bluuebunny/crossref_metadata_2025 huggingface dataset:
How organic farmers practice conservation agriculture in Europe
Authors: Peigné Joséphine , Casagrande Marion , Payet Vincent , David Christophe , Sans F. Xavier , Blanco-Moreno José M. , Cooper Julia , Gascoyne Kate , Antichi Daniele , Bàrberi Paolo , Bigongiali Federica , Surböck Andreas , Kranzler Andreas , Beeckman Annelies , Willekens Koen , Luik Anne , Matt Darja , Grosse Meike , Heß Juergen , Clerc Maurice , Dierauer Hansueli , Mäder Paul
Published: January 2015

The interest of organic farmers in adopting conservation agriculture principles, including minimal soil disturbance, permanent soil cover and crop rotation has been growing since the early 2000s. However, currently there is no network for organic farmers practicing conservation agriculture, and a lack of knowledge on how organic farmers implement conservation agriculture in practice. Consequently, few technical references are available for organic farmers when they start applying conservation agriculture practices, in particular on controlling weeds without the use of herbicides. The main objectives of this study were: (1) to explore the diversity of conservation agriculture techniques (i.e., reduced tillage, no-tillage and green manures) practiced among European farmers, and (2) to identify farmers’ main strategies for implementing conservation agriculture and the agronomic and environmental factors that determine these strategies. Strategies were identified by analyzing survey results on: (1) the type and degree of use of conservation agriculture practices by farmers, and (2) the effects it produces in terms of soil disturbance and soil cover (low, medium and high). We carried out a survey of 159 European organic farmers and collected 125 data sets on management of winter-sown crops. Among the conservation agriculture practices, reduced tillage was used by 89%, no-tillage by 27% and green manure by 74% of the 159 interviewed farmers. Green manures were more frequently used in northern Europe than in the south (below 45°N). Most of the farmers used crop rotations, with a mean duration of 6 years. A wide diversity of conservation agriculture practices were used, with farmers rarely using all three techniques (no-till, reduced till and green manures) within one system. The range of practices was grouped into five strategies ranging from intensive non-inversion tillage without soil cover to very innovative techniques with no-tillage and intercrops. The five strategies for conservation agriculture could be grouped into two larger categories based on weed control approach: (1) intensification of the mechanical work without soil inversion or (2) biological regulation of weeds with cover crops. The diversity of strategies identified in this study shows that organic farmers use innovative approaches to implement conservation agriculture without herbicides. This study's findings will help organic farmers to experiment with innovative practices based on conservation agriculture principles and also benefit conventional farmers who use conservation agriculture practices and would like to reduce or eliminate the use of herbicides.
Attitudes toward Mormons and Voter Behavior in the 2012 Presidential Election
Authors: Hawley George
Published: January 2015

Prior to the 2012 presidential election, some commentators speculated that Mitt Romney's status as a devout and active member of the Church of Jesus Christ of Latter-day Saints would undermine his presidential aspirations. Using the 2012 American National Election Survey, this study examines the relationship between attitudes toward Mormons and voter behavior in the United States in that election year. It finds that attitudes toward Mormons had a statistically-significant effect on turnout — though these effects differed according to party identification. It additionally finds that these attitudes influenced vote choice. In both cases, the substantive effects were small, indicating that anti-Mormon feelings did play a role in the 2012 presidential election, but they did not determine the final outcome.
Alnus peptides modify membrane porosity and induce the release of nitrogen-rich metabolites from nitrogen-fixing Frankia
Authors: Carro Lorena , Pujic Petar , Alloisio Nicole , Fournier Pascale , Boubakri Hasna , Hay Anne E , Poly Franck , François Philippe , Hocher Valerie , Mergaert Peter , Balmand Severine , Rey Marjolaine , Heddi Abdelaziz , Normand Philippe
Published: January 2015

Actinorhizal plant growth in pioneer ecosystems depends on the symbiosis with the nitrogen-fixing actinobacterium Frankia cells that are housed in special root organs called nodules. Nitrogen fixation occurs in differentiated Frankia cells known as vesicles. Vesicles lack a pathway for assimilating ammonia beyond the glutamine stage and are supposed to transfer reduced nitrogen to the plant host cells. However, a mechanism for the transfer of nitrogen-fixation products to the plant cells remains elusive. Here, new elements for this metabolic exchange are described. We show that Alnus glutinosa nodules express defensin-like peptides, and one of these, Ag5, was found to target Frankia vesicles. In vitro and in vivo analyses showed that Ag5 induces drastic physiological changes in Frankia, including an increased permeability of vesicle membranes. A significant release of nitrogen-containing metabolites, mainly glutamine and glutamate, was found in N2-fixing cultures treated with Ag5. This work demonstrates that the Ag5 peptide is central for Frankia physiology in nodules and uncovers a novel cellular function for this large and widespread defensin peptide family.
Total synthesis of periploside A, a unique pregnane hexasaccharide with potent immunosuppressive effects
Authors: Zhang Xiaheng , Zhou Yu , Zuo Jianping , Yu Biao
Published: January 2015

