bluuebunny/crossref_metadata_2025_split huggingface dataset:
Effect of the Sol-Gel Synthesis Parameters on the Incorporation of an Anti-inflammatory Drug in a Ceramic Material
Authors: Hernandez Aracely , Esquivel-Ferriño Patricia , Gomez Idalia , Cantu Lucia 
Published: April 2011

ABSTRACTIn the present work, sol-gel method was used to incorporate in a ceramic material a non steroidal anti-inflammatory drug (piroxicam) as model drug. The incorporation of the drug in the SiO2 network was carried out at different sol-gel synthesis parameters, such as pH (3 and 5) and the alkoxide/water ratio (1:6 and 1:8). The biomaterial obtained was analyzed by thermal analysis TGA-DTA, infrared spectroscopy (FTIR), Scanning Electronic Microscopy (SEM) and X-ray diffraction (XRD); specific surface area and porosity were analyzed from nitrogen adsorption isotherm. Better drug incorporation into the material was achieved at the synthesis conditions of pH 5 and 1:6 alkoxide/water molar ratio.
Covalent Grafting of Organoalkoxysilanes on Silica Surfaces in Water-Rich Medium as Evidenced by 29Si NMR
Authors: Bonhomme Christian , Monredon Sophie De , Ribot François , Babonneau Florence 
Published: April 2011

ABSTRACTDespite the huge amount of experimental investigations dedicated to the grafting of organoalkoxysilanes on silica, the characterization of covalent linkages remains a difficult task from a spectroscopic point of view. In most cases, the formation of a covalent link is taken for granted and not discussed. 29Si NMR, IR or UV spectroscopies are commonly used to study the modification of silica surface. Herein we report an unambiguous method to evidence the formation of covalent links. It is based on NMR spectroscopy analysis coupled with a rigorous synthetic grafting protocol.
Luminescent Silica Thin Films
Authors: Neouze Marie-Alexandra G. G. , Schubert Ulrich 
Published: April 2011

ABSTRACTLuminescent silica films were prepared by sol-gel synthesis under acidic conditions in the presence of fluoride ions. Luminescence was observed for both the pure inorganic film or film of a silica-based inorganic-organic hybrid material. Powders prepared from the same precursor mixtures were only fluorescent after calcination.
Conjugated Polymers as Part of Multifunctional Organic/Inorganic Hybrid Materials for Photovoltaic Applications
Authors: Lira-Cantu Monica , Krebs Frederik C. , Gomez-Romero Pedro , Yanagida Shozo 
Published: April 2011

ABSTRACTThe multifunctionality of hybrid organic-inorganic materials has been clearly demonstrated in recent years. Their application in solar- related devices is a growing research area with important technological implications. Our interest is centered on the interplay between the light-harvesting and hole-conducting properties of conjugated polymers and the wide band gap values observed from different inorganic semiconductor oxides. The materials applied in this work are the combination of semiconductor oxides like TiO2, ZnO, Nb2O5, CeO2 and TiO2-CeO2, and different conjugated polymers like poly[2-methoxy-5-(2'-ethyl-hexyloxy)-1,4-phenylene vinylene] (MEH-PPV) or poly(3,4-ethylenedioxythiophene) (PEDOT). Semiconductor oxides have been applied in different configurations like dense thin films, nanostructured electrodes or as nanoparticles. The conjugated polymers have been chosen depending on their light-harvesting properties (e.g. MEH-PPV) or due to their good electrical conductivity and hole conducting properties (e.g. PEDOT). We have characterized our devices in terms of Voc, Jsc, IV-curves, effect of different atmospheres and device lifetime under simulated sunlight irradiation. Tuning the different device parameters such as type of oxide applied, active layer thickness, starting materials concentration, effect of different atmospheres, effect of UV irradiation, etc., permit the fabrication of devices with well-defined properties. A brief discussion and comparison of hybrid solar cells (HSC) with solid-state Dye Sensitized Solar Cells (ss-DSC) applying nanocomposite materials based on TiO2 and PEDOT, as the electron and hole conducting materials respectively, is also included.
Influence of Lysozyme on the Biomimetic Growth of Silica Tubes in Porous Membranes
Authors: Gautier Clémentine , Courson Rémi , Lopez Pascal Jean , Livage Jacques , Coradin Thibaud 
Published: April 2011

