pore diameter was 8.36 nm. A new stationary phase for HPLC was obtained by using C18-derivatized hollow SiO2 micro-spheres as packing materials and the chromatographic properties were evaluated for the separation of some regular small molecules. The packed column showed low column pressure, high values of efficiency (up to about 43 000 plates/m) and appropriate asymmetry factors.

  5. Production of hollow microspheres for inertial confinement fusion experiments

    International Nuclear Information System (INIS)

    Cook, R.

    1994-12-01

    The targets used in inertial confinement fusion (ICF) experiments at the Lawrence Livermore National Laboratory are plastic capsules roughly 0.5 mm in diameter. The capsules, which typically have wall thicknesses from 20 to 60 μm, must possess extraordinary symmetry and concentricity and must have surface finishes of less than 1000 Angstrom peak-to-valley variation over surface contours of from 10 to 100's of μm. This paper reviews the fabrication of these capsules, focusing on the production of the thin-walled polystyrene microshell mandrel around which the capsule is built. The relationship between the capsule characteristics, especially surface finish, and capsule performance is discussed, as are the methods of surface characterization and modification necessary for experiments designed to study the effects of surface roughness on implosion dynamics. Targets for the next generation of ICF facilities using more powerful laser drivers will have to be larger while meeting the same or even more stringent symmetry and surface finish requirements. Some of the technologies for meeting these needs are discussed briefly

  6. Glass Membrane For Controlled Diffusion Of Gases

    Science.gov (United States)

    Shelby, James E.; Kenyon, Brian E.

    2001-05-15

    A glass structure for controlled permeability of gases includes a glass vessel. The glass vessel has walls and a hollow center for receiving a gas. The glass vessel contains a metal oxide dopant formed with at least one metal selected from the group consisting of transition metals and rare earth metals for controlling diffusion of the gas through the walls of the glass vessel. The vessel releases the gas through its walls upon exposure to a radiation source.

  7. Resin 90Y microsphere activity measurements for liver brachytherapy

    International Nuclear Information System (INIS)

    Dezarn, William A.; Kennedy, Andrew S.

    2007-01-01

    The measurement of the radioactivity administered to the patient is one of the major components of 90 Y microsphere liver brachytherapy. The activity of 90 Y microspheres in a glass delivery vial was measured in a dose calibrator. The calibration value to use for 90 Y in the dose calibrator was verified using an activity calibration standard provided by the microsphere manufacturer. This method allowed for the determination of a consistent, reproducible local activity standard. Additional measurements were made to determine some of the factors that could affect activity measurement. The axial response of the dose calibrator was determined by the ratio of activity measurements at the bottom and center of the dose calibrator. The axial response was 0.964 for a glass shipping vial, 1.001 for a glass V-vial, and 0.988 for a polycarbonate V-vial. Comparisons between activity measurements in the dose calibrator and those using a radiation survey meter were found to agree within 10%. It was determined that the dose calibrator method was superior to the survey meter method because the former allowed better defined measurement geometry and traceability of the activity standard back to the manufacturer. Part of the preparation of resin 90 Y microspheres for patient delivery is to draw out a predetermined activity from a shipping vial and place it into a V-vial for delivery to the patient. If the drawn activity was placed in a glass V-vial, the activity measured in the dose calibrator with a glass V-vial was 4% higher than the drawn activity from the shipping vial standard. If the drawn activity was placed in a polycarbonate V-vial, the activity measured in the dose calibrator with a polycarbonate V-vial activity was 20% higher than the drawn activity from the shipping vial standard. Careful characterization of the local activity measurement standard is recommended instead of simply accepting the calibration value of the dose calibrator manufacturer

  8. Synthesis of magnetic polymeric microspheres

    Energy Technology Data Exchange (ETDEWEB)

    Gervald, A Yu; Gritskova, Inessa A; Prokopov, Nikolai I [M.V. Lomonosov Moscow State Academy of Fine Chemical Technology, Moscow (Russian Federation)

    2010-05-13

    The key types of magnetic polymeric microspheres are considered. Methods of synthesis of different types of magnetic nanoparticles and of preparation of stable magnetic fluids on their basis are outlined. The overview of the methods for the manufacture of magnetic polymeric microspheres is presented. The effect of the synthesis conditions on the characteristics of magnetic polymeric microspheres such as the diameter and the particle size distribution and the content of magnetic material is discussed by particular examples. The application fields of magnetic polymeric microspheres are briefly surveyed.

  9. Synthesis of magnetic polymeric microspheres

    International Nuclear Information System (INIS)

    Gervald, A Yu; Gritskova, Inessa A; Prokopov, Nikolai I

    2010-01-01

    The key types of magnetic polymeric microspheres are considered. Methods of synthesis of different types of magnetic nanoparticles and of preparation of stable magnetic fluids on their basis are outlined. The overview of the methods for the manufacture of magnetic polymeric microspheres is presented. The effect of the synthesis conditions on the characteristics of magnetic polymeric microspheres such as the diameter and the particle size distribution and the content of magnetic material is discussed by particular examples. The application fields of magnetic polymeric microspheres are briefly surveyed.

  10. Zinc oxide hollow micro spheres and nano rods: Synthesis and applications in gas sensor

    International Nuclear Information System (INIS)

    Jamil, Saba; Janjua, Muhammad Ramzan Saeed Ashraf; Ahmad, Tauqeer; Mehmood, Tahir; Li, Songnan; Jing, Xiaoyan

    2014-01-01

    Zinc oxide nano rods and micro hollow spheres are successfully fabricated by adopting a simple solvo-thermal approach without employing any surfactant/template by keeping heating time as variable. The prepared products are characterized by using different instruments such as X-Ray Diffraction (XRD), Scanning Electron Microscopy (SEM) and Transmission Electron Microscopy (TEM). In order to investigate the morphological dependence on the reaction time, analogous experiments with various reaction times are carried out. Depending upon heating time, different morphological forms have been identified such as hollow microsphere (4 μm to 5 μm) and nano rods with an average diameter of approximately 100 nm. The fabricated materials are also tested for ethanol gas sensor applications and zinc oxide hollow microsphere proven to be an efficient gas sensing materials. Nitrogen adsorption–desorption measurement was performed to understand better performance of zinc oxide micro hollow spheres as effective ethanol gas sensing material. - Graphical abstract: Graphical abstract is represented by zinc oxide sphere (prepared by simple solvothermal approach), its XRD pattern(characterization) and finally its application in gas sensing. - Highlights: • Zinc oxide spheres were prepared by using solvothermal method. • Detailed description of the morphology of microspheres assembled by nano rods. • Formation mechanism of zinc oxide spheres assembled by nano rods. • Zinc oxide spheres and nano rods displayed very good gas sensing ability

  11. Hydroxyapatite-armored poly(ε-caprolactone) microspheres and hydroxyapatite microcapsules fabricated via a Pickering emulsion route.

    Science.gov (United States)

    Fujii, Syuji; Okada, Masahiro; Nishimura, Taiki; Maeda, Hayata; Sugimoto, Tatsuya; Hamasaki, Hiroyuki; Furuzono, Tsutomu; Nakamura, Yoshinobu

    2012-05-15

    Hydroxyapatite (HAp) nanoparticle-armored poly(ε-caprolactone) (PCL) microspheres were fabricated via a "Pickering-type" emulsion solvent evaporation method in the absence of any molecular surfactants. It was clarified that the interaction between carbonyl/carboxylic acid groups of PCL and the HAp nanoparticles at an oil-water interface played a crucial role in the preparation of the stable Pickering-type emulsions and the HAp nanoparticle-armored microspheres. The HAp nanoparticle-armored PCL microspheres were characterized in terms of size, size distribution, morphology, and chemical compositions using scanning electron microscopy, laser diffraction, energy dispersive X-ray microanalysis, and thermogravimetric analysis. The presence of HAp nanoparticles at the surface of the microspheres was confirmed by scanning electron microscopy and energy dispersive X-ray microanalysis. Pyrolysis of the PCL cores led to the formation of the corresponding HAp hollow microcapsules. Copyright © 2012 Elsevier Inc. All rights reserved.

  12. Low-Loss Hollow-Core Anti-Resonant Fibers With Semi-Circular Nested Tubes

    DEFF Research Database (Denmark)

    Habib, Selim; Bang, Ole; Bache, Morten

    2016-01-01

    Hollow-core fibers with a single ring of circular antiresonant tubes as the cladding provide a simple way of getting a negative-curvature hollow core, resulting in broadband low-loss transmission with little power overlap in the glass. These fibers show a significant improvement in loss performan...

  13. Low Loss and Highly Birefringent Hollow-Core Photonic Crystal Fiber

    DEFF Research Database (Denmark)

    Roberts, P. John; Williams, D.P.; Mangan, Brian J.

    2006-01-01

    A hollow-core photonic crystal fiber design is proposed which enables both low-loss and polarization-maintained signal propagation. The design relies on an arrangement of antiresonant features positioned on the glass ring that surrounds the air core.......A hollow-core photonic crystal fiber design is proposed which enables both low-loss and polarization-maintained signal propagation. The design relies on an arrangement of antiresonant features positioned on the glass ring that surrounds the air core....

  14. Modified microspheres for cleaning liquid wastes from radioactive nuclides

    International Nuclear Information System (INIS)

    Danilin, Lev; Drozhzhin, Valery

    2007-01-01

    An effective solution of nuclear industry problems related to deactivation of technological and natural waters polluted with toxic and radioactive elements is the development of inorganic sorbents capable of not only withdrawing radioactive nuclides, but also of providing their subsequent conservation under conditions of long-term storage. A successful technical approach to creation of sorbents can be the use of hollow aluminosilicate microspheres. Such microspheres are formed from mineral additives during coal burning in furnaces of boiler units of electric power stations. Despite some reduction in exchange capacity per a mass unit of sorbents the latter have high kinetic characteristics that makes it possible to carry out the sorption process both in static and dynamic modes. Taking into account large industrial resources of microspheres as by-products of electric power stations, a comparative simplicity of the modification process, as well as good kinetic and capacitor characteristics, this class of sorbents can be considered promising enough for solving the problems of cleaning liquid radioactive wastes of various pollution levels. (authors)

  15. Occupational radiation exposure of medical staff performing 90Y-loaded microsphere radioembolization

    International Nuclear Information System (INIS)

    Laffont, Sophie; Ardisson, Valerie; Lenoir, Laurence; Rolland, Yan; Rohou, Tanguy; Edeline, Julien; Pracht, Marc; Sourd, Samuel Le; Lepareur, Nicolas; Garin, Etienne

    2016-01-01

    Radioembolization of liver cancer with 90 Y-loaded microspheres is increasingly used but data regarding hospital staff exposure are scarce. We evaluated the radiation exposure of medical staff while preparing and injecting 90 Y-loaded glass and resin microspheres especially in view of the increasing use of these products. Exposure of the chest and finger of the radiopharmacist, nuclear medicine physician and interventional radiologist during preparation and injection of 78 glass microsphere preparations and 16 resin microsphere preparations was monitored. Electronic dosimeters were used to measure chest exposure and ring dosimeters were used to measure finger exposure. Chest exposure was very low for both products used (<10 μSv from preparation and injection). In our experience, finger exposure was significantly lower than the annual limit of 500 mSv for both products. With glass microspheres, the mean finger exposure was 13.7 ± 5.2 μSv/GBq for the radiopharmacist, and initially 17.9 ± 5.4 μSv/GBq for the nuclear medicine physician reducing to 13.97 ± 7.9 μSv/GBq with increasing experience. With resin microspheres, finger exposure was more significant: mean finger exposure for the radiopharmacist was 295.1 ± 271.9 μSv/GBq but with a reduction with increasing experience to 97.5 ± 35.2 μSv/GBq for the six most recent dose preparations. For administration of resin microspheres, the greatest mean finger exposure for the nuclear medicine physician (the most exposed operator) was 235.5 ± 156 μSv/GBq. Medical staff performing 90 Y-loaded microsphere radioembolization procedures are exposed to safe levels of radiation. Exposure is lower than that from treatments using 131 I-lipiodol. The lowest finger exposure is from glass microspheres. With resin microspheres finger exposure is acceptable but could be optimized in accordance with the ALARA principle, and especially in view of the increasing use of radioembolization. (orig.)

  16. Fiber pigtailed thin wall capillary coupler for excitation of microsphere WGM resonator.

    Science.gov (United States)

    Wang, Hanzheng; Lan, Xinwei; Huang, Jie; Yuan, Lei; Kim, Cheol-Woon; Xiao, Hai

    2013-07-01

    In this paper, we demonstrate a fiber pigtailed thin wall capillary coupler for excitation of Whispering Gallery Modes (WGMs) of microsphere resonators. The coupler is made by fusion-splicing an optical fiber with a capillary tube and consequently etching the capillary wall to a thickness of a few microns. Light is coupled through the peripheral contact between inserted microsphere and the etched capillary wall. The coupling efficiency as a function of the wall thickness was studied experimentally. WGM resonance with a Q-factor of 1.14 × 10(4) was observed using a borosilicate glass microsphere with a diameter of 71 μm. The coupler operates in the reflection mode and provides a robust mechanical support to the microsphere resonator. It is expected that the new coupler may find broad applications in sensors, optical filters and lasers.

  17. Preparation and properties of polyvinyl alcohol microspheres

    International Nuclear Information System (INIS)

    Campbell, J.H.; Grens, J.Z.; Poco, J.F.; Ives, B.H.

    1986-06-01

    Polyvinyl alcohol (PVA) microspheres, having a size range of ∼150- to 250-μm diameter with 1- to 5-μm wall thickness, have been fabricated using a solution droplet technique. The spheres were developed for possible use on the Lawrence Livermore National Laboratory (LLNL) Inertial Confinement Fusion (ICF) Program. PVA, a polymer chosen based on earlier survey work carried out at KMS Fusion, Inc., has good strength, low hydrogen permeability, is optically transparent, and water soluble. The latter property makes it safe and easy to use in our droplet generator system. A unique dual-orifice droplet generator was used to prepare the spheres. The droplet generator operating conditions and the column processing parameters were chosen using results from our 1-D model calculations as a guide. The polymer microsphere model is an extension of the model we developed to support the glass sphere production. After preparation, the spheres were physically characterized for surface quality, sphericity, wall thickness (and uniformity), and size. We also determined the buckling pressure for both uncoated and CH-coated spheres. Radiation stability to beta decay (from tritium) was evaluated by exposing the spheres to a 7-keV electron beam. The results from these and other physical property measurements are presented in this report

  18. Fabrication of silica hollow particles using yeast cells as a template

    Science.gov (United States)

    Liao, Shenglan; Lin, Liqin; Chen, Xiaofang; Liu, Jingru; Zhang, Biao

    2018-04-01

    Inorganic hollow particles have attracted great interest in recent years. In this study, silica micro spheres were produced. Yeast cells were used as a biological template. The silica shell was synthesized by the hydrolysis of tetraethoxysilane (TEOS) in water-alcohol mixtures as solvent using ammonia as a catalyst according to the Stoeber process. Various approaches including X-ray diffraction (XRD), scanning electron microscopy (SEM) and Fourier transformed infrared (FT-IR) spectroscopy were used to characterize the products. The results showed that the thermally treated samples were SiO2 hollow microspheres with a diameter varying between 1-5μm.

  19. Compaction of Ceramic Microspheres, Spherical Molybdenum Powder and Other Materials to 3 GPa

    International Nuclear Information System (INIS)

    Carlson, S R; Bonner, B P; Ryerson, F J; Hart, M M

    2006-01-01

    Pressure-volume relationships were measured at room temperature for eight granular materials and one specimen of epoxy foam. The granular materials included hollow ceramic microspheres, spherical molybdenum powder, Ottawa sand, aluminum, copper, titanium and silicon carbide powders and glassy carbon spheres. Measurements were made to 0.9 GPa in a liquid medium press for all of the granular materials and to 3 GPa in a solid medium press for the ceramic microspheres and molybdenum powder. A single specimen of epoxy foam was compressed to 30 MPa in the liquid medium press. Bulk moduli were calculated as a function of pressure for the ceramic microspheres, the molybdenum powder and three other granular materials. The energy expended in compacting the granular materials was determined by numerically integrating pressure-volume curves. More energy was expended per unit volume in compacting the molybdenum powder to 1 GPa than for the other materials, but compaction of the ceramic microspheres required more energy per gram due to their very low initial density. The merge pressure, the pressure at which all porosity is removed, was estimated for each material by plotting porosity against pressure on a semi-log plot. The pressure-volume curves were then extrapolated to the predicted merge pressures and numerically integrated to estimate the energy required to reach full density for each material. The results suggest that the glassy carbon spheres and the ceramic microspheres would require more energy than the other materials to attain full density

  20. Hollow-Core Fiber Lamp

    Science.gov (United States)

    Yi, Lin (Inventor); Tjoelker, Robert L. (Inventor); Burt, Eric A. (Inventor); Huang, Shouhua (Inventor)

    2016-01-01

    Hollow-core capillary discharge lamps on the millimeter or sub-millimeter scale are provided. The hollow-core capillary discharge lamps achieve an increased light intensity ratio between 194 millimeters (useful) and 254 millimeters (useless) light than conventional lamps. The capillary discharge lamps may include a cone to increase light output. Hollow-core photonic crystal fiber (HCPCF) may also be used.

  1. Evaluation of the Thermosensitive Release Properties of Microspheres Containing an Agrochemical Compound.

    Science.gov (United States)

    Terada, Takatoshi; Ohtsubo, Toshiro; Iwao, Yasunori; Noguchi, Shuji; Itai, Shigeru

    2017-01-01

    The purpose of this study was to develop a deeper understanding of the key physicochemical parameters involved in the release profiles of microsphere-encapsulated agrochemicals at different temperatures. Microspheres consisting of different polyurethanes (PUs) were prepared using our previously reported solventless microencapsulation technique. Notably, these microspheres exhibited considerable differences in their thermodynamic characteristics, including their glass transition temperature (T g ), extrapolated onset temperature (T o ) and extrapolated end temperature (T e ). At test temperatures below the T o of the PU, only 5-10% of the agrochemical was rapidly released from the microspheres within 1 d, and none was released thereafter. However, at test temperatures above the T o of the PU, the rate of agrochemical release gradually increased with increasing temperatures, and the rate of release from the microspheres was dependent on the composition of the PU. Taken together, these results show that the release profiles of the microspheres were dependent on their thermodynamic characteristics and changes in their PU composition.

  2. Solvent/non-solvent sintering: a novel route to create porous microsphere scaffolds for tissue regeneration.

    Science.gov (United States)

    Brown, Justin L; Nair, Lakshmi S; Laurencin, Cato T

    2008-08-01

    Solvent/non-solvent sintering creates porous polymeric microsphere scaffolds suitable for tissue engineering purposes with control over the resulting porosity, average pore diameter, and mechanical properties. Five different biodegradable biocompatible polyphosphazenes exhibiting glass transition temperatures from -8 to 41 degrees C and poly (lactide-co-glycolide), (PLAGA) a degradable polymer used in a number of biomedical settings, were examined to study the versatility of the process and benchmark the process to heat sintering. Parameters such as: solvent/non-solvent sintering solution composition and submersion time effect the sintering process. PLAGA microsphere scaffolds fabricated with solvent/non-solvent sintering exhibited an interconnected porosity and pore size of 31.9% and 179.1 mum, respectively which was analogous to that of conventional heat sintered PLAGA microsphere scaffolds. Biodegradable polyphosphazene microsphere scaffolds exhibited a maximum interconnected porosity of 37.6% and a maximum compressive modulus of 94.3 MPa. Solvent/non-solvent sintering is an effective strategy for sintering polymeric microspheres, with a broad spectrum of glass transition temperatures, under ambient conditions making it an excellent fabrication route for developing tissue engineering scaffolds and drug delivery vehicles. (c) 2007 Wiley Periodicals, Inc.

  3. Gastroretentive Floating Microspheres of Silymarin: Preparation and ...

    African Journals Online (AJOL)

    Methods: Cellulose microspheres – formulated with hydroxylpropyl methylcellulose (HPMC) and ethyl cellulose (EC) – and Eudragit microspheres – formulated with Eudragit® S 100 (ES) and Eudragit® RL (ERL) - were prepared by an emulsion-solvent evaporation method. The floating microspheres were evaluated for flow ...

  4. HOLLOW FIBRE MEMBRANE

    NARCIS (Netherlands)

    Wessling, Matthias; Stamatialis, Dimitrios; Kopec, K.K.; Dutczak, S.M.

    2011-01-01

    The present invention relates to a process for manufacturing a hollow fibre membrane having a supporting layer and a separating layer, said process comprising: (a)extruding a spinning composition comprising a first polymer and a solvent for the first polymer through an inner annular orifice of a

  5. HOLLOW FIBRE MEMBRANE

    NARCIS (Netherlands)

    Wessling, Matthias; Stamatialis, Dimitrios; Kopec, K.K.; Dutczak, S.M.

    2013-01-01

    The present invention relates to a process for manufacturing a hollow fibre membrane having a supporting layer and a separating layer, said process comprising: (a) extruding a spinning composition comprising a first polymer and a solvent for the first polymer through an inner annular orifice of a

  6. Hierarchical Mn₂O₃ Microspheres In-Situ Coated with Carbon for Supercapacitors with Highly Enhanced Performances.

    Science.gov (United States)

    Gong, Feilong; Lu, Shuang; Peng, Lifang; Zhou, Jing; Kong, Jinming; Jia, Dianzeng; Li, Feng

    2017-11-23

    Porous Mn₂O₃ microspheres have been synthesized and in-situ coated with amorphous carbon to form hierarchical C@Mn₂O₃ microspheres by first producing MnCO₃ microspheres in solvothermal reactions, and then annealing at 500 °C. The self-assembly growth of MnCO₃ microspheres can generate hollow structures inside each of the particles, which can act as micro-reservoirs to store biomass-glycerol for generating amorphous carbon onto the surfaces of Mn₂O₃ nanorods consisting of microspheres. The C@Mn₂O₃ microspheres, prepared at 500 °C, exhibit highly enhanced pseudocapacitive performances when compared to the particles after annealed at 400 °C and 600 °C. Specifically, the C@Mn₂O₃ microspheres prepared at 500 °C show high specific capacitances of 383.87 F g -1 at current density of 0.5 A g -1 , and excellent cycling stability of 90.47% of its initial value after cycling for 5000 times. The asymmetric supercapacitors assembled with C@Mn₂O₃ microspheres after annealed at 500 °C and activated carbon (AC) show an energy density of up to 77.8 Wh kg -1 at power density of 500.00 W kg -1 , and a maximum power density of 20.14 kW kg -1 at energy density of 46.8 Wh kg -1 . We can attribute the enhanced electrochemical performances of the materials to their three-dimensional (3D) hierarchical structure in-situ coated with carbon.

  7. Hierarchical Mn2O3 Microspheres In-Situ Coated with Carbon for Supercapacitors with Highly Enhanced Performances

    Science.gov (United States)

    Gong, Feilong; Lu, Shuang; Peng, Lifang; Zhou, Jing; Kong, Jinming; Jia, Dianzeng; Li, Feng

    2017-01-01

    Porous Mn2O3 microspheres have been synthesized and in-situ coated with amorphous carbon to form hierarchical C@Mn2O3 microspheres by first producing MnCO3 microspheres in solvothermal reactions, and then annealing at 500 °C. The self-assembly growth of MnCO3 microspheres can generate hollow structures inside each of the particles, which can act as micro-reservoirs to store biomass-glycerol for generating amorphous carbon onto the surfaces of Mn2O3 nanorods consisting of microspheres. The C@Mn2O3 microspheres, prepared at 500 °C, exhibit highly enhanced pseudocapacitive performances when compared to the particles after annealed at 400 °C and 600 °C. Specifically, the C@Mn2O3 microspheres prepared at 500 °C show high specific capacitances of 383.87 F g−1 at current density of 0.5 A g−1, and excellent cycling stability of 90.47% of its initial value after cycling for 5000 times. The asymmetric supercapacitors assembled with C@Mn2O3 microspheres after annealed at 500 °C and activated carbon (AC) show an energy density of up to 77.8 Wh kg−1 at power density of 500.00 W kg−1, and a maximum power density of 20.14 kW kg−1 at energy density of 46.8 Wh kg−1. We can attribute the enhanced electrochemical performances of the materials to their three-dimensional (3D) hierarchical structure in-situ coated with carbon. PMID:29168756

  8. Hierarchical Mn2O3 Microspheres In-Situ Coated with Carbon for Supercapacitors with Highly Enhanced Performances

    Directory of Open Access Journals (Sweden)

    Feilong Gong

    2017-11-01

    Full Text Available Porous Mn2O3 microspheres have been synthesized and in-situ coated with amorphous carbon to form hierarchical C@Mn2O3 microspheres by first producing MnCO3 microspheres in solvothermal reactions, and then annealing at 500 °C. The self-assembly growth of MnCO3 microspheres can generate hollow structures inside each of the particles, which can act as micro-reservoirs to store biomass-glycerol for generating amorphous carbon onto the surfaces of Mn2O3 nanorods consisting of microspheres. The C@Mn2O3 microspheres, prepared at 500 °C, exhibit highly enhanced pseudocapacitive performances when compared to the particles after annealed at 400 °C and 600 °C. Specifically, the C@Mn2O3 microspheres prepared at 500 °C show high specific capacitances of 383.87 F g−1 at current density of 0.5 A g−1, and excellent cycling stability of 90.47% of its initial value after cycling for 5000 times. The asymmetric supercapacitors assembled with C@Mn2O3 microspheres after annealed at 500 °C and activated carbon (AC show an energy density of up to 77.8 Wh kg−1 at power density of 500.00 W kg−1, and a maximum power density of 20.14 kW kg−1 at energy density of 46.8 Wh kg−1. We can attribute the enhanced electrochemical performances of the materials to their three-dimensional (3D hierarchical structure in-situ coated with carbon.

  9. Temperature influence in crystallinity of polymer microspheres

    International Nuclear Information System (INIS)

    Rezende, Cristiane de P.; Novack, Katia M.

    2011-01-01

    Drug delivery technology is evolving through the creation of new techniques of drug delivery effectively. The new methods used in drugs administration are based in microencapsulation process. Microsphere encapsulation modifies drug delivery bringing benefits and efficiency. In this work has been evaluated the influence of temperature in microspheres preparation. Microspheres were obtained by PMMA-co-PEG (COP) copolymer with indomethacin inserted in polymer matrix. Samples were characterized by SEM, DSC and XRD. SEM micrographs confirmed the formation of different sizes of microspheres and it was verified that higher temperatures make more crystalline microspheres. (author)

  10. Method and apparatus for producing small hollow spheres

    International Nuclear Information System (INIS)

    Hendricks, C.D.

    1979-01-01

    A method and apparatus are described for producing small hollow spheres of glass, metal or plastic, wherein the sphere material is mixed with or contains as part of the composition a blowing agent which decomposes at high temperature (T greater than or equal to 600 0 C). As the temperature is quickly raised, the blowing agent decomposes and the resulting gas expands from within, thus forming a hollow sphere of controllable thickness. The thus produced hollow spheres (20 to 10 3 μm) have a variety of application, and are particularly useful in the fabrication of targets for laser implosion such as neutron sources, laser fusion physics studies, and laser initiated fusion power plants

  11. Hierarchical VOOH hollow spheres for symmetrical and asymmetrical supercapacitor devices

    Science.gov (United States)

    Jing, Xuyang; Wang, Cong; Feng, Wenjing; Xing, Na; Jiang, Hanmei; Lu, Xiangyu; Zhang, Yifu; Meng, Changgong

    2018-01-01

    Hierarchical VOOH hollow spheres with low crystallinity composed of nanoparticles were prepared by a facile and template-free method, which involved a precipitation of precursor microspheres in aqueous solution at room temperature and subsequent hydrothermal reaction. Quasi-solid-state symmetric and asymmetric supercapacitor (SSC and ASC) devices were fabricated using hierarchical VOOH hollow spheres as the electrodes, and the electrochemical properties of the VOOH//VOOH SSC device and the VOOH//AC ASC device were studied by cyclic voltammetry (CV), galvanostatic charge-discharge (GCD) and electrochemical impedance spectroscopy (EIS). Results demonstrated that the electrochemical performance of the VOOH//AC ASC device was better than that of the VOOH//VOOH SSC device. After 3000 cycles, the specific capacitance of the VOOH//AC ASC device retains 83% of the initial capacitance, while the VOOH//VOOH SSC device retains only 7.7%. Findings in this work proved that hierarchical VOOH hollow spheres could be a promising candidate as an ideal electrode material for supercapacitor devices.

  12. Production of Monodisperse Cerium Oxide Microspheres with Diameters near 100 µm by Internal Gelation Sol-Gel Methods

    Energy Technology Data Exchange (ETDEWEB)

    Katalenich, Jeffrey A.; Kitchen, Brian B.; Pierson, Bruce

    2018-05-01

    Internal gelation sol-gel methods have used a variety of sphere forming methods in the past to produce metal oxide microspheres, but typically with poor control over the size uniformity at diameters near 100 µm. This work describes efforts to make and measure internal gelation, sol-gel microspheres with very uniform diameters in the 100 – 200 µm size range using a two-fluid nozzle. A custom apparatus was used to form aqueous droplets of sol-gel feed solutions in silicone oil and heat them to cause gelation of the spheres. Gelled spheres were washed, dried, and sintered prior to mounting on glass slides for optical imaging and analysis. Microsphere diameters and shape factors were determined as a function of silicone oil flow rate in a two-fluid nozzle and the size of a needle dispensing the aqueous sol-gel solution. Nine batches of microspheres were analyzed and had diameters ranging from 65.5 ± 2.4 µm for the smallest needle and fastest silicone oil flow rate to 211 ± 4.7 µm for the largest needle and slowest silicone oil flow rate. Standard deviations for measured diameters were less than 8% for all samples and most were less than 4%. Microspheres had excellent circularity with measured shape factors of 0.9 – 1. However, processing of optical images was complicated by shadow effects in the photoresist layer on glass slides and by overlapping microspheres. Based on calculated flow parameters, microspheres were produced in a simple dripping mode in the two-fluid nozzle. Using flow rates consistent with a simple dripping mode in a two-fluid nozzle configuration allows for very uniform oxide microspheres to be produced using the internal-gelation sol-gel method.

  13. Hollow bunches production

    CERN Document Server

    Hancock, S

    2017-01-01

    Hollow bunches address the issue of high-brightnessbeams suffering from transverse emittance growth in a strongspace charge regime. During the Proton Synchrotron (PS)injection plateau, the negative space charge tune shift canpush the beam onto theQy=6integer resonance. Modify-ing the longitudinal bunch profile in order to reduce the peakline charge density alleviates the detrimental impact of spacecharge. To this end we first produce longitudinally hollowphase space distributions in the PS Booster by exciting aparametric resonance with the phase loop feedback system.These inherently flat bunches are then transferred to the PS,where the beam becomes less prone to the emittance growthcaused by the integer resonance.During the late 2016 machine development sessions inthe PS Booster we profited from solved issues from 2015and managed to reliably extract hollow bunches of1.3eVsmatched longitudinal area. Furthermore, first results to cre-ate hollow bunches with larger longitudinal emittances to-wards the LHC Inject...

  14. Hydrothermal synthesis and electrochemical performance of NiO microspheres with different nanoscale building blocks

    International Nuclear Information System (INIS)

    Wang Ling; Hao Yanjing; Zhao Yan; Lai Qiongyu; Xu Xiaoyun

    2010-01-01

    NiO microspheres were successfully obtained by calcining the Ni(OH) 2 precursor, which were synthesized via the hydrothermal reaction of nickel chloride, glucose and ammonia. The products were characterized by TGA, XRD and SEM. The influences of glucose and reaction temperature on the morphologies of NiO samples were investigated. Moreover, the possible growth mechanism for the spherical morphology was proposed. The charge/discharge test showed that the as-prepared NiO microspheres composed of nanoparticles can serve as an ideal electrode material for supercapacitor due to the spherical hollow structure. -- Graphical Abstract: Fig. 5 is the SEM image of NiO that was prepared in the different hydrothermal reaction temperatures. It showed that reaction temperature played a crucial role for the morphology of products.

  15. Contrast enhancement of microsphere-assisted super-resolution imaging in dark-field microscopy

    Science.gov (United States)

    Zhou, Yi; Tang, Yan; Deng, Qinyuan; Zhao, Lixin; Hu, Song

    2017-08-01

    We report a method of boosting the imaging contrast of microsphere-assisted super-resolution visualization by utilizing dark-field illumination (DFI). We conducted experiments on both 10-µm-diameter silica (SiO2) microspheres with refractive index n ∼ 1.46 under no and partial immersion in ethyl alcohol (n ∼ 1.36) and 20-µm-diameter barium titanate glass (BTG, n ∼ 1.9) microspheres with full immersion to show the super-resolution capability. We experimentally demonstrated that the imaging contrast and uniformity were extraordinarily improved in the DFI mode. The intensity profiles in the visualization also numerically confirm the enhanced sharpness for a better imaging quality when applying DFI.

  16. Development of Risperidone PLGA Microspheres

    Directory of Open Access Journals (Sweden)

    Susan D’Souza

    2014-01-01

    Full Text Available The aim of this study was to design and evaluate biodegradable PLGA microspheres for sustained delivery of Risperidone, with an eventual goal of avoiding combination therapy for the treatment of schizophrenia. Two PLGA copolymers (50 : 50 and 75 : 25 were used to prepare four microsphere formulations of Risperidone. The microspheres were characterized by several in vitro techniques. In vivo studies in male Sprague-Dawley rats at 20 and 40 mg/kg doses revealed that all formulations exhibited an initial burst followed by sustained release of the active moiety. Additionally, formulations prepared with 50 : 50 PLGA had a shorter duration of action and lower cumulative AUC levels than the 75 : 25 PLGA microspheres. A simulation of multiple dosing at weekly or 15-day regimen revealed pulsatile behavior for all formulations with steady state being achieved by the second dose. Overall, the clinical use of Formulations A, B, C, or D will eliminate the need for combination oral therapy and reduce time to achieve steady state, with a smaller washout period upon cessation of therapy. Results of this study prove the suitability of using PLGA copolymers of varying composition and molecular weight to develop sustained release formulations that can tailor in vivo behavior and enhance pharmacological effectiveness of the drug.

  17. Production of microspheres labeled with holmium-166 for liver cancer therapy: the preliminary experience at IPEN/CNEN-SP

    International Nuclear Information System (INIS)

    Costa, Renata F.; Azevedo, Mariangela B.M.; Nascimento, Nanci; Sene, Frank F.; Martinelli, Jose R.; Osso Junior, Joao A.

