bluuebunny/crossref_metadata_2025 huggingface dataset:
Microbial nitrogen dynamics in organic and mineral soil horizons along a latitudinal transect in western Siberia
Authors: Wild Birgit , Schnecker Jörg , Knoltsch Anna , Takriti Mounir , Mooshammer Maria , Gentsch Norman , Mikutta Robert , Alves Ricardo J. Eloy , Gittel Antje , Lashchinskiy Nikolay , Richter Andreas
Published: April 2015

Soil N availability is constrained by the breakdown of N‐containing polymers such as proteins to oligopeptides and amino acids that can be taken up by plants and microorganisms. Excess N is released from microbial cells as ammonium (N mineralization), which in turn can serve as substrate for nitrification. According to stoichiometric theory, N mineralization and nitrification are expected to increase in relation to protein depolymerization with decreasing N limitation, and thus from higher to lower latitudes and from topsoils to subsoils. To test these hypotheses, we compared gross rates of protein depolymerization, N mineralization and nitrification (determined using 15N pool dilution assays) in organic topsoil, mineral topsoil, and mineral subsoil of seven ecosystems along a latitudinal transect in western Siberia, from tundra (67°N) to steppe (54°N). The investigated ecosystems differed strongly in N transformation rates, with highest protein depolymerization and N mineralization rates in middle and southern taiga. All N transformation rates decreased with soil depth following the decrease in organic matter content. Related to protein depolymerization, N mineralization and nitrification were significantly higher in mineral than in organic horizons, supporting a decrease in microbial N limitation with depth. In contrast, we did not find indications for a decrease in microbial N limitation from arctic to temperate ecosystems along the transect. Our findings thus challenge the perception of ubiquitous N limitation at high latitudes, but suggest a transition from N to C limitation of microorganisms with soil depth, even in high‐latitude systems such as tundra and boreal forest.
Estimates of future warming‐induced methane emissions from hydrate offshore west Svalbard for a range of climate models
Authors: Marín‐Moreno Héctor , Minshull Timothy A. , Westbrook Graham K. , Sinha Bablu
Published: April 2015

Methane hydrate close to the hydrate stability limit in seafloor sediment could represent an important source of methane to the oceans and atmosphere as the oceans warm. We investigate the extent to which patterns of past and future ocean‐temperature fluctuations influence hydrate stability in a region offshore West Svalbard where active gas venting has been observed. We model the transient behavior of the gas hydrate stability zone at 400–500 m water depth (mwd) in response to past temperature changes inferred from historical measurements and proxy data and we model future changes predicted by seven climate models and two climate‐forcing scenarios (Representative Concentration Pathways RCPs 2.6 and 8.5). We show that over the past 2000 year, a combination of annual and decadal temperature fluctuations could have triggered multiple hydrate‐sourced methane emissions from seabed shallower than 400 mwd during episodes when the multidecadal average temperature was similar to that over the last century (∼2.6°C). These temperature fluctuations can explain current methane emissions at 400 mwd, but decades to centuries of ocean warming are required to generate emissions in water deeper than 420 m. In the venting area, future methane emissions are relatively insensitive to the choice of climate model and RCP scenario until 2050 year, but are more sensitive to the RCP scenario after 2050 year. By 2100 CE, we estimate an ocean uptake of 97–1050 TgC from marine Arctic hydrate‐sourced methane emissions, which is 0.06–0.67% of the ocean uptake from anthropogenic CO2 emissions for the period 1750–2011.
Determining the source characteristics of explosions near the Earth's surface
Authors: Pasyanos Michael E. , Ford Sean R.
Published: April 2015

We present a method to determine source characteristics of explosions near the Earth's surface. The technique accounts for the reduction in amplitudes as the explosion depth approaches the free surface and less energy is coupled into the ground. We apply the method to the Humming Roadrunner series of shallow explosions in New Mexico where the yields and depths are known. Knowledge of the material properties is needed for both source coupling/excitation and the free surface effect. Although there is the expected trade‐off between depth and yield, the estimated yields are close to the known values when the depth is constrained to the free surface. We then apply the method to a regionally recorded explosion in Syria. We estimate an explosive yield less than the 60 t claimed by sources in the open press. The modifications to the method allow us to apply the technique to new classes of events.
Thrust‐type focal mechanisms of tectonic tremors in Taiwan: Evidence of subduction
Authors: Ide Satoshi , Yabe Suguru , Tai Hsin‐Ju , Chen Kate Huihsuan
Published: April 2015

Unlike tectonic tremors in subduction zones and along transform faults, the hosting structure for tremors in Taiwan remains debated. Tectonic tremors in Taiwan have been discovered at ~30 km depth beneath the southern Central Range, which is a young and active collisional mountain belt. Here we provide the first evidence for the focal mechanism of tremor using moment tensor inversion in the very low frequency band, employing broadband seismograms stacked relative to the hypocentral time of tremor. The best solution corresponds to low‐angle thrust faulting, suggesting the subduction of the Eurasian plate. This mechanism is consistent with strong tidal modulation of tremor activity but differs from the normal‐type faulting that dominates regional shallow earthquakes. This result suggests vertical variations in the tectonic stress regime. Thrust faulting may be facilitated by a decrease in normal stress due to the buoyant roots of the mountain belt and local high fluid pressure.
Self‐consistent multifluid MHD simulations of Europa's exospheric interaction with Jupiter's magnetosphere
Authors: Rubin M. , Jia X. , Altwegg K. , Combi M. R. , Daldorff L. K. S. , Gombosi T. I. , Khurana K. , Kivelson M. G. , Tenishev V. M. , Tóth G. , van der Holst B. , Wurz P.
Published: April 2015