AbstractPore channels of poly-carbonate membranes were recently used as biomimetic models to study the effect of confinement on silicate condensation, leading to the formation of silica tubes exhibiting a core-shell structure. In this work, we pre-immobilized lysozyme on the membrane pores, inducing the modification of the tube shell formation process, and variation in core particle size. These data strengthen previous assumptions on the role of interfacial interactions on the growth of the tube shell and indicate that such interactions also influence the core particle formation. Such approach therefore seems suitable to mimic the formation of silica/protein multilayers as found in several biomineralizing organisms
Carbon and Steel Surfaces Modified by Leptothrix Discophora SP-6: Characterization and Implications
Authors: Nguyen Tuan Anh , Lu Yuzhuo , Song Shizhe , Shi Xianming 
Published: April 2011

AbstractLeptothrix discophoraSP-6, a type of manganese(Mn)-oxidizing bacteria, has been known to accumulate Mn oxides from the aqueous environment and thus play a key role in microbiologically influenced corrosion by increasing the electrochemical potential of steel and other metals. Similarly, this bacterium was found to modify the surface of glassy carbon in aqueous solution and increase its potential (i.e. ennoblement). In the latter case, biomineralized Mn oxides can be used as cathodic reactants for a new generation of microbial fuel cells featuring a bio-cathode. In this preliminary study, factors affecting the biofilm formation and biomineralization processes were examined. The inflow of air into the culture medium was found essential to sustain the ennoblement of substrate electrodes. The OCP and FESEM/EDS data indicated that a smoother initial substrate surface generally led to better ennoblement. Polarizing the carbon electrode at +500mVSCE for 15 minutes was found to facilitate the ennoblement on carbon electrodes, and so did the coating with a poly(L-lysine) layer. Independent of substrate material, initial surface roughness and pretreatment, there were three parameters in the EIS equivalent circuit that correlated well with the OCP indicating the level of ennoblement byL. discophoraSP-6, i.e., electrolyte resistance, double-layer capacitance, and low-frequencies capacitance. These fascinating findings merit further investigation as they may shed light on the fundamental bacteria/substrate interactions and help advance the knowledge base needed for the engineering applications.
Making PEG-based Microparticles for Applications in Biology and Medicine
Authors: McDonald Tom Oliver , Christensen Søren , Ulijn Rein V 
Published: April 2011

AbstractWe demonstrate the polymerisation of PEGA hydrogel microparticles with a mean diameter of 16 µm (similar to that of biological cells), and we show that these particles are compatible with enzymes. Furthermore, we demonstrate that enzyme catalysed reactions occur faster with these microparticles than with commercially available macrobeads which are typically 200-400 µm in diameter.
Novel Collagen Based Material for Local Drug Delivery Systems
Authors: Castaneda Luciano , Pluskat Suzanne , Ky Darline , Te Earry , Slowinska Katarzyna 
Published: April 2011

AbstractIn a search for new drug delivery matrix, the synthesis of a novel collagen material based on tiopronin protected gold clusters (MPC) as a crosslinking agent is proposed. The structure of collagen matrix modified with MPC is studied using transmission electron microscope. The thermal properties are examined with differential scanning calorimetry. To assess the biocompatibility of the matrix, the cytotoxicity assays are conducted.
Fabrication of CMOS Compatible Sub-micron Nails for On-chip Phagocytosis
Authors: Huys Roeland , Bartic Carmen , Meerbergen Bart Van , Braeken Dries , Loo Josine , Winters Kurt , Chen Chang , Yitzchaik S. , Spira M. , Shappir J. , Borghs Gustaaf 
Published: April 2011