    2009-01-01

    Microspheres labeled with therapeutic radionuclides for malignancies of liver are widely used in many countries. The internal radionuclide therapy uses a permanently implanted device, such as Therasphere R or SIR-Spheres R , or a biodegradable device that provides structural support for the radionuclide of choice and causes the tumor reduction. Three different types of material supports have been investigated, i.e., biodegradable polymer-based, glass-based and resin-based microspheres. Nowadays there is a project concerning the labeling of these 3 materials with 166 Ho being developed at IPEN-CNEN/SP and coordinated by the Radiopharmacy Directory. 166 Ho(t 1/2 =26.8 h) is a beta minus emitter (E max =1.84 MeV), with right properties for radiotherapy and can be produced with the low power Brazilian Nuclear Reactor IEA-R1m. The aim of this work is to describe the stage of development of this project. The initial experience used resin-based microspheres, a cation exchange resin labeled with 166 Ho, it showed the essential characteristics for liver therapy. Preliminary results of the preparation of glass-based microspheres labeled with 165 Ho showed that 5% of Ho 2 O 3 was incorporated in an aluminosilicate glass, through the process of spheronization by flame, which produced spherical microspheres with 20-40μm particle size. The preparation of biodegradable material, polymer-based microspheres, is in its initial stage and the objective is to prepare and label with 165 Ho different polymer-based microspheres. These combined efforts have been done to offer a national radiotherapeutic product for the the Brazilian nuclear medicine community at fair value and also to offer a viable possibility of treatment for patients affected by liver malignancies. (author)

  18. Production of microspheres labeled with holmium-166 for liver cancer therapy: the preliminary experience at IPEN/CNEN-SP

    Energy Technology Data Exchange (ETDEWEB)

    Costa, Renata F.; Azevedo, Mariangela B.M.; Nascimento, Nanci; Sene, Frank F.; Martinelli, Jose R.; Osso Junior, Joao A., E-mail: renatafcosta@usp.b [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, SP (Brazil)

    2009-07-01

    Microspheres labeled with therapeutic radionuclides for malignancies of liver are widely used in many countries. The internal radionuclide therapy uses a permanently implanted device, such as Therasphere{sup R} or SIR-Spheres{sup R}, or a biodegradable device that provides structural support for the radionuclide of choice and causes the tumor reduction. Three different types of material supports have been investigated, i.e., biodegradable polymer-based, glass-based and resin-based microspheres. Nowadays there is a project concerning the labeling of these 3 materials with {sup 166}Ho being developed at IPEN-CNEN/SP and coordinated by the Radiopharmacy Directory. {sup 166}Ho(t{sub 1/2}=26.8 h) is a beta minus emitter (E{sub max}=1.84 MeV), with right properties for radiotherapy and can be produced with the low power Brazilian Nuclear Reactor IEA-R1m. The aim of this work is to describe the stage of development of this project. The initial experience used resin-based microspheres, a cation exchange resin labeled with {sup 166}Ho, it showed the essential characteristics for liver therapy. Preliminary results of the preparation of glass-based microspheres labeled with {sup 165}Ho showed that 5% of Ho{sub 2}O{sub 3} was incorporated in an aluminosilicate glass, through the process of spheronization by flame, which produced spherical microspheres with 20-40mum particle size. The preparation of biodegradable material, polymer-based microspheres, is in its initial stage and the objective is to prepare and label with {sup 165}Ho different polymer-based microspheres. These combined efforts have been done to offer a national radiotherapeutic product for the the Brazilian nuclear medicine community at fair value and also to offer a viable possibility of treatment for patients affected by liver malignancies. (author)

  19. Literature Review: An Overview of Epoxy Resin Syntactic Foams with Glass Microballoons

    Energy Technology Data Exchange (ETDEWEB)

    Keller, Jennie [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    2014-03-12

    Syntactic foams are an important category of composite materials that have abundant applications in a wide variety of fields. The bulk phase of syntactic foams is a three-part epoxy resin formulation that consists of a base resin, a curative (curing agent) and a modifier (diluent and/or accelerator) [12]. These thermoset materials [12] are used frequently for their thermal stability [9], low moisture absorption and high compressive strength [10]. The characteristic feature of a syntactic foam is a network of beads that forms pores within the epoxy matrix [3]. In this review, hollow glass beads (known as glass microballoons) are considered, however, solid beads or microballoons made from materials such as ceramic, polymer or metal can also be used [3M, Peter]. The network of hollow beads forms a closed-cell foam; the term closed-cell comes from the fact that the microspheres used in the resin matrix are completely closed and filled with gas (termed hollow). In contrast, the microspheres used in open-cell foams are either not completely closed or broken so that matrix material can fill the spheres [11]. Although closed foams have been found to possess higher densities than open cell foams, their rigid structures give them superior mechanical properties [12]. Past research has extensively studied the effects that changing the volume fraction of microballoons to epoxy will have on the resulting syntactic foam [3,4,9]. In addition, published literature also explores how the microballoon wall thickness affects the final product [4,9,10]. Findings detail that indeed both the mechanical and some thermal properties of syntactic foams can be tailored to a specific application by varying either the volume fraction or the wall thickness of the microballoons used [10]. The major trends in syntactic foam research show that microballoon volume fraction has an inversely proportionate relationship to dynamic properties, while microballoon wall thickness is proportional to those

  20. Preparing microspheres of actinide nitrides from carbon containing oxide sols

    International Nuclear Information System (INIS)

    Triggiani, L.V.

    1975-01-01

    A process is given for preparing uranium nitride, uranium oxynitride, and uranium carboxynitride microspheres and the microspheres as compositions of matter. The microspheres are prepared from carbide sols by reduction and nitriding steps. (Official Gazette)

  1. Preparation of microspheres for slow release drug by radiation-induced suspension polymerization and their properties

    International Nuclear Information System (INIS)

    Yoshida, Masaru; Asano, Masaharu; Kaetsu, Isao

    1982-01-01

    The polymer microspheres containing drugs as drug delivery system were made by means of suspension-polymerization by radiation at low temperature by using glass-forming monomers which have stable supercooling properties and large polymerizability at low temperature. The particle distribution depended on the kind of monomer. It was found that the entrapping yield of drug in polymer microspheres increased with increasing viscosity of monomer and that the maximum value on the particle size distribution curve was also shifted to large particle diameter side. In the case of trimethylolpropane trimethacrylate monomer (43 cps), TMPT, the entrapping yield of drug reached 74% and the maximum value in particle size distribution curve appeared in the neighborhood of 105 to 210 mu m ranges. On the other hand, those values in neopentyl glycol dimethacrylate monomer (4 cps) were 12% in former and 44 -- 105 mu m in the latter. The release phenomenon of drugs from polymer microspheres was investigated. for example, the cumulative amount of mitomycin C (water soluble drug) released from TMPT polymer microsphere was about 90% after 30-day dissolution, while in the case of water-insoluble drug such as testosterone the amount of release was about 49% after 40-day dissolution. In all cases, the release rate is constant during the experimental period. Therefore, it was concluded that the release of drugs from polymer microspheres obtained in this study is possible over the long periods. (author)

  2. Chitosan Microspheres as Radiolabeled Delivery Devices

    International Nuclear Information System (INIS)

    Permtermsin, Chalermsin; Ngamprayad, Tippanan; Phumkhem, Sudkanung; Srinuttrakul, Wannee; Kewsuwan, Prartana

    2007-08-01

    Full text: This study optimized conditions for preparing, characterizing, radiolabeled of chitosan microspheres and the biodistribution of 99mTc-Chitosan microspheres after intravenous administration. Particle size distribution of the microspheres was determined by light scattering. Zeta potential was studied by dynamic light scattering and electrophoresis technique. Biodistribution studies were performed by radiolabeling using 99mTc. The results shown that geometric mean diameter of the microspheres was found to be 77.26?1.96 ?m. Microsphere surface charge of chitosan microspheres was positive charge and zeta potential was 25.80 ? 0.46 mV. The labeling efficiency for this condition was more than 95% and under this condition was stable for at least 6 h. Radioactivity

  3. Mercury - the hollow planet

    Science.gov (United States)

    Rothery, D. A.

    2012-04-01

    Mercury is turning out to be a planet characterized by various kinds of endogenous hole (discounting impact craters), which are compared here. These include volcanic vents and collapse features on horizontal scales of tens of km, and smaller scale depressions ('hollows') associated with bright crater-floor deposits (BCFD). The BCFD hollows are tens of metres deep and kilometres or less across and are characteristically flat-floored, with steep, scalloped walls. Their form suggests that they most likely result from removal of surface material by some kind of mass-wasting process, probably associated with volume-loss caused by removal (via sublimation?) of a volatile component. These do not appear to be primarily a result of undermining. Determining the composition of the high-albedo bluish surface coating in BCFDs will be a key goal for BepiColombo instruments such as MIXS (Mercury Imaging Xray Spectrometer). In contrast, collapse features are non-circular rimless pits, typically on crater floors (pit-floor craters), whose morphology suggests collapse into void spaces left by magma withdrawal. This could be by drainage of either erupted lava (or impact melt) or of shallowly-intruded magma. Unlike the much smaller-scale BCFD hollows, these 'collapse pit' features tend to lack extensive flat floors and instead tend to be close to triangular in cross-section with inward slopes near to the critical angle of repose. The different scale and morphology of BCFD hollows and collapse pits argues for quite different modes of origin. However, BCFD hollows adjacent to and within the collapse pit inside Scarlatti crater suggest that the volatile material whose loss was responsible for the growth of the hollows may have been emplaced in association with the magma whose drainage caused the main collapse. Another kind of volcanic collapse can be seen within a 25 km-wide volcanic vent outside the southern rim of the Caloris basin (22.5° N, 146.1° E), on a 28 m/pixel MDIS NAC image

  4. In vitro Evaluation of Nateglinide-Loaded Microspheres Formulated ...

    African Journals Online (AJOL)

    Keywords: Nateglinide, Microspheres, Micromeritics, Drug release, Ionic ... Oral drug delivery systems (DDS) are commonly divided into immediate release and modified release systems. ..... Albumin Microspheres for Potential Intramuscular.

  5. Evaluation of radiolabelled microspheres as digesta markers

    International Nuclear Information System (INIS)

    Young, B.A.; Turner, B.V.; Dixon, A.E.; Exley, D.M.; Young, S.B.; Abidin, Z.

    1991-01-01

    The suitability of microspheres as markers for measuring digesta kinetics in sheep was examined. Microspheres offer advantages of uniformity of size and density, and stability during passage through the gastrointestinal tract. They are commercially available labelled with the choice of one of eleven different radionuclides and can be easily measured in digesta and faecal material. Tests comparing several types of digesta markers gave different measures of kinetic parameters when the measurements were made concurrently in the same sheep. However, concurrent measurements derived from use of microspheres were consistent. Microspheres offer a new alternative for digestive studies. (author). 19 refs, 4 tabs

  6. Microsphere estimates of blood flow: Methodological considerations

    International Nuclear Information System (INIS)

    von Ritter, C.; Hinder, R.A.; Womack, W.; Bauerfeind, P.; Fimmel, C.J.; Kvietys, P.R.; Granger, D.N.; Blum, A.L.

    1988-01-01

    The microsphere technique is a standard method for measuring blood flow in experimental animals. Sporadic reports have appeared outlining the limitations of this method. In this study the authors have systematically assessed the effect of blood withdrawals for reference sampling, microsphere numbers, and anesthesia on blood flow estimates using radioactive microspheres in dogs. Experiments were performed on 18 conscious and 12 anesthetized dogs. Four blood flow estimates were performed over 120 min using 1 x 10 6 microspheres each time. The effects of excessive numbers of microspheres pentobarbital sodium anesthesia, and replacement of volume loss for reference samples with dextran 70 were assessed. In both conscious and anesthetized dogs a progressive decrease in gastric mucosal blood flow and cardiac output was observed over 120 min. This was also observed in the pancreas in conscious dogs. The major factor responsible for these changes was the volume loss due to the reference sample withdrawals. Replacement of the withdrawn blood with dextran 70 led to stable blood flows to all organs. The injection of excessive numbers of microspheres did not modify hemodynamics to a greater extent than did the injection of 4 million microspheres. Anesthesia exerted no influence on blood flow other than raising coronary flow. The authors conclude that although blood flow to the gastric mucosa and the pancreas is sensitive to the minor hemodynamic changes associated with the microsphere technique, replacement of volume loss for reference samples ensures stable blood flow to all organs over a 120-min period

  7. Thermal analysis of iron hydroxide microspheres

    International Nuclear Information System (INIS)

    Turcanu, C.N.; Cornescu, M.

    1979-03-01

    The thermal treatment is an important step in the preparative technology of the iron oxids microspheres with well established mechanical, physical and chemical characteristics. The first indications on the heating procedure have been obtained from the thermal analysis on iron hydroxide microspheres prepared by the support precipitation and internal gelification methods. (author)

  8. Encapsulated PDMS microspheres with reactive handles

    DEFF Research Database (Denmark)

    Gonzalez, Lidia; Ma, Baoguang; Li, Li

    2014-01-01

    , cured PDMS microspheres are coated with poly(methyl methacrylate) using a chemical process (solvent evaporation technique). Three solvents are used in three different experiments: dichloromethane, tetrahydrofuran, and acetone. The composition and morphology of the cured PDMS microspheres and PMMA coated...

  9. Microencapsulation and microspheres for food applications

    NARCIS (Netherlands)

    Sagis, L.M.C.

    2015-01-01

    This book provides an update on the latest developments, challenges, and opportunities in the highly expanding field of microencapsulation and microspheres for food applications, examining the various types of microspheres and microcapsules essential to those who need to develop stable and

  10. From harmful Microcystis blooms to multi-functional core-double-shell microsphere bio-hydrochar materials.

    Science.gov (United States)

    Bi, Lei; Pan, Gang

    2017-11-13

    Harmful algal blooms (HABs) induced by eutrophication is becoming a serious global environmental problem affecting public health and aquatic ecological sustainability. A novel strategy for the utilization of biomass from HABs was developed by converting the algae cells into hollow mesoporous bio-hydrochar microspheres via hydrothermal carbonization method. The hollow microspheres were used as microreactors and carriers for constructing CaO 2 core-mesoporous shell-CaO 2 shell microspheres (OCRMs). The CaO 2 shells could quickly increase dissolved oxygen to extremely anaerobic water in the initial 40 min until the CaO 2 shells were consumed. The mesoporous shells continued to act as regulators restricting the release of oxygen from CaO 2 cores. The oxygen-release time using OCRMs was 7 times longer than when directly using CaO 2 . More interestingly, OCRMs presented a high phosphate removal efficiency (95.6%) and prevented the pH of the solution from rising to high levels in comparison with directly adding CaO 2 due to the OH - controlled-release effect of OCRMs. The distinct core-double-shell micro/nanostructure endowed the OCRMs with triple functions for oxygen controlled-release, phosphorus removal and less impact on water pH. The study is to explore the possibility to prepare smarter bio-hydrochar materials by utilizing algal blooms.

  11. U3O8 microspheres sintering kinetics

    International Nuclear Information System (INIS)

    Godoy, A.L.E.

    1986-01-01

    U 3 O 8 microspheres sintering kinetics was determined using a hot-stage optical microscopy apparatus, able to reach temperature up to 1350 0 C in controlled atmospheres. The sintered material had its microstructure analysed by optical and electron microscopy. The microspheres were characterized initialy utilizing X-ray diffractometry and thermogravimetry. The equation which describes the microspheres shrinkage in function of the time was obtained using finite difference analysis X-ray diffractometry indicated hexagonal structure for the microspheres main starting material, ammonium diuranate thermogravimetric analysis showed reduction of this material to U 3 O 8 at 600 0 C. Ceramography results showed 5 hours sintered microspheres grain sizes G vary with the temperature. Sintered U 3 O 8 micrographs compared with published results for UO 2 , indicate similar homogeneity microstructural characteristics and suggest the processed micorspheres to be potentially useful as nuclear fuels. (Author) [pt

  12. Magnetic susceptibility characterisation of superparamagnetic microspheres

    Science.gov (United States)

    Grob, David Tim; Wise, Naomi; Oduwole, Olayinka; Sheard, Steve

    2018-04-01

    The separation of magnetic materials in microsystems using magnetophoresis has increased in popularity. The wide variety and availability of magnetic beads has fuelled this drive. It is important to know the magnetic characteristics of the microspheres in order to accurately use them in separation processes integrated on a lab-on-a-chip device. To investigate the magnetic susceptibility of magnetic microspheres, the magnetic responsiveness of three types of Dynabeads microspheres were tested using two different approaches. The magnetophoretic mobility of individual microspheres is studied using a particle tracking system and the magnetization of each type of Dynabeads microsphere is measured using SQUID relaxometry. The magnetic beads' susceptibility is obtained at four different applied magnetic fields in the range of 38-70 mT for both the mobility and SQUID measurements. The susceptibility values in both approaches show a consistent magnetic field dependence.

  13. A new approach for crystallization of copper(ii) oxide hollow nanostructures with superior catalytic and magnetic response

    Science.gov (United States)

    Singh, Inderjeet; Landfester, Katharina; Chandra, Amreesh; Muñoz-Espí, Rafael

    2015-11-01

    We report the synthesis of copper(ii) oxide hollow nanostructures at ambient pressure and close to room temperature by applying the soft templating effect provided by the confinement of droplets in miniemulsion systems. Particle growth can be explained by considering a mechanism that involves both diffusion and reaction control. The catalytic reduction of p-nitrophenol in aqueous media is used as a model reaction to prove the catalytic activity of the materials: the synthesized hollow structures show nearly 100 times higher rate constants than solid CuO microspheres. The kinetic behavior and the order of the reduction reaction change due to the increase of the surface area of the hollow structures. The synthesis also leads to modification of physical properties such as magnetism.We report the synthesis of copper(ii) oxide hollow nanostructures at ambient pressure and close to room temperature by applying the soft templating effect provided by the confinement of droplets in miniemulsion systems. Particle growth can be explained by considering a mechanism that involves both diffusion and reaction control. The catalytic reduction of p-nitrophenol in aqueous media is used as a model reaction to prove the catalytic activity of the materials: the synthesized hollow structures show nearly 100 times higher rate constants than solid CuO microspheres. The kinetic behavior and the order of the reduction reaction change due to the increase of the surface area of the hollow structures. The synthesis also leads to modification of physical properties such as magnetism. Electronic supplementary information (ESI) available: Associated structural and morphological analysis, XPS characterization, BET surface area, catalytic measurements, recycle tests of the catalyst, and magnetic characterizations. See DOI: 10.1039/c5nr05579b

  14. Tensile Strength of GFRP Reinforcing Bars with Hollow Section

    Directory of Open Access Journals (Sweden)

    Young-Jun You

    2015-01-01

    Full Text Available Fiber reinforced polymer (FRP has been proposed to replace steel as a reinforcing bar (rebar due to its high tensile strength and noncorrosive material properties. One obstacle in using FRP rebars is high price. Generally FRP is more expensive than conventional steel rebar. There are mainly two ways to reduce the cost. For example, one is making the price of each composition cost of FRP rebar (e.g., fibers, resin, etc. lower than steel rebar. Another is making an optimized design for cross section and reducing the material cost. The former approach is not easy because the steel price is very low in comparison with component materials of FRP. For the latter approach, the cost could be cut down by reducing the material cost. Therefore, an idea of making hollow section over the cross section of FRP rebar was proposed in this study by optimizing the cross section design with acceptable tensile performance in comparison with steel rebar. In this study, glass reinforced polymer (GFRP rebars with hollow section and 19 mm of outer diameter were manufactured and tested to evaluate the tensile performance in accordance with the hollowness ratio. From the test results, it was observed that the tensile strength decreased almost linearly with increase of hollowness ratio and the elastic modulus decreased nonlinearly.

  15. SU-8 hollow cantilevers for AFM cell adhesion studies

    Science.gov (United States)

    Martinez, Vincent; Behr, Pascal; Drechsler, Ute; Polesel-Maris, Jérôme; Potthoff, Eva; Vörös, Janos; Zambelli, Tomaso

    2016-05-01

    A novel fabrication method was established to produce flexible, transparent, and robust tipless hollow atomic force microscopy (AFM) cantilevers made entirely from SU-8. Channels of 3 μm thickness and several millimeters length were integrated into 12 μm thick and 40 μm wide cantilevers. Connected to a pressure controller, the devices showed high sealing performance with no leakage up to 6 bars. Changing the cantilever lengths from 100 μm to 500 μm among the same wafer allowed the targeting of various spring constants ranging from 0.5 to 80 N m-1 within a single fabrication run. These hollow polymeric AFM cantilevers were operated in the optical beam deflection configuration. To demonstrate the performance of the device, single-cell force spectroscopy experiments were performed with a single probe detaching in a serial protocol more than 100 Saccharomyces cerevisiae yeast cells from plain glass and glass coated with polydopamine while measuring adhesion forces in the sub-nanoNewton range. SU-8 now offers a new alternative to conventional silicon-based hollow cantilevers with more flexibility in terms of complex geometric design and surface chemistry modification.

  16. SU-8 hollow cantilevers for AFM cell adhesion studies

    International Nuclear Information System (INIS)

    Martinez, Vincent; Behr, Pascal; Vörös, Janos; Zambelli, Tomaso; Drechsler, Ute; Polesel-Maris, Jérôme; Potthoff, Eva

    2016-01-01

    A novel fabrication method was established to produce flexible, transparent, and robust tipless hollow atomic force microscopy (AFM) cantilevers made entirely from SU-8. Channels of 3 μm thickness and several millimeters length were integrated into 12 μm thick and 40 μm wide cantilevers. Connected to a pressure controller, the devices showed high sealing performance with no leakage up to 6 bars. Changing the cantilever lengths from 100 μm to 500 μm among the same wafer allowed the targeting of various spring constants ranging from 0.5 to 80 N m −1 within a single fabrication run. These hollow polymeric AFM cantilevers were operated in the optical beam deflection configuration. To demonstrate the performance of the device, single-cell force spectroscopy experiments were performed with a single probe detaching in a serial protocol more than 100 Saccharomyces cerevisiae yeast cells from plain glass and glass coated with polydopamine while measuring adhesion forces in the sub-nanoNewton range. SU-8 now offers a new alternative to conventional silicon-based hollow cantilevers with more flexibility in terms of complex geometric design and surface chemistry modification. (paper)

  17. Biomineralized multifunctional magnetite/carbon microspheres for applications in Li-ion batteries and water treatment.

    Science.gov (United States)

    Shim, Hyun-Woo; Park, Sangbaek; Song, Hee Jo; Kim, Jae-Chan; Jang, Eunjin; Hong, Kug Sun; Kim, T Doohun; Kim, Dong-Wan

    2015-03-16

    Advanced functional materials incorporating well-defined multiscale architectures are a key focus for multiple nanotechnological applications. However, strategies for developing such materials, including nanostructuring, nano-/microcombination, hybridization, and so on, are still being developed. Here, we report a facile, scalable biomineralization process in which Micrococcus lylae bacteria are used as soft templates to synthesize 3D hierarchically structured magnetite (Fe3O4) microspheres for use as Li-ion battery anode materials and in water treatment applications. Self-assembled Fe3O4 microspheres with flower-like morphologies are systematically fabricated from biomineralized 2D FeO(OH) nanoflakes at room temperature and are subsequently subjected to post-annealing at 400 °C. In particular, because of their mesoporous properties with a hollow interior and the improved electrical conductivity resulting from the carbonized bacterial templates, the Fe3 O4 microspheres obtained by calcining the FeO(OH) in Ar exhibit enhanced cycle stability and rate capability as Li-ion battery anodes, as well as superior adsorption of organic pollutants and toxic heavy metals. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  18. Study of the spheronization process of glass particles by the gravitational falling process for internal selective radiotherapy

    International Nuclear Information System (INIS)

    Barros Filho, E.C.; Martinelli, J.R.; Sene, F.F.

    2011-01-01

    The internal selective radiotherapy is an alternative to treat hepatocellular carcinoma. Glass microspheres containing β - emitter radionuclide are introduced in the liver, and they are housed preferentially in the region where the cancer cells are located. The microspheres are trapped in the arterioles which feed the tumors, and the β - particles annihilate the cancer cells. The glass particles must be spherical to avoid unnecessary bleeding, and the particle size must be restricted to a range which optimizes the blocking effect and avoid the migration to other parts of the human body. The particle size distribution of microspheres is not easily predicted since the variation of the aspect ratio and the presence of agglomerates can influence the resulting particle size distribution. In the present work, the spheronization process to obtain microspheres from irregular shape glass particles with suitable diameter and shape for radiotherapy treatment is studied. (author)

  19. Influence of dielectric polarization upon PD transients: Use of hollow dielectric spheres

    DEFF Research Database (Denmark)

    McAllister, Iain Wilson

    1997-01-01

    Hollow glass spheres have recently been employed to provide a reproducible source of partial discharges. The influence of the shell permittivity upon the PD transients is examined. It is shown that, relative to the non-shell situation, the magnitude of such transients may be increased or decrease......, depending on the ratio of the shell-to-bulk dielectric permittivities....

  20. The Effect of Mandrel Configuration on the Warpage in Pultrusion of Rectangular Hollow Profiles

    NARCIS (Netherlands)

    Baran, Ismet; Hattel, Jesper H.; Akkerman, Remko

    2014-01-01

    Thermo-mechanical process simulation of an industrially pultruded rectangular hollow profile is presented. Glass/polyester is used for the continuous filament mat (CFM) and the uni-directional (UD) layers. The process induced residual distortions together with the temperature and degree of cure are

  1. Yttrium 90 microspheres for the treatment of hepatocellular carcinoma.

    Science.gov (United States)

    Memon, Khairuddin; Lewandowski, Robert J; Riaz, Ahsun; Salem, Riad

    2013-01-01

    Yttrium-90 microspheres are radioactive particles which are increasingly being employed for treating patients with unresectable hepatocellular carcinoma (HCC). The procedure is called radioembolization. It involves the injection of micron-sized embolic particles loaded with a radioisotope by use of transarterial techniques. Because of the sensitivity of liver parenchyma and relative insensitivity of tumor, external radiation has played a limited role in treating HCC. (90)Y administered via arterial route directs the highly concentrated radiation to the tumor while healthy liver parenchyma is relatively spared due to its preferential blood supply from portal venous blood. This technique has proven useful for the majority of patients with HCC as most of them present in advanced stage, beyond potentially curative options (resection/liver transplantation). (90)Y microspheres can be used in downstaging large tumors to bring within transplantable criteria, in patients with portal venous thrombosis due to tumor invasion and as palliative therapy. There are two available devices for (90)Y administration; TheraSphere® (glass based) and SIR-Spheres® (resin based). The procedure is performed on an outpatient basis. The incidence of complications is comparatively less and may include nausea, fatigue, abdominal pain, hepatic dysfunction, biliary injury, fibrosis, radiation pneumonitis, GI ulcers, and vascular injury; however, these can be avoided by meticulous pretreatment assessment, careful patient selection, and adequate dosimetry. This article explores the technical and clinical aspects of (90)Y radioembolization with keeping emphasis on patient selection, uses, and complications.

  2. The production of lithium oxide microspheres from the disintegration of a liquid jet

    International Nuclear Information System (INIS)

    Al-Ubaidi, M.R.; Anno, J.N.

    1989-01-01

    Microspheres of lithium hydroxide (LiOH) were produced from in-flight solidification of droplets formed by the disintegration of an acoustically driven, mechanically vibrated cylindrical liquid jet of molten LiOH. The molten material at 470 to 480 degrees C was fed through a 25-gauge (0.0267-cm bore diameter) nozzle, interiorly electroplated with silver, under ∼27.6-kPa (4-psig) pressure, and at a mechanical vibration frequency of 10 Hz. The resulting jet issued into a 5.5-cm-diam vertical glass drop tube entraining a 94.5 cm 3 /s (12 ft 3 /h) argon gas stream at 75 degrees C. The 100-cm-long drop tube was sufficient to allow the droplets of molten LiOH resulting from jet disintegration to solidify in-flight without catastrophic thermal shock, being then collected a solid microspheres. These LiOH microspheres were then vacuum processed to lithium oxide (Li 2 O). Preliminary experiments resulted in microspheres with diameters varying from 120 to 185 μm, but with evidence of impurity contamination occurring during the initial stages of the process

  3. Increasing sensitivity and angle-of-view of mid-wave infrared detectors by integration with dielectric microspheres

    Energy Technology Data Exchange (ETDEWEB)

    Allen, Kenneth W., E-mail: kenneth.allen@gtri.gatech.edu; Astratov, Vasily N., E-mail: astratov@uncc.edu [Department of Physics and Optical Science, Center for Optoelectronics and Optical Communications, University of North Carolina at Charlotte, Charlotte, North Carolina 28223-0001 (United States); Air Force Research Laboratory, Sensors Directorate, Wright Patterson AFB, Ohio 45433 (United States); UES, Dayton, Ohio 45433 (United States); Abolmaali, Farzaneh [Department of Physics and Optical Science, Center for Optoelectronics and Optical Communications, University of North Carolina at Charlotte, Charlotte, North Carolina 28223-0001 (United States); Duran, Joshua M.; Ariyawansa, Gamini; Limberopoulos, Nicholaos I. [Air Force Research Laboratory, Sensors Directorate, Wright Patterson AFB, Ohio 45433 (United States); Urbas, Augustine M. [Air Force Research Laboratory, Materials and Manufacturing Directorate, Wright-Patterson AFB, Ohio 45433 (United States)

    2016-06-13

    We observed up to 100 times enhancement of sensitivity of mid-wave infrared photodetectors in the 2–5 μm range by using photonic jets produced by sapphire, polystyrene, and soda-lime glass microspheres with diameters in the 90–300 μm range. By finite-difference time-domain (FDTD) method for modeling, we gain insight into the role of the microspheres refractive index, size, and alignment with respect to the detector mesa. A combination of enhanced sensitivity with angle-of-view (AOV) up to 20° is demonstrated for individual photodetectors. It is proposed that integration with microspheres can be scaled up for large focal plane arrays, which should provide maximal light collection efficiencies with wide AOVs, a combination of properties highly attractive for imaging applications.

  4. Progress in Preparation of Monodisperse Polymer Microspheres

    Science.gov (United States)

    Zhang, Hongyan

    2017-12-01

    The monodisperse crosslinked polymer microspheres have attracted much attention because of their superior thermal and solvent resistance, mechanical strength, surface activity and adsorption properties. They are of wide prospects for using in many fields such as biomedicine, electronic science, information technology, analytical chemistry, standard measurement and environment protection etc. Functional polymer microspheres prepared by different methods have the outstanding surface property, quantum size effect and good potential future in applications with its designable structure, controlled size and large ratio of surface to volume. Scholars of all over the world have focused on this hot topic. The preparation method and research progress in functional polymer microspheres are addressed in the paper.

  5. Switching a Nanocluster Core from Hollow to Non-hollow

    KAUST Repository

    Bootharaju, Megalamane Siddaramappa

    2016-03-24

    Modulating the structure-property relationship in atomically precise nanoclusters (NCs) is vital for developing novel NC materials and advancing their applications. While promising biphasic ligand-exchange (LE) strategies have been developed primarily to attain novel NCs, understanding the mechanistic aspects involved in tuning the core and the ligand-shell of NCs in such biphasic processes is challenging. Here, we design a single phase LE process that enabled us to elucidate the mechanism of how a hollow NC (e.g., [Ag44(SR)30]4-, -SR: thiolate) converts into a non-hollow NC (e.g., [Ag25(SR)18]-), and vice versa. Our study reveals that the complete LE of the hollow [Ag44(SPhF)30]4- NCs (–SPhF: 4-fluorobenzenethiolate) with incoming 2,4-dimethylbenzenethiol (HSPhMe2) induced distortions in the Ag44 structure forming the non-hollow [Ag25(SPhMe2)18]- by a disproportionation mechanism. While the reverse reaction of [Ag25(SPhMe2)18]- with HSPhF prompted an unusual dimerization of Ag25, followed by a rearrangement step that reproduces the original [Ag44(SPhF)30]4-. Remarkably, both the forward and the backward reactions proceed through similar size intermediates that seem to be governed by the boundary conditions set by the thermodynamic and electronic stability of the hollow and non-hollow metal cores. Furthermore, the resizing of NCs highlights the surprisingly long-range effect of the ligands which are felt by atoms far deep in the metal core, thus opening a new path for controlling the structural evolution of nanoparticles.

  6. The Electrospun Ceramic Hollow Nanofibers

    Directory of Open Access Journals (Sweden)

    Shahin Homaeigohar

    2017-11-01

    Full Text Available Hollow nanofibers are largely gaining interest from the scientific community for diverse applications in the fields of sensing, energy, health, and environment. The main reasons are: their extensive surface area that increases the possibilities of engineering, their larger accessible active area, their porosity, and their sensitivity. In particular, semiconductor ceramic hollow nanofibers show greater space charge modulation depth, higher electronic transport properties, and shorter ion or electron diffusion length (e.g., for an enhanced charging–discharging rate. In this review, we discuss and introduce the latest developments of ceramic hollow nanofiber materials in terms of synthesis approaches. Particularly, electrospinning derivatives will be highlighted. The electrospun ceramic hollow nanofibers will be reviewed with respect to their most widely studied components, i.e., metal oxides. These nanostructures have been mainly suggested for energy and environmental remediation. Despite the various advantages of such one dimensional (1D nanostructures, their fabrication strategies need to be improved to increase their practical use. The domain of nanofabrication is still advancing, and its predictable shortcomings and bottlenecks must be identified and addressed. Inconsistency of the hollow nanostructure with regard to their composition and dimensions could be one of such challenges. Moreover, their poor scalability hinders their wide applicability for commercialization and industrial use.

  7. Glass sealing

    Energy Technology Data Exchange (ETDEWEB)

    Brow, R.K.; Kovacic, L.; Chambers, R.S. [Sandia National Labs., Albuquerque, NM (United States)

    1996-04-01

    Hernetic glass sealing technologies developed for weapons component applications can be utilized for the design and manufacture of fuel cells. Design and processing of of a seal are optimized through an integrated approach based on glass composition research, finite element analysis, and sealing process definition. Glass sealing procedures are selected to accommodate the limits imposed by glass composition and predicted calculations.

