bluuebunny/crossref_metadata_2025 huggingface dataset:
Microstructure and Mechanical Properties of a Biomedical β-Type Titanium Alloy Subjected to Severe Plastic Deformation after Aging Treatment
Authors: Yilmazer H. , Niinomi Mitsuo , Nakai Masaaki , Hieda Junko , Akahori Toshikazu , Todaka Yoshikazu
Published: March 2012

Strengthening by Grain Refinement and Increasing Dislocation Density through High-Pressure Torsion (HPT), which Is an Attractive Technique to Fabricate Ultrafine Grained and Nanostructured Metallic Materials, Is Expected to Provide β-Type Ti-29Nb-13Ta-4.6Zr (TNTZ) Higher Mechanical Strength while Maintaining Low Young’s Modulus because they Keep the Original β Phase. However, the Ductility Shows Reverse Trend. Greater Strength with Enhanced Ductility Can Be Achieved by Controlling Precipitated Phases through HPT Processing after Aging Treatment. Aged TNTZ Subjected to HPT Processing at HighNExhibits a Homogeneous Microstructure with Ultrafine Elongated Grains Having a High Dislocation Density and Consequently Non-Equilibrium Boundaries and Distorted Subgrains with Non-Uniform Shapes and Nanostructured Intergranular Precipitates of αphases. Therefore, the Effect of HPT Processing on the Microstructure and Mechanical Hardness of TNTZ after Aging Treatment Was Systematically Investigated in this Study. TNTZ, which Was Subjected to Aging Treatment at 723 K for 259.2 Ks in Vacuum Followed by Water Quenching, Subjected to HPT Processing at Rotation Numbers (N) of 1 to 20 under a Pressure of around 1.25 GPa at Room Temperature. The Microstructure of TNTZATConsisted of Precipitated Needle-Like α Phases in β Grains. However, TNTZAHPTatN≥ 10 Comprises Very Fine α and Small Amount ω Phases in Ultrafine β Grains. Furthermore, the Hardness of Every TNTZAHPTWas Totally much Greater than that of TNTZAT. The Hardness Increased from the Center to Peripheral Region of TNTZAHPT. In Addition, the Tensile Strength of Every TNTZAHPTWas Greater than that of TNTZAT. The Tensile Strength of TNTZAHPTIncreased, but the Elongation Decreased with IncreasingNand then both of them Saturated atN≥ 10.
Microstructural Change of β′ Phase and Hardness Change in As-Solutionized Dental Ag-20Pd-12Au-14.5Cu Alloy
Authors: Kim Yong Hwan , Niinomi Mitsuo , Hieda Junko , Nakai Masaaki , Fukui Hisao
Published: March 2012

Change in the Microstructure of the L10-Type Ordered β' Phase Precipitated in Ag-20Pd-12Au-14.5Cu Alloy (mass%) Subjected to Solution Treatment with Varying Solution Treatment Time Was Investigated. The Size of the β' Phase Is Found to Decrease with Increasing Solution Treatment Time and the Vickers Hardness of the Alloy after Solution Treatment Decreases. Experimental Observations Show that the Microstructural Change of the β' Phase Strongly Contributes to the Change in Vickers Hardness. In Addition, the Formation and Growth of the β' Phase Are Concluded to Be Affected by the Distribution of Elements through Solution Treatment.
Preparation of SiAlON-cBN Composites Using Ni Nanoparticle Precipitated cBN Powders
Authors: Zhang Jian Feng , Tu Rong , Goto Takashi
Published: March 2012

SiAlON Was Mixed with Ni Nanoparticle Precipitated cBN (SiAlON-cBN/Ni) and Sintered by Spark Plasma Sintering at 1923 K for a Holding Time (tH) of 0 to 1.8 Ks. the Effect of Ni Nanoparticle and Holding Time on the Phase Transformation of cBN to Hexagonal (hBN), Densification, Microstructure and Hardness of the SiAlON-cBN Composites Was Studied. AttH=1.8 Ks , the Relative Density of the SiAlON-20 Vol% cBN/Ni Was 99%, 7% Higher than that of SiAlON-20 Vol% cBN, Indicating that Ni Nanoparticle on cBN Promoted the Densification of SiAlON-cBN Composites. The BN Grains in SiAlON-20 Vol% cNB Showed a Round Morphology, whereas the BN Grains in SiAlON-20 Vol% cBN/Ni Composite Showed a Flake Morphology Characteristic of hBN. The Phase Transformation of cBN Was Accelerated by Ni. the Maximum Hardness of SiAlON-20 Vol% cBN/Ni Was 16.3 GPa Obtained attH= 0 Ks.
Deposition of BaTi2O5 Films on Si Substrates by Using MgO Buffers
Authors: Li L. , Wang Chuan Bin , Shen Qiang , Zhang Lian Meng
Published: March 2012

Using the (100)-Oriented MgO Thin Film as the Buffer Layer, BaTi2O5 Films Were Deposited on Si(100) Substrates by Pulsed Laser Deposition under Various Oxygen Partial Pressures (PO2). the Effects of PO2 on the Crystal Phase, Orientation and Surface Morphology of the as-Deposited Films Were Investigated. Single-Phased Bati2o5 Films Were Obtained at PO2 = 10-15 Pa, and the Preferred Orientation Changed from (710) to (020) with Decreasing PO2. at PO2 = 10 Pa, the BaTi2O5 Films with a Higher Degree of bItalic text-Axis Orientation and a Dense Texture Were Deposited on the Mgo(100)/Si(100) Substrates. The MgO Buffers Played an Important Role as Structural Templates for the Textured Growth of BaTi2O5 Films on Si Substrates.
Effect of Nitridation on Indium-Composition of InGaN Films
Authors: Choi Jung Hun , Kumar Suresh , Ji Shi Yang , Kanako Shojiki , Hanada Takashi , Katayama Ryuji , Matsuoka Takashi
Published: March 2012

