bluuebunny/crossref_metadata_2025 huggingface dataset:
Direct Metal Nano-patterning Using Embossed Solid Electrolyte
Authors: Kumar Anil , Hsu Keng , Jacobs Kyle , Ferreira Placid , Fang Nicholas
Published: September 2009

The recent growth in optoelectronics, nanoelectronics, nanooptics, and chemical and biological sensing has been fueled by the ability to fabricate nanostructures with ever smaller features. However, several significant constraints still remain in terms of cost, limited pattern size, processing conditions, pattern flexibility, and so on. Fabrication of features as small as 50 nm at ambient conditions with high pattern flexibility and low cost remains a serious challenge. Here we report a new solid-state electrochemical imprinting process that is carried out at ambient conditions, requires nominal pressure and very low electric potential, eliminates any liquid electrolytes, shows very high reproducibility, and promises the capability to scale up for large area patterning while retaining a significant cost advantage. Through combination of the best merits of nanoimprint lithography, micro forming, and the solid-state electrochemical imprinting technique, S4, (recently introduced by Hsu et al., Nano Lett., 2007, 7, 446; and Schultz et al., J. Vac. Sci. Techol. B, 2007, 25, 2419), we show a very high pattern flexibility to create nano-scale metallic features.

As a first step, we use a micro-forming-like embossing process to engrave nano-scale features onto a solid electrolyte tool surface using an e-beam fabricated Si mold. Silver sulfide, Ag2S, is used as a solid electrolyte because of its favorable mechanical properties for micro forming and its excellent electrochemical properties. This ionic compound is ductile and has a relatively low yield stress at 80MPa. Followed by embossing, the patterned solid electrolyte surface is then used to carry out the S4 process, creating a negative image on a metallic substrate. This process eliminates the costly Focused Ion Beam milling used by Hsu et al. to create features on the electrolyte tool. It is also highly favorable for large-area patterning as well as mass-production of metallic substrates restricted only by the capability to fabricate the mold at first step. The embossed solid-electrolyte tool surface can be easily trimmed off with a microtome; the tool can then be re-used for embossing and patterning metallic substrates.

Using this process we demonstrate the ability to fabricate silver nanostructures with features <15 nm. Such small features are critical in metal nanostructures for field enhancement that finds applications in SERS and other biological and chemical sensing. So far, a line edge roughness of <10 nm is observed which is significant in the sense that silver is highly mobile and has the tendency to granulate. Finally, we show how this methodology has the capability to fabricate large area patterns at low cost and ambient conditions. As a proof of concept, we demonstrate the ability to fabricate areas >30 sq. mm. Such large scale fabrication is highly desired for applications like biomimetics and patterning for superhydrophobic surfaces.
Failure Analysis and Process Improvement for Through Silicon Via Interconnects
Authors: Majeed Bivragh , Cauwenberghe Marc Van , Tezcan Deniz Sabuncuoglu , Soussan Philippe
Published: September 2009

This paper investigates the failure causes for slopped through silicon vias (TSV) and presents process improvement for implementing the slopped TSV for 3D wafer level packaging (WLP). IMEC is developing slopped and scaled generic approaches for 3D WLP. Previously we have reported on the integrated process flow for the slopped (TSV) and showed the feasibility of Parylene N as a dielectric material. In the TSV process discussed here, firstly 200mm device wafer is bonded facedown on a carrier using temporary glue layer and thinned by grinding. TSV's are realized by dry etching from the wafer backside, followed by dielectric deposition and patterning. Dielectric patterning is done at the bottom of the via on 100 microns thin silicon device wafer supported by the carrier. Finally, conformal plating is done inside the via to obtain the interconnections.

This paper discusses the yield killer or failure causes in the slopped TSV process. There can be many parameter including silicon etch uniformity, dielectric etching at the bottom of the via and resist residue inside the via that can reduce the yield of the process. We report that one of the main factors contributing to the yield loss is silicon dry etching effects including non-uniformity and notching. Using standard Bosch etching process, notching at the interface between landing oxide and silicon has been observed. The notching cause a discontinuity at the bottom of the via resulting in no plating at the bottom interface.

In this paper we report on a new via shape that is a combination of slopped and straight etching sequence to overcome the notching problem. Different parameters including influence of grinding marks, mask opening, wafer thickness variation, etching rate and etching profile across the wafer were investigated. The optimized design rules for mask opening and effect of individual etching parameters on the etching profile will be presented. In etching, firstly a sloped via with slope of 60 degrees is optimized with changing different etching parameters including different gasses and pressure. Slope via facilitates in subsequent dielectric deposition and sputtering processes. Secondly, a straight wall etching process based on Bosch process and soft landing step with longer passivation steps were investigated to obtain the notch free etching profile. The optimized etching process is notch free, very repeatable and total variation across different wafers is less then 2 percent for 100 micron target opening.

