bluuebunny/crossref_metadata_2025_split huggingface dataset:
An LED-induced fluorescence detection system with integrated on-chip lens based on microfluidic chips technology/Ein LED-induziertes Fluoreszenzdetektionssystem mit integrierter „Lens-on-Chip“ basierend auf der mikrofluidischen Chiptechnologie
Authors: Zhao Yingying , Li Qin , Hu Xiao-Ming , Yang Dong-Fang 
Published: January 2013

AbstractThe power density of optical excitation on microfluidic chips is attenuated due to the beam divergence of the optical fiber, making it difficult to collect either the emission or scattering light. The excitation power and coupling efficiency can be significantly increased by using an on-chip microlens system with integrated optical fibers, specially designed and simulated to reshape and collect the optical signal within the microfluidic chip.This article presents research work for designing, fabricating, and testing a type of on-chip microlens. The on-chip microlens was designed by Code VThe export light beam could be focused to a very small point to satisfy the requirements of the fluorescence excitation of samples. On the other hand, the detection efficiency could also be increased with the help of the on-chip microlens. The presented fabrication method does not require any assembly process or external driving force. To fabricate a microlens with a different focus, it is only necessary to change the figures on the mask. This technique can be used in a variety of applications as it is possible to produce customized microlens for specific applications.
Preparation and characterization of poly(2-hydroxyethyl methacrylate)/ Na-montmorillonite intercalated nanocomposites
Authors: Koç Zafer , Çelik Meltem , Önal Müşerref , Sarıkaya Yüksel , Mogulkoc Yesim 
Published: January 2013

Abstract
A series of intercalated nanocomposites were prepared via in situ polymerization of 2-hydroxyethyl methacrylate (HEMA) between the interlayer spacing of hydrous Na-montmorillonite (Na-MMT) using benzoyl peroxide (Bz2O2) as a radical initiator. X-ray diffraction patterns showed the absence of any intercalation up to 61.7 mass% of HEMA, but anhydrous Na-MMT formed by the hydrophilic effect of HEMA. The interlayer spacing (d001) values of hydrous and anhydrous Na-MMT were calculated as 1.19 and 1.03 nm, respectively. At higher monomer contents, the increase in the value of d001 from 1.19 to 2.01 nm indicated intercalation of polymer in the interlayer spacing of Na-MMT. Besides, transmission electron microscopy results supported the formation of the intercalated nanocomposites. Thermogravimetric analysis showed that the thermal stability of the nanocomposites increased considerably by intercalation of pure poly-HEMA. Specific surface area and specific nanopore volume of the nanocomposites decreased with the increasing of the monomer content taken by the preparations. The decrease is due to the nonporous nature of the polymer matrix.
Drying of polyacrylamide-multiwalled carbon nanotube (MWNT) composites with various MWNTs contents: a fluorescence study
Authors: Evingür Gülşen Akın , Pekcan Önder 
Published: January 2013

Abstract
We studied the drying of polyacrylamide (PAAm)-multiwalled carbon nanotube (MWNT) composites, prepared by free radical crosslinking copolymerization in water, with a steady state fluorescence technique. Composite gels were prepared at room temperature with pyranine (Py) doped as a fluorescence probe. Drying experiments were performed in air at various MWNT contents by real time monitoring of the Py fluorescence intensity (I) which increased as the drying proceeded. The Stern-Volmer equation, combined with the moving boundary diffusion model, was used to explain the behavior of I during drying. It was observed that the desorption coefficient (D) increased as the temperature increased. Drying energies (ΔE) were measured for the drying processes for each MWNT content gel, by using fluorescence, gravimetrical and volumetric methods. It is understood that ΔE values decrease by increasing MWNT content, until 1 wt% MWNT, and then increase above the level of this threshold value. The energy of drying is strongly correlated with the MWNT content in the composite. ΔE drops to its lowest value, at which conducting cluster starts to appear.
Study on thermal properties of polyurethane-urea elastomers prepared with different dianiline chain extenders
Authors: Barikani Majid , Fazeli Naghmeh , Barikani Mehdi 
Published: January 2013