The Present Study Aims to Understand the Relation between the Nitridation and Indium-Composition of Ingan Grown on Sapphire Substrate Using the Metalorganic Vapor Phase Epitaxy through X-Ray Diffraction Reciprocal Space Mapping Measurements. In-Composition of InGaN on Nitrided Sapphire Substrate Increased to 13% which Is Higher than the Sample without Nitridation with 7%. Also, Flat Surface Was Observed in the Nitrided Sample. Two Times Larger in-Plane Strain Was Induced at the Nitired Sample. Ingan Grown on Low-Temperature Gan Buffer, however, Did Not Show Clear Effect of Nitridation. The Two Investigated Samples Showed Similar Indium Composition, Surface Flatness, and in-Plane Strain with and without Nitridation. Differences of Indium Incorporation and Relaxation of in-Plane Strain Were Attributed to the Effect of AIN Formed by Nitridation Process.
Ba2TiO4 and Ba4Ti13O30 Thick Films Prepared by Laser Chemical Vapor Deposition and their Microstructure
Authors: Guo Dong Yun , Ito Akihiko , Tu Rong , Goto Takashi
Published: March 2012

Ba2TiO4 and Ba4Ti13O30 Thick Films Were Prepared by Laser Chemical Vapor Deposition Using Ba- and Ti-Dipivaloylmethanate Precursors. Single-Phase Ba2TiO4 Thick Films Were Obtained at 845–946 K and Ba/Ti Source Molar Ratio 2.4. Single-Phase Ba4Ti13O30 Films Were Obtained at 944–1011 K and Ba/Ti Source Molar Ratio 0.38. Ba2TiO4 Thick Films Consisted of Truncated Grains, while Ba4ti13o30 Thick Films Had Shellfish-Like Grains. Ba2TiO4 and Ba4Ti13O30 Thick Films Showed a Columnar Growth and their Deposition Rates Were 72 and 132 μm h−1, Respectively.
Comprehensive Approach for the Construction of New Material for Electronic Multipliers
Authors: Vikulova E.S. , Zherikova K.V. , Zelenina L.N. , Chusova T.P. , Sysoev S.V. , Shevtsov V. , Zubareva A.P. , Morozova N.B. , Igumenov I.K.
Published: March 2012

Volatile Complexes Mg(thd)2(TMEDA) (1) and Cs[Y(ptac)4] (2) (Hthd = 2,2,6,6-Tetramethylheptane-3,5-Dione, TMEDA = N,N,N’,N’-Tetramethylethylenediamine, Hptac = 1,1,1- Trifluoro-5,5-Dimethylhexane-2,4-Dione) Were Synthesized and Characterized. Thermal Properties of (1) and (2) Were Investigated by TG. The Temperature Dependencies of Saturated Vapour Pressure of Compounds Were Measured by Static (for (1)) or Flow (for (2)) Method. The Obtained Data Were Used for Choosing Temperature Parameters of Deposition Mg- and Cs-Containing Films by CVD Using (1) and (2) as Volatile Precursors. MgO Thin Films Were Deposited on Si (100) by Low-Pressure CVD (LPCVD) and Pulse-CVD in Temperature Deposition Range 673-823K. Cs- and Mg,Cs-Containig Films Were Formed by LPCVD. The Deposited Films Were Studied by SEM and AFM, Correlations between Temperature Conditions of Deposition Processes and Film Characteristics Were Found.
Crystal Growth and Scintillation Properties of Ce3+ and Mg2+ Co-Doped LiCaAlF6 Single Crystal
Authors: Yamaji Akihiro , Fujimoto Yutaka , Yanagida Takayuki , Kawaguchi N. , Futami Yoshisuke , Yokota Yuui , Yoshikawa Akira
Published: March 2012

Ce and Mg Co-Doped LiCaAlF6 (LiCAF) Single Crystals Were Grown by Micro-Pulling-down (μ-PD) Method and the Optical and Scintillation Properties of Obtained Crystals Were Measured. The Grown Crystals Were Crack-Free and Had 30-50 mm in Length and 2 Mm in Diameter. Absorption Coefficients Were Proportional to the Ce Nominal Concentrations. the Radioluminescence Spectra under 5.5 Mev Alpha-Ray Irradiation Showed Emission Peak at 290 and 310 nm due to Ce3+ 5d-4f Transitions, and Were Agreement with those of Ce Single-Doped LiCaF. The Highest Light Yield under 5.5 Mev Alpha-Ray Irradiation of Ce 4% and Mg 2% Co-Doped LiCaF Was Found to Be 0.6 Times than that of Lithium Glass Scintillator GS-20. Comparing the Light Yield of Licaf Samples with the Fixed Ce Nominal Concentration and Different Mg Co-Doped Concentrations, the Light Yield Increased with an Increase of Mg Nominal Concentration. the Alpha-Ray Excited Decay Times Were Constantly 45-50 ns.
Preparation of Bi3.6Ho0.4Ti3O12 Ceramics by Hot-Press Sintering
Authors: Wang Chuan Bin , Fu L. , Shen Qiang , Zhang Lian Meng
Published: March 2012