This paper reports the failure analysis of TSV and discuses the processes improvement to obtain higher yielding vias. Different parameters that reduced the yield are discussed with main focus on notching effects during silicon etching. An improved and characterized, notch free uniform silicon etching across the wafer process based on two step etching is presented. An integration flow implementing the above optimized parameters with electrical yield will be detailed in the paper.
Power Delivery, Signaling and Cooling for 3D Integrated Systems
Authors: Bakir Muhannad , Huang Gang
Published: September 2009

Three-dimensional (3D) integration of ICs provides unique opportunities to improve bandwidth, latency, and power dissipation bottlenecks of interconnects (both on- and off-chip). However, while 3D IC integration improves signal interconnection, it also presents new challenges, especially in power delivery and cooling (“thermal interconnects”). The focus of this paper is on some of the key challenges and promising technologies to address power delivery, cooling, and signaling in a 3D stack of logic ICs.
Effect of Cyclic Damage on the Constitutive Behavior & Microstructure of Sn3.0Ag0.5Cu (SAC305) Solder
Authors: Cuddalorepatta Gayatri , Dasgupta Abhijit
Published: September 2009

This study examines the effect of cyclic damage on the constitutive response and microstructural evolution of SAC305 solder. Cyclic damage is induced through isothermal, mechanical cycling tests at high strain rate and room temperature, using modified lap shear microscale specimens (180μm wide solder joint). The properties of interest are elastic, plastic, yield, and viscoplastic material constitutive behavior. In the current study, creep strain accumulation is accommodated when determining the constants, unlike those reported in prior studies [1]. Insights into the evolution of the measured properties are provided by correlating previously reported microstructural grain evolution of microscale SAC305 solder as a function of cyclic damage [2, 3].

The hysteresis response and the elastic, plastic and yield measurements from the initial cycles show significant piece-to-piece variability (similar to prior virgin state viscoplastic measurements [3]). The scatter arises since as-reflowed SAC solder joints at length scales of 200μm consist of only a few anisotropic Sn grains that make the joint mechanically inhomogeneous. However, when subject to mechanical cycling fatigue at room temperature these joints undergo grain homogenization due to recrystallization, which is a possible explanation to the drop in scatter with progressing damage. The observed grain evolution is similar to that seen in solder joints under life-cycle loading.

The elastic-plastic response and yield strength of SAC305 solder do not show significant contribution from creep deformations at the chosen load levels. The properties degrade with increasing accumulated cyclic damage, at a rate that is proportional to the severity of the cyclic load. The yield stress measurements suggest that SAC305 obeys an independent hardening rule, rather than isotropic or kinematic hardening. The performance of a continuum damage mechanics based model from prior studies in representing the measured degradation in elastic, plastic and yield properties is discussed [4,5].

Comparison of the creep behavior of cycled SAC305 specimens (at 50% load drop) with that of uncycled specimens shows that the effective creep compliance and effective secondary creep strain rate increase significantly. As a point of comparison, the creep resistance of cycled SAC305 specimens is even lower than that of as-reflowed Sn37Pb specimens. Similar changes are seen in the stress relaxation behavior. Challenges and limitations of the current studies are included.
Comparison of Carbon-based Nanostructures with Commercial Products as Thermal Interface Materials
Authors: Rosshirt Michael , Fabris Drazen , Cardenas Christopher , Wilhite Patrick , Tu Thanh , Yang Cary Y.
Published: September 2009

Heat dissipation in electronics packaging can be highly dependent on Thermal Interface Materials (TIM). TIM contact, compliance, and conductivity can be the dominant limiting factors in the overall conduction heat transfer across the interface. Mixing multiwall Carbon Nanotubes (CNTs), which have high thermal conductivity, with other thermally conducting materials holds great promise as TIM fillers and has been shown to have higher thermal performance than commercial TIM ‘1’. Such mixtures possess greater thermal conductivity as a result of increased thermal conduction paths through highly conductive, high aspect ratio CNTs.

In this work, we develop and test an advanced apparatus based on the ASTM D5470-06 standard to measure thermal interface resistance. Our experimental findings quantify the thermal performance trends of industry-standard TIM Arctic Silver® 5 along with hybrid TIM mixtures of Arctic Silver®5 and varying weight ratios of CNTs. Early experimental findings show that Arctic Silver®5 mixed with 0.5 to 1% multiwall CNT by weight may improve thermal conductivity over pure Arctic Silver®5.The goal of this research is to investigate the viability of integrating CNTs with commercial products as improved TIM for electronic cooling in chip packages.
Novel Crystallization Temperature Measurement Method for Combinatorial Evaluation using Infrared Thermography
Authors: Aono Yuko , Hata Seiichi , Sakurai Junpei , Shimokohbe Akira
Published: September 2009

In combinatorial method, combinatorial evaluation of thin film library has not been established enough, so efficiency of searching by this method is limited. One of property which has not been available combinatorial evaluation is crystallization temperature (Tx). Conventionally, Tx is measured using differential scanning calorimeter (DSC), but it is impossible to apply to the thin film library. Because its one sample size is 1×1 mm, thickness is several micrometers, and 1,089 samples (33columns and 33 rows) are integrated on one library, so the samples are too small to measure using DSC. In this study, an alternative method using infrared thermography is presented for combinatorial evaluation of Tx. This device detects infrared energy radiated from an object and its temperature can be calculated using its own emissivity.

In crystallization point, electrical resistivity change is lead with structure change, and this derives emissivity change. Low electrical resistivity means less free electron that is low reflectivity and high emissivity. In heating test, while emissivity keeps constant, T-Ta curve (T: true sample temperature, Ta: apparent temperature measured by thermography) gradient is constant, but the point of Tx, T-Ta curve gradient changes by change of emissivity. Therefore transformation point can be detected by T-Ta curve gradient change. This method can be applied to thin film library, because the method requires only observation of sample surface.