Periploside A is a pregnane hexasaccharide identified from the Chinese medicinal plant Periploca sepium, which features a unique seven-membered formyl acetal bridged orthoester (FABO) motif and potent immunosuppressive activities. Here, we show the synthesis of this molecule in a total of 76 steps with the longest linear sequence of 29 steps and 9.2% overall yield. The FABO motif is constructed via a combination of Sinaÿ’s and Crich’s protocol for the formation of orthoester and acetal glycosides, respectively. The 2-deoxy-β-glycosidic linkages are assembled stereoselectively with judicious choice of the glycosylation methods. The epimer at the spiro-quaternary carbon in the FABO motif has also been elaborated in a stereo-controlled manner. This epimer, as well as the synthetic analogues bearing the FABO motif, retain largely the inhibitory activities of periploside A against the proliferation of T-lymphocyte, indicating the importance of the chemical connection of the FABO motif to their immunosuppressive activity.
A dynamically coupled allosteric network underlies binding cooperativity in Src kinase
Authors: Foda Zachariah H. , Shan Yibing , Kim Eric T. , Shaw David E. , Seeliger Markus A.
Published: January 2015

Protein tyrosine kinases are attractive drug targets because many human diseases are associated with the deregulation of kinase activity. However, how the catalytic kinase domain integrates different signals and switches from an active to an inactive conformation remains incompletely understood. Here we identify an allosteric network of dynamically coupled amino acids in Src kinase that connects regulatory sites to the ATP- and substrate-binding sites. Surprisingly, reactants (ATP and peptide substrates) bind with negative cooperativity to Src kinase while products (ADP and phosphopeptide) bind with positive cooperativity. We confirm the molecular details of the signal relay through the allosteric network by biochemical studies. Experiments on two additional protein tyrosine kinases indicate that the allosteric network may be largely conserved among these enzymes. Our work provides new insights into the regulation of protein tyrosine kinases and establishes a potential conduit by which resistance mutations to ATP-competitive kinase inhibitors can affect their activity.
High-temperature supercapacitor with a proton-conducting metal pyrophosphate electrolyte
Authors: Hibino Takashi , Kobayashi Kazuyo , Nagao Masahiro , Kawasaki Shinji
Published: January 2015

Expanding the range of supercapacitor operation to temperatures above 100°C is important because this would enable capacitors to operate under the severe conditions required for next-generation energy storage devices. In this study, we address this challenge by the fabrication of a solid-state supercapacitor with a proton-conducting Sn0.95Al0.05H0.05P2O7 (SAPO)-polytetrafluoroethylene (PTFE) composite electrolyte and a highly condensed H3PO4 electrode ionomer. At a temperature of 200°C, the SAPO-PTFE electrolyte exhibits a high proton conductivity of 0.02 S cm−1 and a wide withstanding voltage range of ±2 V. The H3PO4 ionomer also has good wettability with micropore-rich activated carbon, which realizes a capacitance of 210 F g−1 at 200°C. The resulting supercapacitor exhibits an energy density of 32 Wh kg−1 at 3 A g−1 and stable cyclability after 7000 cycles from room temperature to 150°C.
Silver-gelatine bionanocomposites for qualitative detection of a pesticide by SERS
Authors: Fateixa S. , Soares S. F. , Daniel-da-Silva A. L. , Nogueira H. I. S. , Trindade T.
Published: January 2015

Gelatine based nanocomposites incorporating Ag nanoparticles as a new SERS platform for the detection of diethyldithiocarbamate (EtDTC), aiming controlled release applications.
Selected recent in vivo studies on chemical measurements in invertebrates
Authors: Majdi S. , Ren L. , Fathali H. , Li X. , Ewing A. G.
Published: January 2015

Review ofin vivoanalysis of brain chemicals in invertebrates.
A cloud point extraction procedure for gallium, indium and thallium determination in liquid crystal display and sediment samples
Authors: Mortada Wael I. , Kenawy Ibrahim M. , Hassanien Mohamed M.
Published: January 2015

A simple, sensitive and rapid cloud point extraction (CPE) methodology has been developed for the selective separation and preconcentration of gallium, indium and thallium, after complexation with gallic acid in the presence of Triton X-114 as a non-ionic surfactant.
A new turn on Pd2+-specific fluorescence probe and its use as an imaging reagent for cellular uptake in Hct116 cells
Authors: Reddy G. Upendar , Ali Firoj , Taye Nandaraj , Chattopadhyay Samit , Das Amitava
Published: January 2015

A new molecular probe that is used as an imaging reagent for detection of cellular uptake of Pd(ii) in Hct116 cells and for quantitative estimation of Pd(ii) in biological fluids.
Advances in the molecular understanding of biological zinc transport
Authors: Blindauer Claudia A.
Published: January 2015