Hot-Press Sintering, a Method that Could Effectively Decrease the Densification Temperature due to the Applied Pressure, Was Employed to Prepare a New Kind of Ho3+ Doped Bi4Ti3O12 Ceramics, Bi3.6Ho0.4Ti3O12. The Effect of Preparation Parameters on the Crystal Phase, Density and Microstructure of the Ceramics Were Investigated. at First, Single-Phased Bi3.6Ho0.4Ti3O12 Powders Were Synthesized from Bi2o3, Tio2 and Ho2o3 Raw Powders by Solid-State Reaction and the Optimum Calcined Temperature Should Be 900 °C. The as-Synthesized Powders Were Further Densified at 750-900 °C to Prepare Bi3.6Ho0.4Ti3O12 Ceramics. Dense (relative Density Was 99.4 %) Bi3.6Ho0.4Ti3O12 Ceramics with a Compact Texture Were then Obtained by Hot-Press at 850 °C, about 150-200 °C Lower as Compared with Pressureless Sintering.
Ferromagnetic Resonance Study on FePt Thin Films with In-Plane Magnetization Using Coplanar Waveguide
Authors: Kang J. G. , Mizuguchi M. , Takanashi Koki
Published: March 2012

Ferromagnetic Resonance (FMR) of Epitaxial Fept Thin Films with in-Plane Magnetization Was Investigated by Measuring the Reflection Coefficient (S11) Using Coplanar Waveguides. FMR Signals of Four Fept Films Grown on Mgo (001) Substrates with Different Post-Annealing Temperatures Were Measured, and the Resonant Peaks of Fept Were Successfully Observed. Annealing Temperature Dependence Was Found in the Peak Frequency Shift Depending on the Magnetic Field Applied in the Film-Plane, which Is Attributable to the Difference of Magnetic Anisotropy of Fept Thin Films.
Studies on Properties of Epoxy Resin Base Piezoelectricity Damping Carbon Fiber Composite Materials
Authors: Qin Yan , Zhao Shi Wei , Dai Bi Fang , Mei Qi Lin , Huang Zhi Xiong
Published: March 2012

Damping Materials Have Been Wildly Used in Aerospace, Traffic, Construction Fields and so on. The Piezo-Damping Materials Have Received much Attention due to the Novel Energy Loss Mechanism. In this Paper, Piezo-Damping Composite Materials Were Prepared from the Epoxy Resin (EP) as the Resin Matrix, Nano Lead Titanate (Nano-PT) Ceramics as Piezoelectric Material and Chopped Carbon Fibers (CF) as Conductive Materials. The Mechanical and Damping Properties of the Composites Were Analyzed by Mechanics Test, DMA and Vibration Beam Method. The Results Showed that when the Nano-PT Content Was 60% of EP and CF Content Was 0.25% of EP, the Composite Got the Better Mechanical Properties. Form DMA, the Loss Factor (tanδ) Peak Reached 0.58. Damping Temperature Range △T (tanδ>0.3) Was about 36.3°C. In Comparison, Damping Loss Factor Measured by Vibration Beam Method Was 0.82.
Synthesis and Structural Investigation of Metal Hydride, Y(Mn1-xFex)2Hy (x ≤ 0.3, 4.0 ≤ y ≤ 4.5) and Complex Hydride, Y(Mn1-xFex)2H6
Authors: Kano Mika , Ito Takashi , Matsuo Motoaki , Takagi Shigeyuki , Semboshi Satoshi , Orimo Shinichi
Published: March 2012

It Has Been Reported that the Metal Hydride, Ymn2hy (y≤ 4.5), Wherein the Hydrogen Atoms Are Located into the Interstitial Sites, Transformed into a Complex Hydride, YMn2H6, Containing Complex Anions, [MnH6]5-. We Investigated the Possibility of Synthesizing the Complex Hydride, Y(Mn1-xFex)2H6(x≤ 0.3), where Mn Atoms Were Partially Substituted by Fe. As a Result, the Transformation into the Complex Hydride, Y(Mn1-Xfex)2H6, Was Successfully Realized forx≤ 0.10 upon the Hydrogenation of the Metal Hydride, Y(Mn1-xFex)2Hy(y= 4.4 and 4.5), under 50 Mpa H2, much Lower than the Previously Reported Value of 1 GPa. Our Structural Investigation Suggested that the Fe Substitution in Y(Mn1-xFex)2H6(x≤ 0.10) Resulted in the Form of Complex Anions, I.e., [MnH6]5-Were Partially Substituted by [FeH6]4-.
Tantalum Vacancy Effects on Electrical Conductivity of La3Ta0.5Ga5.5O14 and Ba-Based P321 Crystals
Authors: Chung Chan Yeup , Yaokawa Ritsuko , Mizuseki Hiroshi , Kawazoe Yoshiyuki
Published: March 2012

Single Crystalline Langatate (La3Ta0.5Ga5.5O14, LTG) Has Been Widely Used in Piezoelectric Sensors for High Temperature Applications because of its Structural Stability at High Temperature. however, in the Recent Experiment, an Increase of Electrical Conductivity Has Been Also Observed at the Intermediate Temperature Region Ranges from 300 to 700°C. Also, in Theoretical Calculations, Penta-Valent Ta Vacancy Can Be Easily Generated and Influence Resistivity Degradation of the Crystal. In this Study, to Elucidate the Ta Vacancy Effects on Electrical Conductivity of LTG and Recently Proposed Ba-Based P321 Crystal such as BTGS and BTAS, Electrical Conductivity of those Materials Were Calculated and Compared by Utilizing Boltzmann Transport Theory. The Calculated GW Band Gaps of Perfect BTGS and BTAS (5.94 Ev and 6.69 Ev, Respectivily) Were much Larger than that of LTG (5.36 Ev). Also, at Intermediate Temperature (1000K), the Calculated Electrical Conductivity of LTG with V'''''Ta (in Kröger-Vink Notation [13]) Was around Twelve Times Higher than the Conductivity of BTGS and BTAS with Ta Vacancy.
Silicon Carbide Coating on Diamond Powder by Rotary Chemical Vapor Deposition
Authors: Katsui Hirokazu , He Zhen Hua , Goto Takashi
Published: March 2012