  8. Electrochromic Glasses.

    Science.gov (United States)

    1980-07-31

    this glass and that dipole-dipole correlations contribute to the "ferroelectric-like" character of this amorphous system. The TeO2 -W03 glasses can only...shows the dielectric constant and Fig. I(b) glass from pure TeO2 ot pure WO. In addition, glass the tan 8 of the WO glass as a function of temperature... glasses containing WO, in various glass forming nitworks of LifO-B1O0, Na:O-BzO,, and TeO2 were prepared from reagent grade oxides at 800 C - 9SO C in

  9. Targeting of liver tumour in rats by selective delivery of holmium-166 loaded microspheres: a biodistribution study

    Energy Technology Data Exchange (ETDEWEB)

    Nijsen, F.; Rook, D.; Zonnenberg, B.; Klerk, J. de; Rijk, P. van; Schip, F. van het [Dept. of Nuclear Medicine, University Medical Center, Utrecht (Netherlands); Brandt, C. [Animal Inst., Utrecht Univ. (Netherlands); Meijer, R. [Dept. of Radiology, Univ. Medical Center, Utrecht (Netherlands); Dullens, H. [Dept. of Pathology, Univ. Medical Center, Utrecht (Netherlands); Hennink, W. [Dept. of Pharmaceutics, Utrecht Univ. (Netherlands)

    2001-06-01

    Intra-arterial administration of beta-emitting particles that become trapped in the vascular bed of a tumour and remain there while delivering high doses, represents a unique approach in the treatment of both primary and metastatic liver tumours. Studies on selective internal radiation therapy of colorectal liver metastases using yttrium-90 glass microspheres have shown encouraging results. This study describes the biodistribution of 40-{mu}m poly lactic acid microspheres loaded with radioactive holmium-166, after intra-arterial administration into the hepatic artery of rats with implanted liver tumours. Radioactivity measurements showed >95% retention of injected activity in the liver and its resident tumour. The average activity detected in other tissues was {<=}0.1%ID/g, with incidental exceptions in the lungs and stomach. Very little {sup 166}Ho activity was detected in kidneys (<0.1%ID/g), thereby indicating the stability of the microspheres in vivo. Tumour targeting was very effective, with a mean tumour to liver ratio of 6.1{+-}2.9 for rats with tumour (n=15) versus 0.7{+-}0.5 for control rats (n=6; P<0.001). These ratios were not significantly affected by the use of adrenaline. Histological analysis showed that five times as many large (>10) and medium-sized (4-9) clusters of microspheres were present within tumour and peritumoural tissue, compared with normal liver. Single microspheres were equally dispersed throughout the tumour, as well as normal liver parenchyma. (orig.)

  10. Evaluation of Controlled Release Theophylline Microspheres ...

    African Journals Online (AJOL)

    Erah

    High drug/polymer ratio, low processing temperature and low HLB value of ... Keywords: Microsphere, Emulsion solvent evaporation, Theophylline, Temperature, ... evaporation, stirring rate, viscosity of ... organic solvent is removed from the.

  11. The Riddle of the Apparently Hollow Himalaya

    Indian Academy of Sciences (India)

    The Riddle of the Apparently Hollow Himalaya. Ramesh .... It was as if the Himalayas were hollow inside. ... block would be consistent with the ground elevation in such a ... Alternative models and possible preference: Many refinements of.

  12. Protective amorphous carbon coatings on glass substrates

    Science.gov (United States)

    Silins, Kaspars; Baránková, Hana; Bardos, Ladislav

    2017-11-01

    Thick amorphous carbon films were deposited by the Magnets-in-Motion (M-M) rf linear hollow cathode at varying acetylene contents in Ar in a hybrid PVD/PE-CVD process directly on glass substrates. The hollow cathode plates manufactured from graphite were used as the PVD target. The measurements show that the films can reach thickness of up to 50 μm at deposition rates of up to 2.5 μm/min. Scratch test measurements confirm that well adhering films several μm thick can be achieved at C2H2 contents of up to 0.5%.

  13. Hollow nanotubular toroidal polymer microrings.

    Science.gov (United States)

    Lee, Jiyeong; Baek, Kangkyun; Kim, Myungjin; Yun, Gyeongwon; Ko, Young Ho; Lee, Nam-Suk; Hwang, Ilha; Kim, Jeehong; Natarajan, Ramalingam; Park, Chan Gyung; Sung, Wokyung; Kim, Kimoon

    2014-02-01

    Despite the remarkable progress made in the self-assembly of nano- and microscale architectures with well-defined sizes and shapes, a self-organization-based synthesis of hollow toroids has, so far, proved to be elusive. Here, we report the synthesis of polymer microrings made from rectangular, flat and rigid-core monomers with anisotropically predisposed alkene groups, which are crosslinked with each other by dithiol linkers using thiol-ene photopolymerization. The resulting hollow toroidal structures are shape-persistent and mechanically robust in solution. In addition, their size can be tuned by controlling the initial monomer concentrations, an observation that is supported by a theoretical analysis. These hollow microrings can encapsulate guest molecules in the intratoroidal nanospace, and their peripheries can act as templates for circular arrays of metal nanoparticles.

  14. Immobilisation of radwastes in glass containers and products formed thereby

    International Nuclear Information System (INIS)

    Macedo, P.B.; Simmons, C.J.; Lagakos, N.; Simmons, J.H.; Tran, D.C.

    1980-01-01

    A method of preventing the dissemination of toxic material to the environment comprises forming an admixture of toxic material and glass packing in a hollow doped glass container of high silica content, or forming the admixture in a first container and then depositing at least a portion of the admixture in a hollow doped glass container of high silica content. The glass container is then heated to collapse its walls and to seal the container so that the toxic material is entrapped and sealed within the collapsed doped glass container. The thermal expansion coefficient of the container may be decreased prior to use by exchanging hydrogen ion in pores thereof with other cations followed by collapsing the pores. (author)

  15. Hollow fiber liquid supported membranes

    International Nuclear Information System (INIS)

    Violante, V.

    1987-01-01

    The hollow fiber system are well known and developed in the scientific literature because of their applicability in the process separation units. The authors approach to a mathematical model for a particular hollow fiber system, usin liquid membranes. The model has been developed in order to obtain a suitable tool for a sensitivy analysis and for a scaling-up. This kind of investigation is very usefull from an engineering point of view, to get a spread range of information to build up a pilot plant from the laboratory scale

  16. Yttrium-90 resin microspheres and their use in the treatment of intrahepatic cholangiocarcinoma.

    Science.gov (United States)

    Filippi, Luca; Schillaci, Orazio; Cianni, Roberto; Bagni, Oreste

    2018-04-01

    Intrahepatic cholangiocarcinoma (ICC) is a severe and rapidly progressive hepatic tumor. Surgery is often impracticable due to locally advanced presentation. On the other hand, chemotherapy has demonstrated only limited effectiveness. For these reasons, liver-directed therapies have been successfully applied for treating ICC. In particular, radioembolization with Yttrium-90 ( 90 Y)-labeled spheres has been reported to be a promising therapeutic approach for this neoplasia. Two commercial forms of 90 Y-labeled spheres are available: glass (TheraSphere ® ) and resin (SIR-Spheres ® ) microspheres. The aim of the present paper is to review the existing literature on the use of the resin microspheres for the treatment of unresectable and chemorefractory ICC, focusing on the methodology, clinical applications and side effects.

  17. PLGA/alginate composite microspheres for hydrophilic protein delivery

    International Nuclear Information System (INIS)

    Zhai, Peng; Chen, X.B.; Schreyer, David J.

    2015-01-01

    Poly(lactic-co-glycolic acid) (PLGA) microspheres and PLGA/alginate composite microspheres were prepared by a novel double emulsion and solvent evaporation technique and loaded with bovine serum albumin (BSA) or rabbit anti-laminin antibody protein. The addition of alginate and the use of a surfactant during microsphere preparation increased the encapsulation efficiency and reduced the initial burst release of hydrophilic BSA. Confocal laser scanning microcopy (CLSM) of BSA-loaded PLGA/alginate composite microspheres showed that PLGA, alginate, and BSA were distributed throughout the depths of microspheres; no core/shell structure was observed. Scanning electron microscopy revealed that PLGA microspheres erode and degrade more quickly than PLGA/alginate composite microspheres. When loaded with anti-laminin antibody, the function of released antibody was well preserved in both PLGA and PLGA/alginate composite microspheres. The biocompatibility of PLGA and PLGA/alginate microspheres were examined using four types of cultured cell lines, representing different tissue types. Cell survival was variably affected by the inclusion of alginate in composite microspheres, possibly due to the sensitivity of different cell types to excess calcium that may be released from the calcium cross-linked alginate. - Highlights: • A double emulsion technique is used to prepare protein-loaded PLGA or PLGA/alginate microspheres. • PLGA, alginate and protein are distributed evenly within microsphere structure. • Addition of alginate improves loading efficiency and slows degradation and protein release. • PLGA/alginate microspheres have favorable biocompatibility

  18. PLGA/alginate composite microspheres for hydrophilic protein delivery

    Energy Technology Data Exchange (ETDEWEB)

    Zhai, Peng [Department of Anatomy and Cell Biology, University of Saskatchewan, S7N5E5 (Canada); Division of Biomedical Engineering, University of Saskatchewan, S7N5A9 (Canada); Chen, X.B. [Department of Mechanical Engineering, University of Saskatchewan, S7N5A9 (Canada); Division of Biomedical Engineering, University of Saskatchewan, S7N5A9 (Canada); Schreyer, David J., E-mail: david.schreyer@usask.ca [Department of Anatomy and Cell Biology, University of Saskatchewan, S7N5E5 (Canada); Division of Biomedical Engineering, University of Saskatchewan, S7N5A9 (Canada)

    2015-11-01

    Poly(lactic-co-glycolic acid) (PLGA) microspheres and PLGA/alginate composite microspheres were prepared by a novel double emulsion and solvent evaporation technique and loaded with bovine serum albumin (BSA) or rabbit anti-laminin antibody protein. The addition of alginate and the use of a surfactant during microsphere preparation increased the encapsulation efficiency and reduced the initial burst release of hydrophilic BSA. Confocal laser scanning microcopy (CLSM) of BSA-loaded PLGA/alginate composite microspheres showed that PLGA, alginate, and BSA were distributed throughout the depths of microspheres; no core/shell structure was observed. Scanning electron microscopy revealed that PLGA microspheres erode and degrade more quickly than PLGA/alginate composite microspheres. When loaded with anti-laminin antibody, the function of released antibody was well preserved in both PLGA and PLGA/alginate composite microspheres. The biocompatibility of PLGA and PLGA/alginate microspheres were examined using four types of cultured cell lines, representing different tissue types. Cell survival was variably affected by the inclusion of alginate in composite microspheres, possibly due to the sensitivity of different cell types to excess calcium that may be released from the calcium cross-linked alginate. - Highlights: • A double emulsion technique is used to prepare protein-loaded PLGA or PLGA/alginate microspheres. • PLGA, alginate and protein are distributed evenly within microsphere structure. • Addition of alginate improves loading efficiency and slows degradation and protein release. • PLGA/alginate microspheres have favorable biocompatibility.

  19. Dysprosium lithium borate glass mircrospheres for radiation synovectomy: The in vitro and in vivo performance evaluation

    Energy Technology Data Exchange (ETDEWEB)

    Zhao Di; Yu Jing [Institute of Bioengineering and Information Technology Materials, Center for Advanced Materials and Nano-Biomedicine, Tongji University, Shanghai, 200092 (China); Huang Wenhai, E-mail: whhuang@tongji.edu.cn [Institute of Bioengineering and Information Technology Materials, Center for Advanced Materials and Nano-Biomedicine, Tongji University, Shanghai, 200092 (China); Zhou Nai; Wang Deping [Institute of Bioengineering and Information Technology Materials, Center for Advanced Materials and Nano-Biomedicine, Tongji University, Shanghai, 200092 (China); Yin Wei [Institute of Isotope Research, Sinitic Academy of Atomic Energy, Beijing 102413 (China); Chen Yaqing [The Sixth People' s Hospital, Shanghai 200233 (China)

    2010-08-30

    The radioactive dysprosium lithium borate glass (DyLB) microspheres with different glass compositions were prepared for radiation synovectomy. The biodegradability and biocompatibility of these DyLB microspheres were evaluated in vitro and in vivo. The DyLB microspheres studied in this work were partially biodegradable in a simulated body fluid (SBF), with the final weight loss of the microspheres in the range of 24.6% and 55.0% (wt.%) after 8 days of immersion. The ICP results revealed that the dissolution of lithium significantly decreased from 100% to 53.7% with increasing content of Dy{sub 2}O{sub 3} in the microspheres from 18% to 22% (wt.%, from S-1 to S-3). However, for all of the three samples, nearly all of the dysprosium (> 99.997%, wt.%) remained in the microspheres, in the form of insoluble phosphates and carbonates, which was proved by the SEM and EDX analyses. The degradation of DyLB microspheres in SBF gradually decreased with immersion time and eventually reached equilibrium after 7 days of immersion. Compared to the other two samples, the S-3 sample with the lowest Dy{sup 3+} dissolution (about 0.002%) was considered more secure for clinical application. Furthermore, the S-3 DyLB microspheres exhibited good biocompatibility, since neither tissue damage nor inflammation was observed, after they were implanted in the liver of rat for two weeks. After neutron activation, the radionuclide purity of radioactive S-3 DyLB microspheres was 99.999%, which were suitable for radiation synovectomy.

  20. Natural Rosin-based Phosphate Diester Surfactant Assisted One-step Synthesis of 3D Flowerlikeβ-Ni(OH)2/γ-Ni(OH)2 Composite Nano-microspheres

    Institute of Scientific and Technical Information of China (English)

    BoShi Wu; Juan Li; ChunRui Han; Feng Xu

    2018-01-01

    Self-assembled uniform 3Dflowerlikeβ-Ni(OH)2/g-Ni(OH)2composite nano-microspheres with hollow interiors were successfully synthesized via a facile aqueous-ethanol mixed solvothermal method, using nickel sulfate as a precursor, urea as a precipitant, and dehydroabietic based phosphate diester sodium (DDPDS) as a surfactant. The prepared 3D flowerlikeβ-Ni(OH)2/g-Ni(OH)2composite nano-microspheres were tested as supercapacitors in a two-electrode cell with 6 mol/L KOH electrolyte. In addition, the influence of DDPDS concentration on the morphology and size of 3Dflowerlikeβ-Ni(OH)2/g-Ni(OH)2composite nano-microspheres was studied at 180℃. X-ray diffraction (XRD), scanning electron microscopy (SEM), BET(Brunauer, Emmett and Teller)techniques, and equity default swap (EDS) were used to characterize the structure, morphology, and size of the as-prepared samples. Moreover, a possible formation mechanism of the 3Dflowerlikeβ-Ni(OH)2/g-Ni(OH)2composite nano-microspheres was proposed based on the effects of DDPDS concentrationand reaction time. The surfactant micelles were used as soft templates to induce the self-assembly of nanosheets. The crystallinity of the 3D flowerlikeβ-Ni(OH)2/g-Ni(OH)2composite nano-microspheres improved with the increase of DDPDS concentration, and the morphology and size of synthetic nano-microspheres could be controlled.

  1. Active self-healing encapsulation of vaccine antigens in PLGA microspheres

    Science.gov (United States)

    Desai, Kashappa-Goud H.; Schwendeman, Steven P.

    2013-01-01

    Herein, we describe the detailed development of a simple and effective method to microencapsulate vaccine antigens in poly(lactic-co-glycolic acid) (PLGA) by simple mixing of preformed active self-microencapsulating (SM) PLGA microspheres in a low concentration aqueous antigen solution at modest temperature (10-38 °C). Co-encapsulating protein-sorbing vaccine adjuvants and polymer plasticizers were used to “actively” load the protein in the polymer pores and facilitate polymer self-healing at temperature > hydrated polymer glass transition temperature, respectively. The microsphere formulation parameters and loading conditions to provide optimal active self-healing microencapsulation of vaccine antigen in PLGA was investigated. Active self-healing encapsulation of two vaccine antigens, ovalbumin and tetanus toxoid (TT), in PLGA microspheres was adjusted by preparing blank microspheres containing different vaccine adjuvant (aluminum hydroxide (Al(OH)3) or calcium phosphate). Active loading of vaccine antigen in Al(OH)3-PLGA microspheres was found to: a) increase proportionally with an increasing loading of Al(OH)3 (0.88-3 wt%) and addition of porosigen, b) decrease when the inner Al(OH)3/trehalose phase to 1 mL outer oil phase and size of microspheres was respectively > 0.2 mL and 63 μm, and c) change negligibly by PLGA concentration and initial incubation (loading) temperature. Encapsulation of protein sorbing Al(OH)3 in PLGA microspheres resulted in suppression of self-healing of PLGA pores, which was then overcome by improving polymer chain mobility, which in turn was accomplished by coincorporating hydrophobic plasticizers in PLGA. Active self-healing microencapsulation of manufacturing process-labile TT in PLGA was found to: a) obviate micronization- and organic solvent-induced TT degradation, b) improve antigen loading (1.4-1.8 wt% TT) and encapsulation efficiency (~ 97%), c) provide nearly homogeneous distribution and stabilization of antigen in polymer

  2. DEGRADATION AND INTRAHEPATIC COMPATIBILITY OF ALBUMIN-HEPARIN CONJUGATE MICROSPHERES

    NARCIS (Netherlands)

    CREMERS, HFM; WOLF, RFE; BLAAUW, EH; SCHAKENRAAD, JM; LAM, KH; NIEUWENHUIS, P; VERRIJK, R; KWON, G; BAE, YH; KIM, SW; FEIJEN, J

    The in vitro degradation properties of glutaraldehyde cross-linked albumin and albumin-heparin conjugate microspheres (AMS and AHCMS respectively) were evaluated using light microscopy, turbidity measurements and heparin release determinations, showing that the microspheres are degraded by

  3. Hollow waveguide cavity ringdown spectroscopy

    Science.gov (United States)

    Dreyer, Chris (Inventor); Mungas, Greg S. (Inventor)

    2012-01-01

    Laser light is confined in a hollow waveguide between two highly reflective mirrors. This waveguide cavity is used to conduct Cavity Ringdown Absorption Spectroscopy of loss mechanisms in the cavity including absorption or scattering by gases, liquid, solids, and/or optical elements.

  4. Hollow core plasma channel generation

    International Nuclear Information System (INIS)

    Quast, Heinrich Martin

    2018-03-01

    The use of a hollow plasma channel in plasma-based acceleration has beneficial properties for the acceleration of electron and positron bunches. In the scope of the FLASHForward facility at DESY, the generation of such a plasma structure is examined. Therefore, the generation of a ring-shaped laser intensity profile with different techniques is analyzed. From the obtained intensity profiles the electron density of a hollow plasma channel is simulated in the focal region. Different parameters are scanned to understand their influence on the electron density distribution - an important parameter being, for example, the radius of the central region of the channel. In addition to the simulations, experiments are presented, during which a laser pulse is transformed into a hollow beam with a spiral phase plate. Subsequently, it forms a plasma during the interaction with hydrogen, where the plasma is imaged with interferometry. For energies above 0.9 mJ a hollow plasma structure can be observed at the location of first plasma formation.

  5. The Legend of Sleepy Hollow

    Institute of Scientific and Technical Information of China (English)

    Washington; Irving

    1987-01-01

    Part Ⅰ On the Eastern shore of the Hudson River there was a little valley, among high hills, which was one of the quietest places in the whole world. This little valley had long been known by the name of SIeepy Hollow. Many strange stories about ghosts were told and retold in the village situated there.

  6. Microstructured hollow fibers for ultrafiltration

    NARCIS (Netherlands)

    Culfaz, Pmar Zeynep; Culfaz, P.Z.; Rolevink, Hendrikus H.M.; van Rijn, C.J.M.; Lammertink, Rob G.H.; Wessling, Matthias

    2010-01-01

    Hollow fiber ultrafiltration membranes with a corrugated outer microstructure were prepared from a PES/PVP blend. The effect of spinning parameters such as air gap, take-up speed, polymer dope viscosity and coagulation value on the microstructure and membrane characteristics was investigated. Fibers

  7. Biocompatibility of Polyhydroxybutyrate Microspheres: in vitro and in vivo Evaluation

    OpenAIRE

    Shishatskaya, Ekaterina I.; Voinova, Olga N.; Goreva, Anastasya V.; Mogilnaya, Olga A.; Volova, Tatiana G.

    2008-01-01

    Microspheres have been prepared from the resorbable linear polyester of β-hydroxybutyric acid (polyhydroxybutyrate, PHB) by the solvent evaporation technique and investigated in vitro and in vivo. Biocompatibility of the microspheres has been proved in tests in the culture of mouse fibroblast cell line NIH 3Т3 and in experiments on intramuscular implantation of the microspheres to Wistar rats for 3 months. Tissue response to the implantation of polymeric microspheres has been found to consist...

  8. Glass consistency and glass performance

    International Nuclear Information System (INIS)

    Plodinec, M.J.; Ramsey, W.G.

    1994-01-01

    Glass produced by the Defense Waste Processing Facility (DWPF) will have to consistently be more durable than a benchmark glass (evaluated using a short-term leach test), with high confidence. The DWPF has developed a Glass Product Control Program to comply with this specification. However, it is not clear what relevance product consistency has on long-term glass performance. In this report, the authors show that DWPF glass, produced in compliance with this specification, can be expected to effectively limit the release of soluble radionuclides to natural environments. However, the release of insoluble radionuclides to the environment will be limited by their solubility, and not glass durability

  9. Preparation and Characterization of Sugar Cane Wax Microspheres ...

    African Journals Online (AJOL)

    ... and characterize indomethacin (IM) microspheres prepared with sugar cane wax microsperes. Methods: Microspheres were prepared by melt-emulsified dispersion and cooling-induced solidification method. The microspheres were characterized by scanning electron microscopy (SEM) and differntial scanning calorimetry ...

  10. Preparation of polymer microspheres by radiation-induced polymerization

    International Nuclear Information System (INIS)

    Naka, Y.; Yamamoto, Y.; Yoshida, Y.; Tagawa, S.

    1995-01-01

    Cross-liking monomer, diethylene glycol dimethacrylate gives microspheres from organic solution by radiation-induced polymerization. /One of the remarkable result is that the number of the microspheres is not changing during the polymerization. Ethyl methacrylate, maleic anhydride, styrene and acrylamide are used as comonomers. These comonomers give the microspheres in the range of 0 to 0.4 as mol fractions. (author)

  11. Simultaneous Determination of Glass Transition Temperatures of Several Polymers.

    Science.gov (United States)

    He, Jiang; Liu, Wei; Huang, Yao-Xiong

    2016-01-01

    A simple and easy optical method is proposed for the determination of glass transition temperature (Tg) of polymers. Tg was determined using the technique of microsphere imaging to monitor the variation of the refractive index of polymer microsphere as a function of temperature. It was demonstrated that the method can eliminate most thermal lag and has sensitivity about six fold higher than the conventional method in Tg determination. So the determined Tg is more accurate and varies less with cooling/heating rate than that obtained by conventional methods. The most attractive character of the method is that it can simultaneously determine the Tg of several polymers in a single experiment, so it can greatly save experimental time and heating energy. The method is not only applicable for polymer microspheres, but also for the materials with arbitrary shapes. Therefore, it is expected to be broadly applied to different fundamental researches and practical applications of polymers.

  12. Colloidal glasses

    Indian Academy of Sciences (India)

    First page Back Continue Last page Overview Graphics. Colloidal glasses. Glassy state is attained when system fails to reach equilibrium due to crowding of constituent particles. In molecular glasses, glassy state is reached by rapidly lowering the temperature. In colloidal glasses, glassy state is reached by increasing the ...

  13. Flexible Microsphere-Embedded Film for Microsphere-Enhanced Raman Spectroscopy.

    Science.gov (United States)

    Xing, Cheng; Yan, Yinzhou; Feng, Chao; Xu, Jiayu; Dong, Peng; Guan, Wei; Zeng, Yong; Zhao, Yan; Jiang, Yijian

    2017-09-27

    Dielectric microspheres with extraordinary microscale optical properties, such as photonic nanojets, optical whispering-gallery modes (WGMs), and directional antennas, have drawn interest in many research fields. Microsphere-enhanced Raman spectroscopy (MERS) is an alternative approach for enhanced Raman detection by dielectric microstructures. Unfortunately, fabrication of microsphere monolayer arrays is the major challenge of MERS for practical applications on various specimen surfaces. Here we report a microsphere-embedded film (MF) by immersing a highly refractive microsphere monolayer array in the poly(dimethylsiloxane) (PDMS) film as a flexible MERS sensing platform for one- to three-dimensional (1D to 3D) specimen surfaces. The directional antennas and wave-guided whispering-gallery modes (WG-WGMs) contribute to the majority of Raman enhancement by the MFs. Moreover, the MF can be coupled with surface-enhanced Raman spectroscopy (SERS) to provide an extra >10-fold enhancement. The limit of detection is therefore improved for sensing of crystal violet (CV) and Sudan I molecules in aqueous solutions at concentrations down to 10 -7 M. A hybrid dual-layer microsphere enhancer, constructed by depositing a MF onto a microsphere monolayer array, is also demonstrated, wherein the WG-WGMs become dominant and boost the enhancement ratio >50-fold. The present work opens up new opportunities for design of cost-effective and flexible MERS sensing platforms as individual or associated techniques toward practical applications in ultrasensitive Raman detection.

  14. Titanium phosphate glass microcarriers induce enhanced osteogenic cell proliferation and human mesenchymal stem cell protein expression

    Directory of Open Access Journals (Sweden)

    Nilay J Lakhkar

    2015-11-01

    Full Text Available In this study, we have developed 50- to 100-µm-sized titanium phosphate glass microcarriers (denoted as Ti5 that show enhanced proliferation of human mesenchymal stem cells and MG63 osteosarcoma cells, as well as enhanced human mesenchymal stem cell expression of bone differentiation markers, in comparison with commercially available glass microspheres at all time points. We also demonstrate that these microcarriers provide superior human mesenchymal stem cell proliferation with conventional Dulbecco’s Modified Eagle medium than with a specially developed commercial stem cell medium. The microcarrier proliferative capacity is revealed by a 24-fold increase in MG63 cell numbers in spinner flask bioreactor studies performed over a 7-day period, versus only a 6-fold increase in control microspheres under the same conditions; the corresponding values of Ti5 and control microspheres under static culture are 8-fold and 7-fold, respectively. The capability of guided osteogenic differentiation is confirmed by ELISAs for bone morphogenetic protein-2 and osteopontin, which reveal significantly greater expression of these markers, especially osteopontin, by human mesenchymal stem cells on the Ti5 microspheres than on the control. Scanning electron microscopy and confocal laser scanning microscopy images reveal favorable MG63 and human mesenchymal stem cell adhesion on the Ti5 microsphere surfaces. Thus, the results demonstrate the suitability of the developed microspheres for use as microcarriers in bone tissue engineering applications.

  15. Biosensing by WGM Microspherical Resonators

    Directory of Open Access Journals (Sweden)

    Giancarlo C. Righini

    2016-06-01

    Full Text Available Whispering gallery mode (WGM microresonators, thanks to their unique properties, have allowed researchers to achieve important results in both fundamental research and engineering applications. Among the various geometries, microspheres are the simplest 3D WGM resonators; the total optical loss in such resonators can be extremely low, and the resulting extraordinarily high Q values of 108–109 lead to high energy density, narrow resonant-wavelength lines and a lengthy cavity ringdown. They can also be coated in order to better control their properties or to increase their functionality. Their very high sensitivity to changes in the surrounding medium has been exploited for several sensing applications: protein adsorption, trace gas detection, impurity detection in liquids, structural health monitoring of composite materials, detection of electric fields, pressure sensing, and so on. In the present paper, after a general introduction to WGM resonators, attention is focused on spherical microresonators, either in bulk or in bubble format, to their fabrication, characterization and functionalization. The state of the art in the area of biosensing is presented, and the perspectives of further developments are discussed.

  16. Laser emission in Nd3+ doped barium–titanium–silicate microspheres under continuous and chopped wave pumping in a non-coupled pumping scheme

    International Nuclear Information System (INIS)

    Martín, L L; Pérez-Rodríguez, C; Martín, I R; Navarro-Urrios, D; Ferrarese-Lupi, F; Garrido, B; Montserrat, J; Dominguez, C; Capuj, N

    2013-01-01

    Laser action using non-coupled excitation and detection of microspheres made of Nd 3+ doped barium–titanium–silicate glass has been demonstrated and measured. The microspheres have also been successfully deposited over Si 3 N 4 strip waveguides with a SiO 2 separation layer, thus enabling the laser emission extraction onto a CMOS compatible photonic circuit. The dynamics of the lasing wavelength and intensity has been studied as a function of the pump power and interpreted in terms of thermal effects generated through non-radiative recombination of the excited ions. (paper)

  17. Acoustic radiation force on a double-layer microsphere by a Gaussian focused beam

    International Nuclear Information System (INIS)

    Wu, Rongrong; Cheng, Kaixuan; Liu, Jiehui; Mao, Yiwei; Gong, Xiufen; Liu, Xiaozhou

    2014-01-01

    A new model for calculating the radiation force on double-layer microsphere is proposed based on the ray acoustics approach. The axial acoustic radiation force resulting from a focused Gaussian beam incident on spherical shells immersed in water is examined theoretically in relation to its thickness and the contents of its double-layer. The attenuation both in the water and inside the sphere is considered in this method, which cannot be ignored while the high frequency ultrasonic is used. Results of numerical calculations are presented for fat and low density polyethylene materials, with the hollow region filled with animal oil, water, or air. These results show how the acoustic impedance and the sound velocity of both layers, together with the thickness of the shell, affect the acoustic radiation force.

  18. Silicate glasses

    International Nuclear Information System (INIS)

    Lutze, W.

    1988-01-01

    Vitrification of liquid high-level radioactive wastes has received the greatest attention, world-wide, compared to any other HLW solidification process. The waste form is a borosilicate-based glass. The production of phosphate-based glass has been abandoned in the western world. Only in the Soviet Union are phosphate-based glasses still being developed. Vitrification techniques, equipment and processes and their remote operation have been developed and studied for almost thirty years and have reached a high degree of technical maturity. Industrial demonstration of the vitrification process has been in progress since 1978. This chapter is a survey of world-wide research and development efforts in nuclear waste glasses and its production technology. The principal glasses considered are silicate glasses which contain boron, i.e., borosilicate glasses

  19. Evaluation of aluminosilicate glass sintering during differential scanning calorimetry

    International Nuclear Information System (INIS)

    Souza, Juliana Pereira de

    2015-01-01

    In this work a difference in the baseline in differential scanning calorimetry analyses, observed in a work where aluminosilicate glasses microspheres containing Ho were studied for application in selective internal radiotherapy as hepatocellular carcinoma treatment, was studied. The glasses with nominal composition 53,7 SiO 2 .10,5 Al 2 O 3 . 35,8 MgO in %mol were produced from traditional melting. The first obtained were milled and sieved in the range of 45 a 63 μm. The material was used to produce glass microspheres by the gravitational fall method. The glass powder and the microspheres were characterized by X ray fluorescence spectrometry, laser diffraction, X ray diffraction, differential scanning calorimetry, differential thermal analysis, thermogravimetry, mass spectrometry, and scanning electron microscopy. After the thermal analyses, pellets were formed in the crucibles and were analyzed by scanning electron microscopy, X ray diffraction, and He pycnometry. The difference in the baseline was associated to the viscous flow sintering process and happens because of the decrease in the detected heat flow due to the sample shrinkage. Other events as concurrent crystallization with the sintering process were also studied. (author)

  20. Fabrication of Metallic Hollow Nanoparticles

    Science.gov (United States)

    Kim, Jae-Woo (Inventor); Choi, Sr., Sang H. (Inventor); Lillehei, Peter T. (Inventor); Chu, Sang-Hyon (Inventor); Park, Yeonjoon (Inventor); King, Glen C. (Inventor); Elliott, James R. (Inventor)

    2016-01-01

    Metal and semiconductor nanoshells, particularly transition metal nanoshells, are fabricated using dendrimer molecules. Metallic colloids, metallic ions or semiconductors are attached to amine groups on the dendrimer surface in stabilized solution for the surface seeding method and the surface seedless method, respectively. Subsequently, the process is repeated with additional metallic ions or semiconductor, a stabilizer, and NaBH.sub.4 to increase the wall thickness of the metallic or semiconductor lining on the dendrimer surface. Metallic or semiconductor ions are automatically reduced on the metallic or semiconductor nanoparticles causing the formation of hollow metallic or semiconductor nanoparticles. The void size of the formed hollow nanoparticles depends on the dendrimer generation. The thickness of the metallic or semiconductor thin film around the dendrimer depends on the repetition times and the size of initial metallic or semiconductor seeds.

  1. A microsphere suspension model of metamaterial fluids

    Directory of Open Access Journals (Sweden)

    Qian Duan

    2017-05-01

    Full Text Available Drawing an analogy to the liquid phase of natural materials, we theoretically propose a microsphere suspension model to realize a metamaterial fluid with artificial electromagnetic indexes. By immersing high-ε, micrometer-sized dielectric spheres in a low-ε insulating oil, the structured fluid exhibits liquid-like properties from dispersing phase as well as the isotropic negative electromagnetic parameters caused by Mie resonances from dispersed microspheres. The work presented here will benefit the development of structured fluids toward metamaterials.

  2. Albumin microspheres labeled with Ga-67 by chelation: concise communication

    International Nuclear Information System (INIS)

    Hnatowich, D.J.; Schlegel, P.

    1981-01-01

    Albumin microspheres have been synthesized with EDTA and DTPA chelating groups covalently bound to their surface. The microspheres may be labeled with Ga-67 at high yield (97 +- 2%) by transcomplexation from a 0.1 M Ga-67 acetate solution. With EDTA microspheres the resulting label dissociates only slightly after 24 hr in 50% plasma at 37 0 C, whereas with DTPA microspheres the label shows no detectable dissociation over this period. By contrast, microspheres without chelating groups lose their label virtually completely under these conditions. Following intravenous administration of sized Ga-67 DTPA microspheres in mice, about (84 +- 16)% of the activity localizes in the lungs at 5 min, with (60 +- 7)% remaining after 2 h. Since labeling is by chelation, the microspheres may also be tagged with other metallic radionuclides

  3. Facile Synthesis of Flowerlike LiFe5O8 Microspheres for Electrochemical Supercapacitors.

    Science.gov (United States)

    Lin, Ying; Dong, Jingjing; Dai, Jingjing; Wang, Jingping; Yang, Haibo; Zong, Hanwen

    2017-12-18

    Facile synthesis of porous and hollow spinel materials is very urgent due to their extensive applications in the field of energy storage. In present work, flowerlike porous LiFe 5 O 8 microspheres etched for 15, 30, and 45 min (named as p-LFO-15, p-LFO-30, and p-LFO-45, respectively) are successfully synthesized through a facile chemical etching method based on bulk LiFe 5 O 8 (LFO) particles as precursors, and they are applied as electrode materials for high-performance electrochemical capacitors. In particular, the specific surface area of p-LFO-45 reaches 46.13 m 2 g -1 , which is 112 times greater than that of the unetched counterpart. Therefore, the p-LFO-45 electrode can achieve a higher capacitance of 278 F g -1 at a scan rate of 5 mV s -1 than the unetched counterpart. Furthermore, the p-LFO-45 electrode presents a good cycling stability with 78.3% of capacitive retention after 2000 cycles, which is much higher than that of the unetched LFO particles (66%). Therefore, the flowerlike porous LFO microspheres are very promising candidate materials for supercapacitor applications.