PtSi and PdCuSi amorphous alloys were employed to confirm this method. First, homogeneous amorphous alloy thin films were deposited on alumina wafer (20×20mm). Each of these samples was then heated in vacuum chamber with monitoring infrared images and electrical resistivity, in-situ. Obvious emissivity change could be detected at the same temperature of electrical resistivity change. This temperature also agrees enough with DSC results. In case of Pt67Si33, emissivity change was detected at 511K, and DSC result shows Tx at 516K, there is only 5K error between these values. At this temperature, both electrical resistivity and emissivity decreased and it agrees with the theory. Sample crystallization was confirmed after heating test by X-ray diffraction.

Measurement on the thin film library was then considered. A quarter thin film library was used, 256 samples (16×16) are integrated and each sample size is 1×1mm separated 0.2mm grid made by sputtering on alumina wafer. For first inspection, all samples were same composition PdCuSi amorphous alloy. Every 3×3 samples, center sample were blank, i.e. alumina surface, its emissivity is stable so the surface indicated reference temperature of around samples. Alumina emissivity was calibrated using a thermo couple on the sample wafer. 184 samples in the all samples were measured at one time, Tx can be detected in all 184 samples and these value errors ranged in 15K. Therefore, this method has a great of potential in combinatorial method.
Broadband (0.3∼11THz) reflection spectroscopy using terahertz air photonics
Authors: Guo Xiaoyu , Ho I-Chen , Zhang Xi-Cheng
Published: September 2009

Pulsed THz wave spectroscopy using air as the THz wave emitter with the excitation of femtosecond laser provides intense (>100 kV/cm) and broadband THz waves (usable bandwidth from 0.3 to 11 THz). Using the air-biased-coherent-detection (ABCD) method, air can also coherently detect pulsed THz waves over a broadband spectrum. By utilizing these two technologies, we developed a prototype THz air photonics time-domain reflection spectrometer, and applied it on many materials in normal reflection geometry. Optical properties of CaCO3 crystals and several other samples in the THz range were studied. The system provided a signal-to-noise ratio (SNR) over 1000:1, with 0.1 cm−1 frequency resolution. The results acquired from both transmission and reflection measurements were then compared.
Materials Characterization using THz Ellipsometry
Authors: Hofmann Tino , Herzinger Craig M. , Woollam John A. , Schubert Mathias
Published: September 2009

We employ spectroscopic ellipsometry in the terahertz (0.2 to 1.5 THz) and the mid-infrared (9 to 50 THz) spectral range for the non-contact, non-destructive optical determination of the free-charge-carrier properties of low-doped Silicon bulk and thin film structures. We find that carrier concentrations as low as 1015 cm−3 in thin films can be unambiguously determined. We envision ellipsometry in the THz spectral range for future non-contact, non-destructive monitoring and control applications.
Tb-doped Aluminosilicate Oxyfluoride Scintillating Glass and Glass-ceramic
Authors: Pan Zhengda , James K. , Cui Y. , Burger A. , Cherepy Nerine , Payne S. A. , Ueda A. , Aga R. , Mu R. , Morgan S. H.
Published: September 2009

Two aluminosilicate oxyfluoride glass systems, a lead-cadmium-aluminosilicate oxyfluoride and a lithium-lanthanum-aluminosilicate oxyfluoride, doped with different TbF3 concentrations, have been fabricated and investigated. By appropriate heat treatment of the as-prepared glasses above, transparent glass-ceramics (TGC) were obtained. The glass-ceramics contain Tb:Pb(Cd)F2 or Tb:LaF3 nano-crystals in the glass-matrix. Differential scanning calorimetry, Raman scattering, and luminescence under both UV and β-particle excitation have been investigated on as-prepared glasses and glass-ceramics. It has been found that the terbium-doped lithium-lanthanum-aluminosilicate oxyfluoride glass exhibits good UV excited luminescence and β-induced luminescence. The luminescence yield increases for glass-ceramic compared to that of the as-prepared glass. The including of LaF3 in the glass-matrix is beneficial for a higher Tb-doping concentration and a high light yield. The light yield of lithium-lanthanum-aluminosilicate oxyfluoride glass and glass-ceramic is comparable to that of Schott IQI-301 product. However, the terbium-doped lead-cadmium-aluminosilicate oxyfluoride glass and glass-ceramic have a detrimental luminescence performance. The lead cations in the glass-matrix may create non-bridging oxygen defects, which are a strong source of charge traps, and correlated to a strong Raman “Boson” peak.
The Synthesis and Structures of Elpasolite Halide Scintillators
Authors: Yang Pin , Doty F. Patrick , Rodriguez Mark A. , Sanchez Margaret R. , Zhou Xiaowong , Shah Kanai S.
Published: September 2009

