bluuebunny/crossref_metadata_2025_split huggingface dataset:
Synthesis of polydopamine‐coated graphene–polymer nanocomposites via RAFT polymerization
Authors: Gu Renpeng , Xu William Z. , Charpentier Paul A. 
Published: June 2013

ABSTRACTGraphene‐polymer nanocomposites have significant potential in many applications such as photovoltaic devices, fuel cells, and sensors. Functionalization of graphene is an essential step in the synthesis of uniformly distributed graphene‐polymer nanocomposites, but often results in structural defects in the graphitic sp2 carbon framework. To address this issue, we synthesized graphene oxide (GO) by oxidative exfoliation of graphite and then reduced it into graphene via self‐polymerization of dopamine (DA). The simultaneous reduction of GO into graphene, and polymerization and coating of polydopamine (PDA) on the reduced graphene oxide (RGO) surface were confirmed with XRD, UV–Vis, XPS, Raman, TGA, and FTIR. The degree of reduction of GO increased with increasing DA/GO ratio from 1/4 to 4/1 and/or with increasing temperature from room temperature to 60 °C. A RAFT agent, 2‐(dodecylthiocarbonothioylthio)−2‐methylpropionic acid, was linked onto the surface of the PDA/RGO, with a higher equivalence of RAFT agent in the reaction leading to a higher concentration of RAFT sites on the surface. Graphene‐poly(methyl methacrylate), graphene‐poly(tert‐butyl acrylate), and graphene‐poly(N‐isopropylacrylamide) nanocomposites were synthesized via RAFT polymerization, showing their characteristic solubility in several different solvents. This novel synthetic route was found facile and can be readily used for the rational design of graphene‐polymer nanocomposites, promoting their applications. © 2013 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2013, 51, 3941–3949
Nanoparticles as macromolecules
Authors: Miller Joseph B. , Hobbie Erik K. 
Published: June 2013

AbstractA review of recent trends in the dispersion, purification, and assembly of colloidal nanoparticles highlights a number of growing analogies with ideas borrowed from polymer science. Beyond the similar scales of size, several key concepts lying at the foundation of polymer physics—such as polydispersity, fractionation, phase ordering, and viscoelasticity—are taking on new and unique significance in the contemporary realm of nanotechnology. Leveraging “soft matter” at the nanoscale to simplify materials processing and improve material performance is becoming a reality, with potentially profound implications for a number of emerging technologies. © 2013 Wiley Periodicals, Inc. J Polym Sci Part B: Polym. Phys. 2013, 51, 1195–1208
Pressure‐monitored headspace analysis combined with compound‐specific isotope analysis to measure isotope fractionation in gas‐producing reactions
Authors: Mundle Scott O. C. , Vandersteen Adelle A. , Lacrampe‐Couloume Georges , Kluger Ronald , Sherwood Lollar Barbara 
Published: June 2013

RATIONALEProcesses that lead to pressure changes in closed experimental systems can dramatically increase the total uncertainty in enrichment factors (ε) based on headspace analysis and compound‐specific isotope analysis (CSIA). We report: (1) A new technique to determine ε values for non‐isobaric processes, and (2) a general approach to evaluate the experimental error in calculated ε values.METHODSε values were determined by monitoring the change in headspace pressure from the production of CO2 in a decarboxylation reaction using a pressure gauge and measuring the δ13C values using CSIA. The statistical error was assessed over shorter reaction progress intervals to evaluate the impact of experimental error on the total uncertainty associated with calculated ε values.RESULTSAs an alternative to conventional compositional analysis, calculation of CO2 produced during the reaction monitored with a pressure gauge resulted in rate constants and ε values with improved correlation coefficients and confidence intervals for a non‐isobaric process in a closed system. Further, statistical evaluation of the ε values as a function of reaction progress showed that uncertainty in data points for reaction progress (f) at late stages of the reaction can have a significant impact on the reported ε value.CONCLUSIONSPressure‐monitored headspace analysis reduces the uncertainty associated with monitoring the reaction progress (f) based on estimating substrate removal and headspace dilution during sampling. Statistical calculations over shorter intervals should be used to evaluate the total error for reported ε values. Copyright © 2013 John Wiley & Sons, Ltd.
Probabilistic and combinatorial aspects of the card‐cyclic to random insertion shuffle
Authors: Pinsky Ross G. 
Published: June 2013

