bluuebunny/crossref_metadata_2025 huggingface dataset:
Effect of Hard Coatings on Surface Gray Iron on Fracture Toughness
Authors: Cruz L.D. Rosado , Doñu-Ruíz Marco Antonio , Perrusquia N. López , Cortés Suárez V.J. , Torres San Miguel C.R. , de la Mora Ramírez T.
Published: May 2014

The characterization and fracture toughness with hard coatings formed at the surface of gray cast irons class 30 is evaluated in the present study. The formation of hard coatings was obtained out means of the pack boriding process; the treatment was carried out at temperatures of 1173 and 1223 K during 6 hours. The layers were evaluated by the techniques of X-ray diffraction (XRD), energy dispersive spectrometry (EDS) and microindentation across the thickness of the iron boride layer. Three-point bending tests are carried out to examine the fracture toughness of gray cast irons boriding according to the ASTM 399 standard. Consequently, the stress intensity factor was evaluated by means of the finite element method (FEM) using the package ANSYS 11. 0 creating a two-dimensional model with elements of singularity around the tip crack. The results were compared with the experiments and have been found to be in good correlation.
Modelling and Simulation of Resin Transfer Moulding: A Finite Volume Approach Applied to the Mold Filling Stage
Authors: Coutinho B.G. , Bezerra V.M. França , de Farias Neto Severino Rodrigues , de Lima Antônio Gilson Barbosa
Published: May 2014

RTM process is widely used for the production of high quality fiber reinforced composites parts. Computer simulations can play an important role in optimization of RTM processes by reducing risks and costs. In this paper, we present a two dimensional mathematical modelling for the mold filling stage in RTM process. It was used a two phase model (air-resin) which neglects the capillary and gravitational effects and considers all phases incompressible. The set of partial differential equations, expressed in boundary-fitted coordinates, are discretized by using the finite volume method and solved using a fully implicit methodology and the Newton's method. To validate the methodology, numerical and experimental data of the filling time and flow front position along the process are compared and good agreement was obtained.
Deformability of a Flax Reinforcement for Composite Materials
Authors: Vanleeuw Bart , Carvelli Valter , Lomov Stepan , Barburski Marcin , van Vuure Aart W.
Published: May 2014

In this work, the deformability of a flax fabric adopted as composite reinforcement is experimentally investigated. The fabric (commercialized as FLAXPLY UD 180 by LINEO) is a quasi-unidirectional woven fabric with thin weft yarns connecting thick slightly twisted warp using satin weave interlacing pattern. The study is dedicated to the understanding and measurement of the main deformation mechanisms occurring during forming processes. The deformation during extension is investigated under uniaxial and biaxial loading in the in-plane tow directions (i.e. warp and weft). Particular attention is dedicated to the behavior during shear loading because this is considered the primary deformation mechanism in the reinforcement forming. Uniaxial bias extension and picture frame tests are adopted to measure the shear deformation. The tests are assisted by digital image correlation (DIC) technique to have a continuous measurement of the local deformation in the fabric plane during loading.
A Study of Mold Friction and Wear in Injection Molding of Plastic-Bonded Hard Ferrite
Authors: Crema Luca , Lucchetta Giovanni
Published: May 2014

In injection molding of highly filled polymers, such as plastic-bonded hard ferrite, mold life decreases significantly due to wear and surface damage. This deterioration process leads to lower accuracy concerning the surface finish and the dimensional and geometric tolerance of the molded bonded magnets. In this work, the wear of a steel mold caused by the molding of a plastic-bonded ferrite magnet has been studied with the aim of determining the main wear factors. Furthermore, two different surface treatments have been tested, namely gas nitriding and DLC superlattice coating. Friction and wear induced by part de-molding was investigated by means of tribological pin-on-disc tests. The results of such experiments were analyzed in terms of loads, surface roughness evolution and surface investigations by means of Scanning Electron Microscope observations.
A Virtual Instrument for SEM Uncertainty Analysis
Authors: Gnieser Dominic , Frase Carl Georg , Bosse Harald , Tutsch Rainer
Published: May 2014

To assure the metrological traceability of a measurement, it is required to perform an analysis of the measurement uncertainty specific to the measurement task. An approach to estimate the measurement uncertainty for complex systems is the so-called virtual measuring instrument: The measuring process is simulated taking into account its influencing parameters and a statistical analysis is performed by means of Monte-Carlo calculations. We present the development of such a virtual measuring instrument for scanning electron microscopy (SEM) which allows to estimate the measurement uncertainty in compliance with GUM for dimensional measuring tasks in nano- and microsystems technology. By application of this virtual instrument, model based corrections of systematic errors are made possible and the cognition of the strength of different perturbing influences can lead to recommendations to optimize measurement instruments and methods. The virtual model programmed in MATLAB is called ‘vREM’, it includes all essential components of the measuring chain of an SEM as modules: The electron source, the electron-optical lens-system, the scan-generator, the interaction of the electrons within the object, electron detectors, simple analysis procedures and consideration of external disturbances. By adjusting parameters uncertainty contributions can be assigned to the virtual probe, the virtual specimen and the virtual detector signals.
Experimental Performance Study of Industrial-Grade Coordinate Measuring Machines Using a Calibrated Production Workpiece
Authors: Baldo Crhistian Raffaelo , Donatelli Gustavo Daniel
Published: May 2014