  4. Production of porous titanate microspheres by spray-drying of sols

    International Nuclear Information System (INIS)

    Sizgek, E.; Bartlett, J.R.; Woolfrey, J.L.

    1992-01-01

    Porous, multi-component titanate microspheres (20 to 50 μm in diameter) have been produced on a 10 kg scale by spray-drying a precursor sol containing titania, zirconia and alumina, and calcining the resulting powders at 723 K. The mixed TiO 2 /ZrO 2 sols were produced by hydrolysing tetraisopropyltitanate and peptising the hydrolysate slurry with zirconyl nitrate solution. TiO 2 /ZrO 2 sols with oxide concentrations in excess of 900 g dm -3 were produced. These sols were subsequently mixed with dispersible δ-Al 2 O 3 to produce well-dispersed TiO 2 /ZrO 2 /Al 2 O 3 (TZA) sols. The rheology and degree of aggregation of the multi-component sols were controlled by the addition of Al(NO 3 ) 3 solution. At relatively low electrolyte concentrations, the sols exhibited Newtonian behaviour, and the viscosity increased with increasing addition of electrolyte. However, at higher electrolyte concentrations, the colloidal dispersions exhibited shear-thinning behaviour. Hollow spheres were produced by spray-drying well-dispersed sols. In contrast, 'solid' spheres were produced by using dilute Al(NO 3 ) 3 to produce partially-aggregated TZA sols, prior to spray-drying. Calcined microspheres produced from partially-aggregated sols had total porosities of ∼ 50 %, with average pore diameters of ∼ 8 nm. These particles exhibited a high sorption capacity for simulated High Level Nuclear Waste

  5. Interactive Micromanipulation of Picking and Placement of Nonconductive Microsphere in Scanning Electron Microscope

    Directory of Open Access Journals (Sweden)

    Ning Cao

    2017-08-01

    Full Text Available In this paper, classified theoretical models, consisting of contact with and placement of microsphere and picking operations, are simplified and established to depict the interactive behaviors of external and internal forces in pushing manipulations, respectively. Sliding and/or rolling cases, resulting in the acceleration of micromanipulations, are discussed in detail. Effective contact detection is achieved by combining alterations of light-shadow and relative movement displacement between the tip-sphere. Picking operations are investigated by typical interactive positions and different end tilt angles. Placements are realized by adjusting the proper end tilt angles. These were separately conducted to explore the interactive operations of nonconductive glass microspheres in a scanning electron microscope. The experimental results demonstrate that the proposed contact detection method can efficiently protect the end-tip from damage, regardless of operator skills in initial positioning operations. E-beam irradiation onto different interactive positions with end tilt angles can be utilized to pick up microspheres without bending the end-tip. In addition, the results of releasing deviations away from the pre-setting point were utilized to verify the effectiveness of the placement tilt angles.

  6. Photonic nanojet super-resolution in immersed ordered assembly of dielectric microspheres

    International Nuclear Information System (INIS)

    Geints, Y.E.; Zemlyanov, A.A.

    2017-01-01

    Highlights: • Ordered microassemblies of dielectric microspheres immersed in a transparent matrix exposed to a light wave produce an array of the “photonic nanojets” coupled through the field interference. • “Photonic nanojet” parameters depend on the inter-sphere gap and immersion depth. • Sphere microassembly can produce the jets with the sub-diffraction spatial resolution if the particles are loosely packed and semi-immersed. - Abstract: Specific spatially-localized optical field structure, which is often referred to as a photonic nanojet (PNJ), is formed in the near-field scattering area of non-absorbing dielectric micron-sized particle exposed to an optical radiation. By virtue of the finite-difference time-domain technique we numerically simulate the two-dimensional array of PNJs created by an ordered single-layer microassembly of glass microspheres immersed in a transparent polymer matrix. The behavior of the main PNJ parameters (length, diameter, and intensity) is analyzed subject to the immersion depth of the microparticles and cooperative interference effects of the neighboring microspheres. We show that depending on microassembly configuration, the PNJ quality can be significantly improved; in particular, the PNJ spatial resolution better than λ/5 can be achieved.

  7. Chemical Modifications of Hollow Silica Microspheres for the Removal of Organic Pollutants in Simulated Wastewater

    KAUST Repository

    Torano, Aniela Zarzar

    2017-01-01

    Aqueous industrial effluents containing organic pollutants, such as textile dyes and crude oil, represent environmental and human health concerns due to their toxicity and possible carcinogenic effects. Adsorption is the most promising wastewater

  8. Thermal decomposition of polystyrene in the high temperature fabrication technology of hollow microspheres. Revision 1

    International Nuclear Information System (INIS)

    Dorogotovtsev, V.M.; Akunets, A.A.; Merkuliev, Y.A.; Turivnoy, A.P.

    1997-01-01

    The degree and nature of polymer degradation that occurs in the high temperature microshell formation process developed at the Lebedev Physical Institute has been examined experimentally. We find that significant mass degradation occurs during the final stages of shell formation. This manifests itself both in terms of mass loss and molecular weight degradation as measured by gel permeation chromatography. This decrease in the molecular weight may be in part responsible for the relatively fragile nature of the shells produced by this high temperature process. 9 refs., 6 figs., 2 tabs

  9. Jingle-bell-shaped ferrite hollow sphere with a noble metal core: Simple synthesis and their magnetic and antibacterial properties

    International Nuclear Information System (INIS)

    Li Siheng; Wang Enbo; Tian Chungui; Mao Baodong; Kang Zhenhui; Li Qiuyu; Sun Guoying

    2008-01-01

    In this paper, a simple strategy is developed for rational fabrication of a class of jingle-bell-shaped hollow structured nanomaterials marked as Ag(MFe 2 O 4 ) (M=Ni, Co, Mg, Zn), consisting of ferrite hollow shells and metal nanoparticle cores, using highly uniform colloidal Ag(C) microspheres as template. The final composites were obtained by direct adsorption of metal cations Fe 3+ and M 2+ on the surface of the Ag(C) spheres followed by calcination process to remove the middle carbon shell and transform the metal ions into pure phase ferrites. The as-prepared composites were characterized by X-ray photoelectron spectroscopy (XPS), energy-dispersive X-ray analysis (EDX), X-ray powder diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), UV-vis spectroscopy and SQUID magnetometer. The results showed that the composites possess the magnetic property of the ferrite shell and the optical together with antibacterial property of the Ag core. - Graphical abstract: MFe 2 O 4 (M=Ni, Co, Mg, Zn) hollow spheres with a noble metal nanoparticle core were successfully prepared by using colloidal metal(C) core-shell spheres as templates with no need of surface modification. The shell thickness and magnetic properties of the ferrite hollow spheres could be controlled by varying the synthetic parameters

  10. Space Charge Mitigation With Longitudinally Hollow Bunches

    CERN Multimedia

    Oeftiger, Adrian; Rumolo, Giovanni

    2016-01-01

    Hollow longitudinal phase space distributions have a flat profile and hence reduce the impact of transverse space charge. Dipolar parametric excitation with the phase loop feedback systems provides such hollow distributions under reproducible conditions. We present a procedure to create hollow bunches during the acceleration ramp of CERN’s PS Booster machine with minimal changes to the operational cycle. The improvements during the injection plateau of the downstream Proton Synchrotron are assessed in comparison to standard parabolic bunches.

  11. Hollow Microtube Resonators via Silicon Self-Assembly toward Subattogram Mass Sensing Applications.

    Science.gov (United States)

    Kim, Joohyun; Song, Jungki; Kim, Kwangseok; Kim, Seokbeom; Song, Jihwan; Kim, Namsu; Khan, M Faheem; Zhang, Linan; Sader, John E; Park, Keunhan; Kim, Dongchoul; Thundat, Thomas; Lee, Jungchul

    2016-03-09

    Fluidic resonators with integrated microchannels (hollow resonators) are attractive for mass, density, and volume measurements of single micro/nanoparticles and cells, yet their widespread use is limited by the complexity of their fabrication. Here we report a simple and cost-effective approach for fabricating hollow microtube resonators. A prestructured silicon wafer is annealed at high temperature under a controlled atmosphere to form self-assembled buried cavities. The interiors of these cavities are oxidized to produce thin oxide tubes, following which the surrounding silicon material is selectively etched away to suspend the oxide tubes. This simple three-step process easily produces hollow microtube resonators. We report another innovation in the capping glass wafer where we integrate fluidic access channels and getter materials along with residual gas suction channels. Combined together, only five photolithographic steps and one bonding step are required to fabricate vacuum-packaged hollow microtube resonators that exhibit quality factors as high as ∼ 13,000. We take one step further to explore additionally attractive features including the ability to tune the device responsivity, changing the resonator material, and scaling down the resonator size. The resonator wall thickness of ∼ 120 nm and the channel hydraulic diameter of ∼ 60 nm are demonstrated solely by conventional microfabrication approaches. The unique characteristics of this new fabrication process facilitate the widespread use of hollow microtube resonators, their translation between diverse research fields, and the production of commercially viable devices.

  12. Thermal evolution of structure and photocatalytic activity in polymer microsphere templated TiO{sub 2} microbowls

    Energy Technology Data Exchange (ETDEWEB)

    Erdogan, Deniz Altunoz; Polat, Meryem [Department of Chemistry, Bilkent University, 06800 Ankara (Turkey); Garifullin, Ruslan; Guler, Mustafa O. [Institute of Materials Science and Nanotechnology, National Nanotechnology Research Center (UNAM), Bilkent University, 06800 Ankara (Turkey); Ozensoy, Emrah, E-mail: ozensoy@fen.bilkent.edu.tr [Department of Chemistry, Bilkent University, 06800 Ankara (Turkey)

    2014-07-01

    Polystyrene cross-linked divinyl benzene (PS-co-DVB) microspheres were used as an organic template in order to synthesize photocatalytic TiO{sub 2} microspheres and microbowls. Photocatalytic activity of the microbowl surfaces were demonstrated both in the gas phase via photocatalytic NO(g) oxidation by O{sub 2}(g) as well as in the liquid phase via Rhodamine B degradation. Thermal degradation mechanism of the polymer template and its direct influence on the TiO{sub 2} crystal structure, surface morphology, composition, specific surface area and the gas/liquid phase photocatalytic activity data were discussed in detail. With increasing calcination temperatures, spherical polymer template first undergoes a glass transition, covering the TiO{sub 2} film, followed by the complete decomposition of the organic template to yield TiO{sub 2} exposed microbowl structures. TiO{sub 2} microbowl systems calcined at 600 °C yielded the highest per-site basis photocatalytic activity. Crystallographic and electronic properties of the TiO{sub 2} microsphere surfaces as well as their surface area play a crucial role in their ultimate photocatalytic activity. It was demonstrated that the polymer microsphere templated TiO{sub 2} photocatalysts presented in the current work offer a promising and a versatile synthetic platform for photocatalytic DeNO{sub x} applications for air purification technologies.

  13. Effects of Amino-Functionalized Carbon Nanotubes on the Crystal Structure and Thermal Properties of Polyacrylonitrile Homopolymer Microspheres

    Directory of Open Access Journals (Sweden)

    Hailong Zhang

    2017-08-01

    Full Text Available Amino-functionalized multi-walled carbon nanotube (amino-CNT/polyacrylonitrile (PAN microspheres with diameter of about 300–400 nm were prepared by in situ polymerization under aqueous solution. The morphology, crystal structure, and thermal properties of amino-CNTs on a PAN homopolymer were investigated by scanning electron microscopy, transmission electron microscopy, Fourier transform infrared spectra, X-ray diffraction, and differential scanning calorimetry. The results showed that the amino-CNTs had a significant influence on the morphology of microspheres, and the PAN matrix were grafted onto the surface of amino-CNTs with interfacial bonding between them. The XRD studies showed that the crystal size of amino-CNT/PAN microspheres with lower crystallinity was bigger than in the control PAN homopolymer. The analysis of thermal properties indicated that the amino-CNT/PAN microspheres with lower glass transition temperature had a lower initial temperature and velocity of evolving heat during the exothermic processing as compared with the PAN homopolymer. These results suggested that the incorporation of amino-CNTs into the PAN homopolymer matrix was beneficial for controlling the heat released during the stabilization processing.

  14. Recycle Glass in Foam Glass Production

    DEFF Research Database (Denmark)

    Petersen, Rasmus Rosenlund; König, Jakob; Yue, Yuanzheng

    The foam glass industry turn recycle glass into heat insulating building materials. The foaming process is relative insensitive to impurities in the recycle glass. It is therefore considered to play an important role in future glass recycling. We show and discuss trends of use of recycled glasses...... in foam glass industry and the supply sources and capacity of recycle glass....

  15. Bubble template synthesis of hollow gold nanoparticles and their applications as theranostic agents

    Science.gov (United States)

    Huang, Chienwen

    Hollow gold nanoparticle with a sub-30nm polycrystalline shell and a 50 nm hollow core has been successfully synthesized through the reduction of sodium gold sulfite by electrochemically evolved hydrogen. Such hollow gold nanoparticles exhibit unique plasmonic properties. They strongly scatter and absorb near infrared light. In this thesis we seek to understand the formation mechanism of hollow gold nanoparticles in this new synthesis process and their plasmonic properties. Also, we explore their biomedical applications as theranostic agents (therapeutic and diagnostic imaging). A lithographically patterned electrode consisting of Ag stripes on a glass substrate was used to investigate the formation process of hollow gold nanoparticles. Ag stripes served as working electrode for electrochemically evolution of hydrogen, and adjacent glass areas provided supporting surface for hydrogen nanobubbles nucleation and growth. Hydrogen nanobubbles served as both templates and reducing agents to trigger the autocatalytic disproportionation reaction of sodium gold sulfite. The effects of applied potential and the additives in the electrolyte have been studied. It has been found that the size and size distribution of hollow gold nanoparticle are directly relative to the applied potential, i.e. the hydrogen evolution rate. It has also been found the addition of Ni2+ ions can greatly improve the size distribution of hollow gold nanoparticles that can be contributed to that the newly electrodeposited nickel metal can enhance the hydrogen evolution efficiency. Another additive, ethylenediamine (EDA) can suppress the autocatalytic reaction of gold sulfite to increase the stability of sodium gold sulfite electrolyte. To capture such electrochemically evolved hydrogen nanobubbles, and subsequently to generate hollow gold nanoparticles in large numbers, alumina membranes were placed on the top of the working electrode. Anodic alumina membrane consists of ~200 nm pores, which provides

  16. Separation of PCR-ready DNA from dairy products using magnetic hydrophilic microspheres and poly(ethylene glycol)-NaCl water solutions

    Energy Technology Data Exchange (ETDEWEB)

    Rittich, Bohuslav [Masaryk University, Faculty of Science, Institute of Experimental Biology, Tvrdeho 14, CZ-611 37 Brno (Czech Republic); Brno University of Technology, Faculty of Chemistry, Institute of Food Science and Biotechnology, Purkynova 464/118, CZ-612 00 Brno (Czech Republic)], E-mail: rittich@sci.muni.cz; Spanova, Alena [Masaryk University, Faculty of Science, Institute of Experimental Biology, Tvrdeho 14, CZ-611 37 Brno (Czech Republic); Brno University of Technology, Faculty of Chemistry, Institute of Food Science and Biotechnology, Purkynova 464/118, CZ-612 00 Brno (Czech Republic); Salek, Petr [Brno University of Technology, Faculty of Chemistry, Institute of Food Science and Biotechnology, Purkynova 464/118, CZ-612 00 Brno (Czech Republic); Nemcova, Petra [Masaryk University, Faculty of Science, Institute of Experimental Biology, Tvrdeho 14, CZ-611 37 Brno (Czech Republic); Trachtova, Stepanka [Brno University of Technology, Faculty of Chemistry, Institute of Food Science and Biotechnology, Purkynova 464/118, CZ-612 00 Brno (Czech Republic); Horak, Daniel [Institute of Macromolecular Chemistry, Academy of Sciences of the Czech Republic, Heyrovsky Sq. 2, CZ-162 06 Prague (Czech Republic)

    2009-05-15

    Carboxyl group-containing magnetic nonporous poly(2-hydroxyethyl methacrylate-co-glycidyl methacrylate) (P(HEMA-co-GMA)) and magnetic glass microspheres were used for the isolation of bacterial DNA. P(HEMA-co-GMA) microspheres were prepared by the dispersion polymerization in toluene/2-methylpropan-1-ol mixture in the presence of magnetite nanoparticles obtained by coprecipitation of Fe(II) and Fe(III) salts with ammonium hydroxide. Carboxyl groups were then introduced by oxidation of the microspheres with potassium permanganate. The most extensive DNA recovery was achieved at PEG 6000 concentrations of 12% or 16% and 2 M NaCl. The method proposed was used for bacterial DNA isolation from different dairy products containing Bifidobacterium and Lactobacillus cells. The presence of target DNA and the quality of isolated DNA were checked by polymerase chain reaction (PCR) amplification with specific primers.

  17. Clinical feasibility of {sup 90}Y digital PET/CT for imaging microsphere biodistribution following radioembolization

    Energy Technology Data Exchange (ETDEWEB)

    Wright, Chadwick L.; Binzel, Katherine; Zhang, Jun; Knopp, Michael V. [The Ohio State University Wexner Medical Center, Wright Center of Innovation in Biomedical Imaging, Department of Radiology, Columbus, OH (United States); Wuthrick, Evan J. [The Ohio State University Wexner Medical Center, Department of Radiation Oncology, Columbus, OH (United States)

    2017-07-15

    The purpose of this study was to evaluate the clinical feasibility of next generation solid-state digital photon counting PET/CT (dPET/CT) technology and imaging findings in patients following {sup 90}Y microsphere radioembolization in comparison with standard of care (SOC) bremsstrahlung SPECT/CT (bSPECT/CT). Five patients underwent SOC {sup 90}Y bremsstrahlung imaging immediately following routine radioembolization with 3.5 ± 1.7 GBq of {sup 90}Y-labeled glass microspheres. All patients also underwent dPET/CT imaging at 29 ± 11 h following radioembolization. Matched pairs comparison was used to compare image quality, image contrast and {sup 90}Y biodistribution between dPET/CT and bSPECT/CT images. Volumetric assessments of {sup 90}Y activity using different isocontour thresholds on dPET/CT and bSPECT/CT images were also compared. Digital PET/CT consistently provided better visual image quality and {sup 90}Y-to-background image contrast while depicting {sup 90}Y biodistribution than bSPECT/CT. Isocontour volumetric assessment using a 1% threshold precisely outlined {sup 90}Y activity and the treatment volume on dPET/CT images, whereas a more restrictive 20% threshold on bSPECT/CT images was needed to obtain comparable treatment volumes. The use of a less restrictive 10% threshold isocontour on bSPECT/CT images grossly overestimated the treatment volume when compared with the 1% threshold on dPET/CT images. Digital PET/CT is clinically feasible for the assessment of {sup 90}Y microsphere biodistribution following radioembolization, and provides better visual image quality and image contrast than routine bSPECT/CT with comparable acquisition times. With further optimization and clinical validation, dPET technology may allow faster and more accurate imaging-based assessment of {sup 90}Y microsphere biodistribution. (orig.)

  18. Gastroretentive Floating Microspheres of Silymarin: Preparation and ...

    African Journals Online (AJOL)

    Erah

    simulated gastric fluid for at least 12 h, and, therefore, could potentially ... systems (GRFDDS) have a bulk density ... The objective of this work was to develop and characterise gastroretentive floating microspheres of silymarin which, following oral administration, would exhibit .... hydrochloric acid to maintain sink conditions.

  19. Structuring of diamond films using microsphere lithography

    Czech Academy of Sciences Publication Activity Database

    Domonkos, Mária; Ižák, Tibor; Štolcová, L.; Proška, J.; Demo, Pavel; Kromka, Alexander

    2014-01-01

    Roč. 54, č. 5 (2014), s. 320-324 ISSN 1210-2709 R&D Projects: GA ČR(CZ) GBP108/12/G108 Institutional support: RVO:68378271 Keywords : nanostructuring * diamond thin films * polystyrene microspheres * reactive ion etching * scanning electron microscopy Subject RIV: BM - Solid Matter Physics ; Magnetism

  20. Method and apparatus for producing microspherical particles

    International Nuclear Information System (INIS)

    Egli, W.; Bailey, W.H.; Leary, D.F.; Lansley, R.J.

    1979-01-01

    This invention relates generally to a method and apparatus for producing microspherical particles and more particularly to a method and apparatus which are particularly useful in connection with the sol-gel process for the production of nuclear fuel kernels. (U.K.)

  1. MICROSPHERE SIZE INFLUENCES THE FOREIGN BODY REACTION

    NARCIS (Netherlands)

    Zandstra, J.; Hiemstra, C.; Petersen, A. H.; Zuidema, J.; van Beuge, M. M.; Rodriguez, S.; Lathuile, A. A. R.; Veldhuis, G. J.; Steendam, R.; Bank, R. A.; Popa, E. R.

    2014-01-01

    Biodegradable poly-(DL-lactide-co-glycolide) (PLGA) microspheres (MSP) are attractive candidate vehicles for site-specific or systemic sustained release of therapeutic compounds. This release may be altered by the host's foreign body reaction (FBR), which is dependent on the characteristics of the

  2. Beat-Frequency/Microsphere Medical Ultrasonic Imaging

    Science.gov (United States)

    Yost, William T.; Cantrell, John H.; Pretlow, Robert A., III

    1995-01-01

    Medical ultrasonic imaging system designed to provide quantitative data on various flows of blood in chambers, blood vessels, muscles, and tissues of heart. Sensitive enough to yield readings on flows of blood in heart even when microspheres used as ultrasonic contrast agents injected far from heart and diluted by circulation of blood elsewhere in body.

  3. Study of the spheronization process of glass particles by the gravitational falling process for internal selective radiotherapy; Estudo do processo de esferolizacao por queda gravitacional de particulas vitreas visando a aplicacao em radioterapia interna seletiva

    Energy Technology Data Exchange (ETDEWEB)

    Barros Filho, E.C.; Martinelli, J.R., E-mail: eraldo.filho@usp.br [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), SP (Brazil); Sene, F.F. [Centro Tecnologico da Marinha em Sao Paulo (CTMS), Sao Paulo, SP (Brazil)

    2011-07-01

    The internal selective radiotherapy is an alternative to treat hepatocellular carcinoma. Glass microspheres containing β{sup -} emitter radionuclide are introduced in the liver, and they are housed preferentially in the region where the cancer cells are located. The microspheres are trapped in the arterioles which feed the tumors, and the β{sup -} particles annihilate the cancer cells. The glass particles must be spherical to avoid unnecessary bleeding, and the particle size must be restricted to a range which optimizes the blocking effect and avoid the migration to other parts of the human body. The particle size distribution of microspheres is not easily predicted since the variation of the aspect ratio and the presence of agglomerates can influence the resulting particle size distribution. In the present work, the spheronization process to obtain microspheres from irregular shape glass particles with suitable diameter and shape for radiotherapy treatment is studied. (author)

  4. Emulsion-phase synthesis of honeycomb-like Mg{sub 5}(OH){sub 2}(CO{sub 3}){sub 4}.4H{sub 2}O micro-spheres and subsequent decomposition to MgO

    Energy Technology Data Exchange (ETDEWEB)

    Gao Guo, E-mail: gaogaoguoguo@yahoo.com.c [Department of Bio-Nano-Science and Engineering, National Key Laboratory of Nano/Micro Fabrication Technology, Key Laboratory for Thin Film and Microfabrication of Ministry of Education, Institute of Micro-Nano Science and Technology, Shanghai Jiao Tong University, Shanghai 200240 (China); Beijing Key Laboratory of Green Reaction Engineering and Technology, Department of Chemical Engineering, Tsinghua University, Beijing 100084 (China); Xiang Lan, E-mail: xianglan@mail.tsinghua.edu.c [Beijing Key Laboratory of Green Reaction Engineering and Technology, Department of Chemical Engineering, Tsinghua University, Beijing 100084 (China)

    2010-04-09

    Herein we report a simple emulsion-phase route for the synthesis of honeycomb-like basic magnesium carbonate (BMC, Mg{sub 5}(OH){sub 2}(CO{sub 3}){sub 4}.4H{sub 2}O) micro-spheres at 80 {sup o}C. Magnesium(II) salts in water are precipitated by sodium carbonate in the presence of cetyltrimethylammonium bromide (CTAB). Scanning electron microscopy shows the obtained BMC samples are composed of a lot of micro-spheres (diameter ranging from 8 to 10 {mu}m) which are interweaved by a lot of nano-sized thin sheets (thickness of 20-30 nm and length >1 {mu}m). The BMC micro-spheres prepared by this approach are porous and appear to be hollow structures. The size and shape of BMC are related to the CTAB concentration and temperature. The lower concentration of CTAB resulted in the decrease of the micro-spheres sizes. When the temperature was elevated to 110 {sup o}C, hexagonal tablets (thickness of 20 nm, length of each side varies from 400 to 600 nm) can be prepared. After the calcinations for BMC at 600 {sup o}C for 2 h, BMC are almost completely converted to MgO. Transmission electron microscopy indicates that the obtained MgO samples have a poly-crystalline feature. The possible formation mechanism of BMC micro-spheres has been discussed.

  5. In vitro evaluation of biodegradable microspheres with surface-bound ligands.

    Science.gov (United States)

    Keegan, Mark E; Royce, Sara M; Fahmy, Tarek; Saltzman, W Mark

    2006-02-21

    Protein ligands were conjugated to the surface of biodegradable microspheres. These microsphere-ligand conjugates were then used in two in vitro model systems to evaluate the effect of conjugated ligands on microsphere behavior. Microsphere retention in agarose columns was increased by ligands on the microsphere surface specific for receptors on the agarose matrix. In another experiment, conjugating the lectin Ulex europaeus agglutinin 1 to the microsphere surface increased microsphere adhesion to Caco-2 monolayers compared to control microspheres. This increase in microsphere adhesion was negated by co-administration of l-fucose, indicating that the increase in adhesion is due to specific interaction of the ligand with carbohydrate receptors on the cell surface. These results demonstrate that the ligands conjugated to the microspheres maintain their receptor binding activity and are present on the microsphere surface at a density sufficient to target the microspheres to both monolayers and three-dimensional matrices bearing complementary receptors.

  6. Cosmos & Glass

    DEFF Research Database (Denmark)

    Beim, Anne

    1996-01-01

    The article unfolds the architectural visions of glass by Bruno Taut. It refers to inspirations by Paul Sheerbart and litterature and the Crystal Chain, also it analyses the tectonic univers that can be found in the glass pavillion for the Werkbund exposition in Cologne....

  7. Glass Glimpsed

    DEFF Research Database (Denmark)

    Lock, Charles

    2015-01-01

    Glass in poetry as it reflects the viewer and as its power of reflection are both reduced and enhanced by technology.......Glass in poetry as it reflects the viewer and as its power of reflection are both reduced and enhanced by technology....

  8. Spin glasses

    CERN Document Server

    Bovier, Anton

    2007-01-01

    Spin glass theory is going through a stunning period of progress while finding exciting new applications in areas beyond theoretical physics, in particular in combinatorics and computer science. This collection of state-of-the-art review papers written by leading experts in the field covers the topic from a wide variety of angles. The topics covered are mean field spin glasses, including a pedagogical account of Talagrand's proof of the Parisi solution, short range spin glasses, emphasizing the open problem of the relevance of the mean-field theory for lattice models, and the dynamics of spin glasses, in particular the problem of ageing in mean field models. The book will serve as a concise introduction to the state of the art of spin glass theory, usefull to both graduate students and young researchers, as well as to anyone curious to know what is going on in this exciting area of mathematical physics.

  9. Development and evaluation of floating microspheres of verapamil hydrochloride Desenvolvimento e avaliação de microesferas flutuantes de cloridrato de verapamil

    Directory of Open Access Journals (Sweden)

    Yuveraj Singh Tanwar

    2007-12-01

    Full Text Available The present study involves preparation and evaluation of floating microspheres of verapamil hydrochloride for improving the drug bioavailability by prolongation of gastric residence time. Cellulose acetate, acrycoat S100 and eudragit S100 microspheres loaded with verapamil hydrochloride were prepared by solvent diffusion-evaporation method. The microspheres had smooth surfaces, with free-flowing and good-packing properties. The yield of the microspheres was up to 70.51% and cellulose acetate microspheres entrapped the maximum amount of the drug. Scanning electron microscopy confirmed their hollow structures with sizes in the range 251.80 to 350.75 mm. The prepared microspheres exhibited prolonged drug release and remained buoyant for more than 12 h. Radiographic images of dog stomach revealed that cellulose acetate microspheres loaded with barium sulphate floated on the gastric fluid for about 3.2 h. In vitro release studies demonstrated non-Fickian diffusion of drug from the microspheres.O presente estudo envolve a preparação e a avaliação de microesferas flutuantes de cloridrato de verapamil para o melhoramento da biodisponibilidade do fármaco por meio do prolongamento do tempo de residência gástrica. Prepararam-se, por meio do método de difusão-evaporação de solvente, microesferas de acetato de celulose, acrycoat S100 e eudragit S100 carregadas com cloridrato de verapamil. As microesferas apresentaram superfícies regulares, com propriedades de fluxo livre e de bom empacotamento. O rendimento das microesferas foi superior a 70,51% e as microesferas de acetato de celulose captaram a quantidade máxima do fármaco. Microscopia eletrônica de varredura confirmou as cavidades em suas estruturas, com tamanhos na faixa de 251,80 a 350,75 mm. As microesferas preparadas apresentaram liberação prolongada do fármaco e permaneceram flutuantes por mais que 12 h. Imagens radiográficas do estômago de cão revelaram que as esferas de acetato

  10. Hollow nanocrystals and method of making

    Science.gov (United States)

    Alivisatos, A Paul [Oakland, CA; Yin, Yadong [Moreno Valley, CA; Erdonmez, Can Kerem [Berkeley, CA

    2011-07-05

    Described herein are hollow nanocrystals having various shapes that can be produced by a simple chemical process. The hollow nanocrystals described herein may have a shell as thin as 0.5 nm and outside diameters that can be controlled by the process of making.

  11. From core/shell to hollow Fe/γ-Fe_2O_3 nanoparticles: evolution of the magnetic behavior

    International Nuclear Information System (INIS)

    Nemati, Z; Khurshid, H; Alonso, J; Phan, M H; Mukherjee, P; Srikanth, H

    2015-01-01

    High quality Fe/γ-Fe_2O_3 core/shell, core/void/shell, and hollow nanoparticles with two different sizes of 8 and 12 nm were synthesized, and the effect of morphology, surface and finite-size effects on their magnetic properties including the exchange bias (EB) effect were systematically investigated. We find a general trend for both systems that as the morphology changes from core/shell to core/void/shell, the magnetization of the system decays and inter-particle interactions become weaker, while the effective anisotropy and the EB effect increase. The changes are more drastic when the nanoparticles become completely hollow. Noticeably, the morphological change from core/shell to hollow increases the mean blocking temperature for the 12 nm particles but decreases for the 8 nm particles. The low-temperature magnetic behavior of the 12 nm particles changes from a collective super-spin-glass system mediated by dipolar interactions for the core/shell nanoparticles to a frustrated cluster glass-like state for the shell nanograins in the hollow morphology. On the other hand for the 8 nm nanoparticles core/shell and hollow particles the magnetic behavior is more similar, and a conventional spin glass-like transition is obtained at low temperatures. In the case of the hollow nanoparticles, the coupling between the inner and outer spin layers in the shell gives rise to an enhanced EB effect, which increases with increasing shell thickness. This indicates that the morphology of the shell plays a crucial role in this kind of exchange-biased systems. (paper)

  12. Hollow rods for the oil producing industry

    Energy Technology Data Exchange (ETDEWEB)

    Khalimova, L M; Elyasheva, M A

    1970-01-01

    Hollow sucker rods have several advantages over conventional ones. The hollow rods actuate the well pump and at the same time conduct produced fluids to surface. When paraffin deposition occurs, it can be minimized by injecting steam, hot oil or hot water into the hollow rod. Other chemicals, such as demulsifiers, scale inhibitors, corrosion inhibitors, etc., can also be placed in the well through the hollow rods. This reduces cost of preventive treatments, reduces number of workovers, increases oil production, and reduces cost of oil. Because the internal area of the rod is small, the passing liquids have a high velocity and thereby carry sand and dirt out of the well. This reduces pump wear between the piston and the plunger. Specifications of hollow rods, their operating characteristics, and results obtained with such rods under various circumstances are described.

  13. Optically Levitated Microspheres as a Probe for New Interactions

    Science.gov (United States)

    Rider, Alexander; Moore, David; Blakemore, Charles; Lu, Marie; Gratta, Giorgio

    2016-03-01

    We are developing novel techniques to probe new interactions at micron distances using optically levitated dielectric microspheres. Levitated microspheres are an ideal probe for short-range interactions because they are suspended using the radiation pressure at the focus of a laser beam, which means that the microspheres can be precisely manipulated and isolated from the surrounding environment at high vacuum. We have performed a search for unknown charged particles bound within the bulk of the microspheres. Currently, we are searching for the presence of a Chameleon field postulated to explain the presence of dark energy in the universe. In the future we plan to use optically levitated microspheres to search for micron length-scale gravity like interactions that could couple between a microsphere and another mass. We will present resent results from these experiments and plans for future searches for new interactions.