Low-cost, high-performance gamma-ray spectrometers are urgently needed for nonproliferation and homeland security applications. Available scintillation materials fall short of the requirements for energy resolution and sensitivity at room temperature. The emerging lanthanide halide based materials, while having the desired luminosity and proportionality, have proven difficult to produce in the large sizes and low cost required due to highly anisotropic properties caused by the non-cubic crystal structure. New cubic materials, such as the recently discovered elpasolite family (A2BLnX6; Ln-lanthanide and X-halogen), hold promise for scintillator materials due to their high light output, proportionality, and toughness. The isotropic nature of the cubic elpasolites leads to minimal thermomechanical stresses during single-crystal solidification, and eliminates the problematic light scattering at the grain boundaries. Therefore, it may be possible to produce these materials in large sizes as either single crystals or transparent ceramics with high production yield and reduced costs. In this study, we investigated the “cubic” elpasolite halide synthesis and studied the structural variations of four different compounds, including Cs2NaLaBr6, Cs2LiLaBr6, Cs2NaLaI6, and Cs2LiLaI6. Attempts to produce a large-area detector by a hot forging technique were explored.
Growth of Cu-Rich/Poor CuInS2 thin films by the sequential modulated flux deposition technique
Authors: Bollero Alberto , Grossberg Maarja , Raadik Taavi , Trigo Juan Francisco , Herrero José , Gutiérrez M. Teresa
Published: September 2009

CuInS2 has emerged during recent years as a good candidate to substitute CuInSe2 as polycrystalline absorber in thin film solar cells, mainly due to its direct band gap energy of 1.5 eV. In this study, absorber layers of both Cu-rich and Cu-poor types have been grown on soda-lime glass substrates by proper selection of the deposition parameters. The morphology and the optical properties of the resulting CuInS2 films were studied in dependence of the deposition order of the elemental constituents: alternate evaporation of the precursors, simultaneous deposition of the three constituents and sequential modulation of the evaporation fluxes.
Thermal Conductivity of Confined Ultrathin Polymers
Authors: Ghossoub Marc G , Lee Jung-Hyun , Baris Oksen T , Cahill David G , Sinha Sanjiv
Published: September 2009

We report ultrafast measurements of thermal transport in plasma polymerized CHF3 films deposited on standard Si substrates with Al sputtered on top. We characterize the thin films by X-ray photoelectron spectroscopy (XPS), atomic force microscopy (AFM), and spectroscopic ellipsometry and measure polymer thicknesses ranging from 33 nm down to 6 nm. Time-domain thermoreflectance (TDTR) provides quantitative data on the polymer thermal response to periodic heating from a pulsed laser source. A pump beam heats the Al layer, which acts as an opto-thermal transducer to the stack (Al-Polymer-Si) and a delayed probe beam measures the change in Al surface reflectance. We extract the polymer thermal conductivity by comparing TDTR data to a thermal diffusion model and find it to increase with decreasing polymer thicknesses below 30 nm.
Anharmonic Lifetime of Phonons in Nanophononic Semiconductors
Authors: Hepplestone Steven , Srivastava Gyaneshwar P
Published: September 2009

We present a theory of three-phonon interactions in nanophononic semiconductors at 300˜K. The intrinsic lifetime of phonon modes is estimated from the application of Fermi's Golden Rule, based on realistic phonon dispersion relations and a quasi-continuum model for the cubic anharmonicity. We show that the lifetime of phonon modes in the Si(0.543˜nm)/- Ge(0.543˜nm)[100] superlattice is shorter than the average of results for bulk Si and Ge. This is explained in terms of the availability of additional decay routes and an additional Dual Mass factor which arises due the different densities of Si and Ge.
Controlled Growth and Characterization of Non-tapered InN Nanowires on Si(111) Substrates by Molecular Beam Epitaxy
Authors: Chang Yi-Lu , Fatehi Arya , Li Feng , Mi Zetian
Published: September 2009

We have performed a detailed investigation of the molecular beam epitaxial (MBE) growth and characterization of InN nanowires spontaneously formed on Si(111) substrates under nitrogen rich conditions. Controlled epitaxial growth of InN nanowires (NWs) has been demonstrated by using an in situ deposited thin (˜ 0.5 nm) In seeding layer prior to the initiation of growth. By applying this technique, we have achieved non-tapered epitaxial InN NWs that are relatively free of dislocations and stacking faults. Such InN NW ensembles display strong photoluminescence (PL) at room temperature and considerably reduced spectral broadening, with very narrow spectral linewidths of 22 and 40 meV at 77 K and 300 K, respectively.
Low Melting Metal Catalysed Growth of Tin Disulfide Nanotubes
Authors: Yella Aswani , Mugnaioli Enrico , Panthoefer Martin , Kolb Ute , Tremel Wolfgang
Published: September 2009

We report here the synthesis of tin disulfide nanotubes by a vapour liquid solid growth using bismuth, a low melting metal, as a catalyst. The reaction was carried out in a single step process by heating SnS2 and bismuth in a horizontal tube furnace at 800oC. TEM analysis allowed proposing a plausible mechanism for the formation of SnS2 nanotubes. Pure material could be obtained by optimizing the reaction based on a product analysis using powder X-ray diffraction (XRD) and high-resolution transmission electron microscopy (HRTEM) combined with energy dispersive X-ray spectroscopy (EDX).
Measurements of Liquid Silicon Resistivity on Silicon Microwires
Authors: Bakan Gokhan , Cil Kadir , Cywar Adam , Silva Helena , Gokirmak Ali
Published: September 2009

Nanocrystalline silicon microwires are self-heated through microsecond voltage pulses. Nonlinear changes in current level are observed during the voltage pulse, which end with melting of the microwires. Liquid silicon resistivity is extracted as 65.9 ± 6.1 μΩ.cm from the minimum resistance of the wire during the voltage pulse. The extracted resistivity is in good agreement with previously reported values.
ZnO nanostructures epitaxially grown on ZnO seeded Si (100) substrates by chemical vapor deposition
Authors: Chen Zhuo , Salagaj Tom , Jensen Christopher , Shum Kai
Published: September 2009