Abstract
A number of polyurethane prepolymers based on polycaprolactone diol (PCL) and 4,4′-diphenyl methane diisocyanate (MDI) were synthesized and extended with different dianilines such as: 4,4′-methylenebis(2,6-diisopropylaniline) (M-DIPA), 4,4′-methylenebis(2,6diethylaniline) (M-DEA), 4,4′-methylenebis(ortho chloroaniline) (MOCA), 4,4′-methylenebis(2-isopropyl-6-methylaniline) (M-MIPA) and 4,4′-methylenebis(3-chloro-2,6-diethylaniline) (M-CDEA). Infrared (IR) spectroscopy was used to check the end of the polymerization reaction in addition to the polymer characterization. The effect of the dianiline structure on the thermal properties of the cast films were studied through dynamic mechanical measurements (DMTA), thermogravimetric analysis (TGA) and differential scanning calorimetry (DSC) analysis. It was found that the thermal properties and thermal stability of polyurethane are strongly affected by the molecular structure of the dianiline chain extender.
Relationship between lactation duration and insulin and glucose response among women with prior gestational diabetes
Authors: Chouinard-Castonguay Sarah , Weisnagel S John , Tchernof André , Robitaille Julie 
Published: January 2013

BackgroundFew studies have investigated whether favorable effects of lactation persist after weaning and protect women with prior gestational diabetes mellitus (GDM) against later development of insulin resistance and insulin secretion defects.ObjectiveTo investigate the impact of lactation duration on insulin and glucose response among women with prior GDM.Design/methodsThe study group comprised 144 women with a history of GDM between 2003 and 2010. Plasma insulin and glucose concentrations were obtained from a 75 g oral glucose tolerance test (OGTT). Total lactation duration (exclusive breastfeeding and breast and bottle-feeding) for all infants was self-reported in months.ResultsMean age was 36.5±5.0 years. Time between delivery and metabolic testing was 4.0±1.9 years. Women breastfed for an average of 13.9±16.8 months. Most women (80.6%) reported a history of lactation. Women who lactated had higher homeostasis model assessment for insulin sensitivity (HOMA-IS) and Matsuda indices and lower fasting and 2-h post-OGTT insulin concentrations as well as area under the curve (AUC) for insulin (P≤0.01 for all). Compared with women who lactated for <10 months, women who lactated for ≥10 months had improved insulin sensitivity–secretion index, higher HOMA-IS and Matsuda indices, lower fasting and 2-h post-OGTT insulin concentrations as well as AUC for insulin, and lower incidence of impaired glucose intolerance (P≤0.05 for all). In multiple linear regression analyses, lactation duration emerged as an independent predictor of fasting insulin concentrations (β=−0.02) and insulin sensitivity indices (β=0.02) (P≤0.05 for all).ConclusionsThese results suggest that longer duration of lactation is associated with improved insulin and glucose response among women with prior GDM.
Mapping Quantitative Trait Loci AffectingArabidopsis thalianaSeed Morphology Features Extracted Computationally From Images
Authors: Moore Candace R , Gronwall David S , Miller Nathan D , Spalding Edgar P 
Published: January 2013

AbstractSeeds are studied to understand dispersal and establishment of the next generation, as units of agricultural yield, and for other important reasons. Thus, elucidating the genetic architecture of seed size and shape traits will benefit basic and applied plant biology research. This study sought quantitative trait loci (QTL) controlling the size and shape of Arabidopsis thaliana seeds by computational analysis of seed phenotypes in recombinant inbred lines derived from the small-seeded Landsberg erecta × large-seeded Cape Verde Islands accessions. On the order of 103 seeds from each recombinant inbred line were automatically measured with flatbed photo scanners and custom image analysis software. The eight significant QTL affecting seed area explained 63% of the variation, and overlapped with five of the six major-axis (length) QTL and three of the five minor-axis (width) QTL, which accounted for 57% and 38% of the variation in those traits, respectively. Because the Arabidopsis seed is exalbuminous, lacking an endosperm at maturity, the results are relatable to embryo length and width. The Cvi allele generally had a positive effect of 2.6–4.0%. Analysis of variance showed heritability of the three traits ranged between 60% and 73%. Repeating the experiment with 2.2 million seeds from a separate harvest of the RIL population and approximately 0.5 million seeds from 92 near-isogenic lines confirmed the aforementioned results. Structured for download are files containing phenotype measurements, all sets of seed images, and the seed trait measuring tool.
Comparison of the Performance of Two Commercial Genome-Wide Association Study Genotyping Platforms in Han Chinese Samples
Authors: Jiang Lei , Willner Dana , Danoy Patrick , Xu Huji , Brown Matthew A 
Published: January 2013