The measurement of a part on a coordinate measuring machine may be affected by many factors such as machine frame accuracy, probe configuration, measuring environment, and measurement strategy. In order to understand the effect of some of those factors on measurements performed in industrial-grade machines, a master production workpiece has been chosen and circulated in Brazilian industries for collecting data points of the calibrated workpiece features according to a predefined master measuring protocol. Conclusions could be drawn about the behavior of each machine under varying conditions, measurement divergences from similar machines operating under distinct conditions, the complexity of measurements with CMMs, and the need for good measurement practices in the productive sector.
Efficient Commissioning Processes for the Automotive Final Assembly
Authors: Janssen Christian , Falk Björn , Schmitt Robert
Published: May 2014

At the so-called End-of-Line of the automotive final assembly the vehicles are commissioned, i. e. single systems as well as functions are checked and/or adjusted. For example, on the roll brake test stand, the parking brake and the driving brake are checked, whereas at the wheel alignment station the wheels are aligned. The commissioning processes are characterized by a high amount of manual work conducted by highly skilled workers with expensive equipment. Furthermore, many of the functions, which are commissioned at the End-of-Line (e. g. adjustment of the switching operation of the automatic transmission), have a high impact on the customers quality perception. Therefore, the improvement of the commissioning processes is a promising method to decrease costs in the automotive final assembly and increase the quality perceived by the customer. This paper presents an approach and in extracts its application that enables its users to improve commissioning processes at the End-of-Line of an automotive final assembly, regarding costs and quality perceived by the customer. The use-case employed in order to demonstrate the approach is the improvement of the steering wheel alignment.
Improvement of the Reliability of Information Received from Sensor Devices with Metrological Self-Check
Authors: Backsheeva Yulia , Sapozhnikova Kseniia , Taymanov Roald
Published: May 2014

Sensor devices with metrological self-check represent one of the most advanced directions in the present-day development of measurement technique. Generally, in the process of sensor device operation, results of the metrological self-check enable changes of metrological characteristics to be revealed, automatic correction of an error to be performed, grounds for multiple increase of a calibration interval to be obtained. In the present paper an additional procedure of metrological assurance is substantiated which provides the increase in the reliability of metrological self-check results.
Chemical composition and sources of coastal marine aerosol particles during the 2008 VOCALS-REx campaign
Authors: Lee Y.-N. , Springston S. , Jayne J. , Wang J. , Hubbe J. , Senum G. , Kleinman L. , Daum P. H.
Published: May 2014

Abstract. The chemical composition of aerosol particles (Dp ≤ 1.5 μm) was measured over the southeast Pacific Ocean during the VAMOS (Variability of the American Monsoon Systems) Ocean-Cloud-Atmosphere-Land Study Regional Experiment (VOCALS-Rex) between 16 October and 15 November 2008 using the US Department of Energy (DOE) G-1 aircraft. The objective of these flights was to gain an understanding of the sources and evolution of these aerosols, and of how they interact with the marine stratus cloud layer that prevails in this region of the globe. Our measurements showed that the marine boundary layer (MBL) aerosol mass was dominated by non-sea-salt SO42−, followed by Na+, Cl−, Org (total organics), NH4+, and NO3−, in decreasing order of importance; CH3SO3− (MSA), Ca2+, and K+ rarely exceeded their limits of detection. Aerosols were strongly acidic with a NH4+ to SO42− equivalents ratio typically < 0.3. Sea-salt aerosol (SSA) particles, represented by NaCl, exhibited Cl− deficits caused by both HNO3 and H2SO4, but for the most part were externally mixed with particles, mainly SO42−. SSA contributed only a small fraction of the total accumulation mode particle number concentration. It was inferred that all aerosol species (except SSA) were of predominantly continental origin because of their strong land-to-sea concentration gradient. Comparison of relative changes in median values suggests that (1) an oceanic source of NH3 is present between 72° W and 76° W, (2) additional organic aerosols from biomass burns or biogenic precursors were emitted from coastal regions south of 31° S, with possible cloud processing, and (3) free tropospheric (FT) contributions to MBL gas and aerosol concentrations were negligible. The very low levels of CH3SO3− observed as well as the correlation between SO42− and NO3− (which is thought primarily anthropogenic) suggest a limited contribution of DMS to SO42− aerosol production during VOCALS.
Simulating black carbon and dust and their radiative forcing in seasonal snow: a case study over North China with field campaign measurements
Authors: Zhao C. , Hu Z. , Qian Y. , Leung L. R. , Huang J. , Huang M. , Jin J. , Flanner M. , Zhang R. , Wang H. , Yan H. , Lu Z. , Streets D. G.
Published: May 2014