Recognition of the importance of zinc homeostasis for health has driven a surge in structural data on major zinc-transporting proteins.
Topochemical conversion of protonated titanate single crystals into platelike Ba0.5Sr0.5TiO3 mesocrystals with controllable microstructures
Authors: Hu Dengwei , Luo Xin , Kong Xingang , Wang Yan , Tanaka Yasuhiro , Feng Qi
Published: January 2015

Mesocrystalline Ba0.5Sr0.5TiO3 platelike polycrystals with controllable microstructures are constructed from well-oriented nanocrystals.
On the structural stability of ionic liquid–IRMOF composites: a computational study
Authors: Abroshan Hadi , Kim Hyung J.
Published: January 2015

IRMOFs become unstable in the presence of ILs due to dramatic structural deformation caused mainly by metal-anion electrostatic interactions.
Modeling laser induced molecule excitation using real-time time-dependent density functional theory: application to 5- and 6-benzyluracil
Authors: Bende Attila , Toşa Valer
Published: January 2015

The fully propagated real time-dependent density functional theory method has been applied to study the laser–molecule interaction in 5- and 6-benzyluracil (5BU and 6BU).
Diradical character and nonlinear optical properties of buckyferrocenes: focusing on the use of suitably modified fullerene fragments
Authors: Muhammad Shabbir , Ito Soichi , Nakano Masayoshi , Kishi Ryohei , Yoneda Kyohei , Kitagawa Yasutaka , Shkir Mohd , Irfan Ahmad , Chaudhry Aijaz R. , AlFaify Salem , Kalam Abul , Al-Sehemi Abdullah G.
Published: January 2015

Buckyferrocenes, made up of suitably modified fullerenes fragments having an uninterrupted π-electron network, show intermediate diradical character and robustly large third-order nonlinear optical responses.
Self-assembled trityl radical capsules – implications for dynamic nuclear polarization
Authors: Marin-Montesinos I. , Paniagua J. C. , Vilaseca M. , Urtizberea A. , Luis F. , Feliz M. , Lin F. , Van Doorslaer S. , Pons M.
Published: January 2015

The OX63 radical forms supramolecular capsules hosting tetraalkylammonium cations. Extensive self-association is also observed under standard dynamic nuclear polarization conditions.
Correlation between stoichiometry and surface structure of the polar MgAl2O4(100) surface as a function of annealing temperature
Authors: Jensen Thomas N. , Rasmussen Morten K. , Knudsen Jan , Vlad Alina , Volkov Sergey , Lundgren Edvin , Stierle Andreas , Lauritsen Jeppe V.
Published: January 2015

Experimental characterization of the polar MgAl2O4(100) surface revealing a strong correlation between annealing temperature and surface morphology.
First principles static and dynamic calculations for the transition metal hydride seriesMH4L3(M= Fe, Ru and Os;L= NH3, PH3and PF3)
Authors: Sieffert Nicolas , Kendrick Thomas , Tiana Davide , Morrison Carole A.
Published: January 2015

A DFT study to elucidate how the identity of the metal and auxiliary ligands influences H2→ 2H dynamics.
A perfectly aligned 63helical tubular cuprous bromide single crystal for selective photo-catalysis, luminescence and sensing of nitro-explosives
Authors: Yao Ru-Xin , Hailili Reshalaiti , Cui Xin , Wang Li , Zhang Xian-Ming
Published: January 2015

A perfectly aligned 63helical tubular cuprous bromide single crystal stabilized by organic template cations has been synthesized, which could be a multifunctional material for highly selective degradation, luminescence and sensing of nitro-explosives at the ppm level.
Power-to-What? – Environmental assessment of energy storage systems
Authors: Sternberg André , Bardow André
Published: January 2015

The article tries to answer the question: Given 1 MW h of surplus electricity from renewable energies, which energy storage system brings the greatest environmental benefit?
Environmental impacts of electricity generation at global, regional and national scales in 1980–2011: what can we learn for future energy planning?
Authors: Laurent Alexis , Espinosa Nieves
Published: January 2015

Environmental impacts of electricity generation have globally intensified and burden-shiftings occurred in several countries, calling for more holistic energy planning.
A continuous-flow microfluidic syringe filter for size-based cell sorting
Authors: Song Seungjeong , Kim Minseok S. , Lee Jaeyeon , Choi Sungyoung
Published: January 2015

This communication presents a microfluidic method for size-based cell sorting, which provides a simple and robust approach for cell cycle synchronization by manual and stand-alone operation.
Nickel recognition by bacterial importer proteins
Authors: Chivers Peter T.
Published: January 2015

Nickel recognition for microbial import exhibits coordination features distinct from other cellular functions.
Improved catalytic activity of PrMO3 (M = Co and Fe) perovskites: synthesis of thermally stable nanoparticles by a novel hydrothermal method
Authors: Megarajan Suresh Kumar , Rayalu Sadhana , Nishibori Maiko , Labhsetwar Nitin
Published: January 2015