ZnO nanostructures such as nanowire-networks and vertical nanorods were epitaxially grown on pre-seeded Si (100) substrates by chemical vapor deposition (CVD) method with a solid source. Crystalline ZnO seeds were prepared and controlled by the rapid thermal annealing (RTA) treatment of e-beam deposited amorphous ZnO thin films. Both epitaxially grown ZnO nanostructures and pre-deposited ZnO seeds were characterized by scanning electron microscopy (SEM), and photoluminescence (PL) spectroscopy. Excellent optical characteristics of these nanostructures such as PL line width, linearity of PL intensity as a function of excitation power density were obtained.
Guided growth of in-plane lateral SiNWs led by indium catalysts
Authors: Yu Linwei , Moustapha Oumkelthoum , Oudwan Maher , Roca i Cabarrocas Pere
Published: September 2009

Here we report a new in-plane solid-liquid-solid (IPSLS) mode for obtaining in-plane silicon nanowires (SiNW), which can be controlled and directly guided into various desired patterns for circuit architecture. Indium catalyst drops are firstly formed by a H2 plasma reduction of a thin layer of ITO on Corning glass substrate and then covered by an a-Si:H layer deposited at low temperature (100oC-200oC). The growth of SiNWs is activated in a reacting-gas-free thermal annealing process and led by the indium catalyst drops, that absorb and transform the a-Si:H matrix into crystalline SiNWs behind. At least two guided modes, that is, the a-Si:H channel guided mode and the step edge guided mode, can be applied to effectively control the growth routes for the lateral SiNWs. This guided growth of the IPSLS SiNWs lays an important basis for realizing various SiNWs-based device applications directly on top of low-cost substrates.
Non-Resonant Two-Photon Absorption-Induced Photoluminescence Study on ZnO Nanostructures Epitaxially Grown on Si (100) Substrates by Chemical Vapor Deposition Method
Authors: Chen Zhuo , Salagaj Tom , Jensen Christopher , Strobl Karlheinz , Hongpinyo V , Ooi Boon , Nakarmi Mim , Shum Kai
Published: September 2009

We report on experimental results of non-resonant two-photon absorption-induced photoluminescence in ZnO nanostructures, which may act as a possible route to excite ZnO nanostructure based lasers. Epitaxial ZnO nanorod-like nanostructure was grown on pre-seeded Si (100) substrates by chemical vapor deposition (CVD) method with a mixed ZnO/C solid source. Crystalline ZnO seeds were prepared and controlled by the rapid thermal annealing (RTA) treatment of e-beam deposited amorphous ZnO thin films with various thicknesses.
CdSe Sensitized ZnO nanowire/polymer based p-i-n Heterojunction Solar Cell
Authors: Nadarajah Athavan , Word Robert C , Koenenkamp Rolf
Published: September 2009

We report a novel hybrid p-i-n heterojunction solar cell consisting of an undoped CdSe quantum dot film sandwiched between electrodeposited n-type ZnO nanowires on a compact ZnO thin film/FTO and a spin-coated hole-conducting layer. Microscopic studies show the conversion of CdSe quantum dots into conformal and continuous polycrystalline thin film coatings on ZnO nanowires upon annealing in CdCl2/ambient air. The morphology change of the CdSe quantum dot layers then provided excellent charge transfer between the absorber layer and the contiguous layers. The quantum-dot-sensitized ZnO nanostructured solar cells exhibited short-circuit current densities ranging from 5 to 10 mA/cm2 and open-circuit voltages of 0.4–0.6 V when illuminated with an 85 mW/cm2 quartz-halogen spectrum. External quantum efficiencies as high as 55–60% were also achieved.
Viscoelastic Inks for Direct-Write Microfabrication of Single-Chamber Micro Solid Oxide Fuel Cells with Coplanar Thick Electrodes
Authors: Kuhn Melanie , Rao Ranjeet B. , Therriault Daniel
Published: September 2009

Single-chamber micro solid oxide fuel cells (SC-μSOFCs) with coplanar electrodes were fabricated using a robotically controlled direct-write microfabrication approach. Viscoelastic, gel-based inks were employed to create homogeneous electrodes of controlled width and interelectrode distance as well as uniform cross-sectional thickness. Electrode powders, NiO-YSZ (yttria-stabilized zirconia) for the anode and (La0.8Sr0.2)0.98MnO3-YSZ for the cathode, were first dispersed with a cationic polyethyleneimine solution. Polyacrylic acid was added to induce a fluid-to-gel transition. The rheology of the fabricated inks was characterized. The inks were then extruded through cylindrical micronozzles and deposited onto YSZ electrolyte substrates using a robotic deposition apparatus. Thickness and width of the sintered electrodes were close to the diameter of the extrusion nozzle. The improved shape retention of the deposited electrodes also enabled the fabrication of continuous electrodes with square cross-section. The cathode adhered very well to the electrolyte during sintering. However, the mismatch between the thermal expansion coefficient of anode and electrolyte seems to cause detaching and breaking of the anode so that electrochemical characterization of the fabricated cells was not yet possible.
Magneto-transport and Magnetic Properties of Fe Doped Nanometric Polycrystalline La0.7Sr0.3MnO3 CMR Manganites
Authors: Paul Sanjoy , Nath Tapan K.
Published: September 2009