AbstractNeuronal research requires to efficiently perform long-time experiments on large-scale neuronal networks in a minimally invasive way. Such experiments imply stimulation and measurements of electrical activity on a large number of neurons. This could be achieved by on-chip integration of actuators, sensors and readout electronics with dimensions comparable to the sizes of neurons. Integration of biosensors at this scale creates new challenges: the processing of the sensors must be compatible with state-of-the art CMOS technology, the system must be biocompatible, and the down-scaled technology imposes restrictions on the applicable stimulation voltages and increases the electrical noise.Recently it has been demonstrated that biological phenomena can be exploited in order to achieve the best coupling between cells and sub-micron scale electronics. Engulfment of sub-micron nail structures by the cell membrane minimizes the distance between the sensor and the cell [1], [2].This paper presents two methods to produce nails with sizes from sub-micrometer to micrometer scales, on top of a CMOS chip. Prototype chips have been fabricated, and cells have been cultured to examine the in-vitro bio-compatibility of the chip.
A Potential of Large Scale of Dye Sensitized Solar Cells using Metallic Titanium Sheet as the Substrate for Photoelectrode
Authors: Onoda Kinji , Ngamsinlapasathian Supachai , Fujieda Takuya , Yoshikawa Susumu 
Published: April 2011

AbstractThe photovoltaic properties of dye-sensitized solar cells (DSCs) based on fluorine doped tin oxide (FTO) and Ti substrates were investigated. The sheet resistances of the substrates were correlated to the photovoltaic properties. The efficiency of the Ti substrate based DSC was higher than that of the FTO substrate based DSC, due to a high fill factor (FF). To minimize the internal resistance of the DSCs, Ti plate was used as a support for nanocrystalline TiO2, because of its low sheet resistance. As the light was absorbed by the electrolyte layer, the incident photon to current efficiency (IPCE) values decreased in the range between 400-600 nm. The electrolyte concentrations were optimized to obtain a higher cell performance. When using an electrolyte composed of 0.02 M I2, 0.2 M LiI, and 0.5 M 4-tert-butylpyridine, an efficiency of 4.98% was obtained for the Ti substrate based DSC with a short circuit current density (Jsc) of 11.25 mAcm-2, an open circuit voltage (Voc) of 0.692 V, and a FF of 0.639. The effect of the cell size on the photovoltaic properties was also investigated. The rate of decrease in a FF and efficiency with increase in the cell size was lower for the Ti substrate based DSCs than the FTO substrate based DSCs. This result indicates that Ti plate is a potential candidate for production of large DSCs.
Studies of Potassium Dihydrogen Phosphate (KDP) Crystals Doped with Potassium Dichromate (PD) using ICP and UV Spectrophotometer
Authors: Seif Selemani , Lal Ravindra Behari 
Published: April 2011

AbstractThis paper reports on preparation and characterization of Potassium Dihydrogen Phosphate (KDP) crystals doped with Potassium Dichromate (PD). The crystals were grown at room temperature by solution evaporation technique. The grown crystals were polished, sliced, and analyzed using UV-Spectrophotometer, which showed high concentration of PD impurities in KDP crystals at 200-280 nanometer. These concentrations were then verified using ICP measurements to determine specific amount in ppm of chromium ions in KDP crystals. In additional to that, the UV-transmittance data of these crystals were then converted to absorbance per thickness, and used to calculate absorption coefficients, extinction coefficients, and refractive index as a function of wavelength. The results showed that the presence of PD impurities in the crystal matrix of KDP has played a key reformative role in the UV sensing of Potassium Diphosphate crystals.
Post-annealing Induced Formation of ZnO Nanowires on the ZnO Films in the N2O Ambient
Authors: Lin Ping-Yuan , Liao Wei-Tsai , Yan Kuo-Yi , Chang Chia-Chi , Lin Hsin-Yuen , Wang Cheng-Liang , Gong Jyh-Rong , Lyu Dong-Yuan , Lin Jian-Hao , Lin Tai-Yuan , Lin Hung-Ji , Lin Der-Yuh 
Published: April 2011