Silicon Carbide (SiC) Layers Were Prepared on Diamond Powders by Rotary Chemical Vapor Deposition (RCVD) Using C6H18Si2as a Precursor. Diamond Particles with Cleavable and Sharp Configurations Were Covered with Smooth Layers by RCVD. Infrared Absorption Bands at around 800 and 1000 cm-1Attributed to Si-C Bonding Were Observed in FTIR Spectrum on the Diamond Powders. The Pellet Sample Sintered by Spark Plasma Sintering Using the Diamond Powders Suggested that β-SiC Was Deposited on the Diamond Particles.
Thermophysical and Radiative Properties of Conductive Biopolymer Composite
Authors: Antar Zied , Noel Hervé , Feller Jean François , Glouannec Patrick , Elleuch Khaled
Published: March 2012

Usual plate solar collectors, based on a metal absorber (Cu, Al) selectively coated are technologically very sophisticated, expensive to produce and they are great consumer of fossil raw material. Polymeric materials are considered as a promising alternative for many interesting properties; easy moldability, corrosion resistance, they also offer a significant cost-reduction for solar thermal collectors, and a mass production may thus benefit to a broader utilization of solar energy. Most drawbacks of polymers are their low thermal properties; essentially thermal conductivity coefficient may strongly affect the solar absorber efficiency and deteriorate the collector performance. Polymers used in solar collectors are mainly petroleum-derivative product and mass use of them is not a response to environmental concern. That is why the laboratory chose to explore the potentialities of bio-polymers for the production of absorbers. This group of material presents the same properties as ordinary polymers. It is on the other hand possible to modify the thermal properties of the basic matrix by the addition of loads, such as carbon black, graphite or carbon nanotubes. The thermal performance of a solar collector is closely related to the thermal properties of the absorber. Within this framework, many measurements are necessary, more particularly the conductivity, but also emissivity and absorptivity to solar radiation. The aim of this paper is to study the thermal properties of the PLA bio-polymer charged of exfoliated graphite and/or CNT. Thereafter, the total hemispherical absorptivity, an estimation of the total hemispherical emissivity and the thermal conductivity coefficient were measured for different load rates, we will conclude on the interest and the potentialities of tested materials.
Mechanical, Structural and Diffusion Studies of Hydrogel Polyurethane Nanocomposites Containing Modified Montmorillonite
Authors: Strankowska Justyna , Strankowski Michał , Piszczyk Łukasz , Haponiuk Józef , Kwela Jerzy
Published: March 2012

Polyurethane hydrogels nanocomposites belong to a new class of hybrid biomaterials with unique swelling properties in comparison to unmodified hydrogels. These materials combine the typical properties of gels (elasticity and permeability) with the reinforcing properties of clay nanoparticles. Therefore, nanohydrogels might be applied in pharmacy for the controlled release and delivery of drugs and other biologically active agents, as well as in cosmetology as strong absorbents. We synthesized nanohydrogel polyurethanes with Cloisite® 30B organically modified clay nanoparticles of montmorillonite to obtain hybrid materials possessing great swelling properties. These materials were studied by XRD, DMA, and water absorption capacity measurements. The synthesis procedure yielded stable and homogeneous hydrogel materials. Addition of clay nanoparticles causes an increase in the absorptivity of water molecules in the polyurethane matrix.
Conductive Properties of Inorganic/Organic Nanostructured Systems Based on Block Copolymers
Authors: Tercjak Agnieszka , Gutierrez Junkal , Mondragon Iñaki
Published: March 2012

The main aim of this work was the generation of novel smart materials, in this case thermo-responsive inorganic/organic meso/nanostructured hybrids based on different low molecular weight liquid crystals (LC) and conductive rutile TiO2 nanoparticles. LC as partially miscible with polystyrene (PS) was well-dispersed using amphiphilic poly (styrene-b-ethylene oxide) block copolymers (PS-b-PEO). Simultaneously, LC was used as surfactant for conductive rutile TiO2 nanoparticles.
The Mechanical and Thermal Properties of Polyoxymethylene (POM)/Organically Modified Montmorillonite (OMMT) Engineering Nanocomposites Modified with Thermoplastic Polyurethane (TPU) Compatibilizer
Authors: Leszczyńska Agnieszka , Pielichowski Krzysztof
Published: March 2012

In this work the effect of macromolecular polyurethane compatibilizer on the structure, mechanical and thermal properties of polyoxymethylene/organically modified montmorillonite (POM/OMMT) nanocomposites was investigated. The thermal stability of obtained systems was significantly enhanced by compatibilizer both in oxidative and inert atmosphere. The thermoanalytical methods (TG-FTIR and TG-MS) were used for identification of gaseous products of degradation. The results showed less intensive evolution of formaldehyde and formic acid during the thermal degradation of POM/TPU/OMMT nanocomposites. Both formaldehyde and formic acid had an autocatalytic effect on degradation of neat POM and POM/MMT nanocomposites, especially in the initial stage of the process. However, in the presence of TPU the monomer formed in depolymerization reaction was captured most probably by urethane linkage in a formylation process. The decreased concentration of catalytic agent is considered as a cause of the reduced rate of mass loss of POM/TPU/OMMT nanocomposites. Interestingly, during thermooxidative degradation the temperature of maximum rate of mass loss was shifted towards higher temperature more than it could be anticipated from the TGA results obtained for neat POM, POM/TPU blend and POM/OMMT nanocomposite material with corresponding contents of nanofiller and compatibilizer. It is likely that the mechanism of thermal stabilization may be also related to the physical barrier effect of layered silicate towards oxygen diffusion. Both chemical and physical mechanisms of stabilization are referred to the structure and interfacial area developed in nanocomposite materials and thus can be influenced by addition of a compatibilizer. The obtained POM/TPU/OMMT nanocomposites revealed higher impact strength as compared to POM/OMMT materials due to the presence of elastomeric domains facilitating the dissipation of impact energy.
Bioactivity of Fibrous Polymer Based Nanocomposites for Application in Regenerative Medicine
Authors: Stodolak-Zych Ewa , Góra Aleksander , Zych Łukasz , Szumera Magdalena
Published: March 2012