We have investigated the effect of 3d-transition metal Fe (Iron) doping at Mn site of nanometric polycrystalline La0.7Sr0.3MnO3 (i.e. La0.7Sr0.3Mn1-xFexO3; 0 ≤ x ≤ 0.1) CMR manganites on magneto-transport and magnetic properties. Nanocrystalline Fe doped La0.7Sr0.3MnO3 powders were synthesized through chemical route “Pyrophoric Reaction Process” and calcinated at 850°C for 5 hrs. X-ray diffraction (XRD) patterns of synthesized powder indicate that all samples are having perovskite structure without any secondary impurity phase. Average crystallite size was found to be 20 nm using Debye Scherer formula. Transmission electron micrographs (TEM) show that the average particle sizes are in nanometric regime (φ ˜ 50 nm) and samples are polycrystalline in nature which was observed through selected area electron diffraction (SEAD) patterns. The effect of Fe doping at Mn site of La0.7Sr0.3MnO3 was found to change substantially the magnetic and transport properties without modifying lattice structure. The suppression of magnetic and transport properties were observed due to dilution of double exchange mechanism in Mn3+- O2--Mn4+ network in La0.7Sr0.3MnO3.
Histological and Mechanical Evaluation of the in vivo Bone-bonding Ability on the K2TinO2n+1/β-Ti Alloy as a Novel Bioactive Material
Authors: Cui Chunxiang , Qi Y. M. , Zhang M. F. , Li J. G. , Liu S. J. , Xue X. L. , Huang N.
Published: September 2009

The purpose of this study was to histologically and mechanically appraise the in vivo bone-bonding abilities of K2TinO2n+1 coated and uncoated Ti-15Mo-3Nb (TMN) implants. According to GB/T16886.6－1997 biological evaluation of medical devices Part 6:Tests for local effects after implantation, the two types of implants were implanted into the proximal metaphyses of Chinese white rabbits’ femurs for 12, 26 and 52 weeks and investigated by pushing out test, scanning electron microscopy (SEM) attached to an energy-dispersive X-ray micro-analyzer (EDX) and light microscopy. The bone-bonding abilities of the K2TinO2n+1 biocoating /Ti-15Mo-3Nb (KBT) gradient biomaterial implants were higher than those of T implants at different periods of implantation. The K2TinO2n+1 biocoating (KB) could stimulate new bone rapid formation at the early stages of implantation. And the implants with the biocoating eventually bonded to bone directly, with no intervening soft tissue layer, that was an osseocoalescence. However, the type of bone-bonding between TMN titanium alloy implants and bone was a simple osseocoaptation. The more excellent bone-bonding ability of the KBT implants should be attributed to the superficial characteristics, the bioactivity of low potassium titanate and biostability of high potassium titanate.
Hot Embossing Of Microchannels in Cyclic Olefin Copolymers
Authors: Leech Patrick William
Published: September 2009

The hot embossing properties of Cyclic Olefin Copolymer (COC) have been examined as a function of comonomer content. Six standard grades of COC with varying norbornene content (61-82 wt%) were used in these experiments in order to provide a range of glass transition temperatures, Tg. All grades of COC exhibited sharp increases in embossed depth over a critical range of temperature. The transition temperature in embossed depth increased linearly with norbornene content for both 35 and 70 μm deep structures. At temperatures above this transition, the dimensions of the embossed patterns were essentially independent of COC grade, the applied pressure and duration of loading. Channels formed above the transition in a regime of viscous liquid flow were extremely smooth in morphology for all grades. The average surface roughness, Ra, measured at the base of the channels decreased sharply at the transition temperature, with a levelling off at higher temperatures. Grades of COC with higher norbornene content exhibited extensive micro-cracking during embossing at temperatures close to the transition temperature.
Phosphate-dependent DNA Immobilization on Hafnium Oxide for Bio-Sensing Applications
Authors: Fahrenkopf Nicholas M , Oktyabrsky Serge , Eisenbraun Eric , Bergkvist Magnus , Shi Hua , Cady Nathaniel C
Published: September 2009

Hafnium(IV) oxide (HfO2) has replaced silicon oxide as a gate dielectric material in leading edge CMOS technology, providing significant improvement in gate performance for field effect transistors (FETs). We are currently exploring this high-k dielectric for its use in nucleic acid-based FET biosensors. Due to its intrinsic negative charge, label-free detection of DNA can be achieved in the gate region of high-sensitivity FET devices. Previous work has shown that phosphates and phosphonates coordinate specifically onto metal oxide substrates including aluminum and titanium oxides. This property can therefore be exploited for direct immobilization of biomolecules such as nucleic acids. Our work demonstrates that 5’ phosphate-terminated single stranded DNA (ssDNA) can be directly immobilized onto HfO2 surfaces, without the need for additional chemical modification or crosslinking. Non-phosphorylated ssDNA does not form stable surface interactions with HfO2, indicating that immobilization is dependent upon the 5’ terminal phosphate. Further work has shown that surface immobilized ssDNA can be hybridized to complementary target DNA and that sequence-based hybridization specificity is preserved. These results suggest that the direct DNA-HfO2 immobilization strategy can enable nucleic acid-based biosensing assays on HfO2 terminated surfaces. This work will further enable high sensitivity electrical detection of biological targets utilizing transistor-based technologies.
Content Area Reading Strategy Knowledge Transfer From Preservice to First‐Year Teaching
Authors: Alger Christianna
Published: September 2009

Using interviews and 10 weeks of consecutive lesson plans with supporting documentation, the author analyzes four first‐year teachers' assigned in‐class and out‐of‐class reading assignments and their choices and uses of reading strategies they learned in their preservice program.