A simple hydrothermal method was used to synthesize nanoperovskites using metal cyano complexes as precursors.
Correction: The effect of an ionic liquid on the rate of reaction at a phosphorus centre
Authors: Butler Bradley J. , Harper Jason B.
Published: January 2015

Correction for ‘The effect of an ionic liquid on the rate of reaction at a phosphorus centre' by Bradley J. Butler et al., New J. Chem., 2015, DOI: 10.1039/c4nj01224k.
Hyaluronan-decorated polymer nanoparticles targeting the CD44 receptor for the combined photo/chemo-therapy of cancer
Authors: Maiolino Sara , Moret Francesca , Conte Claudia , Fraix Aurore , Tirino Pasquale , Ungaro Francesca , Sortino Salvatore , Reddi Elena , Quaglia Fabiana
Published: January 2015

CD44-targeted hyaluronan-decorated double-coated nanoparticles delivering the lipophilic chemotherapeutic docetaxel and an anionic porphyrin are developed and tested in human breast cancer cells.
Nano-thermometers with thermo-sensitive polymer grafted USPIOs behaving as positive contrast agents in low-field MRI
Authors: Hannecart Adeline , Stanicki Dimitri , Vander Elst Luce , Muller Robert N. , Lecommandoux Sébastien , Thévenot Julie , Bonduelle Colin , Trotier Aurélien , Massot Philippe , Miraux Sylvain , Sandre Olivier , Laurent Sophie
Published: January 2015

MRI signal linearity with temperature from 15 to 50 °C with thermo-sensitive chains on iron oxide nanoparticles.
Nanocellulose coupled flexible polypyrrole@graphene oxide composite paper electrodes with high volumetric capacitance
Authors: Wang Zhaohui , Tammela Petter , Strømme Maria , Nyholm Leif
Published: January 2015

A robust and flexible nanocellulose coupled PPy@GO paper electrode is straightforwardly prepared, exhibiting a capacitance of 198 F cm−3(301 F cm−3based on PPy) ever reported for flexible polymer-based electrodes.
Ylide formal [4 + 1] annulation
Authors: Zhu Chunyin , Ding Ya , Ye Long-Wu
Published: January 2015

Ylide [4 + 1] annulation: beyond small-ring formation.
Thieno[2,3,a]carbazole donor-based organic dyes for high efficiency dye-sensitized solar cells
Authors: Zhao Jian , Oniwa Kazuaki , Islam Ashraful , Qin Chuanjiang , Asao Naoki , Han Liyuan , Yamamoto Yoshinori , Jin Tienan
Published: January 2015

A new class of D–π-A organic dyes based on thieno[2,3,a]carbazole as an electron donor showed high efficiencies for dye-sensitized solar cells.
Deuterative cyclization of sulfanyl 1,6-diynes: complete and monodeuteration of functional groups on heterocycles
Authors: Ito Yukiteru , Yoshimatsu Mitsuhiro
Published: January 2015

Regioselective H/D exchange reaction of functional groups on heterocycles proceeded via a transition metal-free reductive cyclization of sulfanyl 1,6-diynes using sodium borodeuteride/ethanol-D1.
Ultra-thick Li-ion battery electrodes using different cell size of metal foam current collectors
Authors: Yang Gui-Fu , Song Kyung-Yup , Joo Seung-Ki
Published: January 2015

In this study, ultra-thick Li-ion battery electrodes were prepared using 450, 800 and 1200 μm cell size of metal foam current collectors for large scale energy storage.
High strength nanocomposite hydrogel bilayer with bidirectional bending and shape switching behaviors for soft actuators
Authors: Xu Bo , Jiang Haoyang , Li Huanjun , Zhang Gongzheng , Zhang Qingshan
Published: January 2015

A TiO2 cross-linked nanocomposite hydrogel bilayer with bidirectional bending and shape switching behaviors was reported.
Ruthenium complexes as inhibitors of human islet amyloid polypeptide aggregation, an effect that prevents beta cell apoptosis
Authors: Ma Lijuan , Fu Yuanting , Yu Lianling , Li Xiaoling , Zheng Wenjie , Chen Tianfeng
Published: January 2015

Herein we show that ruthenium complexes could inhibit fibrosis of hIAPP and protect the hIAPP-induced cell damage by suppressing ROS generation, indicating the application potential of the complexes in treatment of T2DM by targeting hIAPP.
Multiple deuteration of alkanes synergistically-catalyzed by platinum and rhodium on carbon as a mixed catalytic system
Authors: Yamada Tsuyoshi , Sawama Yoshinari , Shibata Kyoshiro , Morita Kosuke , Monguchi Yasunari , Sajiki Hironao
Published: January 2015