AbstractConsider a permutation σ ∈ Sn as a deck of cards numbered from 1 to n and laid out in a row, where σj denotes the number of the card that is in the j‐th position from the left. We study some probabilistic and combinatorial aspects of the shuffle on Sn defined by removing and then randomly reinserting each of the n cards once, with the removal and reinsertion being performed according to the original left to right order of the cards. The novelty here in this nonstandard shuffle is that every card is removed and reinserted exactly once. The bias that remains turns out to be quite strong and possesses some surprising features. © 2013 Wiley Periodicals, Inc. Random Struct. Alg., 46, 362–390, 2015
Theoretical AIM and ELI‐D Study of Ammonium Hexahydrohexaborate
Authors: Mebs Stefan , Henn Julian , Luger Peter , Lentz Dieter 
Published: June 2013

AbstractThe theoretically obtained electronic properties of ammonium hexahydrohexaborate are analyzed by means of Atoms In Molecules (AIM) Theory and Electron Localizability Indicator (ELI‐D). For AIM, the electron density (ED) derived from a calculation under periodic boundary conditions and subsequent modeling of the theoretical structure factors is compared to direct analysis of the ED from gas‐phase calculations of packing schemes. Both procedures lead to similar physical properties. The quality of the theoretical multipole model is additionally confirmed by a detailed qualitative and quantitative analysis of the residual densities. (B6H6)2– is not stable in the gas phase. Considering the ELI, this leads to a large distance of the B–B valence basin attractor to the B–B axis. This outwardly curved localization is a sign for a weak B–B interaction. The structure is stabilized in the crystal by an unusual intermolecular contact between the protic hydrogen atoms of ammonium and the centers of the B–B–B triangles of the (B6H6)2– octahedron. All common real space bond descriptors, such as the Laplacian, the energy densities, the delocalization index, and the source function (including local source) classify this bond type as being of closed‐shell character.
Detection of Geopolymer Structure by Spectroscopic and ­Molybdate Measurements
Authors: Lutz Wolfgang , Ritzmann Attila 
Published: June 2013

AbstractGeopolymer binder obtained from metakaolin and potassium water glass has been accepted to substitute classic cement in concretes and is consider as promising component in fibre composites, materials for toxic‐waste storage, or flame proofing agents. The mixture represents likewise a model system for estimation of characterization techniques. Compared to spectroscopic methods like IR or 29Si MAS NMR spectroscopy, the molybdate method allows a deeper insight into the aging mechanism of geopolymer batches.
Combining data from 43 standardized surveys to estimate densities of female American black bears by spatially explicit capture–recapture
Authors: Howe Eric J. , Obbard Martyn E. , Kyle Christopher J. 
Published: June 2013

AbstractSpatially explicit capture–recapture (SECR) models are gaining popularity for estimating densities of mammalian carnivores. They use spatially explicit encounter histories of individual animals to estimate a detection probability function described by two parameters: magnitude (g0), and spatial scale (σ). Carnivores exhibit heterogeneous detection probabilities and home range sizes, and exist at low densities, so g0 and σ likely vary, but field surveys often yield inadequate data to detect and model the variation. We sampled American black bears (Ursus americanus) on 43 study areas in ON, Canada, 2006–2009. We detected 713 animals 1810 times; however, study area‐specific samples were sometimes small (6–34 individuals detected 13–93 times). We compared AICc values from SECR models fit to the complete data set to evaluate support for various forms of variation in g0 and σ, and to identify a parsimonious model for aggregating data among study areas to estimate detection parameters more precisely. Models that aggregated data within broad habitat classes and years were supported over those with study area‐specific g0 and σ (ΔAICc ≥ 30), and precision was enhanced. Several other forms of variation in g0 and σ, including individual heterogeneity, were also supported and affected density estimates. If study design cannot eliminate detection heterogeneity, it should ensure that samples are sufficient to detect and model it. Where this is not feasible, combing sparse data across multiple surveys could allow for improved inference.
HIV or human papillomavirus co‐infection among Brazilian individuals infected with hepatitis B and/or hepatitis C
Authors: Bomfim‐Hyppólito Silvia , Eleuterio Jose , Nunes George Chaves , Bomfim‐Hyppólito Elodie , Franco Eugenio S. , Neto Roberto da Justa Pires 
Published: June 2013