تلخيص البحث: يحلل المؤلف الواجبات المنزلية القرائية داخل الصف وخارجه لدى أربعة معلمين في سنتهم الأولى من العمل واختياراتهم في الاستراتيجيات القرائية وتنفيذاتها التي قد تعلموها في برنامجهم الذي قام قبل الخدمة باستخدام مقابلات والخطط الدراسية التي نفذوها عبر عشرة أسابيع متتالية مع مستندات تدعيمية.

本文作者使用访谈和10個星期的连续课堂教案及其有关的支援文档等研究资料，分析四名正在修读第一年职前训练课程的教师所要做的课堂内与课堂外阅读作业，以及他们如何選擇及如何运用所学到的阅读策略。

En utilisant des entretiens et des plans de leçons consécutives avec support documentaire pour 10 semaines, l'auteur analyse quatre enseignants nommés en première année quant aux lectures qu'ils prescrivent en classe et hors de la classe, ainsi que les choix et l'usage qu'ils font des stratégies de lecture qu'ils ont apprises dans leur programme de formation initiale.

На основе интервью с четырьмя молодыми учительницами, а также их поурочных планов за 10 недель и сопутствующих раздаточных материалов, автор анализирует задания по чтению, которые они дают своим ученикам в классе и на дом, а также то, как они используют методы обучения чтению, с которыми познакомились в университете.

Haciendo entrevistas y examinando 10 semanas consecutivas de planes de lecciones con su documentación de apoyo, la autora analiza las tareas de lecturas asignadas por cuatro maestras de primer grado–tanto dentro como fuera del salón de clase–y las estrategias de lectura que prefieren y usan de las que aprendieron durante su tiempo de preservicio.
ASSESSING CHILDREN'S PHYSICAL ACTIVITY IN THEIR HOMES: THE OBSERVATIONAL SYSTEM FOR RECORDING PHYSICAL ACTIVITY IN CHILDREN‐HOME
Authors: McIver Kerry L. , Brown William H. , Pfeiffer Karin A. , Dowda Marsha , Pate Russell R.
Published: September 2009

The present study describes the development and pilot testing of the Observation System for Recording Physical Activity in Children‐Home version. This system was developed to document physical activity and related physical and social contexts while children are at home. An analysis of interobserver agreement and a description of children's physical activity in various settings are presented. The system, which was shown to be reliable, provides a direct observation tool for researchers who are interested in assessing and intervening in physical activity in the home environment.
AN EVALUATION OF RESURGENCE DURING TREATMENT WITH FUNCTIONAL COMMUNICATION TRAINING
Authors: Volkert Valerie M. , Lerman Dorothea C. , Call Nathan A. , Trosclair‐Lasserre Nicole
Published: September 2009

Extinction‐induced resurgence is the recurrence of previously reinforced behavior when another behavior is placed on extinction (Lieving, Hagopian, Long, & O'Connor, 2004). This phenomenon may account for some instances of treatment relapse when problem behavior recovers during extinction‐based treatments. The current study sought to determine whether resurgence of problem behavior would reliably occur with 5 participants who received treatment with FCT. Results showed that problem behavior reemerged for all but 1 participant when the communicative response was exposed to extinction or thin schedules of reinforcement. These findings suggest that resurgence may account for some instances of response recovery during treatment, and that the described procedure may be useful for the further study of resurgence and eventual prevention of this phenomenon.
CONTINUOUS RECORDING AND INTEROBSERVER AGREEMENT ALGORITHMS REPORTED IN THE JOURNAL OF APPLIED BEHAVIOR ANALYSIS (1995–2005)
Authors: Mudford Oliver C. , Taylor Sarah Ann , Martin Neil T.
Published: September 2009

We reviewed all research articles in 10 recent volumes of the Journal of Applied Behavior Analysis (JABA): Vol. 28(3), 1995, through Vol. 38(2), 2005. Continuous recording was used in the majority (55%) of the 168 articles reporting data on free‐operant human behaviors. Three methods for reporting interobserver agreement (exact agreement, block‐by‐block agreement, and time‐window analysis) were employed in more than 10 of the articles that reported continuous recording. Having identified these currently popular agreement computation algorithms, we explain them to assist researchers, software writers, and other consumers of JABA articles.
PHYSICAL ACTIVITY IN HOMES 13 TEACHING EMPATHY SKILLS TO CHILDREN WITH AUTISM
Authors: Schrandt Jessica A. , Townsend Dawn Buffington , Poulson Claire L.
Published: September 2009

The purpose of this study was to teach empathetic responding to 4 children with autism. Instructors presented vignettes with dolls and puppets demonstrating various types of affect and used prompt delay, modeling, manual prompts, behavioral rehearsals, and reinforcement to teach participants to perform empathy responses. Increases in empathetic responding occurred systematically with the introduction of treatment across all participants and response categories. Furthermore, responding generalized from training to nontraining probe stimuli for all participants. Generalization occurred from dolls and puppets to actual people in a nontraining setting for 2 participants. Generalization was observed initially to the nontraining people and setting for the other participants, but responding subsequently decreased to baseline levels. Introduction of treatment in this setting produced rapid acquisition of target skills.
USING PERCENTILE SCHEDULES TO INCREASE EYE CONTACT IN CHILDREN WITH FRAGILE X SYNDROME
Authors: Hall Scott S. , Maynes Natalee P. , Reiss Allan L.
Published: September 2009