Abstract
Most genome-wide association studies to date have been performed in populations of European descent, but there is increasing interest in expanding these studies to other populations. The performance of genotyping chips in Asian populations is not well established. Therefore, we sought to test the performance of widely used fixed-marker, genome-wide association studies chips in the Han Chinese population. Non-HapMap Chinese samples (n = 396) were genotyped using the Illumina OmniExpress and Affymetrix 6.0 platforms, whereas a subset also were genotyped using the Immunochip. Genotyped markers from the Affymetrix 6.0 and Illumina OmniExpress were used for full genome imputation based on the HapMap 2 JPT+CHB (Japanese from Tokyo, Japan and Chinese from Beijing, China) reference panel. The concordance between markers genotypes for the three platforms was very high whether directly genotyped or genotyped and imputed single nucleotide polymorphisms (SNPs; &gt;99.8% for directly genotyped and &gt;99.5% for genotyped and imputed SNPs, respectively) were compared. The OmniExpress chip data enabled more SNPs to be imputed, particularly SNPs with minor allele frequency &gt;5%. The OmniExpress chip achieved better coverage of HapMap SNPs than the Affymetrix 6.0 chip (73.6% vs. 65.9%, respectively, for minor allele frequency &gt;5%). The Affymetrix 6.0 and Illumina OmniExpress chip have similar genotyping accuracy and provide similar accuracy of imputed SNPs. The OmniExpress chip however provides better coverage of Asian HapMap SNPs, although its coverage of HapMap SNPs is moderate.
Compensatory Mutations in Predicted Metal Transporters Modulate Auxin Conjugate Responsiveness in Arabidopsis
Authors: Rampey Rebekah A , Baldridge Megan T , Farrow David C , Bay Sarah N , Bartel Bonnie 
Published: January 2013

Abstract
Levels of the phytohormone indole-3-acetic acid (IAA) can be altered by the formation and hydrolysis of IAA conjugates. The isolation and characterization of Arabidopsis thaliana mutants with reduced IAA-conjugate sensitivity and wild-type IAA responses is advancing the understanding of auxin homeostasis by uncovering the factors needed for conjugate metabolism. For example, the discovery that the IAA-Ala-resistant mutant iar1 is defective in a protein in the ZIP family of metal transporters uncovered a link between metal homeostasis and IAA-conjugate sensitivity. To uncover additional factors impacting auxin conjugate metabolism, we conducted a genetic modifier screen and isolated extragenic mutations that restored IAA-amino acid conjugate sensitivity to the iar1 mutant. One of these suppressor mutants is defective in a putative cation diffusion facilitator, MTP5 (At3g12100; formerly known as MTPc2). Loss of MTP5 function restored IAA conjugate sensitivity to iar1 but not to mutants defective in IAA-amino acid conjugate amidohydrolases. Our results are consistent with a model in which MTP5 and IAR1 transport metals in an antagonistic fashion to regulate metal homeostasis within the subcellular compartment in which the IAA-conjugate amidohydrolases reside, and support previous suggestions that the ion composition in this compartment influences hydrolase activity.
Optimized Hot-forming of an Intermetallic Multi-phase γ-TiAl Based Alloy
Authors: Gaitzenauer Andrea , Müller Martin , Clemens Helmut , Voigt Patrick , Hempel Robert , Mayer Svea 
Published: January 2013