Abstract. A state-of-the-art regional model, WRF-Chem, is coupled with the SNICAR model that includes the sophisticated representation of snow metamorphism processes available for climate study. The coupled model is used to simulate the black carbon (BC) and dust concentrations and their radiative forcing in seasonal snow over North China in January–February of 2010, with extensive field measurements used to evaluate the model performance. In general, the model simulated spatial variability of BC and dust mass concentrations in the top snow layer (hereafter BCS and DSTS, respectively) are quantitatively or qualitatively consistent with observations. The model generally moderately underestimates BCS in the clean regions but significantly overestimates BCS in some polluted regions. Most model results fall into the uncertainty ranges of observations. The simulated BCS and DSTS are highest with >5000 μg g−1 and up to 5 μg g−1, respectively, over the source regions and reduce to <50 ng g−1 and <1 μg g−1, respectively, in the remote regions. BCS and DSTS introduce a similar magnitude of radiative warming (~10 W m−2) in the snowpack, which is comparable to the magnitude of surface radiative cooling due to BC and dust in the atmosphere. This study represents a significant effort in using a regional modeling framework to simulate BC and dust and their direct radiative forcing in snowpack. Although a variety of observational datasets have been used to attribute model biases, some uncertainties in the results remain, which highlights the need for more observations, particularly concurrent measurements of atmospheric and snow aerosols and the deposition fluxes of aerosols, in future campaigns.
Lidar observation of the 2011 Puyehue-Cordón Caulle volcanic aerosols at Lauder, New Zealand
Authors: Nakamae K. , Uchino O. , Morino I. , Liley B. , Sakai T. , Nagai T. , Yokota T.
Published: May 2014

Abstract. On 4 June 2011, the Puyehue-Cordón Caulle volcanic complex (40.6° S, 72.1° W) in Chile erupted violently and injected volcanic aerosols into the atmosphere. For the safety of civil aviation, continuous lidar observations were made at Lauder, New Zealand (45.0° S, 169.7° E), from 11 June through 6 July 2011. To study the influence of the volcanic aerosols on Greenhouse gases Observing SATellite (GOSAT) products, we analyzed lidar data at a wavelength of 532 nm and derived the backscattering ratio and depolarization ratio profiles. During June and July, within the altitude range of 10–15 km, the volcanic aerosols had high depolarization ratios (20–35%), an indication of non-spherical volcanic ash particles. The time series of the backscattering ratio during continuous observations had three peaks occurring at about 12 day intervals: 26.7 at 11.2 km on 11 June, 18.1 at 12.0 km on 23 June, and 5.3 at 11.1 km on 6 July. The optical depth of the volcanic aerosols was 0.45 on 11 June, when the continuous lidar observation started, 0.31 on 23 June, and 0.12 on 6 July. The depolarization ratio values remained high up to a month after the eruption and the small wavelength exponent calculated from the backscattering coefficients at 532 nm and 1064 nm suggest that a major constituent of the volcanic aerosols was large, non-spherical particles. The presence of volcanic ash in the stratosphere might affect the error in GOSAT XCO2 retrieval using the 1.6 μm band.
Henry's law constants of polyols
Authors: Compernolle S. , Müller J.-F.
Published: May 2014

Abstract. Henry's law constants (HLC) are derived for several polyols bearing between 2 and 6 hydroxyl groups, based on literature data for water activity, vapour pressure and/or solubility. Depending on the case, infinite dilution activity coefficients (IDACs), solid state pressures or activity coefficient ratios are obtained as intermediary results. For most compounds, these are the first values reported, while others compare favourably with literature data in most cases. Using these values and those from a previous work (Compernolle and Müller, 2014), an assessment is made on the partitioning of polyols, diacids and hydroxy acids to droplet and aqueous aerosol.
Tropical montane forests are a larger than expected global carbon store
Authors: Spracklen D. V. , Righelato R.
Published: May 2014

Abstract. Tropical montane forests (TMFs) are recognized for the provision of hydrological services and the protection of biodiversity, but their role in carbon storage is not well understood. We synthesized published observations (n = 94) of above-ground biomass (AGB) from forest inventory plots in TMFs (defined here as forests between 23.5° N and 23.5° S with elevations ≥ 1000 m a.s.l.). We found that mean (median) AGB in TMFs is 271 (254) t per hectare of land surface. We demonstrate that AGB declines moderately with both elevation and slope angle but that TMFs store substantial amounts of biomass, both at high elevations (up to 3500 m) and on steep slopes (slope angles of up to 40°). We combined remotely sensed data sets of forest cover with high resolution data of elevation to show that 75% of the global planimetric (horizontal) area of TMF are on steep slopes (slope angles greater than 27°). We used our remote sensed data sets to demonstrate that this prevalence of steep slopes results in the global land surface area of TMF (1.22 million km2) being 40% greater than the planimetric area that is the usual basis for reporting global land surface areas and remotely sensed data. Our study suggests that TMFs are likely to be a greater store of carbon than previously thought, highlighting the need for conservation of the remaining montane forests.
An articulated handle to improve the ergonomic performance of robotic dextrous instruments for laparoscopic surgery
Authors: Herman B. , Devreker A. , Richer F. , Hassan Zahraee A. , Szewczyk J.
Published: May 2014