  14. Beat frequency ultrasonic microsphere contrast agent detection system

    Science.gov (United States)

    Pretlow, III, Robert A. (Inventor); Yost, William T. (Inventor); Cantrell, Jr., John H. (Inventor)

    1997-01-01

    A system for and method of detecting and measuring concentrations of an ultrasonically-reflective microsphere contrast agent involving detecting non-linear sum and difference beat frequencies produced by the microspheres when two impinging signals with non-identical frequencies are combined by mixing. These beat frequencies can be used for a variety of applications such as detecting the presence of and measuring the flow rates of biological fluids and industrial liquids, including determining the concentration level of microspheres in the myocardium.

  15. Microsphere formation in droplets using antisolvent vapour precipitation technique

    OpenAIRE

    Chew, Sean Jun Liang

    2017-01-01

    In previous studies, the antisolvent vapour precipitation method has been proven to produce uniformly sized lactose microspheres (1.0 µm) from a single droplet (1.2 mm diameter) at atmospheric pressure. These types of particles have potential applications in the pharmaceutical industry, especially due to their high dissolution rate. This project looked into the possibility of using antisolvent vapour precipitation to produce microspheres from finely atomised droplets. Microspheres in the sub-...

  16. Tamper-indicating device having a glass body

    Science.gov (United States)

    Johnston, Roger G.; Garcia, Anthony R. E.

    2003-04-29

    A tamper-indicating device is described. The device has a first glass body member and a second glass body member that are attached to each other through a hasp. The glass body members of the device can be tempered. The body members can be configured with hollow volumes into which powders, microparticles, liquids, gels, or combinations thereof are sealed. The choice, the amount, and the location of these materials can produce a visible, band pattern to provide each body member with a unique fingerprint identifier, which makes it extremely difficult to repair or replace once it is damaged in order to avoid tamper detection.

  17. Intestinal absorption of PLAGA microspheres in the rat.

    Science.gov (United States)

    Damgé, C; Aprahamian, M; Marchais, H; Benoit, J P; Pinget, M

    1996-12-01

    Rhodamine B-labelled poly (DL-lactide-co-glycolide) (PLAGA) microspheres of 2 different sizes, 1-5 microns and 5-10 microns, were administered as a single dose (1.44 x 10(9) and 1.83 x 10(8) particles, respectively) into the ileal lumen of adult rats. The content of rhodamine in the mesenteric vein and ileal lumen was analysed periodically from 10 min to 48 h as well as the distribution of microspheres in the intestinal mucosa and various other tissues. The concentration of rhodamine decreased progressively in the intestinal lumen and was negligible after 24 h. The number of microspheres in the mesenteric vein increased rapidly and reached a maximum after 4 h whatever the size of the particles. It then decreased progressively, but more rapidly with microspheres > 5 microns than with microspheres PLAGA microspheres mainly crossed the intestinal mucosa at the site of Peyer's patches where microspheres of 5 microns were retained in the ileal lumen. A few small microspheres were occasionally observed in the epithelial cells. Only the smallest particles were recovered in the liver, lymph nodes and spleen while basement membranes were always labelled. It is concluded that PLAGA microspheres could be useful for the oral delivery of antigens if their size is between 1 and 5 microns.

  18. Preparation of porous zirconia microspheres by internal gelation method

    International Nuclear Information System (INIS)

    Pathak, Sachin S.; Pius, I.C.; Bhanushali, R.D.; Rao, T.V. Vittal; Mukerjee, S.K.

    2008-01-01

    A modified internal gelation process for the preparation of porous zirconia microspheres has been developed. The conventional method has been modified by adding a surfactant in the feed broth. The effects of variation of surfactant concentration, washing techniques and temperature of calcination on the pore volume and the surface area of the microspheres have been studied. The conditions were optimized to obtain porous stable microspheres suitable for various applications. The microspheres were characterized by surface area analysis, pore volume analysis, thermogravimetric analysis and X-ray diffraction. The ion exchange behavior was studied using pH titration

  19. Microsphere based improved sunscreen formulation of ethylhexyl methoxycinnamate.

    Science.gov (United States)

    Gogna, Deepak; Jain, Sunil K; Yadav, Awesh K; Agrawal, G P

    2007-04-01

    Polymethylmethacrylate (PMMA) microspheres of ethylhexyl methoxycinnamate (EHM) were prepared by emulsion solvent evaporation method to improve its photostability and effectiveness as sunscreening agent. Process parameters like stirring speed and aqueous polyvinyl alcohol (PVA) concentration were analyzed in order to optimize the formulations. Shape and surface morphology of the microspheres were examined using scanning electron microscopy. Particle size of the microspheres was determined using laser diffraction particle size analyzer. The PMMA microspheres of EHM were incorporated in water-removable cream base. The in vitro drug release of EHM in pH 7.4 was performed using dialysis membrane. Thin layer chromatography was performed to determine photostability of EHM inside the microspheres. The formulations were evaluated for sun protection factor (SPF) and minimum erythema dose (MED) in albino rats. Cream base formulation containing microspheres prepared using EHM:PMMA in ratio of 1:3 (C(3)) showed slowest drug (EHM) release and those prepared with EHM: PMMA in ratio of 1:1 showed fastest release. The cream base formulations containing EHM loaded microspheres had shown better SPF (more than 16.0) as compared to formulation C(d) that contained 3% free EHM as sunscreen agent and showed SPF 4.66. These studies revealed that the incorporation of EHM loaded PMMA microspheres into cream base had greatly increased the efficacy of sunscreen formulation approximately four times. Further, photostability was also shown to be improved in PMMA microspheres.

  20. Enhanced photovoltaic performance utilizing effective charge transfers and light scattering effects by the combination of mesoporous, hollow 3D-ZnO along with 1D-ZnO in CdS quantum dot sensitized solar cells.

    Science.gov (United States)

    Chetia, Tridip Ranjan; Barpuzary, Dipankar; Qureshi, Mohammad

    2014-05-28

    A combination of 3-dimensional (3D) hollow mesoporous ZnO microspheres (ZnO HMSP) and vertically grown one-dimensional ZnO nanowires (1D ZnO NWs) on a fluorine doped tin oxide (FTO) coated glass substrate has been investigated as a photoanode for a CdS quantum dot-sensitized solar cell (QSSC). A comparative study of the photovoltaic performance of the solar cell with devices fabricated with pristine ZnO HMSPs and ZnO NWs was carried out. The proposed photovoltaic device exhibits an enhancement in power conversion efficiency (PCE) upto ∼74% and ∼35%, as compared to the 1D ZnO NW and ZnO HMSP based solar cells. The maximum incident photon-to-current conversion efficiency (IPCE) for the solar cell was observed to be ∼40%, whereas for the devices fabricated with bare ZnO HMSP and ZnO NW the IPCE were only ∼32% and ∼19%, respectively. The enhanced photovoltaic performance of the solar cell is attributed to the high Brunauer-Emmett-Teller (BET) surface area, efficient light-scattering effects and facilitated diffusion of the electrolyte for better functioning of the redox couple (S(2-)/Sn(2-)) in the hybrid photoanode. Moreover, a faster electron transport through 1D ZnO NWs provides better charge collection from the photoactive layer, which leads to an increase in the short circuit current density of the device. The present study highlights the design and development of a new hybrid photoanode for solar harvesting.

  1. Histological Comparison of Kidney Tissue Following Radioembolization with Yttrium-90 Resin Microspheres and Embolization with Bland Microspheres

    Energy Technology Data Exchange (ETDEWEB)

    Silva, Suresh de, E-mail: suresh.desilva@unsw.edu.au [Southern Radiology Group, Radiology Department Sutherland Hospital (Australia); Mackie, Simon [Western General Hospital, Department of Urology (United Kingdom); Aslan, Peter [St George Hospital, Department of Urology (Australia); Cade, David [Sirtex Technology Pty Ltd (Australia); Delprado, Warick [Douglass Hanly Moir Pathology (Australia)

    2016-12-15

    BackgroundIntra-arterial brachytherapy with yttrium-90 ({sup 90}Y) resin microspheres (radioembolization) is a procedure to selectively deliver high-dose radiation to tumors. The purpose of this research was to compare the radioembolic effect of {sup 90}Y-radioembolization versus the embolic effect of bland microspheres in the porcine kidney model.MethodsIn each of six pigs, ~25–33 % of the kidney volume was embolized with {sup 90}Y resin microspheres and an equivalent number of bland microspheres in the contralateral kidney. Kidney volume was estimated visually from contrast-enhanced fluoroscopy imaging. Morphologic and histologic analysis was performed 8–9 weeks after the procedure to assess the locations of the microspheres and extent of tissue necrosis from {sup 90}Y-radioembolization and bland embolization. A semi-quantified evaluation of the non-acute peri-particle and perivascular tissue reaction was conducted. All guidelines for the care and use of animals were followed.ResultsKidneys embolized with {sup 90}Y-radioembolization decreased in mass by 30–70 % versus the contralateral kidney embolized with bland microspheres. These kidneys showed significant necrosis/fibrosis, avascularization, and glomerular atrophy in the immediate vicinity of the {sup 90}Y resin microspheres. By contrast, glomerular changes were not observed, even with clusters of bland microspheres in afferent arterioles. Evidence of a foreign body reaction was recorded in some kidneys with bland microspheres, and subcapsular scarring/infarction only with the highest load (4.96 × 10{sup 6}) of bland microspheres.ConclusionThis study showed that radioembolization with {sup 90}Y resin microspheres produces localized necrosis/fibrosis and loss of kidney mass in a porcine kidney model. This result supports the study of {sup 90}Y resin microspheres for the localized treatment of kidney tumors.

  2. A novel route for synthesis and growth formation of metal oxides microspheres: Insights from V_2O_3 microspheres

    International Nuclear Information System (INIS)

    Zhang, Yifu; Huang, Chi; Meng, Changgong; Hu, Tao

    2016-01-01

    Highly polydisperse V_2O_3 solid microspheres with large specific surface area were successfully synthesized via a facile hydrothermal decomposition of VOC_2O_4 solution. The morphology and composition were characterized by scanning electron microscopy (SEM), Energy dispersive spectrometer (EDS), X-ray photoelectron spectroscopy (XPS) and X-ray diffraction (XRD). V_2O_3 microspheres display an obvious Mott phase transition at −128.5 °C (cooling curve) and −114.5 °C (heating curve). Some parameters including the reaction temperature, concentration of VOC_2O_4, reaction time, surfactant, H_2C_2O_4 and precursor were briefly discussed to reveal the formation of V_2O_3 microspheres. It was found that the precursor is crucial for the fabrication of microsphere. A self-assembly growth mechanism was suggested to explain the growth process of microspheres and the autogenic CO and CO_2 gas served as the soft templates. Furthermore, this route was developed to synthesize different metal oxides microspheres, and it was found that AlO(OH), Fe_3O_4, Fe_2O_3, Co_3O_4, Cr_2O_3, MoO_2 and WO_3 microspheres were obtained. All the results showed this process was successfully explored as a methodology to synthesize different metal oxides microspheres using the gas as the templates by this facile hydrothermal route. - Highlights: • Highly uniform V_2O_3 solid microspheres were synthesized. • V_2O_3 microspheres display an obvious Mott phase transition. • The autogenic CO and CO_2 gas served as the soft templates for designed synthesis. • AlO(OH), Fe_3O_4, Fe_2O_3, Co_3O_4, Cr_2O_3, MoO_2 and WO_3 microspheres were obtained. • A methodology to synthesize different metal oxides microspheres was developed.

  3. Histological Comparison of Kidney Tissue Following Radioembolization with Yttrium-90 Resin Microspheres and Embolization with Bland Microspheres

    International Nuclear Information System (INIS)

    Silva, Suresh de; Mackie, Simon; Aslan, Peter; Cade, David; Delprado, Warick

    2016-01-01

    BackgroundIntra-arterial brachytherapy with yttrium-90 ("9"0Y) resin microspheres (radioembolization) is a procedure to selectively deliver high-dose radiation to tumors. The purpose of this research was to compare the radioembolic effect of "9"0Y-radioembolization versus the embolic effect of bland microspheres in the porcine kidney model.MethodsIn each of six pigs, ~25–33 % of the kidney volume was embolized with "9"0Y resin microspheres and an equivalent number of bland microspheres in the contralateral kidney. Kidney volume was estimated visually from contrast-enhanced fluoroscopy imaging. Morphologic and histologic analysis was performed 8–9 weeks after the procedure to assess the locations of the microspheres and extent of tissue necrosis from "9"0Y-radioembolization and bland embolization. A semi-quantified evaluation of the non-acute peri-particle and perivascular tissue reaction was conducted. All guidelines for the care and use of animals were followed.ResultsKidneys embolized with "9"0Y-radioembolization decreased in mass by 30–70 % versus the contralateral kidney embolized with bland microspheres. These kidneys showed significant necrosis/fibrosis, avascularization, and glomerular atrophy in the immediate vicinity of the "9"0Y resin microspheres. By contrast, glomerular changes were not observed, even with clusters of bland microspheres in afferent arterioles. Evidence of a foreign body reaction was recorded in some kidneys with bland microspheres, and subcapsular scarring/infarction only with the highest load (4.96 × 10"6) of bland microspheres.ConclusionThis study showed that radioembolization with "9"0Y resin microspheres produces localized necrosis/fibrosis and loss of kidney mass in a porcine kidney model. This result supports the study of "9"0Y resin microspheres for the localized treatment of kidney tumors.

  4. Optical Microspherical Resonators for Biomedical Sensing

    Directory of Open Access Journals (Sweden)

    Giancarlo C. Righini

    2011-01-01

    Full Text Available Optical resonators play an ubiquitous role in modern optics. A particular class of optical resonators is constituted by spherical dielectric structures, where optical rays are total internal reflected. Due to minimal reflection losses and to potentially very low material absorption, these guided modes, known as whispering gallery modes, can confer the resonator an exceptionally high quality factor Q, leading to high energy density, narrow resonant-wavelength lines and a lengthy cavity ringdown. These attractive characteristics make these miniaturized optical resonators especially suited as laser cavities and resonant filters, but also as very sensitive sensors. First, a brief analysis is presented of the characteristics of microspherical resonators, of their fabrication methods, and of the light coupling techniques. Then, we attempt to overview some of the recent advances in the development of microspherical biosensors, underlining a number of important applications in the biomedical field.

  5. Aptamer Based Microsphere Biosensor for Thrombin Detection

    Directory of Open Access Journals (Sweden)

    Xudong Fan

    2006-08-01

    Full Text Available We have developed an optical microsphere resonator biosensor using aptamer asreceptor for the measurement of the important biomolecule thrombin. The sphere surface ismodified with anti-thrombin aptamer, which has excellent binding affinity and selectivityfor thrombin. Binding of the thrombin at the sphere surface is monitored by the spectralposition of the microsphere’s whispering gallery mode resonances. A detection limit on theorder of 1 NIH Unit/mL is demonstrated. Control experiments with non-aptameroligonucleotide and BSA are also carried out to confirm the specific binding betweenaptamer and thrombin. We expect that this demonstration will lead to the development ofhighly sensitive biomarker sensors based on aptamer with lower cost and higher throughputthan current technology.

  6. GLASS BOX

    National Research Council Canada - National Science Library

    Curtis, Laura

    2008-01-01

    The goals of this effort were to develop Glass Box capabilities to allow for the capturing of analyst activities and the associated data resources, track and log the results of automated processing...

  7. Three-dimensional graphene-polyaniline hybrid hollow spheres by layer-by-layer assembly for application in supercapacitor

    International Nuclear Information System (INIS)

    Luo, Jing; Ma, Qiang; Gu, Huahao; Zheng, Yuan; Liu, Xiaoya

    2015-01-01

    Highlights: •A graphene-polyaniline (GR-PANI) hybrid hollow sphere is fabricated by layer-by-layer (LBL) assembly technique. •The GR-PANI hollow sphere has higher specific capacitance than stacked GR-PANI LBL film. •64% of its initial capacitance is maintained with the current density increased from 0.5 to 20 A g −1 . •A high capacity retention rate of 83% after 1000 cycles can be achieved. -- Abstract: A novel kind of three-dimensional graphene-polyaniline hybrid hollow sphere (RGO-PANI HS) has been prepared via layer-by-layer (LBL) assembly of negatively-charged reduced graphene oxide (RGO) and positively charged polyaniline (PANI) on polystyrene (PS) microsphere, followed by the removal of the PS template. The hollow structure of the obtained RGO-PANI HS is confirmed by transmission electron microscopy (TEM). When used as the electrode materials for supercapacitor, the specific capacitance of the RGO-PANI HS reaches 381 F/g at a current density of 4.0 A/g, which is much higher than 251 F/g of the stacked RGO-PANI LBL film. The higher specific capacitance of RGO-PANI HS should be attributed to its unique hollow structure which provides a larger accessible surface area and facilitate the charge and ion transport. In addition, its specific capacitance can be facilely tailored by changing the assembly cycle number. Furthermore, good cycling stability is also demonstrated with 83% of the original capacitance value maintained after 1000 charging/discharging cycles

  8. Hollow Micro-/Nanostructures: Synthesis and Applications

    KAUST Repository

    Lou, Xiong Wen (David)

    2008-11-03

    Hollow micro-nanostructures are of great interest in many current and emerging areas of technology. Perhaps the best-known example of the former is the use of fly-ash hollow particles generated from coal power plants as partial replacement for Portland cement, to produce concrete with enhanced strength and durability. This review is devoted to the progress made in the last decade in synthesis and applications of hollow micro-nanostructures. We present a comprehensive overview of synthetic strategies for hollow structures. These strategies are broadly categorized into four themes, which include well-established approaches, such as conventional hard-templating and soft-templating methods, as well as newly emerging methods based on sacrificial templating and template-free synthesis. Success in each has inspired multiple variations that continue to drive the rapid evolution of the field. The Review therefore focuses on the fundamentals of each process, pointing out advantages and disadvantages where appropriate. Strategies for generating more complex hollow structures, such as rattle-type and nonspherical hollow structures, are also discussed. Applications of hollow structures in lithium batteries, catalysis and sensing, and biomedical applications are reviewed. © 2008 WILEY-VCH Verlag GmbH & Co. KGaA,.

  9. STRUCTURING OF DIAMOND FILMS USING MICROSPHERE LITHOGRAPHY

    Directory of Open Access Journals (Sweden)

    Mária Domonkos

    2014-10-01

    Full Text Available In this study, the structuring of micro- and nanocrystalline diamond thin films is demonstrated. The structuring of the diamond films is performed using the technique of microsphere lithography followed by reactive ion etching. Specifically, this paper presents a four-step fabrication process: diamond deposition (microwave plasma assisted chemical vapor deposition, mask preparation (by the standard Langmuir-Blodgett method, mask modification and diamond etching. A self-assembled monolayer of monodisperse polystyrene (PS microspheres with close-packed ordering is used as the primary template. Then the PS microspheres and the diamond films are processed in capacitively coupled radiofrequency plasma  using different plasma chemistries. This fabrication method illustrates the preparation of large arrays of periodic and homogeneous hillock-like structures. The surface morphology of processed diamond films is characterized by scanning electron microscopy and atomic force microscope. The potential applications of such diamond structures in various fields of nanotechnology are also briefly discussed.

  10. Yttrium-90 microsphere induced gastrointestinal tract ulceration

    Directory of Open Access Journals (Sweden)

    Rikabi Ali A

    2008-09-01

    Full Text Available Abstract Background Radiomicrosphere therapy (RT utilizing yttrium-90 (90Y microspheres has been shown to be an effective regional treatment for primary and secondary hepatic malignancies. We sought to determine a large academic institution's experience regarding the extent and frequency of gastrointestinal complications. Methods Between 2004 and 2007, 27 patients underwent RT for primary or secondary hepatic malignancies. Charts were subsequently reviewed to determine the incidence and severity of GI ulceration. Results Three patients presented with gastrointestinal bleeding and underwent upper endoscopy. Review of the pretreatment angiograms showed normal vascular anatomy in one patient, sclerosed hepatic vasculature in a patient who had undergone prior chemoembolization in a second, and an aberrant left hepatic artery in a third. None had undergone prophylactic gastroduodenal artery embolization. Endoscopic findings included erythema, mucosal erosions, and large gastric ulcers. Microspheres were visible on endoscopic biopsy. In two patients, gastric ulcers were persistent at the time of repeat endoscopy 1–4 months later despite proton pump inhibitor therapy. One elderly patient who refused surgical intervention died from recurrent hemorrhage. Conclusion Gastrointestinal ulceration is a known yet rarely reported complication of 90Y microsphere embolization with potentially life-threatening consequences. Once diagnosed, refractory ulcers should be considered for aggressive surgical management.

  11. Adsorption behavior of protein onto siloxane microspheres

    Energy Technology Data Exchange (ETDEWEB)

    Liu Bailing [Chengdu Institute of Organic Chemistry, Graduate School of CAS, Chinese Academy of Sciences, Chengdu 610041 (China)]. E-mail: Blliuchem@hotmail.com; Cao Shunsheng [Chengdu Institute of Organic Chemistry, Graduate School of CAS, Chinese Academy of Sciences, Chengdu 610041 (China); Deng Xiaobo [Chengdu Institute of Organic Chemistry, Graduate School of CAS, Chinese Academy of Sciences, Chengdu 610041 (China); Li Songjun [Chengdu Institute of Organic Chemistry, Graduate School of CAS, Chinese Academy of Sciences, Chengdu 610041 (China); Luo Rong [Chengdu Institute of Organic Chemistry, Graduate School of CAS, Chinese Academy of Sciences, Chengdu 610041 (China)

    2006-09-15

    The siloxane microspheres with core-shell structure (PMMA/PMPS) (MMA, methyl methacrylate; MPS, 3-methacryloxypropyl-trimethoxysilane) have been prepared by dispersion polymerization as described in our previous work. In this paper, the developed poly(MMA-MPS) microspheres, as a carrier, are used to investigate the adsorption behavior of bovine serum albumin (BSA) on them. The Langmuir and Freundlich models have been applied to describe the adsorption behavior. The experimental results indicated that the presence of PMPS evidently increases the adsorption rate and the amount of protein, and it also influences the interaction of BSA molecules. The adsorption of BSA on the poly(MMA-MPS) microspheres seems to be sensitive to pH and ionic strength. The fittings curves from Langmuir and Freundlich models showed that the adsorption was actually more complicated than ideal situation because one or more interactions were involved in the process. For understanding the electronic contribution, the Zeta potential was used to measure the reactive system before and after protein adsorption.

  12. Adsorption behavior of protein onto siloxane microspheres

    International Nuclear Information System (INIS)

    Liu Bailing; Cao Shunsheng; Deng Xiaobo; Li Songjun; Luo Rong

    2006-01-01

    The siloxane microspheres with core-shell structure (PMMA/PMPS) (MMA, methyl methacrylate; MPS, 3-methacryloxypropyl-trimethoxysilane) have been prepared by dispersion polymerization as described in our previous work. In this paper, the developed poly(MMA-MPS) microspheres, as a carrier, are used to investigate the adsorption behavior of bovine serum albumin (BSA) on them. The Langmuir and Freundlich models have been applied to describe the adsorption behavior. The experimental results indicated that the presence of PMPS evidently increases the adsorption rate and the amount of protein, and it also influences the interaction of BSA molecules. The adsorption of BSA on the poly(MMA-MPS) microspheres seems to be sensitive to pH and ionic strength. The fittings curves from Langmuir and Freundlich models showed that the adsorption was actually more complicated than ideal situation because one or more interactions were involved in the process. For understanding the electronic contribution, the Zeta potential was used to measure the reactive system before and after protein adsorption

  13. Glass Masonry - Experimental Verification of Bed Joint under Shear

    Science.gov (United States)

    Fíla, J.; Eliášová, M.; Sokol, Z.

    2017-10-01

    Glass is considered as a traditional material for building industry but was mostly used for glazing of the windows. At present, glass is an integral part of contemporary architecture where glass structural elements such as beams, stairs, railing ribs or columns became popular in the last two decades. However, using glass as structural material started at the beginning of 20th century, when masonry from hollow glass blocks were used. Using solid glass brick is very rare and only a few structures with solid glass bricks walls have been built in the last years. Pillars and walls made from solid glass bricks are mainly loaded by compression and/or bending from the eccentricity of vertical load or wind load. Due to high compressive strength of glass, the limiting factor of the glass masonry is the joint between the glass bricks as the smooth surface requires another type of mortar / glue compared to traditional masonry. Shear resistance and failure modes of brick bed joint was determined during series of tests using various mortars, two types of surface treatment and different thickness of the mortar joint. Shear tests were completed by small scale tests for mortar - determination of flexural and compressive strength of hardened mortar.

  14. Study of the spheroidization process of glass particles for selective internal radiotherapy

    International Nuclear Information System (INIS)

    Barros Filho, Eraldo Cordeiro

    2012-01-01

    The selective internal radiotherapy is an alternative method to treat hepatocellular carcinoma. Glass microspheres containing radionuclides are introduced in the liver through the hepatic artery, and they are housed preferentially in the region where the cancer cells are located. The microspheres are trapped in the arterioles which feed the tumors, and the β - particles annihilate the cancer cells. When these particles simultaneously emit γ rays, they can also be used to provide images of the tumor. The glass particles must be spherical to avoid unnecessary bleeding, and the particle size must be restricted to a range which is appropriated to trap them and avoid the migration to other parts of the body. Furthermore, they must have a good chemical durability and be nontoxic. The particle size distribution of microspheres is not easily predicted based on the original irregular particles since the variation of the aspect ratio and the presence of agglomerates can influence the final result. In the present work, the spheroidization process to obtain microspheres for radiotherapy treatment was studied. The glass microspheres were characterized by X-rays diffraction, Energy Dispersive X-rays Fluorescence Spectroscopy, Differential Scanning Calorimetry, Specific Superficial Area and cytotoxicity test. The dissolution rate in distilled water at 90 degree C (DR∼10 -8 g.cm - 2.min -1 ), density (2.79g.cm -3 ), viscosity, and size particle distribution were determined. The surface morphological aspect was evaluated by Scanning Electron Microscopy before and after the chemical durability tests in SBF and after the neutron irradiation. It is proposed that the produced material should be sieved to select the most suitable microspheres

  15. Microring embedded hollow polymer fiber laser

    Energy Technology Data Exchange (ETDEWEB)

    Linslal, C. L., E-mail: linslal@gmail.com; Sebastian, S.; Mathew, S.; Radhakrishnan, P.; Nampoori, V. P. N.; Girijavallabhan, C. P.; Kailasnath, M. [International School of Photonics, Cochin University of Science and Technology, Cochin 22 (India)

    2015-03-30

    Strongly modulated laser emission has been observed from rhodamine B doped microring resonator embedded in a hollow polymer optical fiber by transverse optical pumping. The microring resonator is fabricated on the inner wall of a hollow polymer fiber. Highly sharp lasing lines, strong mode selection, and a collimated laser beam are observed from the fiber. Nearly single mode lasing with a side mode suppression ratio of up to 11.8 dB is obtained from the strongly modulated lasing spectrum. The microring embedded hollow polymer fiber laser has shown efficient lasing characteristics even at a propagation length of 1.5 m.

  16. Hepatic vein tumor thrombus as a risk factor for excessive pulmonary deposition of microspheres during TheraSphere therapy for unresectable hepatocellular carcinoma.

    Science.gov (United States)

    Fleming, Chad J; Andrews, James C; Wiseman, Gregory A; Gansen, Denise N; Roberts, Lewis R

    2009-11-01

    To evaluate the impact of identifiable hepatic vein tumor thrombus on the ability to safely deliver TheraSphere (yttrium 90-containing glass microspheres) for the treatment of hepatocellular carcinoma (HCC). A retrospective review was performed of 87 patients (71 men, 16 women; mean age, 64.5 years; age range, 25-83 y) referred for TheraSphere therapy for HCC during a 2-year period between April 2005 and May 2007. Evaluation included contrast-enhanced computed tomography or magnetic resonance imaging, selective mesenteric angiography, and radionuclide perfusion scintigraphy to measure the arteriovenous shunting through the tumor. Of the 87 patients, 83 underwent angiography and perfusion scintigraphy; 53 were ultimately treated with 65 glass microsphere infusions. Twelve of 83 were identified as having tumor thrombus in a hepatic vein or extending into the inferior vena cava. The mean lung shunt for the patients with hepatic vein tumor thrombus was 30% (range, 11%-60%), compared with 8.2% (range, 3%-23%) for patients without identifiable tumor thrombus. Two of the 12 patients were treated with reduced doses of glass microspheres, and the remaining 10 were offered alternative therapies. The presence of hepatic vein tumor thrombus is a risk factor for an increased lung shunt that may prohibit delivery of a therapeutic dose of TheraSphere to hepatic tumor.

  17. Controlling silk fibroin microspheres via molecular weight distribution

    International Nuclear Information System (INIS)

    Zeng, Dong-Mei; Pan, Jue-Jing; Wang, Qun; Liu, Xin-Fang; Wang, Hui; Zhang, Ke-Qin

    2015-01-01

    Silk fibroin (SF) microspheres were produced by salting out SF solution via the addition of potassium phosphate buffer solution (K 2 HPO 4 –KH 2 PO 4 ). The morphology, size and polydispersity of SF microspheres were adjusted by changing the molecular weight (MW) distribution and concentration of SF, as well as the ionic strength and pH of the buffer solution. Changing the conditions under which the SF fiber dissolved in the Lithium Boride (LiBr) solution resulted in altering the MW distribution of SF solution. Under optimal salting-out conditions (ionic strength > 0.7 M and pH > 7) and using a smaller and narrower SF MW distribution, SF microspheres with smoother shapes and more uniform sizes were produced. Meanwhile, the size and polydispersity of the microspheres increased when the SF concentration was increased from 0.25 mg/mL to 20 mg/mL. The improved SF microspheres, obtained by altering the distribution of molecular weight, have potential in drug and gene delivery applications. - Highlights: • MW distribution was changed by applying different dissolving methods of SF fiber. • Smaller and narrower MW distribution improves the quality of SF microspheres. • Size and polydispersity of microspheres increase as SF concentration increases. • Improved SF microspheres have potential in drug and gene delivery applications

  18. Toward quantum-limited position measurements using optically levitated microspheres

    International Nuclear Information System (INIS)

    Libbrecht, Kenneth G.; Black, Eric D.

    2004-01-01

    We propose the use of optically levitated microspheres as test masses in experiments aimed at reaching and potentially exceeding the standard quantum limit for position measurements. Optically levitated microspheres have low mass and are essentially free of suspension thermal noise, making them well suited for experimentally testing our understanding of quantum-limited measurements

  19. Toward quantum-limited position measurements using optically levitated microspheres

    Energy Technology Data Exchange (ETDEWEB)

    Libbrecht, Kenneth G.; Black, Eric D

    2004-01-26

    We propose the use of optically levitated microspheres as test masses in experiments aimed at reaching and potentially exceeding the standard quantum limit for position measurements. Optically levitated microspheres have low mass and are essentially free of suspension thermal noise, making them well suited for experimentally testing our understanding of quantum-limited measurements.

  20. Development and evaluation of floating microspheres of curcumin in ...

    African Journals Online (AJOL)

    Purpose: To prepare and evaluate floating microspheres of curcumin for prolonged gastric residence and to study their effect on alloxan-induced diabetic rats. Methods: Floating microsphere were prepared by emulsion-solvent diffusion method, using hydroxylpropyl methylcellulose, chitosan and Eudragit S 100 polymer in ...

  1. Development and Evaluation of Floating Microspheres of Curcumin ...

    African Journals Online (AJOL)

    Purpose: To prepare and evaluate floating microspheres of curcumin for prolonged gastric residence time and increased drug bioavailability. Methods: Floating microsphere were prepared by emulsion solvent diffusion method, using hydroxylpropyl methylcellulose (HPMC), ethyl cellulose (EC), Eudragit S 100 polymer in ...

  2. PLGA and PHBV Microsphere Formulations and Solid-State Characterization

    DEFF Research Database (Denmark)

    Yang, Chiming; Plackett, David; Needham, David

    2009-01-01

    To develop and characterize the solid-state properties of poly(DL-lactic-co-glycolic acid) (PLGA) and poly(3-hydroxybutyric acid-co-3-hydroxyvaleric acid) (PHBV) microspheres for the localized and controlled release of fusidic acid (FA). The effects of FA loading and polymer composition on the me...... of a DCM-FA-rich phase in the forming microsphere....

  3. Preparation of mesoporous zirconia microspheres as inert matrix

    Energy Technology Data Exchange (ETDEWEB)

    Guo, Ting [State Key Laboratory of New Ceramics and Fine Processing, Institute of Nuclear and New Energy Technology, Tsinghua University, Beijing, 100084 (China); Wang, Chen; Lv, Jinlong [Beijing Key Laboratory of Fine Ceramics, Institute of Nuclear and New Energy Technology, Tsinghua University, Beijing, 100084 (China); Liang, Tongxiang, E-mail: txliang@tsinghua.edu.cn [State Key Laboratory of New Ceramics and Fine Processing, Institute of Nuclear and New Energy Technology, Tsinghua University, Beijing, 100084 (China)

    2016-12-01

    Mesoporous zirconia microspheres, with a diameter of 900 μm, were prepared as an inert accelerator driven system (ADS) transmutation element matrix by the sol-gel method. The purpose of mesopores is to improve the adsorption capacity of inert matrix fuel (IMF) for minor actinides. The study indicated that the mesoporous zirconia performance was improved after the microspheres were hydrothermally treated at 150 °C, the specific surface area increased from 28.29 m{sup 2}/g to 61.28 m{sup 2}/g, and hydrothermal treatment avoided the cracking of the microspheres. Pre-decomposition of the organics during the hydrothermal process stabilized the mesoporous structure. The average pore diameter of mesoporous microsphere was 14.3 nm. - Highlights: • Mesoporous zirconia microspheres with a diameter of 900 μm were prepared as ADS transmutation element inert matrix. • The mesoporous performance was improved after the microspheres were hydrothermally treated at 150 °C. • The specific surface area increased from 28.29 m{sup 2}/g to 61.28 m{sup 2}/g. • The hydrothermal treatment could avoid the cracking of the microspheres. • The specific surface area of mesoporous microsphere was 61.28 m{sup 2}/g and the average pore diameter was 14.3 nm.