The Jovian moon, Europa, hosts a thin neutral gas atmosphere, which is tightly coupled to Jupiter's magnetosphere. Magnetospheric ions impacting the surface sputter off neutral atoms, which, upon ionization, carry currents that modify the magnetic field around the moon. The magnetic field in the plasma is also affected by Europa's induced magnetic field. In this paper we investigate the environment of Europa using our multifluid MHD model and focus on the effects introduced by both the magnetospheric and the pickup ion populations. The model self‐consistently derives the electron temperature that governs the electron impact ionization process, which is the major source of ionization in this environment. The resulting magnetic field is compared to measurements performed by the Galileo magnetometer, the bulk properties of the modeled thermal plasma population is compared to the Galileo Plasma Subsystem observations, and the modeled surface precipitation fluxes are compared to Galileo Ultraviolet Spectrometer observations. The model shows good agreement with the measured magnetic field and reproduces the basic features of the plasma interaction observed at the moon for both the E4 and the E26 flybys of the Galileo spacecraft. The simulation also produces perturbations asymmetric about the flow direction that account for observed asymmetries.
Surface roughness and breaking wave properties retrieved from polarimetric microwave radar backscattering
Authors: Hwang Paul A. , Fois Franco
Published: April 2015

Ocean surface roughness and wave breaking are the two main contributors of radar backscattering from the ocean surface. The relative weightings of the two contributions vary with the microwave polarization: the VV (vertical transmit vertical receive) is dominated by the Bragg resonance scattering mechanism, and the HH (horizontal transmit horizontal receive) and VH (horizontal transmit vertical receive or vertical transmit horizontal receive) contain nontrivial non‐Bragg contributions mainly produced by breaking features. A method is developed to obtain the short‐scale properties of ocean surface roughness and wave breaking from Ku, C, and L band polarimetric sea returns. The results are used for quantitative evaluation of the ocean surface roughness spectral models and for deriving understanding of the breaking contribution important to microwave ocean remote sensing, in particular its dependence on wind speed, microwave frequency, and incidence angle. Implications of the results to air‐sea interaction applications are discussed.
Programmable Persistent Interfacial Metallic State Induced by Frozen Ions in Inorganic–Glass Solid Electrolyte
Authors: Taniguchi Kouji , Fukamichi Takayuki , Itaka Kenji , Takagi Hidenori
Published: April 2015

Electric field control of charge carrier density through dielectric layers has long been a key technology in the semiconductor industry and condensed‐matter physics. The new carrier‐doping method by the electric double layers (EDLs) opens up the route to access clean carrier doping with high carrier density, but this method is not practical for a switching device due to its slow response to the electric field. However, if this slow response could be stopped at room temperature as an extreme case, the EDL method can become the practical means for materials design, which produces a persistent carrier‐doped state without impurity introduction or continuous supply of external electric fields. Here, it is demonstrated that the thermally programmable persistent interfacial metallic state can be realized around room temperature by all‐solid heterointerface devices using an inorganic–glass solid electrolyte as a gate insulator. The proposed device, in this study, could pave the way for designing a new category of a highly carrier‐doped semiconductor.
A Three Component Self‐Assembled Epitaxial Nanocomposite Thin Film
Authors: Kim Dong Hun , Sun Xue Yin , Aimon Nicolas M. , Kim Jae Jin , Campion Michael J. , Tuller Harry L. , Kornblum Lior , Walker Fred J. , Ahn Charles H. , Ross Caroline A.
Published: April 2015

A self‐assembled three phase epitaxial nanocomposite film is grown consisting of ≈3 nm diameter fcc metallic Cu nanorods within square prismatic SrO rocksalt nanopillars in a Sr(Ti,Cu)O3‐δ perovskite matrix. Each phase has an epitaxial relation to the others. The core–shell‐matrix structures are grown on SrTiO3 substrates and can also be integrated onto Si using a thin SrTiO3 buffer. The structure is made by pulsed laser deposition in vacuum from a SrTi0.75Cu0.25O3 target, and formed as a result of the limited solubility of Cu in the perovskite matrix. Wet etching removes the 3 nm diameter Cu nanowires leaving porous SrO pillars. The three‐phase nanocomposite film is used as a substrate for growing a second epitaxial nanocomposite consisting of CoFe2O4 spinel pillars in a BiFeO3 perovskite matrix, producing dramatic effects on the structure and magnetic properties of the CoFe2O4. This three‐phase vertical nanocomposite provides a complement to the well‐known two‐phase nanocomposites, and may offer a combination of properties of three different materials as well as additional avenues for strain‐mediated coupling within a single film.
A Catalyst‐Free Approach to Construct 3‐(Cyclopentenone)oxindoles Through a Phosphine‐Ylide‐Initiated Triple Domino Sequence
Authors: Du Yanlong , Liu Yufen , Yu Aimin , Qin Dabin , Zhang Kui , Meng Xiangtai
Published: April 2015

A catalyst‐free domino reaction was developed for the synthesis of 3‐(cyclopentenone)oxindoles. This method is the first example of a phosphine‐ylide‐initiated Wittig/Michael addition/Wittig domino sequence. The mild reaction conditions and broad functional groups tolerance make it highly valuable for synthesizing 3‐(cyclopentenone)oxindoles.
Influence of process parameters on sorption capacity of microwave activated biosorbents for urea recovery from human urine: a comparative study
Authors: Ganesapillai M. , Venugopal A. , Ananthkrishna V. , Tapankrishna N.
Published: April 2015