A mild and efficient deuterium labeling method of alkanes based on the synergistic effect of Pt–Rh combination was developed.
Exploring the binding properties of agonists interacting with human TGR5 using structural modeling, molecular docking and dynamics simulations
Authors: Sindhu Thangaraj , Srinivasan Pappu
Published: January 2015

TGR5, act as a potential pharmacological target in the treatment of type II diabetes. In the computational study, structural modeling and binding site prediction of TGR5 receptor was performed. Two well-known agonists of TGR5 used to investigate the mode and mechanism of binding.
Electrohydrodynamic patterning of ultra-thin ionic liquid films
Authors: Nazaripoor Hadi , Koch Charles R. , Sadrzadeh Mohtada , Bhattacharjee Subir
Published: January 2015

In the electrohydrodynamic (EHD) patterning process, electrostatic destabilization of the air–polymer interface results in micro- and nano-size patterns in the form of raised formations called pillars.
Synthesis, characterization and photovoltaic properties of azadipyrromethene-based acceptors: effect of pyrrolic substituents
Authors: Senevirathna Wasana , Liao Jia-yu , Mao Zhenghao , Gu Jun , Porter Matthew , Wang Chunlai , Fernando Roshan , Sauvé Geneviève
Published: January 2015

A structure–property study of non-fullerene acceptors based on azadipyrromethene derivatives was performed. Power conversion efficiencies between 2 and 4% were obtained when blended with poly(3-hexylthiophene) as the donor.
Improvement of the humidity stability of organic–inorganic perovskite solar cells using ultrathin Al2O3layers prepared by atomic layer deposition
Authors: Dong Xu , Fang Xiang , Lv Minghang , Lin Bencai , Zhang Shuai , Ding Jianning , Yuan Ningyi
Published: January 2015

The high polarity of water molecules inevitably causes the decomposition of perovskites. We retard the degradation by introducing an ultrathin ALD–Al2O3layer, which has almost no negative effect on performance.
Growth control of compact CH3NH3PbI3 thin films via enhanced solid-state precursor reaction for efficient planar perovskite solar cells
Authors: Zhou Yuanyuan , Yang Mengjin , Vasiliev Alexander L. , Garces Hector F. , Zhao Yixin , Wang Dong , Pang Shuping , Zhu Kai , Padture Nitin P.
Published: January 2015

A new solution-processing method is demonstrated for the deposition of compact CH3NH3PbI3 perovskite thin films for high-efficiency planar solar cells.
Size-dependent toxicity and interactions of calcium oxalate dihydrate crystals on Vero renal epithelial cells
Authors: Sun Xin-Yuan , Ouyang Jian-Ming , Zhu Wen-Yu , Li Yu-Bao , Gan Qiong-Zhi
Published: January 2015

Size-dependent toxicity and interactions of calcium oxalate dihydrate crystals on Vero renal epithelial cells were demonstrated.
Effects of plasma-generated nitrogen functionalities on the upregulation of osteogenesis of bone marrow-derived mesenchymal stem cells
Authors: Zhang Wei , Liu Jun , Shi Haigang , Liu Na , Yang Kun , Shi Lianxin , Gu Bin , Wang Huaiyu , Ji Junhui , Chu Paul K.
Published: January 2015

A tertiary amine constructed controllably by plasma technology possesses the optimal capability to promote BMSC osteogenesis.
One-pot synthesis of carbon nanodots for fluorescence turn-on detection of Ag+ based on the Ag+-induced enhancement of fluorescence
Authors: Gao Xiaohui , Lu Yizhong , Zhang Ruizhong , He Shuijian , Ju Jian , Liu Minmin , Li Lei , Chen Wei
Published: January 2015

Fluorescent carbon dots prepared by a heat treatment of ethylene glycol solution can act as fluorescence turn-on probes for sensitive and selective detection of Ag+ ions.
Facile fabrication of color-tunable and white light emitting nano-composite films based on layered rare-earth hydroxides
Authors: Liu Liangliang , Yu Minghui , Zhang Jian , Wang Bingkai , Liu Weisheng , Tang Yu
Published: January 2015

A new photoluminescent nano-composite film with color tunable and white-light emission based on organic–inorganic hybrid phosphors and polymethyl methacrylate has been fabricated facilely by taking full unique advantage of layered rare-earth hydroxides.
Correction: Influence of a non-dairy probiotic matrix based on wheat bran and soybean meal on lactic acid bacteria growth
Authors: Zhang Ruohua , Wang Miao , Zhou Weilin
Published: January 2015

Correction for ‘Influence of a non-dairy probiotic matrix based on wheat bran and soybean meal on lactic acid bacteria growth’ by Ruohua Zhang et al., RSC Adv., 2015, 5, 9167–9172.
Discovery of a photoresponse amplification mechanism in compensated PN junctions
Authors: Zhou Yuchun , Liu Yu-Hsin , Rahman Samia N. , Hall David , Sham L. J. , Lo Yu-Hwa
Published: January 2015