AbstractZnO films were grown on (0001) sapphire substrates by atomic layer deposition (ALD) using diethylzinc (DeZn) and nitrous oxide (N2O) in an inductively heated reactor operated at atmospheric pressure. Low-temperature (LT) ZnO buffer layers having various thicknesses were deposited at 400¢J followed by subsequent growth of ZnO films at 600¢J. Some of the ZnO films were then post-annealed at 1000¢J in the N2O flow. Under certain growth conditions, ZnO nanowires were formed on the post-annealed ZnO samples. Room temperature (RT) photoluminescence (PL) spectra of the ZnO nanowires show strong ultraviolet (UV) near band edge emissions at 3.27 eV with a typical full width at half-maximum ( FWHM ) of ~130 meV and quenched defect luminescence at 2.8 eV. 10 K PL spectra of the post-annealed ZnO all exhibit sharp excitonic emissions with the dominant emission being located at 3.36 eV having a FWHM of 4.6 meV.
Improvement of Hydrogen Adsorption on Carbon Nanostructures
Authors: Lafi Lyubov , Chahine Richard , Bénard Pierre , Poirier Éric 
Published: April 2011

AbstractWe present results of a study of the effect of various surface treatments on the adsorption properties of hydrogen on single-walled carbon nanotubes (SWNTs) and activated carbon. The alteration of the surface area by thermal and chemical treatments of SWNTs was studied by Raman spectroscopy, x-ray photoelectron spectroscopy (XPS) and nitrogen adsorption. The Horwath-Kawazoe (HK) method was applied to describe the increase of the surface area and of the pore volume of the SWNT samples. The surface treatments lead to substantially improvement of hydrogen adsorption at 77 K and 1 atm. The averaged heat of adsorption (enthalpy), estimated from a Dubinin-Astakhov (DA) analysis, was found to be about 3.6 and 4.2 kJ/mol for heat-treated and as-received SWNTs, respectively.
Dielectric Relaxation and Dynamic Light Scattering Study of Liposome in the Aqueous Solution
Authors: Kundu Shyamal Kumar , Choe Song Gi , Yamamoto Wataru , Kita Rio , Yagihara Shin 
Published: April 2011

AbstractThe dynamic light scattering (DLS) has been used to investigate the diffusion behavior and the size distribution of liposome. DLS experiments show two classes of particles with their hydrodynamic radii being 4-12 nm and 66-80 nm. The numbers of particles associated with the two peaks are estimated by means of the scattering properties of the particles, which show that the overwhelming majority is big ones.Broadband dielectric spectroscopy (BDS) has been used to investigate the dynamical structure of liposome in aqueous solution of water, which makes it possible to precisely explain the molecular mechanism, structures and various properties as a function of temperature and frequency. We have observed four relaxation processes, where two low frequency processes are commonly observed in charged macromolecules in aqueous solution, third process appeared in the MHz region due to the motion of ions, which is also related to the molecular motion of the lipid, and the high frequency process appeared about 20 GHz is due to free water surrounding liposome. Gel-LC phase transition has been described very accurately from the temperature-dependent shape parameter, β, obtained from the Cole-Cole fitting. The β value in LC phase is smaller than that in gel phase.
Active Polymer Nanoparticles: Delivery of Antibiotics
Authors: Rabinovich Monica , Somayaji Shankari N. , Raghavan Pillai Rajeev , Hudson Michael C. , Ellington J. Kent , Bosse Michael , Horton James , Gonsalves Kenneth E. 
Published: April 2011