The present investigation elicits a comparative study for recovering urea from human urea via adsorption onto three biosorbents: Microwave Activated Carbonized Bamboo Shoots (MACBS), Walnut Shells (MACWS) and Coconut Shells (MACCS). The rate of sorption was investigated under different process parameters including initial sorbate concentration, amount of sorbent, temperature and agitation speed, and further, sorption capacity of MACBS, MACWS and MACCS was compared. Batch results indicated that urea uptake capacity increased with an increase in sorbate concentration and a decrease in sorbent loading and temperature. The experimental data were tested against the Langmuir, Freundlich, Tempkin, Flory–Huggins and Dubinin–Radushkevich (D‐R) isotherms with the D‐R model being a good fit for MACBS and MACCS and the Freundlich model for MACWS. Kinetic studies were performed to understand the order and rate of the sorption process. While pseudo‐second‐order kinetic model fits best for MACBS and MACWS, pseudo‐first order was followed by MACCS. Based on the urea sorption capacity, the following order of suitability of precursors for activated carbon preparation was established: MACBS > MACCS > MACWS. This study illustrates the suitability of biomass‐based precursors for activated carbon preparation and nutrient recovery from wastewater streams like human urine for subsequent use as fertilizers on agricultural land. © 2015 Curtin University of Technology and John Wiley & Sons, Ltd.
Semiconducting polyurethane/polypyrrole/polyaniline for microorganism immobilization and wastewater treatment in anaerobic/aerobic sequential packed bed reactors
Authors: Antonio‐Carmona Iveth D. , Martínez‐Amador Silvia Y. , Martínez‐Gutiérrez Hugo , Ovando‐Medina Víctor M. , González‐Ortega Omar
Published: April 2015

The development of new materials for microorganism immobilization is very important in wastewater treatment. In this work polyurethane (PU) foams were modified polymerizing pyrrole and aniline onto their surface by chemical oxidization to obtain polyurethane/polypyrrole (PU/PPy), polyurethane/polyaniline (PU/PANI), and PU/(PPy‐co‐PANI) supports which were used to immobilize microorganisms for municipal wastewater treatment in batch mode and continuous flow using two sequential (anaerobic/aerobic) packed bed reactors (PBR) varying the total hydraulic retention time (HRT). The supports were characterized by Fourier Transform Infrared (FTIR) spectroscopy and Scanning Electron Microscopy (SEM) and tested in chemical oxygen demand (COD) removal during treatment of a municipal wastewater. It was observed from SEM analysis that globular nanostructures of PPy and PPy‐co‐PANI were formed onto the PU surface with average diameters between 100 and 300 nm, which are typical of aqueous polymerization of pyrrole monomer; however irregular nanostructures were observed when PANI was homopolymerized onto the PU foam. Batch wastewater treatment after 14 days showed COD removal efficiencies of 77%, 69%, 78%, and 80% for PU foam, PU/PPy, PU/PANI, and PU/(PPy‐co‐PANI), respectively; which was explained as a function of polymers morphology deposited onto the PU foam surface. Also it was observed from the sequential PBR that for 24 h and 36 h of HRT, 80 and 90% of COD removal can be achieved; respectively.© 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015, 132, 42242.
Preparation and properties of polycarbonate nanocomposites using attapulgite grafted poly(methyl methacrylate) as a potential nanofiller
Authors: Xu Hang , Yang Haicun , Zhang Liu , Ni Qingting , Gong Fanghong
Published: April 2015

The Core‐shell hybrid particles with attapulgite (ATP) as the core and polymethylmethacrylate (PMMA) as the shell (ATP‐g‐PMMA) were prepared via reversible addition‐fragmentation chain transfer (RAFT) polymerization method. The diameter of ATP‐g‐PMMA was increased to 50–60 nm, and the surface hygroscopicity was decreased observably after surface grafting. Then, ATP‐g‐PMMA hybrid particles were filled into the polycarbonate (PC) by melt mixing to afford nanocomposites, and the mechanical properties, microstructures, thermal stability, and rheological behavior of nanocomposites were investigated by varying ATP‐g‐PMMA concentration in the range 1, 3, 5, and 7 wt % in PC. Fourier Transform infrared spectroscopy (FTIR) suggested that there is no esterification reaction between particles and matrix. Slight changes in tensile strength, and noticeable decrease of elongation and impact strength were observed with the increase in ATP‐g‐PMMA particles loading. The morphology evaluated by field‐emission scanning electron microscopy (FESEM) indicated that ATP‐g‐PMMA was dispersed with a diameter range of 80–100 nm, and phase separation was appeared with increasing ATP‐g‐PMMA loadings. Thermogravimetric analysis (TGA) results revealed the thermal stability of composites was strengthened. The disentanglement and interface slip induced by preferred orientation and directional arrangement of ATP‐g‐PMMA resulted in lower complex viscosity (η*) and higher loss factor (tan δ) compared with the pristine PC. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015, 132, 42262.
One‐pot Sequential Reactions Featuring a Copper‐catalyzed Amination Leading to Pyrido[2′,1′:2,3]imidazo[4,5‐c]quinolines and Dihydropyrido[2′,1′:2,3]imidazo[4,5‐c]quinolines
Authors: Fan Xue‐Sen , Zhang Ju , Li Bin , Zhang Xin‐Ying
Published: April 2015