  4. Antibacterial activity of ciprofloxacin-loaded zein microsphere films

    International Nuclear Information System (INIS)

    Fu Jianxi; Wang Huajie; Zhou Yanqing; Wang Jinye

    2009-01-01

    Our aim was to produce an antibiotic-emitting coating composed of zein microspheres for the prevention of bacterial infection on implanted devices. Ciprofloxacin-loaded zein microspheres were prepared using a phase separation procedure, with particle sizes between 0.5 and 2 μm. Drug encapsulation and drug loading varied with the amount of both zein and ciprofloxacin, and the highest encapsulation efficiency was 8.27% (2 mg/ml ciprofloxacin and 20 mg/ml zein; n = 3). A ciprofloxacin-loaded zein microsphere film (CF-MS film) was generated via solvent evaporation. Continuous drug release from a trypsin-degraded microsphere film was observed for up to 28 days. The liberation of ciprofloxacin from the trypsin-degraded film and the biodegradation of the microsphere film were highly correlated. Proliferation assay of the growth of human umbilical vein endothelial cells (HUVECs) by the MTT method showed that the microsphere film had no toxicity when compared with cells grown on Corning culture plates alone and plates with a zein film alone. Quantification of bacteria adhesion showed that adhesion on the microsphere film is significantly suppressed. In addition, according to the results of bacterial growth tests, ciprofloxacin-loaded microsphere films maintained antibacterial activity for more than 6 days. In contrast, a control medium containing a zein film allowed constant bacterial growth. These results indicate that CF-MS films might be useful as antibacterial films on implanted devices.

  5. Apparatus for manufacturing ceramics microspheres for cementing applications

    NARCIS (Netherlands)

    2012-01-01

    A method and apparatus for manufacturing ceramic microspheres from industrial slag. The micro spheres have a particle size of about 38 microns to about 150 microns. The microspheres are used to create a cement slurry having a density of at least about Illbs/g. The resultant cement slurry may then be

  6. Controlling silk fibroin microspheres via molecular weight distribution

    Energy Technology Data Exchange (ETDEWEB)

    Zeng, Dong-Mei; Pan, Jue-Jing; Wang, Qun; Liu, Xin-Fang; Wang, Hui [National Engineering Laboratory for Modern Silk, College for Textile and Clothing Engineering, Soochow University, Suzhou, Jiangsu 215123 (China); Zhang, Ke-Qin, E-mail: kqzhang@suda.edu.cn [National Engineering Laboratory for Modern Silk, College for Textile and Clothing Engineering, Soochow University, Suzhou, Jiangsu 215123 (China); Research Center of Cooperative Innovation for Functional Organic/Polymer Material Micro/Nanofabrication, Soochow University, Suzhou, Jiangsu 215123 (China)

    2015-05-01

    Silk fibroin (SF) microspheres were produced by salting out SF solution via the addition of potassium phosphate buffer solution (K{sub 2}HPO{sub 4}–KH{sub 2}PO{sub 4}). The morphology, size and polydispersity of SF microspheres were adjusted by changing the molecular weight (MW) distribution and concentration of SF, as well as the ionic strength and pH of the buffer solution. Changing the conditions under which the SF fiber dissolved in the Lithium Boride (LiBr) solution resulted in altering the MW distribution of SF solution. Under optimal salting-out conditions (ionic strength > 0.7 M and pH > 7) and using a smaller and narrower SF MW distribution, SF microspheres with smoother shapes and more uniform sizes were produced. Meanwhile, the size and polydispersity of the microspheres increased when the SF concentration was increased from 0.25 mg/mL to 20 mg/mL. The improved SF microspheres, obtained by altering the distribution of molecular weight, have potential in drug and gene delivery applications. - Highlights: • MW distribution was changed by applying different dissolving methods of SF fiber. • Smaller and narrower MW distribution improves the quality of SF microspheres. • Size and polydispersity of microspheres increase as SF concentration increases. • Improved SF microspheres have potential in drug and gene delivery applications.

  7. Antibacterial activity of ciprofloxacin-loaded zein microsphere films

    Energy Technology Data Exchange (ETDEWEB)

    Fu Jianxi [Shanghai Institute of Organic Chemistry, Chinese Academy of Sciences, 354 Fenglin Road, Shanghai 200032 (China); Henan Normal University, 46 East Construction Road, Xinxiang, Henan 453007 (China); Wang Huajie [College of Life Science and Biotechnology, Shanghai Jiao Tong University, 1954 Huashan Road, Shanghai 200030 (China); Zhou Yanqing [Henan Normal University, 46 East Construction Road, Xinxiang, Henan 453007 (China); Wang Jinye, E-mail: jywang@mail.sioc.ac.cn [Shanghai Institute of Organic Chemistry, Chinese Academy of Sciences, 354 Fenglin Road, Shanghai 200032 (China); College of Life Science and Biotechnology, Shanghai Jiao Tong University, 1954 Huashan Road, Shanghai 200030 (China)

    2009-05-05

    Our aim was to produce an antibiotic-emitting coating composed of zein microspheres for the prevention of bacterial infection on implanted devices. Ciprofloxacin-loaded zein microspheres were prepared using a phase separation procedure, with particle sizes between 0.5 and 2 {mu}m. Drug encapsulation and drug loading varied with the amount of both zein and ciprofloxacin, and the highest encapsulation efficiency was 8.27% (2 mg/ml ciprofloxacin and 20 mg/ml zein; n = 3). A ciprofloxacin-loaded zein microsphere film (CF-MS film) was generated via solvent evaporation. Continuous drug release from a trypsin-degraded microsphere film was observed for up to 28 days. The liberation of ciprofloxacin from the trypsin-degraded film and the biodegradation of the microsphere film were highly correlated. Proliferation assay of the growth of human umbilical vein endothelial cells (HUVECs) by the MTT method showed that the microsphere film had no toxicity when compared with cells grown on Corning culture plates alone and plates with a zein film alone. Quantification of bacteria adhesion showed that adhesion on the microsphere film is significantly suppressed. In addition, according to the results of bacterial growth tests, ciprofloxacin-loaded microsphere films maintained antibacterial activity for more than 6 days. In contrast, a control medium containing a zein film allowed constant bacterial growth. These results indicate that CF-MS films might be useful as antibacterial films on implanted devices.

  8. Formulation and Evaluation of Microspheres Based on Gelatin ...

    African Journals Online (AJOL)

    Formulation and Evaluation of Microspheres Based on Gelatin-Mucin Admixtures for the Rectal Delivery of Cefuroxime Sodium. K C Ofokansi, M U Adikwu. Abstract. Purpose: Swellable microspheres based on polymers or their admixtures are frequently employed as drug delivery systems to achieve a controlled release ...

  9. Microspheres with Ultrahigh Holmium Content for Radioablation of Malignancies

    NARCIS (Netherlands)

    Bult, W.; Seevinck, P.R.; Krijger, G.C.; Visser, T.; Kroon-Batenburg, L.M.J.; Bakker, C.J.G.; Hennink, W.E.; van het Schip, A.D.; Nijsen, J.F.W.

    2009-01-01

    The aim of this study was to develop microspheres with an ultra high holmium content which can be neutron activated for radioablation of malignancies. These microspheres are proposed to be delivered selectively through either intratumoral injections into solid tumors or administered via an

  10. Microspheres with ultrahigh holmium content for radioablation of malignancies

    NARCIS (Netherlands)

    Bult, W; Seevinck, P R; Krijger, G C; Visser, T; Kroon-Batenburg, L M J; Bakker, C J G; Hennink, W E; van het Schip, A D; Nijsen, J F W

    PURPOSE: The aim of this study was to develop microspheres with an ultra high holmium content which can be neutron activated for radioablation of malignancies. These microspheres are proposed to be delivered selectively through either intratumoral injections into solid tumors or administered via an

  11. Microspheres with Ultrahigh Holmium Content for Radioablation of Malignancies

    NARCIS (Netherlands)

    Bult, W.; Seevinck, P.R.; Krijger, G.C.; Visser, T.; Kroon-Batenburg, L.M.J.; Bakker, C.J.G.; Hennink, W.E.; Van het Schip, A.D.; Nijsen, J.F.W.

    Purpose The aim of this study was to develop microspheres with an ultra high holmium content which can be neutron activated for radioablation of malignancies. These microspheres are proposed to be delivered selectively through either intratumoral injections into solid tumors or administered via an

  12. Modeling High Pressure Micro Hollow Cathode Discharges

    National Research Council Canada - National Science Library

    Boeuf, Jean-Pierre; Pitchford, Leanne

    2004-01-01

    This report results from a contract tasking CPAT as follows: The Grantee will perform theoretical modeling of point, surface, and volume high-pressure plasmas created using Micro Hollow Cathode Discharge sources...

  13. optimizing compressive strength characteristics of hollow building

    African Journals Online (AJOL)

    eobe

    Keywords: hollow building Blocks, granite dust, sand, partial replacement, compressive strength. 1. INTRODUCTION ... exposed to extreme climate. The physical ... Sridharan et al [13] conducted shear strength studies on soil-quarry dust.

  14. Hollow Micro-/Nanostructures: Synthesis and Applications

    KAUST Repository

    Lou, Xiong Wen (David); Archer, Lynden A.; Yang, Zichao

    2008-01-01

    for Portland cement, to produce concrete with enhanced strength and durability. This review is devoted to the progress made in the last decade in synthesis and applications of hollow micro-nanostructures. We present a comprehensive overview of synthetic

  15. Optimization of sustained release aceclofenac microspheres using response surface methodology

    Energy Technology Data Exchange (ETDEWEB)

    Deshmukh, Rameshwar K.; Naik, Jitendra B., E-mail: jitunaik@gmail.com

    2015-03-01

    Polymeric microspheres containing aceclofenac were prepared by single emulsion (oil-in-water) solvent evaporation method using response surface methodology (RSM). Microspheres were prepared by changing formulation variables such as the amount of Eudragit® RS100 and the amount of polyvinyl alcohol (PVA) by statistical experimental design in order to enhance the encapsulation efficiency (E.E.) of the microspheres. The resultant microspheres were evaluated for their size, morphology, E.E., and in vitro drug release. The amount of Eudragit® RS100 and the amount of PVA were found to be significant factors respectively for determining the E.E. of the microspheres. A linear mathematical model equation fitted to the data was used to predict the E.E. in the optimal region. Optimized formulation of microspheres was prepared using optimal process variables setting in order to evaluate the optimization capability of the models generated according to IV-optimal design. The microspheres showed high E.E. (74.14 ± 0.015% to 85.34 ± 0.011%) and suitably sustained drug release (minimum; 40% to 60%; maximum) over a period of 12 h. The optimized microspheres formulation showed E.E. of 84.87 ± 0.005 with small error value (1.39). The low magnitudes of error and the significant value of R{sup 2} in the present investigation prove the high prognostic ability of the design. The absence of interactions between drug and polymers was confirmed by Fourier transform infrared (FTIR) spectroscopy. Differential scanning calorimetry (DSC) and X-ray powder diffractometry (XRPD) revealed the dispersion of drug within microspheres formulation. The microspheres were found to be discrete, spherical with smooth surface. The results demonstrate that these microspheres could be promising delivery system to sustain the drug release and improve the E.E. thus prolong drug action and achieve the highest healing effect with minimal gastrointestinal side effects. - Highlights: • Aceclofenac microspheres

  16. Plasma generation using the hollow cathod

    International Nuclear Information System (INIS)

    Moon, K.J.

    1983-01-01

    A hollow cathode of tungsten was adapted to an University of California, Berkely, LBL bucket ion source to investigate ion density fluctuations at the extractior grid. Fluctuations in plasma ion density are observed to range between 100kHz to 2 MHz. The observed fluctuation frequencies of plasma ion density are found to be inversely proportional to the square root of ion masses. It is guessed that the plasma fluctuation are also correlated with the hollow cathode length. (Author)

  17. Adsorption characteristics of activated carbon hollow fibers

    Directory of Open Access Journals (Sweden)

    B. V. Kaludjerović

    2009-01-01

    Full Text Available Carbon hollow fibers were prepared with regenerated cellulose or polysulfone hollow fibers by chemical activation using sodium phosphate dibasic followed by the carbonization process. The activation process increases the adsorption properties of fibers which is more prominent for active carbone fibers obtained from the cellulose precursor. Chemical activation with sodium phosphate dibasic produces an active carbon material with both mesopores and micropores.

  18. Hollow cathode for positive ion sources

    International Nuclear Information System (INIS)

    Schechter, D.E.; Kim, J.; Tsai, C.C.

    1979-01-01

    Development to incorporate hollow cathodes into high power ion sources for neutral beam injection systems is being pursued. Hollow tube LaB 6 -type cathodes, similar to a UCLA design, have been constructed and tested in several ORNL ion source configurations. Results of testing include arc discharge parameters of >1000 and 500 amps for 0.5 and 10 second pulse lengths, respectively. Details of cathode construction and additional performance results are discussed

  19. Hollow-duct radiation delivery system investigation

    Directory of Open Access Journals (Sweden)

    Kramer D.

    2013-05-01

    Full Text Available Investigation of hollow-duct structure for high-power laser-diode-array radiation delivery into the end-pumped large-aperture gain media is reported. A ray tracing method has been used to evaluate the performance of the structure designed for maximum transmission efficiency and output beam profile homogeneity. Variable hollow-duct lengths as well as emanating angles of laser-diode-array have been taken into account.

  20. Preparation and Characterization of Fluorescent SiO2 Microspheres

    Science.gov (United States)

    Xu, Cui; Zhang, Hao; Guan, Ruifang

    2018-01-01

    Fluorescent compound without typical fluorophores was synthesized with citric acid (CA) and aminopropyltriethoxysilane (APTS) firstly, and then it was grafted to the surface of the prepared SiO2 microspheres by chemical reaction. The fluorescent SiO2 microspheres with good fluorescent properties were obtained by optimizing the reaction conditions. And the morphology and structure of the fluorescent SiO2 microspheres have been characterized by scanning electron microscopy (SEM) and fourier transform infrared (FTIR) spectroscopy. The results showed that the preparation of fluorescent SiO2 microspheres have good monodispersity and narrow particle size distribution. Moreover, the fluorescent SiO2 microspheres can be applied to detect Fe3+ in aqueous solution, prepare fluorescent SiO2 rubber, and have potential to be applied in the fluorescent labeling and fingerprint appearing technique fields.

  1. Study on the Degradation of Polylactide Microsphere In Vitro

    Institute of Scientific and Technical Information of China (English)

    HeYing; WeiShuli

    2001-01-01

    This report concentrated on the rules and mechanism of the degradation of polylactide and the microspheres. The rate of degradation was assessed with five methods: observation of microsphere surface morphology by SEM, determination of the weight loss of the microspheres, determination of the molecular mass of the polymers by GPC, determination of pH and determination of the contents of lactic acid by UV spectrophotometry. The degradation of polylactide microspheres showed two-phase characteristics. At the early stage of the degradation, the high molecular mass polymers were cleaved into lower molecular mass fractions and at the late stage, there was a period of erosion and weight loss of the microspheres. The degradation was much slower for polymers with a higher molecular mass. The polylactide degradation showed good regularity.

  2. Glass compositions

    Energy Technology Data Exchange (ETDEWEB)

    France, P W

    1985-05-30

    A fluoride glass for use in the production of optical fibres has an enhanced D/H ratio, preferably such that OD:OH is at least 9:1. In the example, such a glass is prepared by treating with D/sub 2/O a melt comprising 51.53 mole per cent ZrF/sub 4/, 20.47 mole per cent BaF/sub 2/, 5.27 mole per cent LaF/sub 3/, 3.24 mole per cent AlF/sub 3/, and 19.49 mole per cent LiF.

  3. Mesoporous metal oxide microsphere electrode compositions and their methods of making

    Science.gov (United States)

    Parans Paranthaman, Mariappan; Bi, Zhonghe; Bridges, Craig A.; Brown, Gilbert M.

    2017-04-11

    Compositions and methods of making are provided for treated mesoporous metal oxide microspheres electrodes. The compositions include microspheres with an average diameter between about 200 nanometers and about 10 micrometers and mesopores on the surface and interior of the microspheres. The methods of making include forming a mesoporous metal oxide microsphere composition and treating the mesoporous metal oxide microspheres by at least annealing in a reducing atmosphere, doping with an aliovalent element, and coating with a coating composition.

  4. Long pulse microsphere experiments at 3 TW

    International Nuclear Information System (INIS)

    Boyle, M.J.; Attwood, D.T.; Brooks, K.M.

    1977-01-01

    Previous 1.06 μm laser implosion experiments have explored the parameter space associated with microsphere targets of typically less than 100 psec. Exploding pusher experiments have now been performed using long pulses (100 to 200 psec FWHM), and large diameter (100 to 150 μm) targets on the 3 TW Argus laser facility. Absorption, transport, implosion and neutron and α yield characteristics are discussed and compared with earlier short pulse results. The observed neutron yields are discussed in light of the temporal mismatch between the absorption and implosion time scales imposed by the large diameter, long pulse conditions

  5. Kerr Hollow Quarry Remediation Project

    International Nuclear Information System (INIS)

    Walker, K.L.

    1993-01-01

    The Kerr Hollow Quarry is a 3-acre flooded limestone quarry located near the Y-12 Facility on the Oak Ridge Reservation. The quarry was used in the 1940s as a source of construction material for the Department of Energy in Oak Ridge, Tennessee. Its use was discontinued in the early 1950s, and it was allowed to flood with water. The quarry presently has a maximum water depth of approximately 55 ft. During the period between the early 1950s until about 1988, the quarry was used for the treatment and disposal of a variety of materials including water-reactive, alkali metals, shock-sensitive chemicals, and compressed gas cylinders. For some of these materials, the treatment consisted of dropping the vessels containing the materials into the quarry from a high bluff located on one side of the quarry. The vessels were then punctured by gun shot, and the materials were allowed to react with the water and sink to the bottom of the quarry. Very few disposal records exist for the period from 1952 to 1962. The records after that time, from 1962 until 1988, indicate some 50 t of hazardous and nonhazardous materials were disposed of in the quarry. This report documents remediation efforts that have taken place at the quarry beginning in September 1990

  6. Insulin delivery through nasal route using thiolated microspheres.

    Science.gov (United States)

    Nema, Tarang; Jain, Ashish; Jain, Aviral; Shilpi, Satish; Gulbake, Arvind; Hurkat, Pooja; Jain, Sanjay K

    2013-01-01

    The aim of the present study was to investigate the potential of developed thiolated microspheres for insulin delivery through nasal route. In the present study, cysteine was immobilized on carbopol using EDAC. A total of 269.93 µmol free thiol groups per gram polymer were determined. The prepared nonthiolated and thiolated microspheres were studied for particle shape, size, drug content, swellability, mucoadhesion and in vitro insulin release. The thiolated microspheres exhibited higher mucoadhesion due to formation of covalent bonds via disulfide bridges with the mucus gel layer. Drug permeation through goat nasal mucosa of nonthiolated and thiolated microspheres were found as 52.62 ± 2.4% and 78.85 ± 3.1% in 6 h, respectively. Thiolated microspheres bearing insulin showed better reduction in blood glucose level (BGL) in comparison to nonthiolated microspheres as 31.23 ± 2.12% and 75.25 ± 0.93% blood glucose of initial BGL were observed at 6 h after nasal delivery of thiolated and nonthiolated microspheres in streptozotocin-induced diabetic rabbits.

  7. Magnetic poly(glycidyl methacrylate) microspheres for protein capture.

    Science.gov (United States)

    Koubková, Jana; Müller, Petr; Hlídková, Helena; Plichta, Zdeněk; Proks, Vladimír; Vojtěšek, Bořivoj; Horák, Daniel

    2014-09-25

    The efficient isolation and concentration of protein antigens from complex biological samples is a critical step in several analytical methods, such as mass spectrometry, flow cytometry and immunochemistry. These techniques take advantage of magnetic microspheres as immunosorbents. The focus of this study was on the development of new superparamagnetic polymer microspheres for the specific isolation of the tumor suppressor protein p53. Monodisperse macroporous poly(glycidyl methacrylate) (PGMA) microspheres measuring approximately 5 μm and containing carboxyl groups were prepared by multistep swelling polymerization of glycidyl methacrylate (GMA), 2-[(methoxycarbonyl)methoxy]ethyl methacrylate (MCMEMA) and ethylene dimethylacrylate (EDMA) as a crosslinker in the presence of cyclohexyl acetate as a porogen. To render the microspheres magnetic, iron oxide was precipitated within their pores; the Fe content in the particles received ∼18 wt%. Nonspecific interactions between the magnetic particles and biological media were minimized by coating the microspheres with poly(ethylene glycol) (PEG) terminated by carboxyl groups. The carboxyl groups of the magnetic PGMA microspheres were conjugated with primary amino groups of mouse monoclonal DO-1 antibody using conventional carbodiimide chemistry. The efficiency of protein p53 capture and the degree of nonspecific adsorption on neat and PEG-coated magnetic microspheres were determined by western blot analysis. Copyright © 2014 Elsevier B.V. All rights reserved.

  8. Measurement of thermal diffusivity of depleted uranium metal microspheres

    Science.gov (United States)

    Humrickhouse-Helmreich, Carissa J.; Corbin, Rob; McDeavitt, Sean M.

    2014-03-01

    The high void space of nuclear fuels composed of homogeneous uranium metal microspheres may allow them to achieve ultra-high burnup by accommodating fuel swelling and reducing fuel/cladding interactions; however, the relatively low thermal conductivity of microsphere nuclear fuels may limit their application. To support the development of microsphere nuclear fuels, an apparatus was designed in a glovebox and used to measure the apparent thermal diffusivity of a packed bed of depleted uranium (DU) microspheres with argon fill in the void spaces. The developed Crucible Heater Test Assembly (CHTA) recorded radial temperature changes due to an initial heat pulse from a central thin-diameter cartridge heater. Using thermocouple positions and time-temperature data, the apparent thermal diffusivity was calculated. The thermal conductivity of the DU microspheres was calculated based on the thermal diffusivity from the CHTA, known material densities and specific heat capacities, and an assumed 70% packing density based on prior measurements. Results indicate that DU metal microspheres have very low thermal conductivity, relative to solid uranium metal, and rapidly form an oxidation layer even in a low oxygen environment. At 500 °C, the thermal conductivity of the DU metal microsphere bed was 0.431 ± 0.0560 W/m-K compared to the literature value of approximately 32 W/m-K for solid uranium metal.

  9. Measurement of thermal diffusivity of depleted uranium metal microspheres

    Energy Technology Data Exchange (ETDEWEB)

    Humrickhouse-Helmreich, Carissa J., E-mail: carissahelmreich@tamu.edu [Texas A and M University, Department of Nuclear Engineering, 337 Zachry Engineering Center, 3133 TAMU, College Station, TX 77843 (United States); Corbin, Rob, E-mail: rcorbin@terrapower.com [TerraPower, LLC, 330 120th Ave NE, Suite 100, Bellevue, WA 98005 (United States); McDeavitt, Sean M., E-mail: mcdeavitt@tamu.edu [Texas A and M University, Department of Nuclear Engineering, 337 Zachry Engineering Center, 3133 TAMU, College Station, TX 77843 (United States)

    2014-03-15

    The high void space of nuclear fuels composed of homogeneous uranium metal microspheres may allow them to achieve ultra-high burnup by accommodating fuel swelling and reducing fuel/cladding interactions; however, the relatively low thermal conductivity of microsphere nuclear fuels may limit their application. To support the development of microsphere nuclear fuels, an apparatus was designed in a glovebox and used to measure the apparent thermal diffusivity of a packed bed of depleted uranium (DU) microspheres with argon fill in the void spaces. The developed Crucible Heater Test Assembly (CHTA) recorded radial temperature changes due to an initial heat pulse from a central thin-diameter cartridge heater. Using thermocouple positions and time–temperature data, the apparent thermal diffusivity was calculated. The thermal conductivity of the DU microspheres was calculated based on the thermal diffusivity from the CHTA, known material densities and specific heat capacities, and an assumed 70% packing density based on prior measurements. Results indicate that DU metal microspheres have very low thermal conductivity, relative to solid uranium metal, and rapidly form an oxidation layer even in a low oxygen environment. At 500 °C, the thermal conductivity of the DU metal microsphere bed was 0.431 ± 0.0560 W/m-K compared to the literature value of approximately 32 W/m-K for solid uranium metal.

  10. Preparation of nano-hydroxyapatite/poly(l-lactide) biocomposite microspheres

    International Nuclear Information System (INIS)

    Qiu Xueyu; Han Yadong; Zhuang Xiuli; Chen Xuesi; Li Yuesheng; Jing Xiabin

    2007-01-01

    Nano-hydroxyapatite (HA)/poly(l-lactide) (PLLA) composite microspheres with relatively uniform size distribution were prepared by a solid-in-oil-in-water (s/o/w) emusion solvent evaporation method. The encapsulation of the HA nanopaticles in microshperes was significantly improved by grafting PLLA on the surface of the HA nanoparticles (p-HA) during emulsion process. This procedure gave a possibility to obtain p-HA/PLLA composite microspheres with uniform morphology and the encapsulated p-HA nanoparticle loading reached up to 40 wt% (33 wt% of pure HA) in the p-HA/PLLA composite microspheres. The microstructure of composite microspheres from core-shell to single phase changed with the variation of p-HA to PLLA ratios. p-HA/PLLA composite microspheres with the diameter range of 2-3 μm were obtained. The entrapment efficiency of p-HA in microspheres could high up to 90 wt% and that of HA was only 13 wt%. Surface and bulk characterizations of the composite microspheres were performed by measurements such as wide angle X-ray diffraction (WAXD), thermal gravimetric analysis (TGA), environmental scanning electron microscope (ESEM) and transmission electron microscopy (TEM)

  11. Current knowledge on biodegradable microspheres in drug delivery.

    Science.gov (United States)

    Prajapati, Vipul D; Jani, Girish K; Kapadia, Jinita R

    2015-08-01

    Biodegradable microspheres have gained popularity for delivering a wide variety of molecules via various routes. These types of products have been prepared using various natural and synthetic biodegradable polymers through suitable techniques for desired delivery of various challenging molecules. Selection of biodegradable polymers and technique play a key role in desired drug delivery. This review describes an overview of the fundamental knowledge and status of biodegradable microspheres in effective delivery of various molecules via desired routes with consideration of outlines of various compendial and non-compendial biodegradable polymers, formulation techniques and release mechanism of microspheres, patents and commercial biodegradable microspheres. There are various advantages of using biodegradable polymers including promise of development with different types of molecules. Biocompatibility, low dosage and reduced side effects are some reasons why usage biodegradable microspheres have gained in popularity. Selection of biodegradable polymers and formulation techniques to create microspheres is the biggest challenge in research. In the near future, biodegradable microspheres will become the eco-friendly product for drug delivery of various genes, hormones, proteins and peptides at specific site of body for desired periods of time.

  12. Measurement of thermal diffusivity of depleted uranium metal microspheres

    International Nuclear Information System (INIS)

    Humrickhouse-Helmreich, Carissa J.; Corbin, Rob; McDeavitt, Sean M.

    2014-01-01

    The high void space of nuclear fuels composed of homogeneous uranium metal microspheres may allow them to achieve ultra-high burnup by accommodating fuel swelling and reducing fuel/cladding interactions; however, the relatively low thermal conductivity of microsphere nuclear fuels may limit their application. To support the development of microsphere nuclear fuels, an apparatus was designed in a glovebox and used to measure the apparent thermal diffusivity of a packed bed of depleted uranium (DU) microspheres with argon fill in the void spaces. The developed Crucible Heater Test Assembly (CHTA) recorded radial temperature changes due to an initial heat pulse from a central thin-diameter cartridge heater. Using thermocouple positions and time–temperature data, the apparent thermal diffusivity was calculated. The thermal conductivity of the DU microspheres was calculated based on the thermal diffusivity from the CHTA, known material densities and specific heat capacities, and an assumed 70% packing density based on prior measurements. Results indicate that DU metal microspheres have very low thermal conductivity, relative to solid uranium metal, and rapidly form an oxidation layer even in a low oxygen environment. At 500 °C, the thermal conductivity of the DU metal microsphere bed was 0.431 ± 0.0560 W/m-K compared to the literature value of approximately 32 W/m-K for solid uranium metal

  13. Glass: Rotary Electric Glass Furnace

    Energy Technology Data Exchange (ETDEWEB)

    Recca, L.

    1999-01-29

    Compared to conventional gas-fired furnaces, the new rotary electric furnace will increase energy efficiency while significantly reducing air emissions, product turnaround time, and labor costs. As this informative new fact sheet explains, the thousand different types of glass optical blanks produced for the photonics industry are used for lasers, telescopes, cameras, lights, and many other products.

  14. Brownian dynamics simulations of insulin microspheres formation

    Science.gov (United States)

    Li, Wei; Chakrabarti, Amit; Gunton, James

    2010-03-01

    Recent experiments have indicated a novel, aqueous process of microsphere insulin fabrication based on controlled phase separation of protein from water-soluble polymers. We investigate the insulin microsphere crystal formation from insulin-PEG-water systems via 3D Brownian Dynamics simulations. We use the two component Asakura-Oosawa model to simulate the kinetics of this colloid polymer mixture. We first perform a deep quench below the liquid-crystal boundary that leads to fractal formation. We next heat the system to obtain a break-up of the fractal clusters and subsequently cool the system to obtain a spherical aggregation of droplets with a relatively narrow size distribution. We analyze the structure factor S(q) to identify the cluster dimension. S(q) crosses over from a power law q dependence of 1.8 (in agreement with DLCA) to 4 as q increases, which shows the evolution from fractal to spherical clusters. By studying the bond-order parameters, we find the phase transition from liquid-like droplets to crystals which exhibit local HCP and FCC order. This work is supported by grants from the NSF and Mathers Foundation.

  15. Thyroid artery embolization with microspheres for hyperthyroidism

    International Nuclear Information System (INIS)

    Du Yahui; Zhong Chenfu; Chen Weijun; Zhang Ying; Luo Jun; Li Xiaoguang; Cao Junjie; Gan Changli; Cao Junjie; Gan Changli

    2006-01-01

    Objective: To evaluate the method and efficacy of thyroid artery embolization as a new therapy for hyperthyroidism. Methods: Thirteen patients with hyperthyroidism underwent selective thyroid artery embolization. Totally 25 thyroid arteries were embolized with microspheres. The indications for this therapy were as followings: 1) To give hyperthyroid patients having an alternative for surgical and 131 I treatment, and 2) To provide a new method for those clinically being difficult to get control with medicine. Results: Serum level of thyroid hormones dropped significantly[T3 from 2.84-9.0 ng/ml to 0.8-2.2 ng/ml, T4 from 162.9-277.2 ng/ml to 50-126 ng/ml] and symptoms of hyperthyroidism were under control in 12 patients within 1 month after the embolization. One patient remained no change 1 month later and refused to be embolized again. The symptoms of twelve patients were effectively controlled through low dose antithyroid medication for more than 6 months follow up with no serious complications. Conclusion: Thyroid artery embolization with microspheres is an effective alternative for surgical and 131 I treatment of hyperthyroidism. (authors)

  16. Storage stability of biodegradable polyethylene glycol microspheres

    Science.gov (United States)

    Jain, Era; Sheth, Saahil; Polito, Kristen; Sell, Scott A.; Zustiak, Silviya P.

    2017-10-01

    Degradable hydrogel microspheres are popular choices for multiple biomedical applications, including drug, protein, or cell carriers for minimally invasive delivery. Clinical transitioning of such new, sensitive pharmaceutical preparations requires investigation of storage methods that retain key properties for extended time. In this study, we sought to determine the influence of seven common storage conditions on the physical and mechanical properties of degradable polyethylene glycol (PEG) hydrogel microspheres: 25 °C, 4 °C, -80 °C, lyophilization/-20 °C, dimethyl sulfoxide/-80 °C, dimethyl sulfoxide/lyophilization/-20 °C, vacuum/-20 °C. We have outlined the storage conditions in detail and explained their effect on swelling ratio, stiffness and degradation rate post-storage. Additionally, we have implemented protein-loaded hydrogels to evaluate the effect of storage conditions on diffusivity as well as protein stability post-storage. We found that hydrogels could be stored short-term (1-4 d) under moist conditions (i.e. storage without drying) without a substantial loss of properties. For extended storage (7-28 d), they could be stored either at  -80 °C (moist condition) or vacuum drying (dry condition).

  17. Development of nuclear fuel microsphere handling techniques and equipment

    International Nuclear Information System (INIS)

    Mack, J.E.; Suchomel, R.R.; Angelini, P.

    1979-01-01

    Considerable progress has been made in the development of microsphere handling techniques and equipment for nuclear applications. Work at Oak Ridge National Laboratory with microspherical fuel forms dates back to the early sixties with the development of the sol-gel process. Since that time a number of equipment items and systems specifically related to microsphere handling and characterization have been identified and developed for eventual application in a remote recycle facility. These include positive and negative pressure transfer systems, samplers, weighers, a blender-dispenser, and automated devices for particle size distribution and crushing strength analysis. The current status of these and other components and systems is discussed

  18. Effects of whispering gallery mode in microsphere super-resolution imaging

    Science.gov (United States)

    Zhou, Song; Deng, Yongbo; Zhou, Wenchao; Yu, Muxin; Urbach, H. P.; Wu, Yihui

    2017-09-01

    Whispering Gallery modes have been presented in microscopic glass spheres or toruses with many applications. In this paper, the possible approaches to enhance the imaging resolution by Whispering Gallery modes are discussed, including evanescent waves coupling, transformed and illustration by Whispering Gallery modes. It shows that the high-order scattering modes play the dominant role in the reconstructed virtual image when the Whispering Gallery modes exist. Furthermore, we find that the high image resolution of electric dipoles can be achieved, when the out-of-phase components exist from the illustration of Whispering Gallery modes. Those results of our simulation could contribute to the knowledge of microsphere-assisted super-resolution imaging and its potential applications.

  19. Experiments with polymer coated microspheres irradiated by the Shiva laser system

    International Nuclear Information System (INIS)

    Auerbach, J.M.; Manes, K.R.; Matthews, D.L.

    1979-01-01

    Polymer coated spherical targets have been irradiated by the Shiva laser system in an effort to compress the contained 10 mg/cc DT fuel to super liquid densities. Glass microspheres of 140 μm ID and 5 μm wall thickness with polymer coatings 15 μm to 100 μm thick have been irradiated with laser pulses of 4 kilojoules in 200 psec FWHM. Target performance was diagnosed with neutron yield measurements, radiochemistry, Argon line imaging, and x-ray imaging techniques. Ball in plate targets achieved greater implosion symmetry than free-standing ball targets. With yields of 10 7 to 10 8 neutrons, targets reached DT fuel compressions of several times liquid density

  20. Hollow Mill for Extraction of Stripped Titanium Screws: An Easy ...

    African Journals Online (AJOL)

    countries. The known alternative in such condition is ... Key words: Hollow mill, stripped screws, titanium locked plates ... used a locally manufactured stainless steel hollow mill, ... head ‑ plate hole” assembly as a mono‑block single unit. In.