Aim of the work was production of nanocomposite polymer fibres containing ceramic particles using the electrospinning method and characterisation of morphology and bioactivity of the produced materials. The first stage of investigations consisted in preparation of a series of poly-L-lactide (PLA) solutions in various solvents mixtures in order to reach viscosity which would allow formation of fibres by the electrospinning method. Ceramic nanoparticles such as tricalcium phosphate (TCP) and silica (SiO2) were used as nanofillers of the polymer matrix. Their particle size distribution in the solvent solution as well as in the polymer suspension was determined by dynamic light scattering method (DLS). Morphology of the nanoparticles was observed using transmission electron microscopy (TEM). Distribution of the nanofillers in the nanocomposite fibres as well as diameter and morphology of the fibres was assessed using scanning electron microscopy with energy dispersive spectroscopy method (SEM/EDS). Effect of the nanofillers addition and the shaping method on the structure of the PLA matrix was investigated on the basis of the thermal analysis methods (TG/DSC) on the nanocomposite foils prepared by casting. It was revealed that the nanocomposite fibres showed apatite nucleation in in vitro conditions i.e. after incubation in SBF (37°C/ 3 days).
Recycled Carbon Fibres: Contact Angles and Interfacial Bonding with Thermoset Resins
Authors: Jiang Guo Zhan , Pickering Stephen J.
Published: March 2012

Recycled T800S carbon fibre from a polymer composite using a pyrolysis process was compared with virgin T800S fibre and the contact angle and interfacial shear strength with epoxy and vinyl ester resins were measured. The contact angles were measured using drop length-height method, and the interfacial shear strengths were measured using micro-bond method. For the same type of resin, the recycled T800S carbon fibre had a greater contact angle and lower interfacial shear strength than those of the virgin fibre.
In Vitro Drug Release Activity from Core/Shell Electrospun MATS of sPLA-cPEG/GS and sPLA/CA-cPEG/GS
Authors: Vichitchote Koravee , Threepopnatkul Poonsub , Suttiruengwong Supakij , Kulsetthanchalee Chanin
Published: March 2012

In this research, the core-shell structured fiber was fabricated by coaxial electrospinning technique. A set of biodegradable polymers namely polylactic acid (PLA) and cellulose acetate (CA) were used as the shell material. Gentamicin sulfate (GS) as antimicrobial drug with polyethylene glycol (PEG) was used as the core structure. PEG formed the core section of the coreshell fibers for GS encapsulation. In-vitro drug release activity of the core-shell fibers was determined by total immersion method in pH 7.4 phosphate buffer solutions (PBS). It was found that core-shell fibers sPLA-cPEG/GS exhibit higher initial release compared to that of core-shell fibers sPLA/CA-cPEG/GS.
Multiscale Modeling Electrospun Nanofiber Structures
Authors: Agić Ante
Published: March 2012

The carbon nanotube (CNT) structure is a promising building block for future nanocomposite structures. Mechanical properties of the electrospun butadiene elastomer reinforced with CNT are analyzed by multiscale method. Effective properties of the fiber at microscale determined by homogenization procedure using modified shear-lag model, while on the macro scale effective properties for the point-bonded stochastic fibrous network determined by volume homogenization procedure using multilevel finite element. Random fibrous network was generated according experimentally determined stochastic quantificators. Influence of CNT reinforcement on elastic modulus of electrospun sheet on macroscopic level is determined.
Photo-Induced Optical Anisotropy and Morphological Study in Azobenzene Containing Block Copolymers
Authors: Fernández Raquel , Zalakain Iñaki , Ramos José Angel , Martin Loli , Mondragon Iñaki
Published: March 2012

In this work, different types of nanostructured systems containing azobenzene groups were studied. With that aim, firstly, novel azo-functionalised block copolymers (BCP) were synthesized from epoxidized poly (styrene-b-butadiene-b-styrene) (SBS) modified with azobenzene units by one-step facile reaction between the epoxy groups and an azo-amine. The epoxy/amine reaction was verified by Fourier transform infrared spectroscopy. In addition, the effect of covalent attachment of the azobenzene moieties was investigated by analyzing the morphology and the optical anisotropic response of the resulting azo-containing BCP, with respect to solution mixing of the azobenzene as a guest in the BCP host without chemical bonding. On the other hand, epoxidized SBS was also used as template for the generation of nanostructured thermosetting epoxy matrices with azobenzene groups covalently linked. This BCP can self-assemble in the epoxy matrix to produce microphase-separated domains, thanks to the selective segregation of polystyrene blocks due to reaction induced microphase separation. In this case, the influence of the azobenzene content and the amount of epoxidized SBS on the generated morphologies and the photo-induced anisotropy was studied.
Phase Morphology and Molecular Structure Correlations in Model Fullerene-Polymer Nanocomposites
Authors: Bucknall David G. , Bernardo Gabriel , Shofner Meisha L. , Nabankur Deb , Raghavan Dharmaraj , Sumpter Bobby G. , Sides Scott , Huq Abul , Karim Alamgir
Published: March 2012

In this work we have performed a systematic study of blends of [6,-phenyl C61 butyric acid methyl ester (PCBM) with the following amorphous and semi-crystalline polymers: atactic polystyrene (PS), syndiotactic polystyrene (syn-PS), poly (2-vinyl-naphthalene) (P2VN), poly (9-vinyl-phenanthrene) (P9VPh), poly (vinylidene-fluoride) (PVdF) and poly (3-hexyl-thiophene) (P3HT). Experimental measurements using DSC, x-ray and neutron scattering coupled with molecular modeling (MD and DFT) have been utilized to determine the solubility and phase morphology of these model polymer-fullerene blends.
Elastomer Composites Containing Layered Fillers Modified with Ionic Liquids
Authors: Lipinska Magdalena , Laskowska Anna , Zaborski Marian
Published: March 2012