Abstract. Hand-held robotic instruments with dextrous end-effectors offer increased accessibility and gesture precision in minimally invasive laparoscopic surgery. They combine advantages of both intuitive but large, complex, and expensive telesurgery systems, and much cheaper but less user-friendly steerable mechanical instruments. However, the ergonomics of such instruments still needs to be improved in order to decrease surgeon discomfort. Based on the results of former experimental studies, a handle connected to the instrument shaft through a lockable ball joint was designed. An experimental assessment of ergonomic and gesture performance was performed on a custom-made virtual reality simulator. Results show that this solution improves ergonomics, demanding less wrist flexion and deviation and elbow elevation, while providing gesture performance similar to a robotic dextrous instrument with standard pistol-like handle configuration.
A Defined, Controlled Culture System for Primary Bovine Chromaffin Progenitors Reveals Novel Biomarkers and Modulators
Authors: Masjkur Jimmy , Levenfus Ian , Lange Sven , Arps-Forker Carina , Poser Steve , Qin Nan , Vukicevic Vladimir , Chavakis Triantafyllos , Eisenhofer Graeme , Bornstein Stefan R. , Ehrhart-Bornstein Monika , Androutsellis-Theotokis Andreas
Published: May 2014

We present a method to efficiently culture primary chromaffin progenitors from the adult bovine adrenal medulla in a defined, serum-free monolayer system. Tissue is dissociated and plated for expansion under support by the mitogen basic fibroblast growth factor (bFGF). The cultures, although not homogenous, contain a subpopulation of cells expressing the neural stem cell marker Hes3 that also propagate. In addition, Hes3 is also expressed in the adult adrenal medulla from where the tissue is taken. Differentiation is induced by bFGF withdrawal and switching to Neurobasal medium containing B27. Following differentiation, Hes3 expression is lost, and cells acquire morphologies and biomarker expression patterns of chromaffin cells and dopaminergic neurons. We tested the effect of different treatments that we previously showed regulate Hes3 expression and cell number in cultures of fetal and adult rodent neural stem cells. Treatment of the cultures with a combination of Delta4, Angiopoietin2, and a Janus kinase inhibitor increases cell number during the expansion phase without significantly affecting catecholamine content levels. Treatment with cholera toxin does not significantly affect cell number but reduces the ratio of epinephrine to norepinephrine content and increases the dopamine content relative to total catecholamines. These data suggest that this defined culture system can be used for target identification in drug discovery programs and that the transcription factor Hes3 may serve as a new biomarker of putative adrenomedullary chromaffin progenitor cells.
Depression: An Insight and Need for Personalized Psychological Stress Monitoring and Management
Authors: Sandeep Kumar Vashist  , E. Marion Schneider
Published: May 2014

Editorial
Identifying Coping Profiles and Profile Differences in Role Engagement and Subjective Well-Being
Authors: Saija Mauno  , Marika Rantanen  , Asko Tolvanen
Published: May 2014

Coping strategies are not necessarily mutually exclusive and can be used simultaneously, a fact which has rarely been examined in coping research. We examined what kinds of coping profiles could be found in data concerning Finnish health care and service employees (n = 2756). We also studied whether role engagement (family-to-work-enrichment, work-to-family-enrichment, emotional energy at work, and work engagement) and subjective well-being (life, parental, and marital satisfaction, and psychological distress) differ between coping profiles. The data were analyzed through latent profile (LPA) and covariance analyses (Ancovas). LPA revealed seven distinct coping profiles: two active groups, one passive group, one low and two high copers’ groups and one moderate group. These results indicate that coping strategies are not mutually exclusive and that people might use different strategies simultaneously. The covariance analyses revealed that the most significant differences concerned role engagement: active copers showed higher role engagement (e.g. enrichment, work engagement) than moderate or low copers. The findings imply that the indicators of role engagement deserve more attention in coping research in healthy working adults.
Diversité et abondance des pucerons [Homoptera : Aphididae] et leur impact sur la dissémination des virus infectant la pomme de terre au Mali
Authors: Yattara Almouner A.A. , Coulibaly Amadou K. , Francis Frédéric
Published: May 2014

Des études sur l’abondance et la diversité des pucerons ont été menées pendant trois campagnes agricoles au Mali. Sur la base de relevés de bacs jaunes installés dans des cultures de pomme de terre à Kati et à Sikasso, 2 525 pucerons ont été capturés et identifiés. Dix-neuf espèces de pucerons ont été recensées, dont deux qui ont été observées in situ sur la culture : Aphis gossypii (Glover) et Myzus persicae (Sulzer). La plupart de ces espèces sont des ravageurs de cultures et elles contribuent également à la transmission virale. Des échantillons foliaires prélevés dans des parcelles de pomme de terre dans les deux régions ont été testés par la technique ELISA pour la détection des deux principaux virus dommageables, soit le Potato Virus Y (PVY) et le Potato Leaf Roll Virus (PLRV). Le taux de plantes virosées dans les deux localités pendant les trois années variait de 19,3 % à 21,8 % pour le PVY, alors qu’il était de 8,5 % à 9,3 % pour le PLRV. L’occurrence de ces maladies virales s’est révélée être très homogène d’une année à l’autre, avec des taux relativement importants. Cette étude est une première quantification dans cette région du Mali de l’importance des relations pucerons vecteurs–virus en culture de pomme de terre.
Evidence of Xyleborinus attenuatus (Blandford 1894) (Coleoptera: Curculionidae: Scolytinae: Xyleborini) populations in Quebec, Canada
Authors: Popa Valentin , Guertin Claude , Werbiski Robert
Published: May 2014