AbstractAntibiotic-encapsulated PLA and PLGA nanoparticles were prepared by the single emulsion-solvent evaporation technique. Different PLA and PLGA systems were prepared, varying the copolymer composition and the amount of the surfactant polyvinyl alcohol. Characterization and drug loading studies were performed by UV-Visible spectrophotometry, dynamic light scattering, and scanning electron microscopy (SEM).Simultaneously, in order to model the diffusion of the nanoparticles within the osteoblast, QDs such as functionalized InGaP/ZnS and polymer encapsulated InGaP/ZnS nanoparticles were added to confluent cultures of primary mouse osteoblasts. Following PreFer fixation, cultures were examined via confocal microscopy. QDs were clearly visible within osteoblasts.
Time evolution of Nano Dots created on InP(111) surfaces by keV irradiation
Authors: Paramanik Dipak , Majumdar Subrata , Sahoo Smruti Ranjan , Varma Shikha 
Published: April 2011

AbstractFabrication of Nanodots on semiconductor surfaces has immense importance due to their application in memory and optoelectronic devices. Ion irradiation methods display an easy and cost effective route for developing self assembled structures. We have studied the formation of Nano-dots on InP(111) surfaces by 3keV Ar ion irradiation. The distribution of nano Dots on InP surfaces has been investigated by Scanning Probe Microscopy (SPM). A 5 min irradiation of InP surface with Ar ions leads to the appearance of dots on the surface. The density of dots is, however very small. These dots have been obtained at room temperature, in the absence of sample rotation, with an angle of 15 degree between the ion axis and the sample normal. After an irradiation of 10 min a large density of dots appear on InP surface and display a narrow distribution of size and height. The dots at this stage have an average diameter of 25nm and a height of 4nm. With increased irradiation time the average size and the height of the dots increase and their distribution also become broader. This scenario, however, changes after a 40 min irradiation where large rectangular shaped dots of about 100 nm diameters and 40 nm height are observed. Surprisingly, for larger irradiation times a reduction in the size and heights is observed. The studies suggest “Critical Time” tc at t= 40 min such that the dot structures grow with time below tc but diminish in size beyond it.
Controlled Growth of Conducting Carbon Nanowires by Ion Irradiation: Electrical and Field Emission properties
Authors: Kumar Amit , Filip L D , Carey J. D. , Pivin J. C. , Tripathi A. , Avasthi D. K. 
Published: April 2011

AbstractThe conducting carbon nanowires embedded in fullerene matrix are synthesized by high energy heavy ion irradiation of thin fullerene film. We report the control growth of carbon nanowires, their electrical and field emission properties. The typical diameter of the conducting tracks is observed to be about 40 to 100 nm. The conductivity of the conducting zone is about seven orders of magnitude higher than that of the fullerene matrix. Conducting atomic force microscopy evidences the conducting nano wires. All the nanowires are parallel to each other and are perpendicular to the substrate. The density (spacing), growth direction and length of these carbon nanowires simply can be changed by ion fluence, angle of irradiation and the film thickness, respectively. The field emission measurements on these nanowires reveal that the threshold voltage is about ( ~13 V/mm), whereas the as deposited fullerene films shows a break down at ( ~ 51 V/mm). The present approach of making controlled conducting carbon nanowires is quite promising, as it takes few seconds of ion irradiation and no catalyst is required.
Pulsed Low-energy Ion-beam Induced Nucleation and Growth of Ge Nanocrystals on SiO2
Authors: Dvurechenskii Anatoly , Stepina Nataly , Novikov Pavel , Armbrister Vladislav , Kesler Valery , Gutakovskii Anton , Kirienko Victor , Smagina Zhanna , Groetzschel Reiner 
Published: April 2011