Montmorillonite is usually modified with ammonium salts, in our study the selected ionic liquids were applied as modifying agents for the intercalation of montmorillonite. Surface properties of modified fillers, the zeta potential of suspended solids in the water, the oil absorption number, the impact of modifications on the tendency to agglomerate in the non-polar and polar medium were studied. The modified fillers were used in two matrices with different polarity: the ethylene-propylene copolymer EPM and hydrogenated acrylonitrile-butadiene rubber HNBR. Elastomers were crosslinked with dicumyl peroxide DCP. The influence of the variously modified fillers on the cross-linking density of the vulcanizates, rheometric and mechanical properties of filled systems were investigated. The ageing studies (thermal, atmospheric and under UV radiations) were conducted.
Crystallinity and Crystallization Kinetics in Poly(Ethylene Oxide)/Layered Silicate Nanocomposites
Authors: Papananou Hellen , Fotiadou Sapfo , Chrissopoulou Kiriaki , Anastasiadis Spiros H.
Published: March 2012

Polymer materials are often filled with inorganic compounds in order to improve their properties [. The optimization of the properties is mostly achieved when the dimensions of the additive is in the nanometer range, producing a nanocomposite. Of particular interest among different organic / inorganic nanohybrids are polymer / layered silicate nanocomposites, which constitute a relatively new class of materials that has attracted growing scientific and technological interest due to the unique improvement of properties like strength, stiffness, scratch resistance, thermal and oxidative stability, gas permeability, flammability and biodegradability. These improved properties make them candidates for a number of potential applications in many industrial sectors like, for example, automotive, aerospace, electronics and biotechnology.
Modelling the partitioning of ammonium nitrate in the convective boundary layer
Authors: Aan de Brugh J. M. J. , Henzing J. S. , Schaap M. , Morgan W. T. , van Heerwaarden C. C. , Weijers E. P. , Coe H. , Krol M. C.
Published: March 2012

Abstract. An explanatory model study is presented on semi-volatile secondary inorganic aerosols on three clear days in May 2008 during the IMPACT campaign at the Cabauw tower in the Netherlands. A single column model in combination with the equilibrium aerosol model ISORROPIA is used. This model uses surface observations from IMPACT and calculates the gas-aerosol partitioning of ammonium nitrate. The calculated gas-aerosol equilibrium overestimates the gas phase fraction during daytime, and overestimates the aerosol phase fraction during night-time. This discrepancy can partly be solved when the approach of the gas-aerosol equilibrium is forced to proceed with a delay timescale of up to two hours. Although it is shown that the delay itself has a small effect, the most important effect is caused by the mixing of air from higher altitudes at which the equilibrium is shifted to the aerosol phase. Thus, vertical mixing is shown to have a significant influence on the calculated partitioning at the surface. On some occasions, the correspondence to the observed partitioning improves dramatically. Even though gas-aerosol partitioning of ammonium nitrate is not instantaneous, observations show that a different equilibrium in the upper boundary layer causes aerosol ammonium nitrate concentrations to increase with altitude. Our model calculates similar vertical gradients depending on the assumed speed of gas-aerosol equilibrium. The calculated optical properties of the aerosol show a similar behaviour. The aerosol optical properties depend on the aerosol size distribution both directly, because light scattering depends on particle size, and indirectly, because the equilibration timescale depends on the aerosol sizes. Future studies should therefore focus on a fully size-resolved treatment of the gas-aerosol partitioning. Finally, coarser-resolution models may treat the gas-aerosol equilibrium of ammonium nitrate by calculating the equilibrium with a temperature and humidity sampled at a different altitude. We found that the equilibrium at an altitude of 200 m (night) up to 600 m (day) is representative for the partitioning of ammonium nitrate at the surface in the beginning of May 2008.
Study of the applicability of the curlometer technique with the four Cluster spacecraft in regions close to Earth
Authors: Grimald S. , Dandouras I. , Robert P. , Lucek E.
Published: March 2012

Abstract. Knowledge of the inner magnetospheric current system (intensity, boundaries, evolution) is one of the key elements for the understanding of the whole magnetospheric current system. In particular, the calculation of the current density and the study of the changes in the ring current is an active field of research as it is a good proxy for the magnetic activity. The curlometer technique allows the current density to be calculated from the magnetic field measured at four different positions inside a given current sheet using the Maxwell-Ampere's law. In 2009, the CLUSTER perigee pass was located at about 2 RE allowing a study of the ring current deep inside the inner magnetosphere, where the pressure gradient is expected to invert direction. In this paper, we use the curlometer in such an orbit. As the method has never been used so deep inside the inner magnetosphere, this study is a test of the curlometer in a part of the magnetosphere where the magnetic field is very high (about 4000 nT) and changes over small distances (ΔB = 1nT in 1000 km). To do so, the curlometer has been applied to calculate the current density from measured and modelled magnetic fields and for different sizes of the tetrahedron. The results show that the current density cannot be calculated using the curlometer technique at low altitude perigee passes, but that the method may be accurate in a [3 RE; 5 RE] or a [6 RE; 8.3 RE] L-shell range. It also demonstrates that the parameters used to estimate the accuracy of the method are necessary, but not sufficient conditions.
Equinoctial asymmetry in solar activity variations of NmF2 and TEC
Authors: Chen Y. , Liu L. , Wan W. , Ren Z.
Published: March 2012