Tetracyclic skeletons combining an imidazo[1,2‐a]pyridine moiety with a quinoline framework such as pyrido[2′,1′:2,3]imidazo[4,5‐b]quinoline are stimulating increasing interests since they are close isosteres of a series of powerful antiproliferative compounds. In this paper, we report a novel methodology for the synthesis of pyrido[2′,1′:2,3]imidazo[4,5‐c]quinolines through one‐pot sequential reactions of commercially available or readily obtainable 2‐aminopyridines, 2‐bromophenacyl bromides, aqueous ammonia, and aldehydes. Moreover, dihydropyrido[2′,1′:2,3]imidazo[4,5‐c]quinolines could also be obtained in a similar manner by using various ketones as the substrates in place of aldehydes. Notably, the whole procedure combines condensation/amination/cyclization reactions in one pot to give complex compounds in a simple and practical manner. Compared with literature methods, the synthetic strategy reported herein has the advantages of readily available starting materials, structural diversity of products, good functional group tolerance, and obviation of step‐by‐step operations.
Highly Chemoselective and Versatile Method for Direct Conversion of Carboxylic Acids to Ketones Utilizing Zinc Ate Complexes
Authors: Murata Ryo , Hirano Keiichi , Uchiyama Masanobu
Published: April 2015

Various carboxylic acids were directly transformed into the corresponding ketones by utilizing organozinc ate complexes, which provide high chemoselectivity without any overreaction to the undesired tertiary carbinol, owing to formation of a stable tetrahedral zincioketal intermediate. This method offers good overall atom/step/pot economy and operational simplicity.
Highly sensitive fluorescence detection of glycoprotein based on energy transfer between CuInS2 QDs and rhodamine B
Authors: Gao Xue , Li Dan , Tong Ying , Ge Dan , Tang Yiwei , Zhang Defu , Li Jianrong
Published: April 2015

A highly sensitive fluorescence method for glycoprotein detection has been established based on fluorescence resonance energy transfer (FRET) between CuInS2 quantum dots (QDs) and rhodamine B (RB). Lectins comprise a group of proteins with unique affinities toward carbohydrate structures, so the process of FRET can occur between lectin‐coated QDs (CuInS2 QDs–Con A conjugates, acceptors) and carbohydrate‐coated RB (RB–NH2‐glu conjugates, donors). The fluorescence of lectin‐coated QDs was recovered in the presence of a glycoprotein such as glucose oxidase (GOx) and transferrin (TRF), which significantly reduced the FRET efficiency between the donor and the acceptor. Under optimal conditions, a linear correlation was established between the fluorescence intensity ratio I654/I577 and the TRF concentration over the range of 6.90 × 10‐10 to 3.45 × 10‐8 mol/L, with a detection limit of 2.5 × 10‐10 mol/L. The linear range for GOx is 3.35 × 10‐10 to 6.70 × 10‐8 mol/L, with a detection limit of 1.5 × 10‐10 mol/L. The proposed method was applied to the determination of glycoprotein in human serum and cell‐extract samples with satisfactory results. Furthermore, CuInS2 QDs–Con A conjugates are used as safe and efficient optical nanoprobes in HepG2 cell imaging. Copyright © 2015 John Wiley & Sons, Ltd.
Development of protein mimics for intracellular delivery
Authors: deRonde Brittany M. , Tew Gregory N.
Published: April 2015

Designing delivery agents for therapeutics is an ongoing challenge. As treatments and desired cargoes become more complex, the need for improved delivery vehicles becomes critical. Excellent delivery vehicles must ensure the stability of the cargo, maintain the cargo's solubility, and promote efficient delivery and release. In order to address these issues, many research groups have looked to nature for design inspiration. Proteins, such as HIV‐1 trans‐activator of transcription (TAT) and Antennapedia homeodomain protein, are capable of crossing cellular membranes. However, due to the complexities of their structures, they are synthetically challenging to reproduce in the laboratory setting. Being able to incorporate the key features of these proteins that enable cell entry into simpler scaffolds opens up a wide range of opportunities for the development of new delivery reagents with improved performance. This review charts the development of protein mimics based on cell‐penetrating peptides (CPPs) and how structure‐activity relationships (SARs) with these molecules and their protein counterparts ultimately led to the use of polymeric scaffolds. These scaffolds deviate from the normal peptide backbone, allowing for simpler, synthetic procedures to make carriers and tune chemical compositions for application specific needs. Successful design of polymeric protein mimics would allow researchers to further understand the key features in proteins and peptides necessary for efficient delivery and to design the next generation of more efficient delivery reagents. © 2015 Wiley Periodicals, Inc. Biopolymers (Pept Sci) 104: 265–280, 2015.
Kartogenin, transforming growth factor‐β1 and bone morphogenetic protein‐7 coordinately enhance lubricin accumulation in bone‐derived mesenchymal stem cells
Authors: Liu Chun , Ma Xueqin , Li Tao , Zhang Qiqing
Published: April 2015