AbstractPulsed low-energy (200 eV) ion-beam-induced nucleation during Ge deposition on thin SiO2 film was used to form dense homogeneous arrays of Ge nanocrystals. The ion-beam action is shown to stimulate the nucleation of Ge nanocrystals when being applied after thin Ge layer deposition. Temperature and flux variation was used to optimize the nanocrystal size and array density required for memory device. Kinetic Monte Carlo simulation shows that ion impacts open an additional channel of atom displacement from a nanocrystal onto SiO2 surface. This results both in decrease of the average nanocrystal size and in increase of nanocrystal density.
Fabrication of Nanoscale Gold Clusters by Low Energy Ion Irradiation
Authors: Abidzina Volha , Tereshko I. , Elkin I. , Red'ko V. , Budak S. , Muntele C. , Walker D. , Ila D. 
Published: April 2011

AbstractThis work is focused on nanoscale gold particle formation by low-energy ion irradiation in glow-discharge plasma and studying particle growth by increasing time of exposure.SiO2+Au films on SiO2 substrates produced by ion beam assisted deposition (IBAD) were exposed to ion irradiation at 1.2 keV energy for 1-2 hours. Plasmon resonance appearance caused by nanoparticle formation was observed by Optical Absorption Spectrometry (OAS).
Properties of Nano-layers of Nanoclusters of Ag in SiO2 Host produced by MeV Si ion bombardment
Authors: Smith C.C. , Budak S. , Guner S. , Muntele C. , Minamisawa R. A. , Zimmerman R. L. , ILA D. 
Published: April 2011

AbstractWe prepared 50 periodic nano-layers of SiO2/AgxSiO2(1-x). The deposited multi-layer films have a periodic structure consisting of alternating layers where each layer is between 1-10 nm thick. The purpose of this research is to generate nanolayers of nanocrystals of Ag with SiO2 as host and as buffer layer using a combination of co-deposition and MeV ion bombardment taking advantage of the electronics energy deposited in the MeV ion track due to ionization in order to nucleate nanoclusters. Our previous work showed that these nanoclusters have crystallinity similar to the bulk material. Nanocrystals of Ag in silica produce an optical absorption band at about 420 nm. Due to the interaction of nanocrystals between sequential nanolayers there is widening of the absorption band. The electrical and thermal properties of the layered structures were studied before and after 5 MeV Si ions bombardment at various fluences to form nanocrystals in layers of SiO2 containing few percent of Ag. Rutherford Backscattering Spectrometry (RBS) was used to monitor the stoichiometry before and after MeV bombardments.
Molecular Dynamics Simulations of Diffusive-Ballistic Heat Conduction in Carbon Nanotubes
Authors: Shiomi Junichiro , Maruyama Shigeo 
Published: April 2011

AbstractHeat conduction of finite-length single-walled carbon nanotubes (SWNTs) has been studied by means of non-equilibrium molecular dynamics (MD) simulations. The length-dependence of the thermal conductivity was quantified for a range of nanotube-lengths at room temperature. The length dependence of thermal conductivity exhibits a gradual transition from nearly pure ballistic heat conduction to diffusive-ballistic heat conduction. The results show that the thermal conductivity profile does not converge even beyond a micrometer nanotube-length. Furthermore, the diameter dependence suggests that the phonon diffusion is reduced with the diameter.
Hydrogen Purification using Ultra-Thin Palladium Films Supported on Porous Anodic Alumina Membranes
Authors: Kirchner Alexander , Brown Ian W.M. , Bowden Mark E. , Kemmitt Tim 
Published: April 2011

AbstractNanostructured anodic alumina membranes have been utilized as high-temperature stable supports for 150 nm thick continuous palladium films. The palladium has been deposited by vacuum evaporation onto the rotating substrate. The thermal stability of the resulting compound membranes has been demonstrated for temperatures up to 700ºC under a reducing atmosphere. Hydrogen permeation has been measured up to 280ºC, where the permeability has a value of 2.5·10-7mol m-2s-1Pa-1. At the same time the selectivity factor over carbon dioxide is at least 33.