ABSTRACTA robust processing route at low cost is an essential requirement for high-temperature materials used in automotive engines. Because of their excellent high-temperature properties, their low density, high elastic modulus as well as high specific strength, intermetallic γ-TiAl based alloys are potential candidates for application in advanced automotive turbochargers. So-called 3rdgeneration alloys, such as TNM™ alloys with a nominal composition of Ti-43.5Al-4Nb-1Mo-0.1B (in at%), are multi-phase alloys consisting of γ-TiAl, α2-Ti3Al and a low volume fraction of βo-TiAl phase. In this paper a novel hot-processing route, which is a combination of a one-shot hot-forging step and a controlled cooling treatment, leads to mechanical properties required for turbocharger turbine wheels. The observed strength can be attributed to the small lamellar spacing within the α2/γ colonies of the nearly lamellar microstructure. In order to analyze the microstructure and the prevailing phase fractions microscopic examinations and X-ray diffraction measurements were conducted. The mechanical properties were determined by hardness measurements as well as tensile and creep tests. The evolution of the microstructure during the hot-forming process is described and its relation to the obtained mechanical properties.
High Temperature Oxidation Protection of Multi-Phase Mo-Containing TiAl-Alloys by the Fluorine Effect
Authors: Donchev Alexander , Pflumm Raluca , Mayer Svea , Clemens Helmut , Schütze Michael 
Published: January 2013

ABSTRACTIntermetallic titanium aluminides are potential materials for application in high temperature components. In particular, alloys solidifying via the β-phase are of great interest because they possess a significant volume fraction of the disordered body-centered cubic β-phase at elevated temperatures ensuring good processing characteristics during hot-working. Nevertheless, their practical use at temperatures as high as 800°C requires improvements of the oxidation resistance. This paper reports on the fluorine effect on a multi-phase TiAl-alloy in the cast and hot-isostatically pressed condition at 800°C in air. The behavior of the so-called TNM material (Ti-43.5Al-4Nb-1Mo-0.1B, in at %) was compared with that of two other TiAl-alloys which are Nb-free and contain different amounts of Mo (3 and 7 at%, respectively). The oxidation resistance of the fluorine treated samples was significantly improved compared to the untreated samples. After fluorine treatment all alloys exhibit slow alumina kinetics indicating a positive fluorine effect. Results of isothermal and thermocyclic oxidation tests at 800°C in air are presented and discussed in the view of composition and microstructure of the TiAl-alloys investigated, along with the impact of the fluorine effect on the oxidation resistance of these materials.
Collocation and Integration of Back-End Fuel Cycle Facilities with the Repository: Implications for Waste Forms
Authors: Forsberg Charles 
Published: January 2013

ABSTRACTThe organization of the fuel cycle is a legacy of World War II and the cold war. Fuel cycle facilities were developed and deployed without consideration of the waste management implications. This led to the fuel cycle model of an isolated single-purpose geological repository for disposal of wastes shipped from distant processing facilities. There is an alternative: collocation and integration of reprocessing and other backend facilities with the repository. Such an option alters waste form functional requirements by reducing storage and transport requirements. This, in turn, broadens the choice of waste forms by relaxing the incentives to minimize waste volumes. Waste forms can be chosen primarily on meeting two goals: repository performance and minimizing costs. Less restrictive waste volume constraints enable termination of safeguards on all wastes, enable use of solubility-limited waste forms, and reduce radiation damage as a waste form limitation. The implications of such changes in waste form requirements are discussed.
Impact of Annealing on the Thermoelectric Properties of Ge2Sb2Te5Films
Authors: Lee Jaeho , Kodama Takashi , Won Yoonjin , Asheghi Mehdi , Goodson Kenneth E. 
Published: January 2013

ABSTRACTThermoelectric phenomena strongly influence the behavior of chalcogenide materials in nanoelectronic devices including phase-change memory cells. This paper presents the annealing temperature and phase dependent thermoelectric properties of Ge2Sb2Te5films including the thermoelectric power factor and the figure of merit. The Ge2Sb2Te5films annealed at different temperatures contain varying fractions of the amorphous and crystalline phases which strongly influence the thermoelectric properties. The thermoelectric power factor increases fom 3.2 μW/mK2to 65 μW/mK2as the crystal phase changes from face-centered cubic to hexagonal close-packed. The data are consistent with modeling based on effective medium theory and suggest that careful consideration of phase purity is needed to improve the figures of merit for phase change memories and potentially for thermoelectric energy conversion applications.
Relaxation Processes at High Temperature in TiAl-Nb-Mo Intermetallics
Authors: Simas Pablo , Schmoelzer Thomas , Mayer Svea , Nó Maria L. , Clemens Helmut , San Juan Jose 
Published: January 2013