AbstractObjectiveTo investigate the incidence of co‐infection with HIV and human papillomavirus (HPV) among Brazilian individuals with hepatitis B virus (HBV) or hepatitis C virus (HCV) infection.MethodsA prospective study was conducted that enrolled 103 individuals from the Ceará region of Brazil between January 4, 2010, and August 9, 2012. Eligible participants were men (n = 45) or women (n = 58) infected with HBV and/or HCV. Pap smears were collected from female patients. Material from male (urethra) and female (cervix) patients was then collected via DNA‐HPV test and visual inspection with acetic acid.ResultsIn all, 48 participants tested positive for HBV and 55 tested positive for HCV; 2 had dual infection with HBV and HCV. Co‐infection with HIV was detected among 15 participants, whereas 20 participants were found to be co‐infected with HPV.ConclusionA high prevalence of co‐infection with HIV and HPV was detected among Brazilian individuals with HBV and/or HCV.
Learning from the Japanese railways: Experience in the Netherlands
Authors: van de Velde Didier M 
Published: June 2013

Abstract
This paper focuses on the lessons drawn by the Dutch railways in their contacts with the Japanese railway sector over the last two decades. The transfers described in this paper do not result from a thorough problem analysis by policy-makers followed by a conscious policy transfer. Rather they result from largely uncoordinated actions that led to a growing consciousness within the Dutch railway sector of the existence of a useful benchmark located in the Japanese railway practices.
The paper attempts to provide an answer to a number of questions: how have these contacts appeared, which factors contributed to or impeded their appearance, which lessons were learned, how are these lessons perceived by the railway sector, how much has been implemented, and is there more to come?
To do this, the paper starts by providing an overview of the Dutch railway context, highlighting a few elements that were conducive to more openness for new solutions and presenting the main differences between the Dutch and Japanese institutional contexts, before presenting the contacts that took place, some resulting publications and their main findings. Using an explorative survey method, the paper then presents the perceptions of top and senior representatives of the Dutch railway sector who visited Japan, shedding more light on the perception that the sector currently has of the nature of the Japanese lessons and on the extent to which these are likely to be implemented. The paper then draws some general conclusions about this learning process, the change in stance that took place during the last two decades and on the remaining challenges for further learning.
Specific carbonate–microbe interactions in the modern microbialites of Lake Alchichica (Mexico)
Authors: Gérard Emmanuelle , Ménez Bénédicte , Couradeau Estelle , Moreira David , Benzerara Karim , Tavera Rosaluz , López-García Purificación 
Published: June 2013

Abstract
The role of microorganisms in microbialite formation remains unresolved: do they induce mineral precipitation (microbes first) or do they colonize and/or entrap abiotic mineral precipitates (minerals first)? Does this role vary from one species to another? And what is the impact of mineral precipitation on microbial ecology? To explore potential biogenic carbonate precipitation, we studied cyanobacteria–carbonate assemblages in modern hydromagnesite-dominated microbialites from the alkaline Lake Alchichica (Mexico), by coupling three-dimensional imaging of molecular fluorescence emitted by microorganisms, using confocal laser scanning microscopy, and Raman scattering/spectrometry from the associated minerals at a microscale level. Both hydromagnesite and aragonite precipitate within a complex biofilm composed of photosynthetic and other microorganisms. Morphology and pigment-content analysis of dominant photosynthetic microorganisms revealed up to six different cyanobacterial morphotypes belonging to Oscillatoriales, Chroococcales, Nostocales and Pleurocapsales, as well as several diatoms and other eukaryotic microalgae. Interestingly, one of these morphotypes, Pleurocapsa-like, appeared specifically associated with aragonite minerals, the oldest parts of actively growing Pleurocapsa-like colonies being always aragonite-encrusted. We hypothesize that actively growing cells of Pleurocapsales modify local environmental conditions favoring aragonite precipitation at the expense of hydromagnesite, which precipitates at seemingly random locations within the biofilm. Therefore, at least part of the mineral precipitation in Alchichica microbialites is most likely biogenic and the type of biominerals formed depends on the nature of the phylogenetic lineage involved. This observation may provide clues to identify lineage-specific biosignatures in fossil stromatolites from modern to Precambrian times.
Nitrite oxidation in the upper water column and oxygen minimum zone of the eastern tropical North Pacific Ocean
Authors: Beman J Michael , Leilei Shih Joy , Popp Brian N 
Published: June 2013