Osteoarthritis, a common joint degeneration, can cause breakdown of articular cartilage with the presence of lubricin metabolic abnormalities. Lubricin is a multi‐level chondroprotective mucinous glycoprotein in articular joints. Joint defect and infection is elevated and accompanied by accelerated cartilage lesions involving degradation and loss of lubricin. However, a novel, heterocyclic compound called kartogenin (KGN) was discovered to stimulate chondrogenic differentiation of bone‐derived mesenchymal stem cells (BMSCs). And the synergistic effect of transforming growth factor‐β1 (TGF‐β1) and bone morphogenetic protein‐7 (BMP‐7) could provoke lubricin accumulation. This paper attempted to explore the connection between accumulation of lubricin and the effect of TGF‐β1, BMP‐7 and/or KGN. Hence, we investigated the expression and secretion of lubricin in BMSCs treated with different combinations of TGF‐β1, BMP‐7, and/or KGN. Using an in vitro BMSCs system, we observed the content of lubricin from BMSCs treated with TGF‐β1, BMP‐7, and KGN was the highest at both the protein level and the gene level. The accumulation of lubricin was enhanced coordinately by the increase of synthesis and decrease of degradation possibly via c‐Myc and adamts5 pathway. These results further suggested that supplementation of the defect parts with lubricin by using growth factors and small molecules showed a promising potential on preventing joint deterioration in patients with acquired or genetic deficiency of lubricin in the future of regenerative medicine.
Palmitate exerts opposite effects on proliferation and differentiation of skeletal myoblasts
Authors: Grabiec Kamil , Milewska Marta , Błaszczyk Maciej , Gajewska Małgorzata , Grzelkowska‐Kowalczyk Katarzyna
Published: April 2015

The purpose of the study was to examine mechanisms controlling cell cycle progression/arrest and differentiation of mouse C2C12 myoblasts exposed to long‐chain saturated fatty acid salt, palmitate. Treatment of proliferating myoblasts with palmitate (0.1 mmol/l) markedly decreased myoblast number. Cyclin A and cyclin D1 levels decreased, whereas total p21 and p21 complexed with cyclin‐dependent kinase‐4 (cdk4) increased in myoblasts treated with palmitate. In cells induced to differentiation addition of palmitate augmented the level of cyclin D3, the early (myogenin) and late (α‐actinin, myosin heavy chain) markers of myogenesis, and caused an increase of myotube diameter. In conclusion, exposure to palmitate inhibits proliferation of myoblasts through a decrease in cyclin A and cyclin D1 levels and an increase of p21‐cdk4 complex formation; however, it promotes cell cycle exit, myogenic differentiation and myotube growth.
Moschusduft und Patchouliöl
Authors: Frister Thore , Beutel Sascha
Published: April 2015

Moschus und Patchouliöl spielen in der Herstellung von Parfüms, diversen Kosmetik‐ und Haushaltsprodukten eine wichtige Rolle: Es gibt kaum ein Parfüm das ohne Patchouli‐ oder Moschusduft auskommt. Während Patchouliöl bis heute überwiegend aus pflanzlichen Quellen gewonnen wird, sind die verwendeten Moschusduftstoffe schon längst nicht mehr natürlichen Ursprungs. Dank der modernen Synthesechemie existieren für Moschus zahlreiche synthetische Ersatzstoffe. Der Trend zu mehr nachhaltig produzierten Kosmetikprodukten, stellt die konventionellen Produktionsprozesse vor Herausforderungen. Die Biotechnologie steht daher schon in den Startlöchern, um Duft‐ und Aromastoffe in Zukunft wirtschaftlich, umweltfreundlich und qualitativ hochwertig, produzieren zu können.
Selbstheilende Polymere
Authors: Döhler Diana , Michael Philipp , Neumann Steve , Binder Wolfgang H.
Published: April 2015

Auch wenn das Gebiet erst kurze Zeit beforscht wird: Selbstheilende Materialien sind bereits seit tausenden Jahren über intuitive Entwicklung “am Markt” – doch erst die moderne Wissenschaft und eine konsequente chemische Materialforschung haben die zugrundeliegenden Mechanismen der Selbstheilung im Detail erkennen lassen. Auf diesem Materialdesign aufbauend, können selbstheilende Materialien mit nahezu beliebigen Eigenschaften entwickelt werden, die breit anwendbar sind – vorausgesetzt der “Markt”‐preis stimmt, und die verlängerte Lebensdauer ermöglicht tatsächlich einen entsprechenden Vorteil: Wie schon bei Beton und Autolacken gezeigt, stimmt der eingeschlagene Weg zu einer verbesserten Materialwissenschaft mit resultierender verbesserter Nachhaltigkeit.
Exploring compatible facility colors and associated colors for outdoor recreational spaces
Authors: Cheng Chia‐Kuen , Lee Yin‐Chieh , Shen Li
Published: April 2015

Many studies have demonstrated that people associate customary colors to buildings and facilities, and these colors significantly influence people's evaluations of the environment. However, whether customary colors also exist in the environments where building facilities have been installed is rarely discussed. Using correspondence analysis, this study explored the colors associated with five different outdoor recreational spaces (theme parks, national parks, recreational farms, riverside parks, and historic heritage sites) and fitted facility colors. The study acquired a valid sample of 103 college students and demonstrated that people judge colors in recreational spaces according to past experience and their impressions of the spaces. Hue, value, and saturation are not independent factors for color consideration; a color with a specific value and saturation is particularly suitable for some spaces. In addition, the color associated with an environment and the compatible color for facilities are not exactly the same. The possible factors that influence different environment colors and future research directions were also discussed. © 2015 Wiley Periodicals, Inc. Col Res Appl, 41, 424–432, 2016
Analog circuits fault diagnosis using multi‐valued Fisher's fuzzy decision tree (MFFDT)
Authors: Cui Yiqian , Shi Junyou , Wang Zili
Published: April 2015