Six species of the genus Xyleborinus (Reitter 1913) have been reported in North America. Five of these species were introduced, and one species is considered native to North and South America. Xyleborinus attenuatus (Blandford 1894), which was introduced into the Americas from Asia, was first recorded in 1995 in western Canada, in the province of British Columbia, and then in 2007 in the province of Nova Scotia, in eastern Canada. In Quebec, X. attenuatus was initially recorded in 2009 based on a single captured specimen. In this study, we present additional evidence of the presence of this alien ambrosia beetle in Quebec, Canada.
Protestants, the Liberal State, and the Practice of Politics: Revisiting R.J. Fleming and the 1890s Toronto Streetcar Controversy
Authors: Van Die Marguerite
Published: May 2014

Through the lens of R. J. Fleming, Irish Methodist businessman, alderman, and four times mayor of Toronto in the 1890s, this paper re-examines the moral reform campaigns of middle-class Protestants described by Christopher Armstrong and H. V. Nelles in their now classic study, The Revenge of the Methodist Bicycle Company (1977). Instead of looking at the Sunday car issue from the perspective of the promoters and as evidence of secularization, it presents as a case study Fleming’s conflicted and controversial role as an evangelical politician confronted with a divisive moral and religious issue within the late nineteenth-century liberal state. Scholarly debates on the process of secularization in late nineteenth-century Canada have given little attention to the influence of the timing and nature of the country’s political arrangements and have thus neglected the contradictions and tensions devout politicians faced within the new state and social order. This paper argues the need to make an important but often overlooked distinction between political and social secularization. With close attention to detail, it examines Fleming as an “evangelical modernizer” who as a politician had to maintain the neutrality of the state and at the same time address the concerns of a religious constituency that feared a favourable vote on Sunday cars would lead to social secularization.
Seasonal variations of the nighttime O(1S) and OH (8‐3) airglow intensity at Adelaide, Australia
Authors: Reid Iain M. , Spargo Andrew J. , Woithe Jonathan M.
Published: May 2014

We analyze 15 years of atomic oxygen (OI) 558 nm and hydroxyl (OH) (8‐3) 730 nm nightglow emission intensities from heights near 96 and 87 km, respectively, measured using filter photometers at the Buckland Park Field Station (34.6°S, 138.6°E) near Adelaide, Australia. The intensity of both emissions exhibits clear seasonal and interannual periodicities, with annual, semiannual, and quasi‐biennial oscillations, as well as a solar cycle influence. In addition, there is a terannual and 4.1 year component in the OI airglow intensity and both a quasi‐biennial and quasi‐triennial oscillation in the OH intensity. The results are in very good agreement with simultaneous collocated measurements made with an imager, and with global satellite climatologies of OI and OH intensities reported for the Wind Imaging Interferometer instrument. The mean value of the OI annual oscillation intensity is the same as that of the semiannual oscillation at this location to within the experimental uncertainty. The OI annual oscillation maximizes in summer, and the semiannual oscillation maximizes in autumn and spring, with the largest maximum in autumn. The terannual component in the OI nightglow maximizes in early summer, autumn, and spring. The quasi‐biennial oscillation in the OI nightglow takes its first maximum value in autumn 1996, and the 4.1 year period in this emission first maximizes in summer 1998. The OH annual and semiannual oscillation intensities also agree to within the experimental uncertainties and are observed to peak in early winter. The quasi‐biennial and quasi‐triennial oscillations in this emission take their first maximum value in summer 1996.
The seasonality of Antarctic sea ice trends
Authors: Holland Paul R.
Published: May 2014

Antarctic sea ice is experiencing a weak overall increase in area that is the residual of opposing regional trends. This study considers their seasonal pattern. In addition to traditional ice concentration and total ice area, temporal derivatives of these quantities are investigated (“intensification” and “expansion,” respectively). This is crucial to the attribution of trends, since changes in forcing directly affect ice areal change (rather than ice area). Diverse regional trends all contribute significantly to the overall increase. Trends in the Weddell and Amundsen‐Bellingshausen regions compensate in magnitude and seasonality. The largest concentration trends, in autumn, are actually caused by intensification trends during spring. Autumn intensification trends directly oppose autumn concentration trends in most places, seemingly as a result of ice and ocean feedbacks. Springtime trends are reconcilable with wind trends, but further study of changes during the spring melting season is required to unravel the Antarctic sea ice increase.
Self‐Assembly of Graphene Oxide at Interfaces
Authors: Shao Jiao‐Jing , Lv Wei , Yang Quan‐Hong
Published: May 2014

Due to its amphiphilic property, graphene oxide (GO) can achieve a variety of nanostructures with different morphologies (for example membranes, hydrogel, crumpled particles, hollow spheres, sack‐cargo particles, Pickering emulsions, and so on) by self‐assembly. The self‐assembly is mostly derived from the self‐concentration of GO sheets at various interfaces, including liquid‐air, liquid‐liquid and liquid‐solid interfaces. This paper gives a comprehensive review of these assembly phenomena of GO at the three types of interfaces, the derived interfacial self‐assembly techniques, and the as‐obtained assembled materials and their properties. The interfacial self‐assembly of GO, enabled by its fantastic features including the amphiphilicity, the negatively charged nature, abundant oxygen‐containing groups and two‐dimensional flexibility, is highlighted as an easy and well‐controlled strategy for the design and preparation of functionalized carbon materials, and the use of self‐assembly for uniform hybridization is addressed for preparing hybrid carbon materials with various functions. A number of new exciting and potential applications are also presented for the assembled GO‐based materials. This contribution concludes with some personal perspectives on future challenges before interfacial self‐assembly may become a major strategy for the application‐targeted design and preparation of functionalized carbon materials.
Insight into the intraparticle diffusion of residue oil components in catalysts during hydrodesulfurization reaction
Authors: Wang Zhigang , Chen Sheng‐Li , Pei Jianing , Chen Aicheng , Zhang Junhui , Xu Zhiming , Benziger Jay B.
Published: May 2014