  1. Low content Ag-coated poly(acrylonitrile) microspheres and graphene for enhanced microwave absorption performance epoxy composites

    Science.gov (United States)

    Zhang, Bin; Wang, Jun; Chen, Xiaocheng; Su, Xiaogang; Zou, Yi; Huo, Siqi; Chen, Wei; Wang, Junpeng

    2018-04-01

    Silver nanoparticles was uniformly anchored on the surface of hollow poly(acrylonitrile) microspheres with a facile chemical method using hydrazine hydrate as reductant. Integrating these conducting hollow spheres (PANS@Ag) with chemical reduced graphene oxide (RGO) dispersed in epoxy resin, a lightweight microwave absorber was successfully prepared with enhanced microwave absorption performance. The chemical constitution and surface morphology of as-synthesized RGO and PANS@Ag powders were characterized by XRD, XPS, FE-SEM and SAED, while the electromagnetic properties of these different proportion PANS@Ag-RGO/EP samples were analyzed through vector network analyzer (VNA). The minimum reflection loss (RL) could reach up to ‑28.1 dB at 8.8 GHz with a layer thickness of 2 mm, and the corresponding effective absorption bandwidth (RL values less than ‑10 dB) was from 7.9 GHz to 9.8 GHz. However, the dosage of PANS@Ag and RGO was merely 3 wt% and 1 wt%, respectively. As the content of PANS@Ag powders decreased to 1 wt%, the PANS@Ag-RGO/EP samples still retained effective microwave absorption performance and the optimal RL was ‑14.7 dB. The density of as-prepared absorbers was in the range of 0.49 ∼ 0.87 g cm‑3. The low content, low density and enhanced microwave absorption performance endow the hybrid composites with competitive application prospect in stealth technology field.

  2. Self-construction of core-shell and hollow zeolite analcime icositetrahedra: a reversed crystal growth process via oriented aggregation of nanocrystallites and recrystallization from surface to core.

    Science.gov (United States)

    Chen, Xueying; Qiao, Minghua; Xie, Songhai; Fan, Kangnian; Zhou, Wuzong; He, Heyong

    2007-10-31

    Zeolite analcime with a core-shell and hollow icositetrahedron architecture was prepared by a one-pot hydrothermal route in the presence of ethylamine and Raney Ni. Detailed investigations on samples at different preparation stages revealed that the growth of the complex single crystalline geometrical structure did not follow the classic crystal growth route, i.e., a crystal with a highly symmetric morphology (such as polyhedra) is normally developed by attachment of atoms or ions to a nucleus. A reversed crystal growth process through oriented aggregation of nanocrystallites and surface recrystallization was observed. The whole process can be described by the following four successive steps. (1) Primary analcime nanoplatelets undergo oriented aggregation to yield discus-shaped particles. (2) These disci further assemble into polycrystalline microspheres. (3) The relatively large platelets grow into nanorods by consuming the smaller ones, and meanwhile, the surface of the microspheres recrystallizes into a thin single crystalline icositetrahedral shell via Ostwald ripening. (4) Recrystallization continues from the surface to the core at the expense of the nanorods, and the thickness of the monocrystalline shell keeps on increasing until all the nanorods are consumed, leading to hollow single crystalline analcime icositetrahedra. The present work adds new useful information for the understanding of the principles of zeolite growth.

  3. Nitrate glass

    International Nuclear Information System (INIS)

    Kirilenko, I.A.; Vinogradov, E.E.

    1977-01-01

    Experimental evidence on behaviour of nitrate glasses is reviewed in terms of relationships between the presence of water in vitrescent nitrate systems and the properties of the systems. The glasses considered belong to systems of Mg(NO 3 ) 2 - Nd(NO 3 ) 3 ; Hg(NO 3 ) 2 -Nd(NO 3 ) 3 ; NaNO 3 -Mg(NO 3 ) 2 -Nd(NO 3 ) 3 ; M-Zn(NO 3 ) 3 , where M is a mixture of 20% mass NaNO 3 and 80% mass Mg(NO 3 ) 2 , and Zn is a rare earth ion. Nitrate glass is shown to be a product of dehydration. Vitrification may be regarded as a resusl of formation of molecular complexes in the chain due to hydrogen bonds of two types, i.e. water-water, or water-nicrate group. Chain formation, along with low melting points of the nitrates, hinder crystallization of nitrate melts. Provided there is enough water, this results in vitrification

  4. Low-Loss Hollow Waveguide Fibers for Mid-Infrared Quantum Cascade Laser Sensing Applications

    Directory of Open Access Journals (Sweden)

    James A. Harrington

    2013-01-01

    Full Text Available We report on single mode optical transmission of hollow core glass waveguides (HWG coupled with an external cavity mid-IR quantum cascade lasers (QCLs. The QCL mode results perfectly matched to the hybrid HE11 waveguide mode and the higher losses TE-like modes have efficiently suppressed by the deposited inner dielectric coating. Optical losses down to 0.44 dB/m and output beam divergence of ~5 mrad were measured. Using a HGW fiber with internal core size of 300 µm we obtained single mode laser transmission at 10.54 µm and successful employed it in a quartz enhanced photoacoustic gas sensor setup.

  5. Identification of Bloch-modes in hollow-core Photonic Crystal Fiber cladding

    DEFF Research Database (Denmark)

    Couny, F.; Benabid, F.; Roberts, John

    2007-01-01

    We report on the experimental visualization of the cladding Bloch-modes of a hollow-core photonic crystal fiber. Both spectral and spatial field information is extracted using the approach, which is based on measurement of the near-field and Fresnel-zone that results after propagation over a short...... length of fiber. A detailed study of the modes near the edges of the band gap shows that it is formed by the influence of three types of resonator: the glass interstitial apex, the silica strut which joins the neighboring apexes, and the air hole. The cladding electromagnetic field which survives...

  6. Design of low-loss and highly birefringent hollow-core photonic crystal fiber

    DEFF Research Database (Denmark)

    Roberts, Peter John; Williams, D.P.; Sabert, H.

    2006-01-01

    A practical hollow-core photonic crystal fiber design suitable for attaining low-loss propagation is analyzed. The geometry involves a number of localized elliptical features positioned on the glass ring that surrounds the air core and separates the core and cladding regions. The size of each...... feature is tuned so that the composite core-surround geometry is antiresonant within the cladding band gap, thus minimizing the guided mode field intensity both within the fiber material and at material / air interfaces. A birefringent design, which involves a 2-fold symmetric arrangement of the features...

  7. Development of tree hollows in pedunculate oak (Quercus robur)

    OpenAIRE

    Ranius, Thomas; Niklasson, Mats; Berg, Niclas

    2009-01-01

    Many invertebrates, birds and mammals are dependent on hollow trees. For landscape planning that aims at persistence of species inhabiting hollow trees it is crucial to understand the development of such trees. In this study we constructed an individual-based simulation model to predict diameter distribution and formation of hollows in oak tree populations. Based on tree-ring data from individual trees, we estimated the ages when hollow formation commences for pedunculate oak (Quercus robur) ...

  8. Transmission properties of hollow-core photonic bandgap fibers

    DEFF Research Database (Denmark)

    Falk, Charlotte Ijeoma; Hald, Jan; Petersen, Jan C.

    2010-01-01

    Variations in optical transmission of four types of hollow-core photonic bandgap fibers are measured as a function of laser frequency. These variations influence the potential accuracy of gas sensors based on molecular spectroscopy in hollow-core fibers.......Variations in optical transmission of four types of hollow-core photonic bandgap fibers are measured as a function of laser frequency. These variations influence the potential accuracy of gas sensors based on molecular spectroscopy in hollow-core fibers....

  9. Investigation Into Accessible Surface Vinyl Concentrations of Nonstoichiometric PDMS Microspheres from Hydrosilylation Reactions and Their Further Crosslinking Reactions

    DEFF Research Database (Denmark)

    Ma, Baoguang; Hansen, Jens Henrik; Hvilsted, Søren

    2015-01-01

    The introduction of surface vinyl groups to PDMS microspheres broadens the latter's applicability range since the microspheres can be further functionalized or crosslinked into elastomers. Quantification of the surface vinyl concentration of PDMS microspheres is therefore essential. Here, a novel...

  10. Hierarchical Li1.2Mn0.54Ni0.13Co0.13O2 hollow spherical as cathode material for Li-ion battery

    Science.gov (United States)

    Zhang, Yu; Zhu, Tianjiao; Lin, Liu; Yuan, Mengwei; Li, Huifeng; Sun, Genban; Ma, Shulan

    2017-11-01

    Lithium-rich manganese-based layered materials have been considered as the most promising cathode materials for future high-energy-density lithium-ion batteries. However, a great loss of irreversible capacity at the initial cycle, poor cycle stability, and rate performance severely restrict its application. Herein, we develop a new strategy to synthesize hierarchical hollow Li1.2Mn0.54Ni0.13Co0.13O2 microspheres using sucrose and cetyltrimethylammonium bromide as a soft template combined with hydrothermal assisted homogeneous precipitation method. The hollow microspheres are assembled by the primary particles with the size of 50 nm. As a result, the as-prepared material exhibits high reversible capacity, good cycling stability, and excellent rate property. It delivers a high initial discharge capacity of 305.9 mAh g-1 at 28 mA g-1 with coulombic efficiency of 80%. Even at high current density of 560 mA g-1, the sample also shows a stable discharge capacity of 215 mAh g-1. The enhanced electrochemical properties are attributed to the stable hierarchical hollow sphere structure and the appropriate contact area between electrode and electrolyte, thus effectively improve the lithium-ion intercalation and deintercalation kinetics. [Figure not available: see fulltext.

  11. Adiabatic Rearrangement of Hollow PV Towers

    Directory of Open Access Journals (Sweden)

    Eric A Hendricks

    2010-10-01

    Full Text Available Diabatic heating from deep moist convection in the hurricane eyewall produces a towering annular structure of elevated potential vorticity (PV. This structure has been referred to as a hollow PV tower. The sign reversal of the radial gradient of PV satisfies the Charney-Stern necessary condition for combined barotropic-baroclinic instability. For thin enough annular structures, small perturbations grow exponentially, extract energy from the mean flow, and lead to hollow tower breakdown, with significant vortex structural and intensity change. The three-dimensional adiabatic rearrangements of two prototypical hurricane-like hollow PV towers (one thick and one thin are examined in an idealized framework. For both hollow towers, dynamic instability causes air parcels with high PV to be mixed into the eye preferentially at lower levels, where unstable PV wave growth rates are the largest. Little or no mixing is found to occur at upper levels. The mixing at lower and middle levels is most rapid for the breakdown of the thin hollow tower, consistent with previous barotropic results. For both hollow towers, this advective rearrangement of PV affects the tropical cyclone structure and intensity in a number of ways. First, the minimum central pressure and maximum azimuthal mean velocity simultaneously decrease, consistent with previous barotropic results. Secondly, isosurfaces of absolute angular momentum preferentially shift inward at low levels, implying an adiabatic mechanism by which hurricane eyewall tilt can form. Thirdly, a PV bridge, similar to that previously found in full-physics hurricane simulations, develops as a result of mixing at the isentropic levels where unstable PV waves grow most rapidly. Finally, the balanced mass field resulting from the PV rearrangement is warmer in the eye between 900 and 700 hPa. The location of this warming is consistent with observed warm anomalies in the eye, indicating that in certain instances the hurricane

  12. Air annealing induced transformation of cubic CdSe microspheres into hexagonal nanorods and micro-pyramids

    Energy Technology Data Exchange (ETDEWEB)

    Kale, Rohidas B., E-mail: rb_kale@yahoo.co.in [Department of Physics, Institute of Science, Mumbai 400032, M.S. (India); Lu, Shih-Yuan, E-mail: sylu@mx.nthu.edu.tw [Department of Chemical Engineering, National Tsing-Hua University, Hsin-Chu 30013, Taiwan (China)

    2015-08-15

    Highlights: • Nanocrystalline CdSe thin films were deposited using inexpensive CBD method. • Air annealing induced structural and interesting morphological transformation. • The as-deposited CdSe thin films showed a blue shift in its optical spectra. • The films showed a red shift in their optical spectra after annealing. - Abstract: CdSe thin films have been deposited onto glass substrates using a chemical bath deposition method at relatively low temperatures (40 °C). The precursors used for the deposition of the thin films are cadmium nitrate hexahydrate, freshly prepared sodium selenosulfate solution and aqueous ammonia solution as a complex as well as pH adjusting reagent. In order to study the influence of air annealing on their physicochemical properties, the as-deposited CdSe thin films were further annealed at 200 °C and 400 °C for 3 h in air atmosphere. Significant changes in the morphology and photonic properties were clearly observed after the thermal annealing of the CdSe thin films. The as-deposited CdSe films grow with the cubic phase that transforms into mixed cubic and hexagonal wurtzite phase with improved crystalline quality of the films after the air annealing. Morphological observation reveals that the as-deposited thin films grow with multilayer that consists of network or mesh like structure, uniformly deposited on the glass substrate over which microspheres are uniformly distributed. After air annealing, CdSe nanorods emerged from the microspheres along with conversion of few microspheres into micro-pyramids. The UV–visible study illustrates that the as-deposited thin film shows blue shifts in its optical spectrum and the spectrum was red-shifted after annealing the CdSe thin films. The band gap of the CdSe thin films were found to be decreased after the thermal treatment.

  13. Studies on pulsed hollow cathode capillary discharges

    Energy Technology Data Exchange (ETDEWEB)

    Choi, P; Dumitrescu-Zoita, C; Larour, J; Rous, J [Ecole Polytechnique, 91 - Palaiseau (France). Lab. de Physique des Milieux Ionises; Favre, M; Moreno, J; Chuaqui, H; Wyndham, E [Pontificia Univ. Catolica de Chile, Santiago (Chile). Facultad de Fisica; Zambra, M [Comision Chilena de Energia Nuclear, Santiago (Chile); Wong, C S [Univ. of Malaya, Kuala Lumpur (Malaysia). Plasma Research Lab

    1997-12-31

    Preliminary results on radiation characteristics of pulsed hollow cathode capillary discharges are presented. The device combines the on axis electron beam assisted ionization capabilities of the transient hollow cathode discharge with a novel high voltage low inductance geometrical design, which integrates the local energy storage into the electrode system. A nanosecond regime high temperature plasma is produced in a long, high aspect ratio capillary, with light emission in the UV to XUV region. The discharge is operated from near vacuum to pressure in the 1000 mTorr range. (author). 2 figs., 7 refs.

  14. Microfabricated hollow microneedle array using ICP etcher

    Science.gov (United States)

    Ji, Jing; Tay, Francis E. H.; Miao, Jianmin

    2006-04-01

    This paper presents a developed process for fabrication of hollow silicon microneedle arrays. The inner hollow hole and the fluidic reservoir are fabricated in deep reactive ion etching. The profile of outside needles is achieved by the developed fabrication process, which combined isotropic etching and anisotropic etching with inductively coupled plasma (ICP) etcher. Using the combination of SF6/O2 isotropic etching chemistry and Bosch process, the high aspect ratio 3D and high density microneedle arrays are fabricated. The generated needle external geometry can be controlled by etching variables in the isotropic and anisotropic cases.

  15. Microfabricated hollow microneedle array using ICP etcher

    International Nuclear Information System (INIS)

    Ji Jing; Tay, Francis E H; Miao Jianmin

    2006-01-01

    This paper presents a developed process for fabrication of hollow silicon microneedle arrays. The inner hollow hole and the fluidic reservoir are fabricated in deep reactive ion etching. The profile of outside needles is achieved by the developed fabrication process, which combined isotropic etching and anisotropic etching with inductively coupled plasma (ICP) etcher. Using the combination of SF 6 /O 2 isotropic etching chemistry and Bosch process, the high aspect ratio 3D and high density microneedle arrays are fabricated. The generated needle external geometry can be controlled by etching variables in the isotropic and anisotropic cases

  16. Microfabricated hollow microneedle array using ICP etcher

    Energy Technology Data Exchange (ETDEWEB)

    Ji Jing [Mechanical Engineering National University of Singapore, 119260, Singapore (Singapore); Tay, Francis E H [Mechanical Engineering National University of Singapore, 119260, Singapore (Singapore); Miao Jianmin [MicroMachines Center, School of Mechanical and Aerospace Engineering, Nanyang Technological University, 50 Nanyang Avenue, 639798 (Singapore)

    2006-04-01

    This paper presents a developed process for fabrication of hollow silicon microneedle arrays. The inner hollow hole and the fluidic reservoir are fabricated in deep reactive ion etching. The profile of outside needles is achieved by the developed fabrication process, which combined isotropic etching and anisotropic etching with inductively coupled plasma (ICP) etcher. Using the combination of SF{sub 6}/O{sub 2} isotropic etching chemistry and Bosch process, the high aspect ratio 3D and high density microneedle arrays are fabricated. The generated needle external geometry can be controlled by etching variables in the isotropic and anisotropic cases.

  17. Computational predictions of zinc oxide hollow structures

    Science.gov (United States)

    Tuoc, Vu Ngoc; Huan, Tran Doan; Thao, Nguyen Thi

    2018-03-01

    Nanoporous materials are emerging as potential candidates for a wide range of technological applications in environment, electronic, and optoelectronics, to name just a few. Within this active research area, experimental works are predominant while theoretical/computational prediction and study of these materials face some intrinsic challenges, one of them is how to predict porous structures. We propose a computationally and technically feasible approach for predicting zinc oxide structures with hollows at the nano scale. The designed zinc oxide hollow structures are studied with computations using the density functional tight binding and conventional density functional theory methods, revealing a variety of promising mechanical and electronic properties, which can potentially find future realistic applications.

  18. Optical diffraction by ordered 2D arrays of silica microspheres

    International Nuclear Information System (INIS)

    Shcherbakov, A.A.; Shavdina, O.; Tishchenko, A.V.; Veillas, C.; Verrier, I.; Dellea, O.; Jourlin, Y.

    2017-01-01

    The article presents experimental and theoretical studies of angular dependent diffraction properties of 2D monolayer arrays of silica microspheres. High-quality large area defect-free monolayers of 1 μm diameter silica microspheres were deposited by the Langmuir-Blodgett technique under an accurate optical control. Measured angular dependencies of zeroth and one of the first order diffraction efficiencies produced by deposited samples were simulated by the rigorous Generalized Source Method taking into account particle size dispersion and lattice nonideality. - Highlights: • High quality silica microsphere monolayer was fabricated. • Accurate measurements of diffraction efficiency angular dependencies. • Rigorous diffraction simulation of both ideal hexagonal and realistic microsphere arrangements. • Qualitative rationalization of the obtained results and the observed differences between the experiment and the theory.

  19. BIOCOMPATIBLE FLUORESCENT MICROSPHERES: SAFE PARTICLES FOR MATERIAL PENETRATION STUDIES

    Energy Technology Data Exchange (ETDEWEB)

    Farquar, G; Leif, R

    2009-07-15

    Biocompatible polymers with hydrolyzable chemical bonds have been used to produce safe, non-toxic fluorescent microspheres for material penetration studies. The selection of polymeric materials depends on both biocompatibility and processability, with tailored fluorescent properties depending on specific applications. Microspheres are composed of USFDA-approved biodegradable polymers and non-toxic fluorophores and are therefore suitable for tests where human exposure is possible. Micropheres were produced which contain unique fluorophores to enable discrimination from background aerosol particles. Characteristics that affect dispersion and adhesion can be modified depending on use. Several different microsphere preparation methods are possible, including the use of a vibrating orifice aerosol generator (VOAG), a Sono-Tek atomizer, an emulsion technique, and inkjet printhead. Applications for the fluorescent microspheres include challenges for biodefense system testing, calibrants for biofluorescence sensors, and particles for air dispersion model validation studies.

  20. Preparation of UN microspheres by internal gelation process

    Energy Technology Data Exchange (ETDEWEB)

    Shirasu, Yoshiro; Yamagishi, Shigeru [Japan Atomic Energy Research Inst., Tokai, Ibaraki (Japan). Tokai Research Establishment

    1997-07-01

    UN microspheres were prepared from (UO{sub 3}+C) microspheres internally gelled in a hot silicone oil column. The gel microspheres were calcined at 480degC in nitrogen, after washing and drying. The calcined ones were carbothermically nitrided at 1400-1800degC in a nitrogen-based atmosphere in two ways: one in N{sub 2} followed by N{sub 2}-8%H{sub 2}, and the other in N{sub 2}-8%H{sub 2} only. In both cases, highly pure UN microspheres around 500 ppm of both oxygen and carbon impurities were obtained, although their densities were still low. (author)

  1. Silicon microspheres for near-IR communication applications

    International Nuclear Information System (INIS)

    Serpengüzel, Ali; Demir, Abdullah

    2008-01-01

    We have performed transverse electric and transverse magnetic polarized elastic light scattering calculations at 90° and 0° in the o-band at 1.3 µm for a 15 µm radius silicon microsphere with a refractive index of 3.5. The quality factors are on the order of 10 7 and the mode/channel spacing is 7 nm, which correlate well with the refractive index and the optical size of the microsphere. The 90° elastic light scattering can be used to monitor a dropped channel (drop port), whereas the 0° elastic scattering can be used to monitor the transmission channel (through port). The optical resonances of the silicon microspheres provide the necessary narrow linewidths that are needed for high-resolution optical communication applications. Potential telecommunication applications include filters, modulators, switches, wavelength converters, detectors, amplifiers and light sources. Silicon microspheres show promise as potential building blocks for silicon-based electrophotonic integration

  2. XPS analysis of aluminosilicate microspheres bioactivity tested in vitro

    Energy Technology Data Exchange (ETDEWEB)

    Todea, M.; Vanea, E. [Faculty of Physics and Institute of Interdisciplinary Research on Bio-Nano-Sciences, Babes Bolyai University, Cluj-Napoca 400084 (Romania); Bran, S. [University of Medicine and Pharmacy “Iuliu Haţieganu”, Department of Cranio-Maxillofacial Surgery, 400029 Cluj-Napoca (Romania); Berce, P. [Technical University of Cluj-Napoca, Faculty of Machine Building and National Centre of Rapid Prototyping, 400641 Cluj-Napoca (Romania); Simon, S., E-mail: simons@phys.ubbcluj.ro [Faculty of Physics and Institute of Interdisciplinary Research on Bio-Nano-Sciences, Babes Bolyai University, Cluj-Napoca 400084 (Romania)

    2013-04-01

    The study aims to characterize surface properties of aluminosilicate microspheres incorporating yttrium, with potential biomedical applications. Micrometric particles of spherical shape were obtained by spray drying method. The behavior of aluminosilicate microspheres without yttrium and with yttrium was investigated under in vitro conditions, by seven days incubation in simulated body fluid (SBF). The surface elemental composition and the atomic environments on outermost layer of the microspheres, prior to and after incubation in SBF were evaluated by X-ray photoelectron spectroscopy (XPS) in order to investigate their bioactivity. The results were analyzed to underline the effect of yttrium addition on surface properties of the aluminosilicate microspheres and implicitly on the behavior of the samples in simulated body environments.

  3. Investigation of defects on PAMS microspheres fabricated with microencapsulation method

    International Nuclear Information System (INIS)

    Chen Sufen; Li Bo; Liu Yiyang; Zhang Zhanwen; Qi Xiaobo

    2012-01-01

    Poly-(α-methylstyrene) (PAMS) microspheres were fabricated with W1/O/W2 double emulsion microencapsulation method, and the effects of polyvinylalcohol (PVA) and CaCl 2 weight concentrations and the O/W2 phase ratio on the percentages of defected PAMS microspheres were studied. The weight concentrations of PVA and CaCl 2 and the O/W2 phase ratio in the fabrication process of PAMS microspheres were optimized. The results show that, for the three parameters being 1.0%, 1.5%, and 0.01, respectively, the percentage of the defect-free PAMS microspheres without vacuoles in the shell wall can be up to 60%. (authors)

  4. Preparation and In-vitro Evaluation of Metformin Microspheres Using ...

    African Journals Online (AJOL)

    . Methods: Metformin microspheres were prepared by non-aqueous solvent evaporation method using various polymers, including ethylcellulose (EC), hydroxypropyl methylcellulose (HPMC), carbopol 934P (CA) and chitosan (CH). The effect ...

  5. Resonant microsphere gyroscope based on a double Faraday rotator system.

    Science.gov (United States)

    Xie, Chengfeng; Tang, Jun; Cui, Danfeng; Wu, Dajin; Zhang, Chengfei; Li, Chunming; Zhen, Yongqiu; Xue, Chenyang; Liu, Jun

    2016-10-15

    The resonant microsphere gyroscope is proposed based on a double Faraday rotator system for the resonant microsphere gyroscope (RMSG) that is characterized by low insertion losses and does not destroy the reciprocity of the gyroscope system. Use of the echo suppression structure and the orthogonal polarization method can effectively inhibit both the backscattering noise and the polarization error, and reduce them below the system sensitivity limit. The resonance asymmetry rate dropped from 34.2% to 2.9% after optimization of the backscattering noise and the polarization noise, which greatly improved the bias stability and the scale factor linearity of the proposed system. Additionally, based on the optimum parameters for the double Faraday rotator system, a bias stability of 0.04°/s has been established for an integration time of 10 s in 1000 s in a resonator microsphere gyroscope using a microsphere resonator with a diameter of 1 mm and a Q of 7.2×106.

  6. Facile preparation of hierarchically porous polymer microspheres for superhydrophobic coating

    Science.gov (United States)

    Gao, Jiefeng; Wong, Julia Shuk-Ping; Hu, Mingjun; Li, Wan; Li, Robert. K. Y.

    2013-12-01

    A facile method, i.e., nonsolvent assisted electrospraying, is proposed to fabricate hierarchically porous microspheres. The pore size on the microsphere surface ranges from a few tens to several hundred nanometers. Thermally and nonsolvent induced phase separation as well as breath figure is responsible for the formation of the hierarchical structures with different nano-sized pores. The nonsolvent could not only induce phase separation, but also stabilize the interface between the droplet and air, which can prevent the droplet from strong deformation, and is therefore beneficial to the formation of regular and uniform microspheres. On the other hand, solvent evaporation, polymer diffusion and Coulomb fission during electrospraying influence the morphology of finally obtained products. In this paper, the influence of polymer concentration, the weight ratio between nonsolvent and polymer and the flowing rate on the morphology of the porous microsphere is carefully studied. The hierarchically porous microsphere significantly increases the surface roughness and thus the hydrophobicity, and the contact angle can reach as high as 152.2 +/- 1.2°. This nonsolvent assisted electrospraying opens a new way to fabricate superhydrophobic coating materials.A facile method, i.e., nonsolvent assisted electrospraying, is proposed to fabricate hierarchically porous microspheres. The pore size on the microsphere surface ranges from a few tens to several hundred nanometers. Thermally and nonsolvent induced phase separation as well as breath figure is responsible for the formation of the hierarchical structures with different nano-sized pores. The nonsolvent could not only induce phase separation, but also stabilize the interface between the droplet and air, which can prevent the droplet from strong deformation, and is therefore beneficial to the formation of regular and uniform microspheres. On the other hand, solvent evaporation, polymer diffusion and Coulomb fission during

  7. [Optimization of riboflavin sodium phosphate loading to calcium alginate floating microspheres by response surface methodology].

    Science.gov (United States)

    Zhang, An-yang; Fan, Tian-yuan

    2009-12-18

    To investigate the preparation, optimization and in vitro properties of riboflavin sodium phosphate floating microspheres. The floating microspheres composed of riboflavin sodium phosphate and calcium alginate were prepared using ion gelatin-oven drying method. The properties of the microspheres were investigated, including the buoyancy, release, appearance and entrapment efficiency. The formulation was optimized by response surface methodology (RSM). The optimized microspheres were round. The entrapment efficiency was 57.49%. All the microspheres could float on the artificial gastric juice over 8 hours. The release of the drug from the microspheres complied with Fick's diffusion.

  8. A review on target drug delivery: magnetic microspheres

    OpenAIRE

    Amit Chandna; Deepa Batra; Satinder Kakar; Ramandeep Singh

    2013-01-01

    Novel drug delivery system aims to deliver the drug at a rate directed by the needs of the body during the period of treatment, and target the active entity to the site of action. A number of novel drug delivery systems have emerged encompassing various routes of administration, to achieve controlled and targeted drug delivery, magnetic micro carriers being one of them. Magnetic microsphere is newer approach in pharmaceutical field. Magnetic microspheres as an alternative to traditional ra...

  9. Development and Evaluation of Isoniazid Loaded Silk Fibroin Microsphere

    Directory of Open Access Journals (Sweden)

    Narinder Singh

    Full Text Available Aim: Current experimental investigation is dedicated to prepare microspheres with small size and good sphericity by Phase Separation method using Isoniazid (INH as model drug. Silk fibroin has unique intrinsic qualities like biodegradability, biocompatibility or release properties and their tunable drug loading capacity. The delivery loading proficiency of the drug molecules in silk spheres be contingent on their charge, and hydrophobicity or subsequent in altered drug release profiles. Methods: In the present work Isoniazid loaded silk fibroin microsphere was prepared by using phase separation method. Microsphere was evaluated for Ultraviolet-visible spectroscopy, Fourier Transform infrared spectroscopy, Entrapment efficiency, Scanning electron microscopy Studies. Results: Scanning electron microscopy studies revealed that Isoniazid Loaded Silk Fibroin Microspheres were spherical. Entrapment Efficiency of Isoniazid loaded Microspheres of different Formulation from F1 to F5 was in range of 53 to 68 %. F3 showed 68.47 % entrapment Efficiency and the optimized formulation drug release was 93.56 % at 24 hours. Conclusion: Experimental report disclosed a new aqueous based formulation method for silk spheres with controllable shape or size and sphere. Isoniazid loaded silk microspheres may act as ideal nano formulation with elaborated studies.

  10. Synthesis and characterization of Supeparamagnetics Microspheres (PMMA via suspension polymerization

    Directory of Open Access Journals (Sweden)

    Paulo Emilio Feuser

    2014-02-01

    Full Text Available Magnetics nanoparticles (NPMs has found many applications in biomedical and technological areas. The objective of this work is the preparation and characterization of PMMA microspheres containing NPMs coated with oleic acid (NPMs-AO. For the preparation of MNPs-AO was used the coprecipitation method in an aqueous medium. For the preparation of the superparamagnetic microspheres used in suspension polymerization technique. The microspheres showed a size distribution particles of approximately 150um and a spherical morphology. From the analysis of gel permeation chromatography (GPC determined the number average molecular weight (Mw of the magnetics microspheres and there was a variation in the Mw depending on the concentration of MNPs-AO in this reaction. To analyze the magnetic properties used the vibrating sample magnetometer (MAV. The microspheres showed superparamagnetic properties and a value of saturation magnetization (Ms of about 8 emu/g MNPs. Therefore you can conclude that it is possible to obtain superparamagnetics microspheres for a particular application, either, biomedical or technological.

  11. Microspheres and Nanotechnology for Drug Delivery.

    Science.gov (United States)

    Jóhannesson, Gauti; Stefánsson, Einar; Loftsson, Thorsteinn

    2016-01-01

    Ocular drug delivery to the posterior segment of the eye can be accomplished by invasive drug injections into different tissues of the eye and noninvasive topical treatment. Invasive treatment involves the risks of surgical trauma and infection, and conventional topical treatments are ineffective in delivering drugs to the posterior segment of the eye. In recent years, nanotechnology has become an ever-increasing part of ocular drug delivery. In the following, we briefly review microspheres and nanotechnology for drug delivery to the eye, including different forms of nanotechnology such as nanoparticles, microparticles, liposomes, microemulsions and micromachines. The permeation barriers and anatomical considerations linked to ocular drug delivery are discussed and a theoretical overview on drug delivery through biological membranes is given. Finally, in vitro, in vivo and human studies of x03B3;-cyclodextrin nanoparticle eyedrop suspensions are discussed as an example of nanotechnology used for drug delivery to the eye. © 2016 S. Karger AG, Basel.

  12. Hollow-in-Hollow Carbon Spheres for Lithium-ion Batteries with Superior Capacity and Cyclic Performance

    International Nuclear Information System (INIS)

    Zang, Jun; Ye, Jianchuan; Fang, Xiaoliang; Zhang, Xiangwu; Zheng, Mingsen; Dong, Quanfeng

    2015-01-01

    Highlights: • Hollow-in-hollow structured HIHCS was synthesized via a facile templating strategy. • The HCS core and hollow carbon shell constitute the hollow-in-hollow structure. • The HIHCS exhibited superior rate capability and cycle stability as anode material. • The excellent performance is attributed to the unique hollow-in-hollow structure. - Abstract: Hollow spheres structured materials have been intensively pursued due to their unique properties for energy storage. In this paper, hollow-in-hollow carbon spheres (HIHCS) with a multi-shelled structure were successfully synthesized using a facile hard-templating procedure. When evaluated as anode material for lithium-ion batteries, the resultant HIHCS anode exhibited superior capacity and cycling stability than HCS. It could deliver reversible capacities of 937, 481, 401, 304 and 236 mAh g −1 at current densities of 0.1 A g −1 , 1 A g −1 , 2 A g −1 , 5 A g −1 and 10 A g −1 , respectively. And capacity fading is not apparent in 500 cycles at 5 A g −1 . The excellent performance of the HIHCS anode is ascribed to its unique hollow-in-hollow structure and high specific surface area.

  13. Chitosan microspheres in novel drug delivery systems.

    Science.gov (United States)

    Mitra, Analava; Dey, Baishakhi

    2011-07-01

    The main aim in the drug therapy of any disease is to attain the desired therapeutic concentration of the drug in plasma or at the site of action and maintain it for the entire duration of treatment. A drug on being used in conventional dosage forms leads to unavoidable fluctuations in the drug concentration leading to under medication or overmedication and increased frequency of dose administration as well as poor patient compliance. To minimize drug degradation and loss, to prevent harmful side effects and to increase drug bioavailability various drug delivery and drug targeting systems are currently under development. Handling the treatment of severe disease conditions has necessitated the development of innovative ideas to modify drug delivery techniques. Drug targeting means delivery of the drug-loaded system to the site of interest. Drug carrier systems include polymers, micelles, microcapsules, liposomes and lipoproteins to name some. Different polymer carriers exert different effects on drug delivery. Synthetic polymers are usually non-biocompatible, non-biodegradable and expensive. Natural polymers such as chitin and chitosan are devoid of such problems. Chitosan comes from the deacetylation of chitin, a natural biopolymer originating from crustacean shells. Chitosan is a biocompatible, biodegradable, and nontoxic natural polymer with excellent film-forming ability. Being of cationic character, chitosan is able to react with polyanions giving rise to polyelectrolyte complexes. Hence chitosan has become a promising natural polymer for the preparation of microspheres/nanospheres and microcapsules. The techniques employed to microencapsulate with chitosan include ionotropic gelation, spray drying, emulsion phase separation, simple and complex coacervation. This review focuses on the preparation, characterization of chitosan microspheres and their role in novel drug delivery systems.