Fault diagnosis of analog circuits is more challenging compared with digital circuits as a result of the parametric deviation and the difficulty in signal discretization. There still lacks effective approaches to realize reliable fault detection and isolation for a comprehensive diagnosis. A new fault diagnosis technique called multi‐valued Fisher's fuzzy decision tree (MFFDT) is proposed in this paper to solve the problem. This technique uses the decision tree as the diagnosis model and incorporates the Fisher's linear discriminant principles. The fuzzification mechanism is devised to discretize the input monitoring data. The proposed MFFDT method is composed of two aspects: decision tree training and real fault diagnosis processes. The former uses the benchmark data to train a decision tree, while the latter sends the monitoring data into the decision tree to generate diagnosis results. The proposed method is validated using simulated data and the real‐time data for an active filter circuit and an audio amplifying circuit. The comparative analysis is also presented to evaluate diagnosis performances. Copyright © 2015 John Wiley & Sons, Ltd.
Energy efficiency optimization for downlink OFDMA system in heterogeneous network with QoS constraints
Authors: Bastos Joaquim , Huq Kazi Mohammed Saidul , Mumtaz Shahid , Rodriguez Jonathan , Verikoukis Christos
Published: April 2015

Energy efficiency (EE) has currently turn into one of the major issues in heterogeneous networks (HetNet) paradigm of today's wireless communication industry. In this paper, we optimize EE for downlink OFDMA system in HetNet, taking into account realistic network power consumption model, that is, considering circuit power. This paper investigates the EE maximization using convex optimization theory where primary optimization criterion is data rate in a downlink multiuser HetNet. Given QoS (data rate) requirement, for maximizing EE, a constrained based optimization problem is devised. Because the optimization problem is non‐convex in nature, we reconstruct the optimization problem as a convex one and devise a pragmatically efficient novel resource assignment algorithm for maximizing achievable EE, with quick convergence. The considered optimization problem is transformed into a convex optimization problem by redefining the constraint using cubic inequality, which results in an efficient iterative resource allocation algorithm. In each iteration, the transformed problem is solved by using dual decomposition with a projected gradient method. Analytical insights and numerical results exhibit the potency of the devised scheme for the targeted complex wireless systems. Copyright © 2015 John Wiley & Sons, Ltd.
A Bioinspired System for Light‐Driven Water Oxidation with a Porphyrin Sensitizer and a Tetrametallic Molecular Catalyst
Authors: Natali Mirco , Deponti Elisa , Vilona Debora , Sartorel Andrea , Bonchio Marcella , Scandola Franco
Published: April 2015

Inspired by natural photosynthesis, the aim of light‐driven water splitting is to produce renewable fuels by exploiting solar radiation. Sustained hydrogen production is desirable in such systems, and the oxidation of water to oxygen is currently recognized as the bottleneck of the entire process. Therefore, solutions for this difficult task retain a fundamental interest. In this paper, we present a bioinspired, three‐component system for water oxidation that comprises a tetracationic porphyrin ZnII complex as the photosensitizer, a tetraruthenium water‐oxidation catalyst, and sodium persulfate as the electron acceptor. An in‐depth photophysical study reveals the photogeneration of a pentacation radical of the porphyrin (quantum yield up to Φ = 1.01) upon oxidative quenching of the triplet excited state by persulfate. Electron transfer from the water‐oxidation catalyst to the pentacation radical (hole scavenging) is slow (bimolecular rate constant, k < 4 × 107 M–1 s–1), and this is likely the main reason for the low efficiency of the system in photocatalytic tests for water oxidation. Perspectives for improvements of the system and for the development of a light‐activated device for water splitting are discussed.
Determining the Ligand Properties of N‐Heterocyclic Carbenes from 77Se NMR Parameters
Authors: Verlinden Kathrin , Buhl Hannes , Frank Walter , Ganter Christian
Published: April 2015

The 1JCSe coupling constants for a range of NHC–selenium adducts have been measured and used to establish a correlation with the σ‐donor strength of the respective carbenes. For the subclass of amido‐carbenes, the 1JCSe values revealed a high donor capacity, very much in contrast to what the DFT‐calculated HOMO energies suggest. The 1JCH coupling constants for the C‐2 atoms in azolium‐type NHC precursors were more readily obtained and show the same trend as the 1JCSe coupling constants. In addition, the use of 77Se chemical shifts to determine π‐acidity has been extended to a broader range of derivatives, namely 1·Se–22·Se. The superior resolution of the δ(77Se) method in comparison with the Tolman electronic parameters derived from IR spectroscopy is demonstrated for the caffeine‐derived bis‐carbene 19.
Spray Coating for Polymer Solar Cells: An Up‐to‐Date Overview
Authors: Reale Andrea , La Notte Luca , Salamandra Luigi , Polino Giuseppina , Susanna Gianpaolo , Brown Thomas M. , Brunetti Francesca , Di Carlo Aldo
Published: April 2015

Solution processing is the most appealing aspect of organic photovoltaic (OPV) devices. The possibility of printing low‐cost, lightweight, and efficient polymer solar cells (PSC) is the commonly accepted paradigm associated with printable materials deposited as inks using solution‐processing techniques. In addition to slot–die, serigraphy, and flexo/gravure printing, spray coating can be used for photo‐active polymer blends, interface materials for hole and electron extraction, and electrodes. This technique is widely accepted in the industrial world as one of the most suitable for coating thin layers onto virtually any kind of substrate (e.g., glass, metal, plastic) with a degree of conformability insuperable by any other high‐speed coating technique. We present the basic principles governing the mechanisms of atomization, the main techniques adopted for PSCs, the state of the art applications of spray coating for building up each layer of a PSC, and an overview of the perspectives for industrialization.
Application of factor analysis in a large‐scale industrial wastewater treatment plant simulation using principal component analysis–artificial neural network hybrid approach: (Case Study: Fajr Industrial Wastewater Treatment Plant, Mahshahr, Iran)
Authors: Hasanlou Hamed , Abdolabadi Hamid , Aghashahi Mohsen
Published: April 2015