We report the experimental evidence of uncovering a photoresponse amplification mechanism in heavily doped, partially compensated silicon p-n junctions under very low bias voltage. We show that the observed photocurrent gain occurs at a bias that is more than an order of magnitude below the threshold voltage for conventional impact ionization. Moreover, contrary to the case of avalanche detectors and p-i-n diodes, the amplified photoresponse is enhanced rather than suppressed with increasing temperature. These distinctive characteristics lead us to hypothesize that the inelastic scattering between energetic electrons (holes) and the ionized impurities in the depletion and charge neutral regions of the p-n junction in a cyclic manner plays a significant role in the amplification process. Such an internal signal amplification mechanism, which occurs at much lower bias than impact ionization and favors room temperature over cryogenic temperature, makes it promising for practical device applications.
Change of translational-rotational coupling in liquids revealed by field-cycling 1H NMR
Authors: Meier R. , Schneider E. , Rössler E. A.
Published: January 2015

Applying the field-cycling nuclear magnetic resonance technique, the frequency dependence of the 1H spin-lattice relaxation rate, R1ω=T1−1ω, is measured for propylene glycol (PG) which is increasingly diluted with deuterated chloroform. A frequency range of 10 kHz–20 MHz and a broad temperature interval from 220 to about 100 K are covered. The results are compared to those of experiments, where glycerol and o-terphenyl are diluted with their deuterated counter-part. Reflecting intra- as well as intermolecular relaxation, the dispersion curves R1ω,x (x denotes mole fraction PG) allow to extract the rotational time constant τrot(T, x) and the self-diffusion coefficient D(T, x) in a single experiment. The Stokes-Einstein-Debye (SED) relation is tested in terms of the quantity D(T, x) τrot(T, x) which provides a measure of an effective hydrodynamic radius or equivalently of the spectral separation of the translational and the rotational relaxation contribution. In contrast to o-terphenyl, glycerol and PG show a spectral separation much larger than suggested by the SED relation. In the case of PG/chloroform mixtures, not only an acceleration of the PG dynamics is observed with increasing dilution but also the spectral separation of rotational and translational relaxation contributions continuously decreases. Finally, following a behavior similar to that of o-terphenyl already at about x = 0.6; i.e., while D(T, x) τrot(T, x) in the mixture is essentially temperature independent, it strongly increases with x signaling thus a change of translational-rotational coupling. This directly reflects the dissolution of the hydrogen-bond network and thus a change of solution structure.
High-speed microscopy with an electrically tunable lens to image the dynamics of in vivo molecular complexes
Authors: Nakai Yuichiro , Ozeki Mitsunori , Hiraiwa Takumi , Tanimoto Ryuichi , Funahashi Akira , Hiroi Noriko , Taniguchi Atsushi , Nonaka Shigenori , Boilot Viviane , Shrestha Roshan , Clark Joanna , Tamura Naoka , Draviam Viji M. , Oku Hiromasa
Published: January 2015

We provide an evaluation for an electrically tunable lens (ETL), combined with a microscope system, from the viewpoint of tracking intracellular protein complexes. We measured the correlation between the quantitative axial focus shift and the control current for ETL, and determined the stabilization time for refocusing to evaluate the electrical focusing behaviour of our system. We also confirmed that the change of relative magnification by the lens and associated resolution does not influence the ability to find intracellular targets. By applying the ETL system to observe intracellular structures and protein complexes, we confirmed that this system can obtain 10 nm order z-stacks, within video rate, while maintaining the quality of images and that this system has sufficient optical performance to detect the molecules.
Fiber-fed time-resolved photoluminescence for reduced process feedback time on thin-film photovoltaics
Authors: Repins I. L. , Egaas B. , Mansfield L. M. , Contreras M. A. , Muzzillo C. P. , Beall C. , Glynn S. , Carapella J. , Kuciauskas D.
Published: January 2015

Fiber-fed time-resolved photoluminescence is demonstrated as a tool for immediate process feedback after deposition of the absorber layer for CuInxGa1-xSe2 and Cu2ZnSnSe4 photovoltaic devices. The technique uses a simplified configuration compared to typical laboratory time-resolved photoluminescence in the delivery of the exciting beam, signal collection, and electronic components. Correlation of instrument output with completed device efficiency is demonstrated over a large sample set. The extraction of the instrument figure of merit, depending on both the initial luminescence intensity and its time decay, is explained and justified. Limitations in the prediction of device efficiency by this method, including surface effect, are demonstrated and discussed.
Effect of the hydroaffinity and topology of pore walls on the structure and dynamics of confined water
Authors: Harrach Michael F. , Klameth Felix , Drossel Barbara , Vogel Michael
Published: January 2015