Well‐defined and uniform pore structure catalysts were used to study the intraparticle diffusion of fractionated Saudi vacuum residue under hydrodesulfurization (HDS) reaction conditions. HDS rates of residue oil cuts with different molecular weights are determined as functions of pore size, temperature, and pressure in a trickle‐bed reactor. Credible intrinsic and bulk diffusivities of organosulfur compounds in residue oil were obtained for the first time, from the apparent and intrinsic reaction kinetic constants. Intrinsic diffusivities ranged from 2 × 10−7 to 8 × 10−7 cm2/s for the residual oil molecules; diffusivity decreases with increasing molecular weight of the residual oil. The intrinsic diffusivity for molecular weights ∼1000 Daltons increases with pore size for pores <70 nm, but is nearly independent of pore size for pores >70 nm. The diffusivity dependences on pore size and molecular weight suggest that the onset of restricted diffusion occurs for ratios of molecular diameter to pore diameter of ∼0.04. © 2014 American Institute of Chemical Engineers AIChE J, 60: 3267–3275, 2014
Novel Product Chemistry from Mechanistic Analysis of ent‐Copalyl Diphosphate Synthases from Plant Hormone Biosynthesis
Authors: Potter Kevin , Criswell Jared , Zi Jiachen , Stubbs Alisha , Peters Reuben J.
Published: May 2014

An active‐site water molecule coordinated by conserved histidine and asparagine residues seems to serve as the catalytic base in all ent‐copalyl diphosphate synthases (CPSs). When these residues are substituted by alanine, the mutant CPSs produce stereochemically novel ent‐8‐hydroxy‐CPP. Given the requisite presence of CPSs in all land plants for gibberellin phytohormone biosynthesis, such plasticity presumably underlies the observed extensive diversification of the resulting labdane‐related diterpenoids.
Coordination‐Driven Folding and Assembly of a Short Peptide into a Protein‐like Two‐Nanometer‐Sized Channel
Authors: Sawada Tomohisa , Matsumoto Asami , Fujita Makoto
Published: May 2014

Short peptide helices have attracted attention as suitable building blocks for soft functional materials, but they are rarely seen in crystalline materials. A new artificial nanoassembly of short peptide helices in the crystalline state is presented in which peptide helices are arranged three‐dimensionally by metal coordination. The folding and assembly processes of a short peptide ligand containing the Gly‐Pro‐Pro sequence were induced by silver(I) coordination in aqueous alcohol, and gave rise to a single crystal composed of polyproline II helices. Crystallographic studies revealed that this material possesses two types of unique helical nanochannel; the larger channel measures more than 2 nm in diameter. Guest uptake properties were investigated by soaking the crystals in polar solutions of guest molecules; anions, organic chiral molecules, and bio‐oligomers are effectively encapsulated by this peptide‐folded porous crystal, with moderate to high chiral recognition for chiral molecules.
Microflow injection potassium bioassay based on G‐quadruplex DNAzyme‐enhanced chemiluminescence
Authors: Song Lifang , Pan Xiaoyan , Shen Hong , Yu Yaling
Published: May 2014

By taking advantage of microflow injection chemiluminescence analysis, we developed a distinctive microfluidic bioassay method based on G‐Quadruplex DNAzyme‐enhanced chemiluminescence for the determination of K+ in human serum. AGRO100, the G‐rich oligonucleotide with high hemin binding affinity was primarily selected as a K+ recognition element. In the presence of K+, AGRO100 folded into G‐quadruplex and bound hemin to form DNAzyme, which catalyzed the oxidation of luminol by H2O2 to produce chemiluminescence. The intensity of chemiluminescence increased with the K+ concentration. In the study, the DNAzyme showed both long‐term stability and high catalytic activity; other common cations at their physiological concentration did not cause notable interference. With only 6.7 × 10−13 mol of AGRO100 consumption per sample, a linear response of K+ ranged from 1 to 300 µmol/L, the concentration detection limit 0.69 µmol/L (S/N = 3) and the absolute detection limit 1.38 × 10−12 mol were obtained. The precision of 10 replicate measurements of 60 µmol/L K+ was found to be 1.72% (relative standard deviation). The accuracy of the method was demonstrated by analyzing real human serum samples. Copyright © 2014 John Wiley & Sons, Ltd.
Simultaneous determination of six index constituents and comparative analysis of four ethnomedicines from genus Gentiana using a UPLC‐UV‐MS method
Authors: Pan Yu , Shen Tao , Zhang Ji , Zhao Yan‐Li , Wang Yuan‐Zhong , Li Wan‐Yi
Published: May 2014