Abstract. The ionosonde NmF2 data (covering several solar cycles) and the JPL TEC maps (from 1998 through 2009) were collected to investigate the equinoctial asymmetries in ionospheric electron density and its variation with solar activity. With solar activity increasing, the equinoctial asymmetry of noontime NmF2 increases at middle latitudes but decreases or changes little at low latitudes, while the equinoctial asymmetry of TEC increases at all latitudes. The latitudinal feature of the equinoctial asymmetry at high solar activity is different from that at low solar activity. The increases of NmF2 and TEC with the solar proxy P = (F10.7+F10.7A)/2 also show equinoctial asymmetries that depend on latitudes. The increase rate of NmF2 with P at March equinox (ME) is higher than that at September equinox (SE) at middle latitudes, but the latter is higher than the former at the EIA crest latitudes, and the difference between them is small at the EIA trough latitudes. The phenomenon of higher increase rate at SE than at ME does not appear in TEC. The increase rate of noontime TEC with P at ME is higher than that at SE at all latitudes, and the difference between them peaks at both sides of dip equator. It is mentionable that the equinoctial asymmetries of NmF2 and TEC increase rates present some longitudinal dependence at low latitude. The influences of equinoctial differences in the thermosphere and ionospheric dynamics processes on the equinoctial asymmetry of the electron density were briefly discussed.
The effect of weather and its changes on emotional state – individual characteristics that make us vulnerable
Authors: Spasova Z.
Published: March 2012

Abstract. Given the proven effects of weather on the human organism, an attempt to examine its effects on a psychological and emotional level has been made. Emotions affect the bio tone, working ability, and concentration; hence their significance in various domains of economic life such as health care, education, transportation, and tourism. The present pilot study was conducted in Sofia, Bulgaria over a period of eight months, using five psychological methods: Eysenck Personality Questionnaire, State-Trait Anxiety Inventory, Test for Self-assessment of the emotional state, Test for evaluation of moods and Test ''Self-confidence-Activity-Mood''. The Fiodorov-Chubukov's complex-climatic method was used to characterize meteorological conditions in order to include a maximal number of meteorological elements in the analysis. Sixteen weather types are defined depending on the meteorological elements values according to this method. Abrupt weather changes from one day to another, defined by the same method, were also considered. The results obtained by t-test showed that the different categories of weather led to changes in the emotional status, which indicates a character either positive or negative for the organism. The abrupt weather changes, according to expectations, have negative effects on human emotions – but only when a transition to the cloudy weather or weather type, classified as ''unfavorable'', has been realized. The relationship between weather and human emotions is rather complicated since it depends on individual characteristics of people. One of these individual psychological characteristics, marked by the dimension ''neuroticism'', has a strong effect on emotional reactions in different weather conditions. Emotionally stable individuals are more ''resistant'' to the weather influence on their emotions, while those who are emotionally unstable have a stronger dependence on the impacts of weather.
Differences between the glacial cycles of Antarctic temperature and greenhouse gases
Authors: Omta A. W.
Published: March 2012

Abstract. Ice-core measurements have indicated that the atmospheric concentrations of the greenhouse gases CO2 and CH4 show glacial-interglacial variations in step with Antarctic temperature. To obtain more insight into the nature of this relationship for cycles of different frequencies, measured time series of temperature, CO2, and CH4 are reanalysed. The results indicate that the temperature signal consists of a linear superposition of a component related to CO2 with a period of ~100 000 yr and a component related to variations in the obliquity of the Earth's orbital plane with a period of ~41 000 yr. This suggests that either there operate very different feedback mechanisms at the different time scales or that CO2 is not merely a~passive follower and amplifier of the glacial-interglacial variations in Antarctic temperature.
An algorithm for generating soil moisture and snow depth maps from microwave spaceborne radiometers: Hydroalgo
Authors: Santi E. , Pettinato S. , Paloscia S. , Pampaloni P. , Macelloni G. , Brogioni M.
Published: March 2012

Abstract. A systematic and timely monitoring of land surface parameters that affect the hydrological cycle at local and global scales is of primary importance in obtaining a better understanding of geophysical processes and in managing environmental resources as well as natural disasters. Soil moisture and snow water equivalent are two quantities that play a major role in these applications. In this paper an algorithm (HydroAlgo) which is able to generate maps of snow depth (SD) and soil moisture content (SMC) from AMSR-E data has been developed and implemented within the framework of the JAXA ADEOS-II/AMSR-E and GCOM/AMSR-2 programs, as well as of a project of the Italian Space Agency that is devoted to civil protection from floods and landslides. As auxiliary output, the algorithm also generates maps of vegetation biomass (VB). An initial phase of pre-processing includes the improvement of spatial resolution, as well as masking for urban areas, water bodies, and dense vegetation. The algorithm was then split into two branches, the first of which focused on the retrieval of SMC and the second, on SD. Both parameters were retrieved using Artificial Neural Network (ANN) methods. The algorithm was calibrated using a wide set of experimental data collected on three sites: Mongolia and Australia (for SMC), and Siberia (for SD), integrated with model simulations. These results were then validated by comparing the algorithm outputs with experimental data collected on two additional sites: a part of a watershed in Northern Italy, and a large portion of Scandinavia. An additional test of the algorithm was also performed on a large scale, and included sites characterized by differing climatic and meteorological conditions.
Parameter identification and analysis of soluble chemical transfer from soil to surface runoff
Authors: Tong J. X. , Yang J. Z. , Hu B. X.
Published: March 2012