Abstract
Nitrogen (N) is an essential nutrient in the sea and its distribution is controlled by microorganisms. Within the N cycle, nitrite (NO2−) has a central role because its intermediate redox state allows both oxidation and reduction, and so it may be used by several coupled and/or competing microbial processes. In the upper water column and oxygen minimum zone (OMZ) of the eastern tropical North Pacific Ocean (ETNP), we investigated aerobic NO2− oxidation, and its relationship to ammonia (NH3) oxidation, using rate measurements, quantification of NO2−-oxidizing bacteria via quantitative PCR (QPCR), and pyrosequencing. 15NO2− oxidation rates typically exhibited two subsurface maxima at six stations sampled: one located below the euphotic zone and beneath NH3 oxidation rate maxima, and another within the OMZ. 15NO2− oxidation rates were highest where dissolved oxygen concentrations were &lt;5 μm, where NO2− accumulated, and when nitrate (NO3−) reductase genes were expressed; they are likely sustained by NO3− reduction at these depths. QPCR and pyrosequencing data were strongly correlated (r2=0.79), and indicated that Nitrospina bacteria numbered up to 9.25% of bacterial communities. Different Nitrospina groups were distributed across different depth ranges, suggesting significant ecological diversity within Nitrospina as a whole. Across the data set, 15NO2− oxidation rates were decoupled from 15NH4+ oxidation rates, but correlated with Nitrospina (r2=0.246, P&lt;0.05) and NO2− concentrations (r2=0.276, P&lt;0.05). Our findings suggest that Nitrospina have a quantitatively important role in NO2− oxidation and N cycling in the ETNP, and provide new insight into their ecology and interactions with other N-cycling processes in this biogeochemically important region of the ocean.
Inorganic Nanomaterials for the Deacidification of Paper
Authors: Giorgi R. 
Published: June 2013

The conservation of manuscripts and books is one of the most challenging issues in conservation science, because the organic biomolecule of cellulose is susceptible to rapid degradation as a result of the combination of several factors, both environmental and connected with the papermaking techniques that have been used since the end of the 19th century. Basically, paper undergoes degradation because it contains materials that catalyse degradation reactions.The chapter focuses on some of these aspects and, in particular, discusses the role of acidity in the degradation processes. Within this conceptual framework, state-of-the-art methods for mass-deacidification, single-item treatment and application of anti-oxidants are discussed. The recent important contribution of nanotechnology to the development of innovative deacidification methods is then presented.
The mitochondrial carrier Rim2 co-imports pyrimidine nucleotides and iron
Authors: Froschauer Elisabeth M. , Rietzschel Nicole , Hassler Melanie R. , Binder Markus , Schweyen Rudolf J. , Lill Roland , Mühlenhoff Ulrich , Wiesenberger Gerlinde 
Published: June 2013

Mitochondrial iron uptake is of key importance both for organelle function and cellular iron homoeostasis. The mitochondrial carrier family members Mrs3 and Mrs4 (homologues of vertebrate mitoferrin) function in organellar iron supply, yet other low efficiency transporters may exist. In Saccharomyces cerevisiae, overexpression of RIM2 (MRS12) encoding a mitochondrial pyrimidine nucleotide transporter can overcome the iron-related phenotypes of strains lacking both MRS3 and MRS4. In the present study we show by in vitro transport studies that Rim2 mediates the transport of iron and other divalent metal ions across the mitochondrial inner membrane in a pyrimidine nucleotide-dependent fashion. Mutations in the proposed substrate-binding site of Rim2 prevent both pyrimidine nucleotide and divalent ion transport. These results document that Rim2 catalyses the co-import of pyrimidine nucleotides and divalent metal ions including ferrous iron. The deletion of RIM2 alone has no significant effect on mitochondrial iron supply, Fe–S protein maturation and haem synthesis. However, RIM2 deletion in mrs3/4Δ cells aggravates their Fe–S protein maturation defect. We conclude that under normal physiological conditions Rim2 does not play a significant role in mitochondrial iron acquisition, yet, in the absence of the main iron transporters Mrs3 and Mrs4, this carrier can supply the mitochondrial matrix with iron in a pyrimidine-nucleotide-dependent fashion.
A Biomechanical Modeling Study of the Effects of the Orbicularis Oris Muscle and Jaw Posture on Lip Shape
Authors: Stavness Ian , Nazari Mohammad Ali , Perrier Pascal , Demolin Didier , Payan Yohan 
Published: June 2013

Purpose
The authors' general aim is to use biomechanical models of speech articulators to explore how possible variations in anatomical structure contribute to differences in articulatory strategies and phone systems across human populations. Specifically, they investigated 2 issues: (a) the link between lip muscle anatomy and variability in lip gestures and (b) the constraints of coupled lip/jaw biomechanics on jaw posture in labial sounds.