Aversion to eye contact is a common behavior of individuals diagnosed with Fragile X syndrome (FXS); however, no studies to date have attempted to increase eye‐contact duration in these individuals. In this study, we employed a percentile reinforcement schedule with and without overcorrection to shape eye‐contact duration of 6 boys with FXS. Results showed that although aversion to eye contact is often thought to be unamenable to change in FXS, it can be shaped in some individuals using percentile schedules either alone or in combination with overcorrection.
A DEMONSTRATION OF INDIVIDUAL PREFERENCE FOR NOVEL MANDS DURING FUNCTIONAL COMMUNICATION TRAINING
Authors: Winborn‐Kemmerer Lisa , Ringdahl Joel E. , Wacker David P. , Kitsukawa Kana
Published: September 2009

Preference for mand topography was evaluated for 2 individuals with developmental disabilities who exhibited problem behavior. The results of a functional analysis showed that each participant's problem behavior was maintained by social reinforcement. Participants were taught two novel mand topographies for the same functional reinforcer, and each proved to be effective in reducing problem behavior. Finally, preference for mand topography was assessed within a concurrent‐schedules design. Results indicated that functional communication training was an effective treatment, regardless of the mand used, and that each participant demonstrated a preference for one mand topography relative to the other.
USING VIDEO MODELING TO TEACH RECIPROCAL PRETEND PLAY TO CHILDREN WITH AUTISM
Authors: MacDonald Rebecca , Sacramone Shelly , Mansfield Renee , Wiltz Kristine , Ahearn William H.
Published: September 2009

The purpose of the present study was to use video modeling to teach children with autism to engage in reciprocal pretend play with typically developing peers. Scripted play scenarios involving various verbalizations and play actions with adults as models were videotaped. Two children with autism were each paired with a typically developing child, and a multiple‐probe design across three play sets was used to evaluate the effects of the video modeling procedure. Results indicated that both children with autism and the typically developing peers acquired the sequences of scripted verbalizations and play actions quickly and maintained this performance during follow‐up probes. In addition, probes indicated an increase in the mean number of unscripted verbalizations as well as reciprocal verbal interactions and cooperative play. These findings are discussed as they relate to the development of reciprocal pretend‐play repertoires in young children with autism.
INFLUENCING CHILDREN'S PREGAMBLING GAME PLAYING VIA CONDITIONAL DISCRIMINATION TRAINING
Authors: Johnson Taylor E. , Dixon Mark R.
Published: September 2009

Past research has demonstrated a transformation of stimulus functions under similar conditions using gambling tasks and adults (e.g., Zlomke & Dixon, 2006), and the present study attempted to extend this research. Experimenters exposed 7 children (ages 7 to 10 years) to a simulated board game with concurrently available dice differing only by color. Following initial exposure to the game, participants were trained to discriminate between two contextual cues representing the relational frames of more than and less than. Following the training procedure, experimenters reexposed participants to the simulated board game. Six of the 7 participants demonstrated an increased preference toward the die with the color that had been paired with more than during the conditional discrimination training.
APPLIED IMPLICATIONS OF REINFORCEMENT HISTORY EFFECTS
Authors: Pipkin Claire St. Peter , Vollmer Timothy R.
Published: September 2009

Although the influence of reinforcement history is a theoretical focus of behavior analysis, the specific behavioral effects of reinforcement history have received relatively little attention in applied research and practice. We examined the potential effects of reinforcement history by reviewing nonhuman, human operant, and applied research and interpreted the findings in relation to possible applied significance. The focus is on reinforcement history effects in the context of reinforcement schedules commonly used either to strengthen behavior (e.g., interval schedules) or commonly used to decrease behavior (e.g., extinction).
Influence of the Tooth‐ and Implant‐Side Marginal Bone Level on the Interproximal Papilla Dimension in a Single Implant With a Microthread, Conical Seal, and Platform‐Switched Design
Authors: Kwon Hee‐Jun , Lee Dong‐Won , Park Kwang‐Ho , Kim Chong‐Kwan , Moon Ik‐Sang
Published: September 2009

Background: The purpose of the present study was to investigate whether bone level on the tooth side was the single dominant factor on the dimension of an interproximal papilla around single‐tooth restorations made on a microthread, conical seal, and platform‐switched design implant.

Methods: Periapical radiographs were taken of 17 patients, each of whom was treated with a single implant. The bone levels on the tooth (Dt) and implant (Di) sides were recorded. The dimension of the papilla (Ph) was measured as the shortest distance from the top of the papilla to the crestal bone. The marginal bone levels of the implants were also measured. The Pearson correlation coefficient was used to correlate the variables, and a regression analysis was used to determine whether Di or Dt had a significant (P <0.05) influence on Ph.

Results: A positive correlation existed between Ph and Di (r = 0.413; P = 0.023) and between Ph and Dt (r = 0.830; P <0.0001). However, only Dt had a significant influence on Ph.

Conclusion: Dt is the dominant factor that influences the interproximal soft tissue dimension between a natural tooth and a single implant with a microthread, conical seal, and platform‐switched design.