We perform molecular dynamics simulations to observe the structure and dynamics of SPC/E water in amorphous silica pores and amorphous ice pores with radii slightly larger than 10 Å. In addition to atomically rough pores, we construct completely smooth pores such that the potential felt at a given distance from the pore wall is an averaged atomic potential. As compared to rough walls, smooth walls induce stronger distortions of water structure for both silica and ice confinements. On the other hand, unlike the smooth pores, the rough pores strongly slow down water dynamics at the pore wall. The slowdown vanishes when reducing the atomic charges in the wall, i.e., when varying the hydroaffinity, while keeping the surface topology, indicating that it is not a geometric effect. Rather, it is due to the fact that the wall atoms provide a static energy landscape along the surface, e.g., fixed anchor-points for hydrogen bonds, to which the water molecules need to adapt, blocking channels for structural rearrangement. In the smooth pores, water dynamics can be faster than in the bulk liquid not only at the pore wall but also in the pore center. Changes in the tetrahedral order rather than in the local density are identified as the main cause for this change of the dynamical behavior in the center of smooth pores.
Structure and osmotic pressure of ionic microgel dispersions
Authors: Hedrick Mary M. , Chung Jun Kyung , Denton Alan R.
Published: January 2015

We investigate structural and thermodynamic properties of aqueous dispersions of ionic microgels—soft colloidal gel particles that exhibit unusual phase behavior. Starting from a coarse-grained model of microgel macroions as charged spheres that are permeable to microions, we perform simulations and theoretical calculations using two complementary implementations of Poisson-Boltzmann (PB) theory. Within a one-component model, based on a linear-screening approximation for effective electrostatic pair interactions, we perform molecular dynamics simulations to compute macroion-macroion radial distribution functions, static structure factors, and macroion contributions to the osmotic pressure. For the same model, using a variational approximation for the free energy, we compute both macroion and microion contributions to the osmotic pressure. Within a spherical cell model, which neglects macroion correlations, we solve the nonlinear PB equation to compute microion distributions and osmotic pressures. By comparing the one-component and cell model implementations of PB theory, we demonstrate that the linear-screening approximation is valid for moderately charged microgels. By further comparing cell model predictions with simulation data for osmotic pressure, we chart the cell model’s limits in predicting osmotic pressures of salty dispersions.
Parametric modeling of energy filtering by energy barriers in thermoelectric nanocomposites
Authors: Zianni Xanthippi , Narducci Dario
Published: January 2015

We present a parametric modeling of the thermoelectric transport coefficients based on a model previously used to interpret experimental measurements on the conductivity, σ, and Seebeck coefficient, S, in highly Boron-doped polycrystalline Si, where a very significant thermoelectric power factor (TPF) enhancement was observed. We have derived analytical formalism for the transport coefficients in the presence of an energy barrier assuming thermionic emission over the barrier for (i) non-degenerate and (ii) degenerate one-band semiconductor. Simple generic parametric equations are found that are in agreement with the exact Boltzmann transport formalism in a wide range of parameters. Moreover, we explore the effect of energy barriers in 1-d composite semiconductors in the presence of two phases: (a) the bulk-like phase and (b) the barrier phase. It is pointed out that significant TPF enhancement can be achieved in the composite structure of two phases with different thermal conductivities. The TPF enhancement is estimated as a function of temperature, the Fermi energy position, the type of scattering, and the barrier height. The derived modeling provides guidance for experiments and device design.
Reusable bi-directional 3ω sensor to measure thermal conductivity of 100-μm thick biological tissues
Authors: Lubner Sean D. , Choi Jeunghwan , Wehmeyer Geoff , Waag Bastian , Mishra Vivek , Natesan Harishankar , Bischof John C. , Dames Chris
Published: January 2015

Accurate knowledge of the thermal conductivity (k) of biological tissues is important for cryopreservation, thermal ablation, and cryosurgery. Here, we adapt the 3ω method—widely used for rigid, inorganic solids—as a reusable sensor to measure k of soft biological samples two orders of magnitude thinner than conventional tissue characterization methods. Analytical and numerical studies quantify the error of the commonly used “boundary mismatch approximation” of the bi-directional 3ω geometry, confirm that the generalized slope method is exact in the low-frequency limit, and bound its error for finite frequencies. The bi-directional 3ω measurement device is validated using control experiments to within ±2% (liquid water, standard deviation) and ±5% (ice). Measurements of mouse liver cover a temperature ranging from −69 °C to +33 °C. The liver results are independent of sample thicknesses from 3 mm down to 100 μm and agree with available literature for non-mouse liver to within the measurement scatter.
Hartree-Fock calculation of the differential photoionization cross sections of small Li clusters
Authors: Galitskiy S. A. , Artemyev A. N. , Jänkälä K. , Lagutin B. M. , Demekhin Ph. V.
Published: January 2015