  14. Arrays of hollow out-of-plane microneedles made by metal electrodeposition onto solvent cast conductive polymer structures

    International Nuclear Information System (INIS)

    Mansoor, I; Liu, Y; Stoeber, B; Häfeli, U O

    2013-01-01

    Transdermal drug delivery using microneedles is a technique to potentially replace hypodermic needles for injection of many vaccines and drugs. Fabrication of hollow metallic microneedles so far has been associated with time-consuming steps that restrict batch production of these devices. Here, we are presenting a novel method for making metallic microneedles with any desired height, spacing, and lumen size. In our process, we use solvent casting to coat a mold, which contains an array of pillars, with a conductive polymer composite layer. The conductive layer is then used as a seed layer in a metal electrodeposition process. To characterize the process, the conductivity of the polymer composite with respect to different filler concentrations was investigated. In addition, plasma etching of the polymer was characterized. The electroplating process was also studied further to control the thickness of the microneedle array plate. The strength of the microneedle devices was evaluated through a series of compression tests, while their performance for transdermal drug delivery was tested by injection of 2.28 µm fluorescent microspheres into animal skin. The fabricated metallic microneedles seem appropriate for subcutaneous delivery of drugs and microspheres. (paper)

  15. Occupational exposure following Yttrium-90 microspheres SIR therapy

    International Nuclear Information System (INIS)

    Fontaine, P.; Boirie, G.; Dieudonne, A.; Leguludec, D.; Lebtahi, R.; Ben Reguiga, M.

    2015-01-01

    Full text of publication follows. Introduction: Selective Internal Radiation Therapy (SIRT) is a promising technique for solid hepatic neoplasms treatment. SIRT consists in implanting radioactive microspheres (RMS) in targeted hepatic lesions via femoral artery. Two RMS-Therapsheres [glass-microspheres/TSR] and Sir-Spheres [resin-spheres/SSR]- are marketed in the European market, both radiolabeled with Yttrium-90. The objective of this study is to assess occupational exposure for nuclear medicine, radiology and clinical staff involved in Y 90 -RMS preparation and implantation. Materials and methods: The study was conducted on 20 patients treated for Hepato-Cellular Carcinoma: 10 treated with TSR and 10 with SSR. Dose rate (DR, mSv/h) or absorbed doses (mSv) measurements were made during all steps of TSR and SSR handling: sources receipt and unpacking, preparation, transport to radiology, implantation, and patient care. Measurements were made with portable ionization chamber(Babyline/Nardeux), spectrometer(FieldSpect/Aries), digital dosimeter (NED/Unfors) and operational dosimeter (Mk2/Siemens). Values were expressed as mean±SD. Results: patients received of 1.8 GBq to 3.1 GBq of TSR and 0.55 GBq to 2.4 GBq of SSR. TSR were delivered ready-to-use with the prescribed activity. For SSR only one activity was commercially available and shipped (3 GBq at calibration-time)requiring a preparation step to adjust needed activity. DR measured during RMS was 1723 ± 157 μSv/h SSR and 1189 ± 92 μSv/h for TSR. When preparing spheres in radiopharmacy, fingers and whole body doses were respectively 8326 ± 2360 μSv and 12.3 ± 5,2 μSv for Sir-Spheres vs. 33.5 ± 7.8 μSv and 1.1 ± 0.3 μSv for TSR. DR in contact with carrying case during RMS transfer to radiology were 299 ± 102 μSv/h for SSR and 5.3 ± 1.2 μSv/h for TSR. During RMS infusion, radiologist's finger doses were limited to 3.6 ± 1 μSv for SSR and 0.7± 0.3 μSv for TSR. Finally, following RMS

  16. Molecular motor transport through hollow nanowires

    DEFF Research Database (Denmark)

    Lard, Mercy; Ten Siethoff, Lasse; Generosi, Johanna

    2014-01-01

    -driven motion of fluorescent probes (actin filaments) through 80 nm wide, Al2O 3 hollow nanowires of micrometer length. The motor-driven transport is orders of magnitude faster than would be possible by passive diffusion. The system represents a necessary element for advanced devices based on gliding assays...

  17. Hollow micro string based calorimeter device

    DEFF Research Database (Denmark)

    2014-01-01

    positions so as to form a free released double clamped string in-between said two longitudinally distanced positions said micro-channel string comprising a microfluidic channel having a closed cross section and extending in the longitudinal direction of the hollow string, acoustical means adapted...

  18. Hollow fibre supported liquid membrane extraction of ...

    African Journals Online (AJOL)

    A simple sample pre-treatment method utilizing hollow fibre supported liquid membrane (HFSLM) was carried out on pharmaceuticals samples comprising of cough syrups (CS1 and CS2) and an anti-inflammatory product (AI). The active ingredients targeted in the extraction process were diphenylhydramine (DPH), ...

  19. TEACHING PHYSICS: Biking around a hollow sphere

    Science.gov (United States)

    Mak, Se-yuen; Yip, Din-yan

    1999-11-01

    The conditions required for a cyclist riding a motorbike in a horizontal circle on or above the equator of a hollow sphere are derived using concepts of equilibrium and the condition for uniform circular motion. The result is compared with an empirical analysis based on a video show. Some special cases of interest derived from the general solution are elaborated.

  20. Inverted opal luminescent Ce-doped silica glasses

    Directory of Open Access Journals (Sweden)

    R. Scotti

    2006-01-01

    Full Text Available Inverted opal Ce-doped silica glasses (Ce : Si molar ratio 1 ⋅ 10−3 were prepared by a sol-gel method using opals of latex microspheres as templates. The rare earth is homogeneously dispersed in silica host matrix, as evidenced by the absence of segregated CeO2, instead present in monolithic Ce-doped SG with the same cerium content. This suggests that the nanometric dimensions of bridges and junctions of the host matrix in the inverted opal structures favor the RE distribution avoiding the possible segregation of CeO2.

  1. Clinical impact of 99mTc-MAA SPECT/CT-based dosimetry in the radioembolization of liver malignancies with 90Y-loaded microspheres

    International Nuclear Information System (INIS)

    Garin, Etienne; Rolland, Yan; Laffont, Sophie; Edeline, Julien

    2016-01-01

    Radioembolization with 90 Y-loaded microspheres is increasingly used in the treatment of primary and secondary liver cancer. Technetium-99 m macroaggregated albumin (MAA) scintigraphy is used as a surrogate of microsphere distribution to assess lung or digestive shunting prior to therapy, based on tumoral targeting and dosimetry. To date, this has been the sole pre-therapeutic tool available for such evaluation. Several dosimetric approaches have been described using both glass and resin microspheres in hepatocellular carcinoma (HCC) and liver metastasis. Given that each product offers different specific activities and numbers of spheres injected, their radiobiological properties are believed to lightly differ. This paper summarizes and discusses the available studies focused on MAA-based dosimetry, particularly concentrating on potential confounding factors like clinical context, tumor size, cirrhosis, previous or concomitant therapy, and product used. In terms of the impact of tumoral dose in HCC, the results were concordant and a response relationship and tumoral threshold dose was clearly identified, especially in studies using glass microspheres. Tumoral dose has also been found to influence survival. The concept of treatment intensification has recently been introduced, yet despite several studies publishing interesting findings on the tumor dose-metastasis relationship, no consensus has been reached, and further clarification is thus required. Nor has the maximal tolerated dose to the liver been well documented, requiring more accurate evaluation. Lung dose was well described, despite recently identified factors influencing its evaluation, requiring further assessment. MAA SPECT/CT dosimetry is accurate in HCC and can now be used in order to achieve a fully customized approach, including treatment intensification. Yet further studies are warranted for the metastasis setting and evaluating the maximal tolerated liver dose. (orig.)

  2. Clinical impact of {sup 99m}Tc-MAA SPECT/CT-based dosimetry in the radioembolization of liver malignancies with {sup 90}Y-loaded microspheres

    Energy Technology Data Exchange (ETDEWEB)

    Garin, Etienne [Cancer Institute Eugene Marquis, Department of Nuclear Medicine, Rennes (France); University of Rennes 1, Rennes (France); INSERM, U-991, Liver Metabolisms and Cancer, Rennes (France); Rolland, Yan [Cancer Institute Eugene Marquis, Department of Medical Imaging, Rennes (France); Laffont, Sophie [University of Rennes 1, Rennes (France); Edeline, Julien [University of Rennes 1, Rennes (France); INSERM, U-991, Liver Metabolisms and Cancer, Rennes (France); Cancer Institute Eugene Marquis, Department of Medical Oncology, Rennes (France)

    2016-03-15

    Radioembolization with {sup 90}Y-loaded microspheres is increasingly used in the treatment of primary and secondary liver cancer. Technetium-99 m macroaggregated albumin (MAA) scintigraphy is used as a surrogate of microsphere distribution to assess lung or digestive shunting prior to therapy, based on tumoral targeting and dosimetry. To date, this has been the sole pre-therapeutic tool available for such evaluation. Several dosimetric approaches have been described using both glass and resin microspheres in hepatocellular carcinoma (HCC) and liver metastasis. Given that each product offers different specific activities and numbers of spheres injected, their radiobiological properties are believed to lightly differ. This paper summarizes and discusses the available studies focused on MAA-based dosimetry, particularly concentrating on potential confounding factors like clinical context, tumor size, cirrhosis, previous or concomitant therapy, and product used. In terms of the impact of tumoral dose in HCC, the results were concordant and a response relationship and tumoral threshold dose was clearly identified, especially in studies using glass microspheres. Tumoral dose has also been found to influence survival. The concept of treatment intensification has recently been introduced, yet despite several studies publishing interesting findings on the tumor dose-metastasis relationship, no consensus has been reached, and further clarification is thus required. Nor has the maximal tolerated dose to the liver been well documented, requiring more accurate evaluation. Lung dose was well described, despite recently identified factors influencing its evaluation, requiring further assessment. MAA SPECT/CT dosimetry is accurate in HCC and can now be used in order to achieve a fully customized approach, including treatment intensification. Yet further studies are warranted for the metastasis setting and evaluating the maximal tolerated liver dose. (orig.)

  3. Evidence of fire resistance of hollow-core slabs

    DEFF Research Database (Denmark)

    Hertz, Kristian Dahl; Sørensen, Lars Schiøtt; Giuliani, Luisa

    is therefore going on in the Netherlands about the fire resistance of hollow-core slabs. In 2014 the producers of hollow-core slabs have published a report of a project called Holcofire containing a collection of 162 fire tests on hollow-core slabs giving for the first time an overview of the fire tests made....... The present paper analyses the evidence now available for assessment of the fire resistance of extruded hollow-core slabs. The 162 fire tests from the Holcofire report are compared against the requirements for testing from the product standard for hollow-core slabs EN1168 and knowledge about the possible......Hollow-core slabs have during the past 50 years comprised a variety of different structures with different cross-sections and reinforcement. At present the extruded hollow-core slabs without cross-reinforcement in the bottom flange and usually round or oval longitudinal channels (holes...

  4. Evolution of nickel sulfide hollow spheres through topotactic transformation

    Science.gov (United States)

    Wei, Chengzhen; Lu, Qingyi; Sun, Jing; Gao, Feng

    2013-11-01

    In this study, a topotactic transformation route was proposed to synthesize single-crystalline β-NiS hollow spheres with uniform phase and morphology evolving from polycrystalline α-NiS hollow spheres. Uniform polycrystalline α-NiS hollow spheres were firstly prepared with thiourea and glutathione as sulfur sources under hydrothermal conditions through the Kirkendall effect. By increasing the reaction temperature the polycrystalline α-NiS hollow spheres were transformed to uniform β-NiS hollow spheres. The β-NiS crystals obtained through the topotactic transformation route not only have unchanged morphology of hollow spheres but are also single-crystalline in nature. The as-prepared NiS hollow spheres display a good ability to remove the organic pollutant Congo red from water, which makes them have application potential in water treatment.In this study, a topotactic transformation route was proposed to synthesize single-crystalline β-NiS hollow spheres with uniform phase and morphology evolving from polycrystalline α-NiS hollow spheres. Uniform polycrystalline α-NiS hollow spheres were firstly prepared with thiourea and glutathione as sulfur sources under hydrothermal conditions through the Kirkendall effect. By increasing the reaction temperature the polycrystalline α-NiS hollow spheres were transformed to uniform β-NiS hollow spheres. The β-NiS crystals obtained through the topotactic transformation route not only have unchanged morphology of hollow spheres but are also single-crystalline in nature. The as-prepared NiS hollow spheres display a good ability to remove the organic pollutant Congo red from water, which makes them have application potential in water treatment. Electronic supplementary information (ESI) available: XRD patterns; SEM images and TEM images. See DOI: 10.1039/c3nr03371f

  5. CRYSTALLIZATION IN MULTICOMPONENT GLASSES

    Energy Technology Data Exchange (ETDEWEB)

    KRUGER AA; HRMA PR

    2009-10-08

    In glass processing situations involving glass crystallization, various crystalline forms nucleate, grow, and dissolve, typically in a nonuniform temperature field of molten glass subjected to convection. Nuclear waste glasses are remarkable examples of multicomponent vitrified mixtures involving partial crystallization. In the glass melter, crystals form and dissolve during batch-to-glass conversion, melter processing, and product cooling. Crystals often agglomerate and sink, and they may settle at the melter bottom. Within the body of cooling glass, multiple phases crystallize in a non-uniform time-dependent temperature field. Self-organizing periodic distribution (the Liesegnang effect) is common. Various crystallization phenomena that occur in glass making are reviewed.

  6. Crystallization In Multicomponent Glasses

    International Nuclear Information System (INIS)

    Kruger, A.A.; Hrma, P.R.

    2009-01-01

    In glass processing situations involving glass crystallization, various crystalline forms nucleate, grow, and dissolve, typically in a nonuniform temperature field of molten glass subjected to convection. Nuclear waste glasses are remarkable examples of multicomponent vitrified mixtures involving partial crystallization. In the glass melter, crystals form and dissolve during batch-to-glass conversion, melter processing, and product cooling. Crystals often agglomerate and sink, and they may settle at the melter bottom. Within the body of cooling glass, multiple phases crystallize in a non-uniform time-dependent temperature field. Self-organizing periodic distribution (the Liesegnang effect) is common. Various crystallization phenomena that occur in glass making are reviewed.

  7. The synthesis and photocatalytic activity of ZnSe microspheres

    International Nuclear Information System (INIS)

    Cao Huaqiang; Xiao Yujiang; Zhang Sichun

    2011-01-01

    This paper reports the synthesis of semiconductor ZnSe microspheres composed of nanoparticles via a solvothermal route between the organic molecule selenophene (C 4 H 4 Se) and ZnCl 2 without adding any surfactant. The ZnSe microspheres were characterized by x-ray diffraction (XRD), Raman spectroscopy, scanning electron microscopy (SEM), field emission scanning electron microscopy (FE-SEM), transmission electron microscopy (TEM), high resolution transmission electron microscopy (HRTEM), specific surface area measurement, and photoluminescence (PL) spectra. A strong and broad blue PL emission at 443 nm in wavelength (∼2.79 eV in photon energy) is attributed to the near-band-edge (NBE) emission of ZnSe, while the 530 nm peak is a defect-related (DL) emission. The photocatalytic activity of the as-prepared ZnSe microspheres was evaluated by photodegradation of methyl orange (MO) dye under ultraviolet (UV) light and visible light irradiation. The degradations of MO reach 94% or 95.1%, close to 100%, in the presence of the as-synthesized ZnSe microspheres or commercial ZnSe powder after 7 or 10 h under UV irradiation, respectively. Meanwhile the degradations of MO reach 94.3% or 60.6% in the presence of the as-synthesized ZnSe microspheres or commercial ZnSe powder after 12 h, respectively. The degradation rate of ZnSe microspheres is twice that of ZnSe commercial powder under UV light irradiation, and three times under visible light irradiation. The degradation process of MO dye on ZnSe microspheres under UV or visible light is also discussed.

  8. Microsphere-based super-resolution scanning optical microscope.

    Science.gov (United States)

    Huszka, Gergely; Yang, Hui; Gijs, Martin A M

    2017-06-26

    High-refractive index dielectric microspheres positioned within the field of view of a microscope objective in a dielectric medium can focus the light into a so-called photonic nanojet. A sample placed in such nanojet can be imaged by the objective with super-resolution, i.e. with a resolution beyond the classical diffraction limit. However, when imaging nanostructures on a substrate, the propagation distance of a light wave in the dielectric medium in between the substrate and the microsphere must be small enough to reveal the sample's nanometric features. Therefore, only the central part of an image obtained through a microsphere shows super-resolution details, which are typically ∼100 nm using white light (peak at λ = 600 nm). We have performed finite element simulations of the role of this critical distance in the super-resolution effect. Super-resolution imaging of a sample placed beneath the microsphere is only possible within a very restricted central area of ∼10 μm 2 , where the separation distance between the substrate and the microsphere surface is very small (∼1 μm). To generate super-resolution images over larger areas of the sample, we have fixed a microsphere on a frame attached to the microscope objective, which is automatically scanned over the sample in a step-by-step fashion. This generates a set of image tiles, which are subsequently stitched into a single super-resolution image (with resolution of λ/4-λ/5) of a sample area of up to ∼10 4 μm 2 . Scanning a standard optical microscope objective with microsphere therefore enables super-resolution microscopy over the complete field-of-view of the objective.

  9. Silica hollow core microstructured fibers for beam delivery in industrial and medical applications

    Directory of Open Access Journals (Sweden)

    Jonathan Dale Shephard

    2015-04-01

    Full Text Available The focus of this review is our recent work to develop microstructured hollow core fibers for two applications where the flexible delivery of a single mode beam is desired. Also, a review of other fiber based solutions is included.High power, short-pulsed lasers are widely used for micro-machining, providing high precision and high quality. However, the lack of truly flexible beam delivery systems limits their application to the processing of relatively small planar components. To address this, we developed hollow-core optical fibers for the 1 μm and green wavelength ranges. The hollow core overcomes the power delivery limitations of conventional silica fibers arising from nonlinear effects and material damage in the solid core. We have characterized such fibers in terms of power handling capability, damage threshold, bend loss and dispersion, and practically demonstrated delivery of high peak power pulses from the nanosecond to the femtosecond regime. Such fibers are ideal candidates for industrial laser machining applications.In laser surgical applications, meanwhile, an Er:YAG laser (2.94 μm is frequently the laser of choice because the water contained in tissue strongly absorbs this wavelength. If this laser beam is precisely delivered damage to surrounding tissue can be minimized. A common delivery method of surgical lasers, for use in the operating theatre, is articulated arms that are bulky, cumbersome and unsuitable for endoscopic procedures. To address this need for flexible mid-IR delivery we developed silica based hollow core fibers. By minimizing the overlap of the light with glass it is possible to overcome the material absorption limits of silica and achieve low attenuation. Additionally, it is possible to deliver pulse energies suitable for the ablation of both hard and soft tissue even with very small bend radii. The flexibility and small physical size of systems based on these fibers will enable new minimally invasive surgical

  10. Matrimid® derived carbon molecular sieve hollow fiber membranes for ethylene/ethane separation

    KAUST Repository

    Xu, Liren

    2011-09-01

    Carbon molecular sieve (CMS) membranes have shown promising separation performance compared to conventional polymeric membranes. Translating the very attractive separation properties from dense films to hollow fibers is important for applying CMS materials in realistic gas separations. The very challenging ethylene/ethane separation is the primary target of this work. Matrimid® derived CMS hollow fiber membranes have been investigated in this work. Resultant CMS fiber showed interesting separation performance for several gas pairs, especially high selectivity for C2H4/C2H6. Our comparative study between dense film and hollow fiber revealed very similar selectivity for both configurations; however, a significant difference exists in the effective separation layer thickness between precursor fibers and their resultant CMS fibers. SEM results showed that the deviation was essentially due to the collapse of the porous substructure of the precursor fiber. Polymer chain flexibility (relatively low glass transition temperature (Tg) for Matrimid® relative to actual CMS formation) appears to be the fundamental cause of substructure collapse. This collapse phenomenon must be addressed in all cases involving intense heat-treatment near or above Tg. We also found that the defect-free property of the precursor fiber was not a simple predictor of CMS fiber performance. Even some precursor fibers with Knudsen diffusion selectivity could be transformed into highly selective CMS fibers for the Matrimid® precursor. To overcome the permeance loss problem caused by substructure collapse, several engineering approaches were considered. Mixed gas permeation results under realistic conditions demonstrate the excellent performance of CMS hollow fiber membrane for the challenging ethylene/ethane separation. © 2011 Elsevier B.V.

  11. Arrays of Hollow Silica Half-Nanospheres Via the Breath Figure Approach

    KAUST Repository

    Gao, Yangqin; Hou, Yuanfang; Beaujuge, Pierre

    2015-01-01

    Breath figures (BFs) are patterns of liquid droplets that usually form upon condensation on a cold surface. Earlier work has shown that BFs can be used to produce continuous films of porous honeycomb-structured patterns on various types of materials, paving the path to a number of important applications such as the manufacturing of highly ordered nano- and micron-sized templates, micro lenses, and superhydrophobic coatings. It is worth noting, however, that few new findings have been reported in this area in recent years, limiting pursuits of novel architectures and key applications. In this report, an alternative method is described by which arrays of hollow silica half-nanospheres can be produced via BF templates. In the present method, a chemical vapor deposition (CVD) protocol performed while the BF is formed on a glass substrate yields a nanostructured pattern of silica half-spheres, which size (100-700 nm) and density across the glass surface vary with substrate modification and with the relative rates of water condensation and hydrolysis from silica precursors (a process carried out at room temperature). This method of forming arrays of hollow half-nanospheres via the BF approach may be applicable to various other oxides and a broad range of substrates including large-area flexible plastics. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  12. Arrays of Hollow Silica Half-Nanospheres Via the Breath Figure Approach

    KAUST Repository

    Gao, Yangqin

    2015-04-21

    Breath figures (BFs) are patterns of liquid droplets that usually form upon condensation on a cold surface. Earlier work has shown that BFs can be used to produce continuous films of porous honeycomb-structured patterns on various types of materials, paving the path to a number of important applications such as the manufacturing of highly ordered nano- and micron-sized templates, micro lenses, and superhydrophobic coatings. It is worth noting, however, that few new findings have been reported in this area in recent years, limiting pursuits of novel architectures and key applications. In this report, an alternative method is described by which arrays of hollow silica half-nanospheres can be produced via BF templates. In the present method, a chemical vapor deposition (CVD) protocol performed while the BF is formed on a glass substrate yields a nanostructured pattern of silica half-spheres, which size (100-700 nm) and density across the glass surface vary with substrate modification and with the relative rates of water condensation and hydrolysis from silica precursors (a process carried out at room temperature). This method of forming arrays of hollow half-nanospheres via the BF approach may be applicable to various other oxides and a broad range of substrates including large-area flexible plastics. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  13. Preparation of open porous polycaprolactone microspheres and their applications as effective cell carriers in hydrogel system

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Qingchun [Key Laboratory for Ultrafine Materials of Ministry of Education, School of Materials Science and Engineering (China); Tan, Ke; Ye, Zhaoyang [State Key Laboratory of Bioreactor Engineering, School of Bioengineering, East China University of Science and Technology, Shanghai, 200237 China (China); Zhang, Yan, E-mail: zhang_yan@ecust.edu.cn [Key Laboratory for Ultrafine Materials of Ministry of Education, School of Materials Science and Engineering (China); Tan, Wensong [State Key Laboratory of Bioreactor Engineering, School of Bioengineering, East China University of Science and Technology, Shanghai, 200237 China (China); Lang, Meidong, E-mail: mdlang@ecust.edu.cn [Key Laboratory for Ultrafine Materials of Ministry of Education, School of Materials Science and Engineering (China)

    2012-12-01

    Common hydrogel, composed of synthetic polymers or natural polysaccharides could not support the adhesion of anchorage-dependent cells due to the lack of cell affinitive interface and high cell constraint. The use of porous polyester microspheres as cell-carriers and introduction of cell-loaded microspheres into the hydrogel system might overcome the problem. However, the preparation of the open porous microsphere especially using polycaprolactone (PCL) has been rarely reported. Here, the open porous PCL microspheres were fabricated via the combined emulsion/solvent evaporation and particle leaching method. The microspheres exhibited porous surface and inter-connective pore structure. Additionally, the pore structure could be easily controlled by adjusting the processing parameters. The surface pore size could be altered from 20 {mu}m to 80 {mu}m and the internal porosities were varied from 30% to 70%. The obtained microspheres were evaluated to delivery mesenchymal stem cells (MSCs) and showed the improved cell adhesion and growth when compared with the non-porous microspheres. Then, the MSCs loaded microspheres were introduced into agarose hydrogel. MSCs remained alive and sustained proliferation in microsphere/agarose composite in 5-day incubation while a decrement of MSCs viabilities was found in agarose hydrogel without microspheres. The results indicated that the microsphere/hydrogel composite had a great potential in cell therapy and injectable system for tissue regeneration. Highlights: Black-Right-Pointing-Pointer The open porous polycaprolactone microspheres were fabricated using paraffin as a porogen. Black-Right-Pointing-Pointer The microspheres exhibited porous surface and inter-connective pore structure. Black-Right-Pointing-Pointer The surface and internal pore size and porosity of microsphere could be controlled. Black-Right-Pointing-Pointer The porous microspheres exhibited an improved cell adhesion and proliferation. Black

  14. Jingle-bell-shaped ferrite hollow sphere with a noble metal core: Simple synthesis and their magnetic and antibacterial properties

    Science.gov (United States)

    Li, Siheng; Wang, Enbo; Tian, Chungui; Mao, Baodong; Kang, Zhenhui; Li, Qiuyu; Sun, Guoying

    2008-07-01

    In this paper, a simple strategy is developed for rational fabrication of a class of jingle-bell-shaped hollow structured nanomaterials marked as Ag@ MFe 2O 4 ( M=Ni, Co, Mg, Zn), consisting of ferrite hollow shells and metal nanoparticle cores, using highly uniform colloidal Ag@C microspheres as template. The final composites were obtained by direct adsorption of metal cations Fe 3+ and M 2+ on the surface of the Ag@C spheres followed by calcination process to remove the middle carbon shell and transform the metal ions into pure phase ferrites. The as-prepared composites were characterized by X-ray photoelectron spectroscopy (XPS), energy-dispersive X-ray analysis (EDX), X-ray powder diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), UV-vis spectroscopy and SQUID magnetometer. The results showed that the composites possess the magnetic property of the ferrite shell and the optical together with antibacterial property of the Ag core.

  15. Recycling of Glass

    DEFF Research Database (Denmark)

    Christensen, Thomas Højlund; Damgaard, Anders

    2011-01-01

    Glass is used for many purposes, but in the waste system glass is predominantly found in terms of beverage and food containers with a relatively short lifetime before ending up in the waste. Furthermore there is a large amount of flat glass used in building materials which also ends up in the waste...... system; this glass though has a long lifetime before ending up in the waste. Altogether these product types add up to 82% of the production of the European glass industry (IPCC, 2001). Recycling of glass in terms of cleaning and refilling of bottles as well as the use of broken glass in the production...... of new glass containers is well established in the glass industry. This chapter describes briefly howglass is produced and howwaste glass is recycled in the industry. Quality requirements and use of recycled products are discussed, as are the resource and environmental issues of glass recycling....

  16. Ulex europaeus 1 lectin targets microspheres to mouse Peyer's patch M-cells in vivo.

    Science.gov (United States)

    Foster, N; Clark, M A; Jepson, M A; Hirst, B H

    1998-03-01

    The interaction of latex microspheres with mouse Peyer's patch membranous M-cells was studied in a mouse gut loop model after the microspheres were coated with a variety of agents. Carboxylated microspheres (diameter 0.5 micron) were covalently coated with lectins Ulex europaeus 1, Concanavalin A, Euonymus europaeus and Bandeiraea simplicifolia 1 isolectin-B4, human immunoglobulin A or bovine serum albumin. Of the treatments examined, only Ulex europaeus (UEA1) resulted in significant selective binding of microspheres to M-cells. UEA1-coated microspheres bound to M-cells at a level 100-fold greater than BSA-coated microspheres, but binding to enterocytes was unaffected. Incubation of UEA1-coated microspheres with alpha-L-fucose reduced M-cell binding to a level comparable with BSA-coated microspheres. This indicated that targeting by UEA1 was via a carbohydrate receptor on the M-cell surface. Adherence of UEA1-coated microspheres to M-cells occurred within 10 min of inoculation into mouse gut loops and UEA1-coated microspheres were transported to 10 microns below the apical surface of M-cells within 60 min of inoculation. UEA1-coated microspheres also targeted mouse Peyer's patch M-cells after intragastric administration. These results demonstrated that altering the surface chemistry of carboxylated polystyrene microspheres increased M-cell targeting, suggesting a strategy to enhance delivery of vaccine antigens to the mucosal immune system.

  17. A reproducible accelerated in vitro release testing method for PLGA microspheres.

    Science.gov (United States)

    Shen, Jie; Lee, Kyulim; Choi, Stephanie; Qu, Wen; Wang, Yan; Burgess, Diane J

    2016-02-10

    The objective of the present study was to develop a discriminatory and reproducible accelerated in vitro release method for long-acting PLGA microspheres with inner structure/porosity differences. Risperidone was chosen as a model drug. Qualitatively and quantitatively equivalent PLGA microspheres with different inner structure/porosity were obtained using different manufacturing processes. Physicochemical properties as well as degradation profiles of the prepared microspheres were investigated. Furthermore, in vitro release testing of the prepared risperidone microspheres was performed using the most common in vitro release methods (i.e., sample-and-separate and flow through) for this type of product. The obtained compositionally equivalent risperidone microspheres had similar drug loading but different inner structure/porosity. When microsphere particle size appeared similar, porous risperidone microspheres showed faster microsphere degradation and drug release compared with less porous microspheres. Both in vitro release methods investigated were able to differentiate risperidone microsphere formulations with differences in porosity under real-time (37 °C) and accelerated (45 °C) testing conditions. Notably, only the accelerated USP apparatus 4 method showed good reproducibility for highly porous risperidone microspheres. These results indicated that the accelerated USP apparatus 4 method is an appropriate fast quality control tool for long-acting PLGA microspheres (even with porous structures). Copyright © 2015 Elsevier B.V. All rights reserved.

  18. N-doped hollow urchin-like anatase TiO2@C composite as a novel anode for Li-ion batteries

    Science.gov (United States)

    Xing, Yalan; Wang, Shengbin; Fang, Baizeng; Song, Ge; Wilkinson, David P.; Zhang, Shichao

    2018-05-01

    N-doped hollow urchin-like anatase TiO2 spheres (HUTSs) with carbon coating (HUTS@C) are prepared through a facile and scalable hydrothermal reaction followed by coating of polypyrrole and carbonization. The HUTS is composed of radially grown anatase nanorods and possesses an enhanced percentage of exposed {001} facets compared with P25 TiO2 nanoparticles. After the carbon coating, the HUTS@C retains the hollow nanostructure although covered with an N-doped carbon layer. As an anode for Li-ion batteries, the HUTS@C delivers a higher capacity of 165.1 mAh g-1 at 1C after 200 cycles and better rate capability (111.7 mAh g-1 at 10C) than the HUTS. Further electrochemical studies reveal that the HUTS@C has a better electrochemical reversibility, lower charge-transfer resistance, and higher Li-ion diffusion coefficient due to its unique nanosctructure including the hollow core, anatase phase of TiO2 microspheres with high exposed {001} facets and the N-doped carbon layer, which facilitates mass transport and enhances electrical conductivity.

  19. Solvothermal synthesis of monodisperse LiFePO4 micro hollow spheres as high performance cathode material for lithium ion batteries.

    Science.gov (United States)

    Yang, Shiliu; Hu, Mingjun; Xi, Liujiang; Ma, Ruguang; Dong, Yucheng; Chung, C Y

    2013-09-25

    A microspherical, hollow LiFePO4 (LFP) cathode material with polycrystal structure was simply synthesized by a solvothermal method using spherical Li3PO4 as the self-sacrificed template and FeCl2·4H2O as the Fe(2+) source. Scanning electron microscopy (SEM) and transmission electron microscopy (TEM) show that the LFP micro hollow spheres have a quite uniform size of ~1 μm consisting of aggregated nanoparticles. The influences of solvent and Fe(2+) source on the phase and morphology of the final product were chiefly investigated, and a direct ion exchange reaction between spherical Li3PO4 templates and Fe(2+) ions was firstly proposed on the basis of the X-ray powder diffraction (XRD) transformation of the products. The LFP nanoparticles in the micro hollow spheres could finely coat a uniform carbon layer ~3.5 nm by a glucose solution impregnating-drying-sintering process. The electrochemical measurements show that the carbon coated LFP materials could exhibit high charge-discharge capacities of 158, 144, 125, 101, and even 72 mAh g(-1) at 0.1, 1, 5, 20, and 50 C, respectively. It could also maintain 80% of the initial discharge capacity after cycling for 2000 times at 20 C.

  20. A review on target drug delivery: magnetic microspheres

    Directory of Open Access Journals (Sweden)

    Amit Chandna

    2013-01-01

    Magnetic microsphere is newer approach in pharmaceutical field. Magnetic microspheres as an alternative to traditional radiation methods which use highly penetrating radiation that is absorbed throughout the body. Its use is limited by toxicity and side effects. The aim of the specific targeting is to enhance the efficiency of drug delivery & at the same time to reduce the toxicity & side effects. This kind of delivery system is very much important which localises the drug to the disease site. In this larger amount of freely circulating drug can be replaced by smaller amount of magnetically targeted drug. Magnetic carriers receive magnetic responses to a magnetic field from incorporated materials that are used for magnetic microspheres are chitosan, dextran etc. magnetic microspheres can be prepared from a variety of carrier material. One of the most utilized is serum albumin from human or other appropriate species. Drug release from albumin microspheres can be sustained or controlled by various stabilization procedures generally involving heat or chemical cross-linking of the protein carrier matrix.