Many species from genus Gentiana (Gentianaceae) have a long history of applications as folk medicines in the world. A simple rapid UPLC‐UV‐MS/MS method has been developed and validated for the simultaneous determination of six index constituents (gentiopicroside, swertiamarin, loganic acid, sweroside, mangiferin and ferulic acid) from the four ethnomedicines (G. rigescens Franch. ex Hemsl., G. rhodantha Franch. ex Hemsl., G. scabra Bunge and G. farreri Balf. f.). The UPLC analysis was performed on Shim‐Pack XR‐ODS III (150 × 2.0 mm, 2.2 µm). The mobile phase was consisted of acetonitrile–0.1% formic acid water using gradient elution. The wavelength 242 nm was chose for the four iridoids as well as mangiferin and 320 nm was set for ferulic acid. Mass spectrometry was applied for identification and quantification for analytes with low concentration. All the regression equations revealed a good linear relationship (R2 > 0.9993). Accuracy and precision were all within the required limits. The chromatogram fingerprints analysis combined with principal component analysis showed the similarity values of the four species were <0.788 while the similarity values of G. scabra Bunge and G. rigescens Franch. ex Hemsl. were >0.993, which provided reasonable foundation for utilization and clinical application of the four ethnomedicines. This developed method appears to be a useful tool for quality control of the four ethnomedicines. Copyright © 2014 John Wiley & Sons, Ltd.
Real‐time physical deformation and cutting of heterogeneous objects via hybrid coupling of meshless approach and finite element method
Authors: Yang Chen , Li Shuai , Wang Lili , Hao Aimin , Qin Hong
Published: May 2014

This paper advocates a method for real‐time physical deformation and arbitrary cutting simulation of heterogeneous objects with multi‐material distribution, whose originality centers on the tight coupling of domain‐specific finite element method (FEM) and material distance‐aware meshless approach in a CUDA‐centric parallel simulation framework. We employ hierarchical hexahedron serving as basic building blocks for accurate material‐aware FEM simulation. Meanwhile, local meshless systems are designed to support cross‐FEM‐domain coupling and material‐sensitive propagation while respecting the regularity of finite elements. Directly benefiting from the structural regularity and uniformity of finite elements, our hybrid solution enables the local stiffness matrix pre‐computation and dynamic assembling, adaptive topological updating and precise cutting reconstruction. Moreover, our mathematically‐rigorous solver guarantees unconditional stableness. Experiments demonstrate the superiorities of our system. Copyright © 2014 John Wiley & Sons, Ltd.
Real‐time simulation of ductile fracture with oriented particles
Authors: Choi Min Gyu
Published: May 2014

This paper proposes a practical approach for real‐time simulation of large deformation and ductile fracture. We adopt the oriented particles approach for robust and efficient simulation of large deformation and develop a practical model for plastic flow and fracture. The proposed method finds the optimal rotation and the optimal stretch in shape matching. The newly introduced optimal stretch leads to a material strain that can be employed in the plastic flow and fracture criteria. We also propose a graphics processing unit skinning method for real‐time rendering of a deformed, fractured visual mesh. Experimental results show that the proposed method can robustly simulate large, elastoplastic deformation and ductile fracture of large visual meshes in real time. Copyright © 2014 John Wiley & Sons, Ltd.
A Selective Release System Based on Dual‐Drug‐Loaded Mesoporous Silica for Nanoparticle‐Assisted Combination Therapy
Authors: Wang Wenqian , Wen Yongqiang , Xu Liping , Du Hongwu , Zhou Yabin , Zhang Xueji
Published: May 2014

A selective release system was demonstrated with a dual‐cargo loaded MSNs. When stimulated by different signals (UV or H+), this system could selectively release different kinds of cargoes individually. Furthermore, this system has been used to provide a combination of chemotherapy and biotherapy for cancer treatment. This controlled release system could be an important step in the development of more effective and sophisticated nanomedicine and nanodevices, due to the possibility of selective release of a complex multi‐drug.
Extremely Fast Gas/Liquid Reactions in Flow Microreactors: Carboxylation of Short‐Lived Organolithiums
Authors: Nagaki Aiichiro , Takahashi Yusuke , Yoshida Jun‐ichi
Published: May 2014

Carboxylation of short‐lived organolithiums bearing electrophilic functional groups such as nitro, cyano, and alkoxycarbonyl groups with CO2 to give carboxylic acids and active esters was accomplished in a flow microreactor system. The successful reactions indicate that gas/liquid mass transfer and the subsequent chemical reaction with CO2 are extremely fast.
The Role of Vitamin Supplementation in the Prevention of Cardiovascular Disease Events
Authors: Desai Chirag K. , Huang Jennifer , Lokhandwala Adil , Fernandez Aaron , Riaz Irbaz Bin , Alpert Joseph S.
Published: May 2014

The production, sale, and consumption of multiple vitamins is a multibillion‐dollar industry. Most Americans take some form of supplement ostensibly for prevention of cardiovascular disease. It has been claimed that vitamin A retards atherogenesis. Vitamin C is an antioxidant and is thought to possibly decrease free radical‐induced endothelial injury, which can lead to atherosclerotic plaque formation. Vitamin E has been extensively studied for its possible effects on platelet function as well as inhibition of foam‐cell formation. Low levels of vitamin D have been thought to negatively impact myocardial structure and increase the risk for cardiovascular events. Increased intake of vitamin B6, B12, and folate has been associated with reduction of homocysteine levels; elevated homocysteine blood levels have been associated with the occurrence of stroke, heart attack, and cardiovascular death. The purpose of this study was to review the currently available literature for vitamin supplementation with respect to prevention of cardiovascular disease. Unfortunately, the current evidence suggests no benefit exists with vitamin supplementation in the general US population. Further research is needed to evaluate whether there are specific populations that might benefit from vitamin supplementation.
Challenges and Approaches for High‐Voltage Spinel Lithium‐Ion Batteries
Authors: Kim Jung‐Hyun , Pieczonka Nicholas P. W. , Yang Li
Published: May 2014