The effective operation of industrial wastewater treatment plants is quite complicated due to having diverse qualitative and quantitative variations in their effluent characteristics during a day. In this article, we take full advantages of well‐known prediction models to acquire an applicable and constructive operation over industrial treatment plants. We combine multilayer perceptron feed forward neural networks with Levenberg–Marquardt training function (Trainlm) and principal component analysis method to estimate pH, chemical oxygen demand, total dissolved solid, Cl−, turbidity, and achieve appropriate operation of Fajr petrochemical industrial treatment plant for the first time in Iran. Moreover, factor analysis approach was applied to determine the paramount input parameters of the models to reduce the parameters' dimension. Mean square error, root mean square error, and correlation coefficient (R) were used for evaluating the performance of the models. Results indicate that correlation coefficients (R) in the range of 0.8–0.94 showed excellent accuracy of the models in estimating qualitative profile of wastewater. Simulation of a whole treatment plant, better prediction of parameters, and proposing a new hybrid model could be some advantages of this study. © 2015 American Institute of Chemical Engineers Environ Prog, 34: 1322–1331, 2015
Oil droplet ingestion and oil fouling in the copepod Calanus finmarchicus exposed to mechanically and chemically dispersed crude oil
Authors: Nordtug Trond , Olsen Anders J. , Salaberria Iurgi , Øverjordet Ida B. , Altin Dag , Størdal Ingvild F. , Hansen Bjørn Henrik
Published: April 2015

The rates of ingestion of oil microdroplets and oil fouling were investigated in the zooplankton filter-feeder Calanus finmarchicus (Gunnerus, 1770) at 3 concentrations of oil dispersions ranging from 0.25 mg/L to 5.6 mg/L. To compare responses to mechanically and chemically dispersed oil, the copepods were exposed to comparable dispersions of micron-sized oil droplets made with and without the use of a chemical dispersant (similar oil droplet size range and oil concentrations) together with a constant supply of microalgae for a period of 4 d. The filtration rates as well as accumulation of oil droplets decreased with increasing exposure concentration. Thus the estimated total amount of oil associated with the copepod biomass for the 2 lowest exposures in the range 11 mL/kg to 17 mL/kg was significantly higher than the approximately 6 mL/kg found in the highest exposure. For the 2 lowest concentrations the filtration rates were significantly higher in the presence of chemical dispersant. Furthermore, a significant increase in the amount of accumulated oil in the presence of dispersant was observed in the low exposure group. Environ Toxicol Chem 2015;34:1899–1906. © 2015 SETAC
Modelling surface runoff to evaluate the effects of wildfires in multiple semi‐arid, shrubland‐dominated catchments
Authors: Moussoulis Elias , Mallinis Giorgos , Koutsias Nikos , Zacharias Ierotheos
Published: April 2015

Wildfires change the infiltration properties of soil, reduce the amount of interception and result in increased runoff. A wildfire at Northeast Attica, Central Greece, in August 2009, destroyed approximately one third of a study area consisting of a mixture of shrublands, pastures and pines. The present study simultaneously models multiple semi‐arid, shrubland‐dominated Mediterranean catchments and assesses the hydrological response (mean annual and monthly runoff and runoff coefficients) during the first few years following wildfires. A physically based, hydrological model (MIKE SHE) was chosen. Calibration and validation results of mean monthly discharge presented very good agreement with the observed data for the pre‐wildfire and post‐wildfire period for two subcatchments (Nash–Sutcliffe Efficiency coefficient of 79.7%). The model was then used to assess the pre‐wildfire and post‐wildfire runoff responses for each of seven catchments in the study area. Mean annual surface runoff increased for the first year and after the second year following the wildfires increased by 112% and 166%, respectively. These values are within the range observed in similar cases of monitored sites. This modelling approach may provide a way of prioritizing catchment selection with respect to post‐fire remediation activities. Additionally, this modelling assessment methodology would be valuable to other semi‐arid areas because it provides an important means for comprehensively assessing post‐wildfire response over large regions and therefore attempts to address some of the scaled issues in the specific literature field of research. Copyright © 2015 John Wiley & Sons, Ltd.
Whole cell bioconversion of (+)‐valencene to (+)‐nootkatone by Yarrowia lipolytica using a three phase partitioning bioreactor
Authors: Palmerín‐Carreño Dulce M , Castillo‐Araiza Carlos O , Rutiaga‐Quiñones Olga M , Verde Calvo José R , Trejo‐Aguilar Gloria M , Dutta Abhishek , Huerta‐Ochoa Sergio
Published: April 2015

BACKGROUND

Low permeability of substrates across the cell membrane, cofactor regeneration and product inhibition are some drawbacks of (+)‐nootkatone bioconversion. The aim of this work was to evaluate and enhance the bioconversion of (+)‐valencene to (+)‐nootkatone with Yarrowia lipolytica in a partitioning bioreactor using orange essential oil as the dispersed phase.