ABSTRACTIn the last decades there was a growing interest in developing new light-weight intermetallic alloys, which are able to substitute the heavy superalloys at a certain temperature range. At present a new Ti-Al-Nb-Mo family, called TNM™ alloys, is being optimized to fulfill the challenging requirements. The aim of the present work was to study the microscopic mechanisms of defect mobility at high temperature in TNM alloys in order to contribute to the understanding of their influence on the mechanical properties and hence to promote the further optimization of these alloys. Mechanical spectroscopy has been used to study the internal friction and the dynamic modulus up to 1460 K of a TNM alloy under different thermal treatments. These measurements allow to follow the microstructural evolution during in-situ thermal treatments. A relaxation process has been observed at about 1050 K and was characterized as a function of temperature and frequency in order to obtain the activation parameters of the responsible mechanism. In particular, the activation enthalpy has been determined to be H= 3 eV. The results are discussed and an atomic mechanism is proposed to explain the observed relaxation process.
Crystal Polarity and Electrical Properties of Heavily Doped ZnO Films
Authors: Adachi Yutaka , Ohashi Naoki , Sakaguchi Isao , Haneda Hajime 
Published: January 2013

ABSTRACTIn this study, ZnO f ilms heavily doped with Al or Ga were grown on a polarity-controlled buffer layer using pulsed laser deposition. The films prepared using a 1 mol% Al-doped target with the buffer layer grown at 700 °C had the c(+)-face, whereas the films with the buffer layer grown at 400 °C had the c(-)-face, which means that the polarity control can be successfully carried out using the buffer layer. However, the films prepared using targets doped with more than 1 mol% Al or Ga had the c(+)-face regardless of the polarity of the buffer layer. The 1 mol% Al-doped ZnO film with the c(+)-face had lower electron concentration and higher growth rate than the film with the c(-)-face. This result indicates that the Al content in the film with the c(-)-face was larger than that in the film with the c(+)-face.
Optical, Structural, and Electrical Properties of Vanadium Dioxide Grown on Sapphire Substrates with Different Crystallographic Orientations
Authors: Nazari M. , Zhao Y. , Zhu Y. , Kuryatkov V. V. , Bernussi A. A. , Fan Z. , Holtz M. 
Published: January 2013

ABSTRACTThe phase transition of VO2 grown on sapphire having different crystallographic growth planes is examined experimentally. Measurements of electrical resistivity are compared with spectroscopic ellipsometry studies, to obtain complex index of refraction and plasma frequency, and transmission in the terahertz frequency range, each as a function of temperature.
Development of Plasma-Assisted Processing for Selenization and Sulfurization of Absorber Layers
Authors: Kosaraju S. , Repins I. , Wolden C. A. 
Published: January 2013

AbstractIn the synthesis of copper chalcopyrite solar absorbers the chalcogen source is always supplied in excess due to its low reactivity. This paper describes preliminary work aimed at addressing this issue through plasma processing. An inductively coupled plasma (ICP) was use to activate both sulfur and selenium vapors. First, the thermodynamic arguments for using activated chalcogens are presented. Next, this paper describes the experimental ICP setup and its characterization using optical emission spectroscopy (OES). Stable discharges have been achieved with both sulfur and selenium vapors using argon as a carrier gas. The potential of this approach was demonstrated by converting indium films into In2Se3 and InSx. The indium samples were inserted into chalcogen-containing ICP plasmas. Through X-ray diffraction it was observed that chalcogen conversion was achieved in a matter of minutes at room temperature by plasma processing.
Effect of thermal cycling on performance of Poly(3-hexylthiophene) Transistors
Authors: Mattis Brian A. , Chang Paul C. , Subramanian Vivek 
Published: January 2013

AbstractWe present the results of studies on the electrical and physical modifications to Poly(3-hexylthiophene), upon thermal annealing. Thermally-induced performance modifications and thermal stability of polythiophene thin film transistors are explored. We observe substantial mobility improvements in devices annealed at low temperatures (>80°C), as well as increases in on/off ratios by two orders of magnitude at moderate anneal temperatures (~120°C). We document changes in conductivity, mobility, on current, and on/off ratio with anneal temperature and total thermal budget. In conjunction with material analysis, we develop qualitative models for the mechanisms involved in the annealing/degradation processes. Hence, this study provides a comprehensive analysis of the effect of thermal cycling of polythiophene TFTs on various device performance metrics, and identifies the relevant thermal limits and failure mechanisms.