Lithium‐ion (Li‐ion) batteries have been developed for electric vehicle (EV) applications, owing to their high energy density. Recent research and development efforts have been devoted to finding the next generation of cathode materials for Li‐ion batteries to extend the driving distance of EVs and lower their cost. LiNi0.5Mn1.5O4 (LNMO) high‐voltage spinel is a promising candidate for a next‐generation cathode material based on its high operating voltage (4.75 V vs. Li), potentially low material cost, and excellent rate capability. Over the last decade, much research effort has focused on achieving a fundamental understanding of the structure–property relationship in LNMO materials. Recent studies, however, demonstrated that the most critical barrier for the commercialization of high‐voltage spinel Li‐ion batteries is electrolyte decomposition and concurrent degradative reactions at electrode/electrolyte interfaces, which results in poor cycle life for LNMO/graphite full cells. Despite scattered reports addressing these processes in high‐voltage spinel full cells, they have not been consolidated into a systematic review article. With this perspective, emphasis is placed herein on describing the challenges and the various approaches to mitigate electrolyte decomposition and other degradative reactions in high‐voltage spinel cathodes in full cells.
Reactivity of Graphene and Hexagonal Boron Nitride In‐Plane Heterostructures with Oxygen: A DFT Study
Authors: Nguyen Manh‐Thuong
Published: May 2014

A density‐functional study has been undertaken to investigate the chemical properties of in‐plane heterostructures of graphene and hexagonal boron nitride. The interactions of armchair and zigzag linking edges with oxygen are looked at in detail. The results of the calculations indicate that the linking edges are highly reactive to oxygen atoms and predict that oxygen molecules can accordingly be adsorbed dissociatively. Furthermore, because oxygen atoms cooperatively interact with the heterostructures, the process can lead to opening of the linking edges, thus splitting the two materials.
Cytological diagnosis of osteoblastoma of cervical spine: A case report with review of literature
Authors: Venugopal Suguna Belur , Prasad Sruthi
Published: May 2014

Osteoblastomas are rare benign but sometimes aggressive primary bone tumors (1%), usually seen in males in the 2nd decade. Osteoblastomas, occurring in the spine, constitute a medical emergency due to impending cord compression. Hence a rapid and simple diagnostic modality, such as fine‐needle aspiration (FNA) plays an important role in clinical decision making. Cytological diagnosis of osteoblastoma is rare. We report a case of a young female patient presenting with a swelling in the left cervical paravertebral region. The X‐ray findings were non‐diagnostic and the patient was sent for an FNA. Aspiration yielded moderately cellular hemorrhagic smears with plasmacytoid cells, spindle cells, and osteoclastic giant cells in a background of matrix material. A diagnosis favoring osteoblastoma was made. The CT scan findings were in agreement with the cytological diagnosis and the lesion was excised. Histopathological examination confirmed the same. We describe here, the clinical and cytological features of osteoblastoma with their differential diagnosis, along with review of the literature. FNA can be used as an important tool in the pre‐operative diagnosis of osteoblastoma. Diagn. Cytopathol. 2015;43:218–221. © 2014 Wiley Periodicals, Inc.
Variation and quantification among a target set of phosphopeptides in human plasma by multiple reaction monitoring and SWATH‐MS2 data‐independent acquisition
Authors: Zawadzka Anna M. , Schilling Birgit , Held Jason M. , Sahu Alexandria K. , Cusack Michael P. , Drake Penelope M. , Fisher Susan J. , Gibson Bradford W.
Published: May 2014

Human plasma contains proteins that reflect overall health and represents a rich source of proteins for identifying and understanding disease pathophysiology. However, few studies have investigated changes in plasma phosphoproteins. In addition, little is known about the normal variations in these phosphoproteins, especially with respect to specific sites of modification. To address these questions, we evaluated variability in plasma protein phosphorylation in healthy individuals using multiple reaction monitoring (MRM) and SWATH‐MS2 data‐independent acquisition. First, we developed a discovery workflow for phosphopeptide enrichment from plasma and identified targets for MRM assays. Next, we analyzed plasma from healthy donors using an analytical workflow consisting of MRM and SWATH‐MS2 that targeted phosphopeptides from 58 and 68 phosphoproteins, respectively. These two methods produced similar results showing low variability in 13 phosphosites from 10 phosphoproteins (CVinter < 30%) and high interpersonal variation of 16 phosphosites from 14 phosphoproteins (CVinter > 30%). Moreover, these phosphopeptides originate from phosphoproteins involved in cellular processes governing homeostasis, immune response, cell–extracellular matrix interactions, lipid and sugar metabolism, and cell signaling. This limited assessment of technical and biological variability in phosphopeptides generated from plasma phosphoproteins among healthy volunteers constitutes a reference for future studies that target protein phosphorylation as biomarkers.