RESULTS

Preliminary experiments in shake flasks allowed enhancing (+)‐nootkatone bioconversion to obtain favorable operating conditions (0.2% w/v of CTAB, 2.0 mmol L−1 of niacin and 11.5 g L−1 of biomass) to produce 420.9 mg L−1. Bioreactor experiments in a two‐phase system using 0.2% (w/v) of CTAB, 2.0 mmol L−1 of niacin and 22.5 g L−1 of biomass produced a maximum (+)‐nootkatone concentration of 619.8 mg L−1 which was around the product inhibition concentration. Nevertheless, the partitioning three‐phase system using orange essential oil overcame product inhibition, obtaining concentrations up to 852.3 mg L−1.

CONCLUSIONS

This is the first report of a wild type Y. lipolytica with the enzymatic machinery to carry out this bioconversion. The multiphase partitioning bioreactor concept seems to have good potential for enhancing the productivity of (+)‐nootkatone. The bioconversion approach presents an attractive way to produce and recover (+)‐nootkatone in situ using a natural (+)‐valencene source. © 2015 Society of Chemical Industry
The bronze panel (paliotto) ofSan Moisèin Venice: materials and causes of deterioration
Authors: Chiavari C. , Martini C. , Montalbani S. , Franzoni E. , Bignozzi M.C. , Passeri M.C.
Published: April 2015

This paper reports on the diagnostic investigations on the bronze panel in the Church ofSan Moisèin Venice (Italy), aiming at the identification of materials and causes of corrosion. Both the bulk metal and surface layers were investigated by a wide range of techniques: alloy composition and microstructure were determined by VP‐SEM/EDS, the corrosion products by Raman spectroscopy and XRD. The organic compounds were analysed by pyrolysis gas chromatography mass spectrometry (Py‐GC‐MS). The adjacent mortars were analysed in terms of mineralogical composition and soluble salts content, in order to highlight their role in the degradation processes at the contact areas between the masonry and the bronze panel.

The alloy is a quaternary bronze (Cu‐Sn‐Zn‐Pb): high‐relief figures were cast separately then mechanically joined to the panel. Traces of the clay core were detected in the back of the panel. The bronze surface was artificially patinated by potassium sulphide. The organic protective layer consisted of stearin and paraffinic wax. However, siccative oil was detected at the interface with the metal, likely corresponding to the original protective treatment. Also pine resin traces were detected.

The corrosion products mainly consisted of basic copper chlorides (paratacamite, atacamite) and mixed copper/sodium carbonates (chalconatronite), deriving from the interaction with mortar.
Fourth‐order compact difference schemes for 1D nonlinear Kuramoto–Tsuzuki equation
Authors: Hu Xiuling , Chen Shanzhen , Chang Qianshun
Published: April 2015

In this article, first, we establish some compact finite difference schemes of fourth‐order for 1D nonlinear Kuramoto–Tsuzuki equation with Neumann boundary conditions in two boundary points. Then, we provide numerical analysis for one nonlinear compact scheme by transforming the nonlinear compact scheme into matrix form. And using some novel techniques on the specific matrix emerged in this kind of boundary conditions, we obtain the priori estimates and prove the convergence in norm. Next, we analyze the convergence and stability for one of the linearized compact schemes. To obtain the maximum estimate of the numerical solutions of the linearized compact scheme, we use the mathematical induction method. The treatment is that the convergence in norm is obtained as well as the maximum estimate, further the convergence in norm. Finally, numerical experiments demonstrate the theoretical results and show that one of the linearized compact schemes is more accurate, efficient and robust than the others and the previous. It is worthwhile that the compact difference methods presented here can be extended to 2D case. As an example, we present one nonlinear compact scheme for 2D Ginzburg–Landau equation and numerical tests show that the method is accurate and effective. © 2015 Wiley Periodicals, Inc. Numer Methods Partial Differential Eq 31: 2080–2109, 2015
Cytoprotective and Anti‐secretory Effects of Azadiradione Isolated from the Seeds of Azadirachta indica (neem) on Gastric Ulcers in Rat Models
Authors: Singh Rohit , Mishra Vaibhav , Pandeti Sukanya , Palit Gautam , Barthwal Manoj K. , Pandey Haushila Prasad , Narender Tadigoppula
Published: April 2015

Azadirachta indica is well known medicinal plant mentioned in ancient herbal texts. It has been extensively used in Ayurvedic, Unani and Homoeopathic medicine and has become a luminary of modern medicine. As part of our drug discovery program we isolated azadiradione from the ethanolic extract of seeds of A. indica and evaluated for in‐vivo antiulcer activity in cold restraint induced gastric ulcer model, aspirin induced gastric ulcer model, alcohol induced gastric ulcers model and pyloric ligation induced ulcer model. Azadiradione exhibited potent antiulcer activity through the inhibition of H+ K+‐ATPase (proton pump) activity via its cytoprotective effect and also via its antisecretory effect. This combined effect has valuable potential in the future treatment of peptic ulceration. Copyright © 2015 John Wiley & Sons, Ltd.
Knowledge retention, student learning, and blended course work: Evidence from principles of economics courses
Authors: Cosgrove Sarah B. , Olitsky Neal H.
Published: April 2015

Over the past decade, there has been a large increase in the number of colleges and universities that offer fully online courses and blended courses (courses with a face‐to‐face component and with an online component). The number of students enrolling in these courses has also increased. These courses are less costly for universities to offer and provide students with more flexibility than traditional classes. This study examines the relationship between online learning and knowledge retention in introductory economics courses. Student assessment data are matched to transcript and demographic information to control for individual student attributes. Using a differences‐in‐differences matching estimator, we determine the effect online coursework has on knowledge retention by comparing performance on the assessment. Results suggest that while there is no significant difference in student learning, students in more traditional, technology‐free courses retain the material better than students.