Abstract. A two-layer mathematical model is used to predict the chemical transfer from the soil into the surface runoff with ponding water. There are two incomplete infiltration-related parameter γ and runoff-related parameter α in the analytical solution to the model, which were assumed to be constant in previous studies (Tong et al., 2010). In this study, experimental data are used to identify the variable γ and α based on the analytical solution. The soil depth of the mixing zone is kept to be constant in different experiments, and the values of γ and α before the surface runoff occurs are constant and equal to their values at the moment the runoff starts. From the study results, it is found that γ will decrease with the increase of the surface runoff time, the increase of the ponding-water depth, hp, or with the decrease of the initial volumetric water content. The variability of γ will decrease with the increase of the initial volumetric water content. Similarly, α will decrease with time for the initially unsaturated experimental soils, but will increase with time for the initially saturated experimental soils. The larger the infiltration, the less chemical concentration in the surface runoff is. The analytical solution is not valid for experimental soil without any infiltration if α is expected to be less or equal to 1. The results will help to quantify chemical transfer from soil into runoff, a significant problem in agricultural pollution management.
Edwin James' and John Hinton's revisions of Maclure's geologic map of the United States
Authors: Aalto K. R.
Published: March 2012

Abstract. William Maclure's pioneering geologic map of the eastern United States, published first in 1809 with Observations on the Geology of the United States, provided a foundation for many later maps – a template from which geologists could extend their mapping westward from the Appalachians. Edwin James, botanist, geologist and surgeon for the 1819/1820 United States Army western exploring expedition under Major Stephen H. Long, published a full account of this expedition with map and geologic sections in 1822–1823. In this he extended Maclure's geology across the Mississippi Valley to the Colorado Rockies. John Howard Hinton (1791–1873) published his widely read text: The History and Topography of the United States in 1832, which included a compilations of Maclure's and James' work in a colored geologic map and vertical sections. All three men were to some degree confounded in their attempts to employ Wernerian rock classification in their mapping and interpretations of geologic history, a common problem in the early 19th Century prior to the demise of Neptunist theory and advent of biostratigraphic techniques of correlation. However, they provided a foundation for the later, more refined mapping and geologic interpretation of the eastern United States.
Limitations of a coupled regional climate model in the reproduction of the observed Arctic sea-ice retreat
Authors: Dorn W. , Dethloff K. , Rinke A.
Published: March 2012

Abstract. The effects of internal model variability on the simulation of Arctic sea-ice extent and volume have been examined with the aid of a seven-member ensemble with a coupled regional climate model for the period 1948–2008. Beyond general weaknesses related to insufficient representation of feedback processes, it is found that the model's ability to reproduce observed summer sea-ice retreat depends mainly on two factors: the correct simulation of the atmospheric circulation during the summer months and the sea-ice volume at the beginning of the melting period. Since internal model variability shows its maximum during the summer months, the ability to reproduce the observed atmospheric summer circulation is limited. In addition, the atmospheric circulation during summer also significantly affects the sea-ice volume over the years, leading to a limited ability to start with reasonable sea-ice volume into the melting period. Furthermore, the sea-ice volume pathway shows notable decadal variability which amplitude varies among the ensemble members. The scatter is particularly large in periods when the ice volume increases, indicating limited skill in reproducing high-ice years.
Equipoise and Equanimity in Motivational Interviewing
Authors: Miller William R.
Published: March 2012

The spirit of MI bespeaks a kind of equanimity as a general characteristic of MI practice. This desirable counselor quality is quite distinct from the conscious choice of counselor aspiration: whether to strategically move toward a particular change target, or to intentionally maintain neutrality withregard to change goal (the latter being referred to as equipoise). Both choices would involve equanimity, and both require intentional, conscious and skillful attention to the interpersonal dynamics of change talk that have been elucidated through the development of and research on MI.
Client-centered Direction: Or How to Get There When You’re Not Sure Where You’re Going
Authors: Wagner Christopher C.
Published: March 2012

Change is broader than behavior, and often starts before a goal or plan is conceived, with clients first opening up to the vague possibility of betterness. Collaboration is a hallmark of MI spirit, and therapeutic direction can be developed collaboratively in MI through the process of evokingclient values, desires, needs, hopes, and goals. Counselors may initially aspire to help clients find better lives, and narrow the focus to discrete change goals when specific client behaviors are collaboratively identified as obstacles to achieving a better life, or when absence of behaviors is identified as inhibiting progress toward it
Guidance for New Motivational Interviewing Trainers When Training Addiction Professionals
Authors: Schumacher Julie A. , Coffey Scott F. , Walitzer Kimberly S. , Burke Randy S. , Williams Daniel C. , Norquist Grayson , Elkin T. David
Published: March 2012

Evidence-based practices, such as motivational interviewing (MI), are not widely used in community alcohol and drug treatment settings. Successfully broadening the dissemination of MI will require numerous trainers and supervisors who are equipped to manage common barriers  to technology transfer. The aims of the our survey of 36 MI trainers were: 1) to gather opinions about the optimal format, duration, and content for beginning level addiction-focused MI training conducted by novice trainers and 2) to identify the challenges most likely to be encountered during provision of beginninglevel MI training and supervision, as well as the most highly recommended strategies for managing those challenges in addiction treatment sites. It is hoped that the findings of this survey will help beginning trainers equip themselves for successful training experiences
Delivering Quality Motivational Interviewing Training: A Survey of MI Trainers
Authors: Madson Michael B. , Lane Claire , Noble Jeremy J.
Published: March 2012

The MI community places an emphasis on attempting to understand the training process. Yet little is known about what MI trainers perceive as the important variables in training MI. A mixed method survey of 92 members of the Motivational Interviewing Network of Trainers was used to elicit important variables to consider in providing quality MI training. Based on results, it appears that MI trainers are familiar with Miller and Moyers’ (2006) eight stages of learning MI and used them to develop trainings. However, the respondents reported that they do not use these stages to evaluate trainings. Moreover, the respondents emphasized the importance of trainee and trainer variables in organizing trainings. They also provided varied opinions regarding the important ingredients in developing MI competency. The authors discuss the need for further empirical exploration of the important training ingredients and the eight stages model. Finally, the need for exploration of how these ingredients help trainees develop competency and future focus on the integration of best practices in adult learning is discussed.