Method

The authors used a model coupling the jaw, tongue, and face. First, the influence of the orbicularis oris (OO) anatomical implementation was analyzed by assessing how changes in depth (from epidermis to the skull) and peripheralness (proximity to the lip horn center) affected lip shaping. Second, the capability of the lip/jaw system to generate protrusion and rounding, or
labial closure
, was evaluated for different jaw heights.

Results
Results showed that a peripheral and moderately deep OO implementation is most appropriate for protrusion and rounding; a superficial implementation facilitates closure; protrusion and rounding require a high jaw position; and closure is achievable for various jaw heights.

Conclusions
Models provide objective information regarding possible links between anatomical and speech production variability across humans. Comparisons with experimental data will illustrate how motor control and cultural factors cope with these constraints.
High peak power actively Q‐switched Ho3 +, Pr3 +‐co‐doped fluoride fibre laser
Authors: Hu T. , Hudson D.D. , Jackson S.D. 
Published: June 2013

An actively Q‐switched diode‐pumped Ho3 +, Pr3 +‐co‐doped fluoride glass fibre laser operating in the first‐order diffraction mode is demonstrated. At a repetition a rate of 1 kHz, the laser produces pulses with a maximum peak power of 576 W and a pulse width of 33 ns at an average power of 19 mW at 2.87 µm.
Reference spur suppression technique using ratioed current charge pump
Authors: Kamal N. , Al‐Sarawi S.F. , Abbott D. 
Published: June 2013

Reference spurs are one of the main problems in integer‐N phase‐locked loops (PLLs). A ratioed current charge pump is proposed to suppress reference spur magnitude in the PLL output. The ratioed current charge pump can be implemented by resizing the source and drain network of the charge pump. A formula to calculate the ratioed current and transistor size is presented. The reference spur magnitude for a PLL with a ratioed current charge pump is compared to a conventional charge pump PLL, resulting in about 4 dBc/Hz improvement in the reference spur magnitude.
74 GHz, 17.2 dBm power amplifier in 45 nm SOI CMOS
Authors: Tai W. , Ricketts D.S. 
Published: June 2013

A millimetre‐wave power amplifier (PA) fabricated in 45 nm SOI CMOS is reported that achieves 17.2 dBm saturated output power at 74 GHz without power combining using a 2.2 V supply, over twice the output power of previously reported single CMOS PAs. The peak gain and PAE are 14.3 dB and 11.1%, respectively. The PA also achieves a 3 dB bandwidth of 31 GHz while occupying a small die area of 0.23 mm2.
Dual‐band bandpass filter based on CPW series‐connected resonators
Authors: Al‐Khateeb L. , Abu Safia O. 
Published: June 2013

A new design of a three‐pole dual‐band bandpass filter using coplanar waveguide (CPW) series‐connected resonators and impedance inverters is proposed. The circuit conversions that lead to the lumped element model of the proposed filter are introduced. The resonators of the filter are implemented using special compact series‐connected resonators patterned in the centre conductor of a CPW transmission line. The filter operates at the two centre band frequencies 1.8 and 2.4 GHz. Hence, it is considered an excellent candidate for GSM/Wi‐Fi applications. Experimental results show very good agreement with simulated results, which validates the proposed filter.
Effects of extreme surface roughness on 3D printed horn antenna
Authors: Garcia C.R. , Rumpf R.C. , Tsang H.H. , Barton J.H. 
Published: June 2013

3D printing is an emerging technology in manufacturing. It is the long‐term goal of the industry to print complex and fully functional products from cell phones to vehicles. A drawback of many 3D printing technologies is rough surface finish. It is known that metals with high surface roughness severely degrade the propagation of electromagnetic waves. Presented is the first known evaluation of the electromagnetic impact of the typical surface roughness in metal parts produced by electron beam melting. Two Ku‐band (12–15 GHz) horn antennas were 3D printed, with different surface roughness, and compared to a standard horn antenna purchased from Pasternack.