Cross sections and angular distribution parameters for the single-photon ionization of all electron orbitals of Li2−8 are systematically computed in a broad interval of the photoelectron kinetic energies for the energetically most stable geometry of each cluster. Calculations of the partial photoelectron continuum waves in clusters are carried out by the single center method within the Hartree-Fock approximation. We study photoionization cross sections per one electron and analyze in some details general trends in the photoionization of inner and outer shells with respect to the size and geometry of a cluster. The present differential cross sections computed for Li2 are in a good agreement with the available theoretical data, whereas those computed for Li3−8 clusters can be considered as theoretical predictions.
A 90° fair circular waveguide bend
Authors: Yu Xin-hua , Deng Ji-liang , Cao Wei-ping , Li Si-min , Gao Xi , Jiang Yan-nan
Published: January 2015

We propose a synthesis method to design a 90° bent fair circular waveguide TE01 mode transition based on the non-uniform rational B-spline technique. The transition by this method has advantages of small geometry, high transmission with wide band and high profile fairness. An example of design of such a transition is presented. The simulation shows that the transition exhibits a transmission as high as 99.3% at the central frequency 35 GHz and has a bandwidth of 16.7% when keeping the transmission over 95%. Furthermore, the profile is extremely fair, which meets the requirements to decrease the geometry errors between actual device and its design, to reduce the machining difficulty in the machining process. The hot test data indicate that good transmission of the TE01 mode is obtained.
Bulk GaN flip-chip violet light-emitting diodes with optimized efficiency for high-power operation
Authors: Hurni Christophe A. , David Aurelien , Cich Michael J. , Aldaz Rafael I. , Ellis Bryan , Huang Kevin , Tyagi Anurag , DeLille Remi A. , Craven Michael D. , Steranka Frank M. , Krames Michael R.
Published: January 2015

We report on violet-emitting III-nitride light-emitting diodes (LEDs) grown on bulk GaN substrates employing a flip-chip architecture. Device performance is optimized for operation at high current density and high temperature, by specific design consideration for the epitaxial layers, extraction efficiency, and electrical injection. The power conversion efficiency reaches a peak value of 84% at 85 °C and remains high at high current density, owing to low current-induced droop and low series resistance.
Tetrel, chalcogen, and CH⋅⋅O hydrogen bonds in complexes pairing carbonyl-containing molecules with 1, 2, and 3 molecules of CO2
Authors: Azofra Luis M. , Scheiner Steve
Published: January 2015

The complexes formed by H2CO, CH3CHO, and (CH3)2CO with 1, 2, and 3 molecules of CO2 are studied by ab initio calculations. Three different types of heterodimers are observed, most containing a tetrel bond to the C atom of CO2, and some supplemented by a CH⋅⋅O H-bond. One type of heterodimer is stabilized by an anti-parallel arrangement of the C=O bonds of the two molecules. The binding energies are enhanced by methyl substitution on the carbonyl, and vary between 2.4 and 3.5 kcal/mol. Natural bond orbital analysis identifies a prime source of interaction as charge transfer into the π*(CO) antibonding orbital. Heterotrimers and tetramers carry over many of the geometrical and bonding features of the binary complexes, but also introduce O⋅⋅O chalcogen bonds. These larger complexes exhibit only small amounts of cooperativity.
Deformation of a flexible fiber in a viscous flow past an obstacle
Authors: López H. M. , Hulin J.-P. , Auradou H. , D’Angelo M. V.
Published: January 2015

We study the deformation and transport of elastic fibers in a viscous Hele-Shaw flow with curved streamlines. The variations of the global velocity and orientation of the fiber follow closely those of the local flow velocity. The ratios of the curvatures of the fibers by the corresponding curvatures of the streamlines reflect a balance between elastic and viscous forces: this ratio is shown experimentally to be determined by a dimensionless Sperm number Sp combining the characteristic parameters of the flow (transverse velocity gradient, viscosity, fiber diameter/cell gap ratio) and those of the fiber (diameter, effective length, Young’s modulus). For short fibers, the effective length is that of the fiber; for long ones, it is equal to the transverse characteristic length of the flow. For Sp ≲ 250, the ratio of the curvatures increases linearly with Sp; for Sp ≳ 250, the fiber reaches the same curvature as the streamlines.
Arbitrary order permanent Cartesian multipolar electrostatic interactions
Authors: Boateng H. A. , Todorov I. T.
Published: January 2015

Recently, there has been a concerted effort to implement advanced classical potential energy surfaces by adding higher order multipoles to fixed point charge electrostatics in a bid to increase the accuracy of simulations of condensed phase systems. One major hurdle is the unwieldy nature of the expressions which in part has limited developers mostly to including only dipoles and quadrupoles. In this paper, we present a generalization of the Cartesian formulation of electrostatic multipolar interactions that enables the specification of an arbitrary order of multipoles. Specifically, we derive formulas for arbitrary order implementation of the particle mesh Ewald method and give a closed form formula for the stress tensor in the reciprocal space. In addition, we provide recurrence relations for common electrostatic potentials employed in molecular simulations, which allows for the generalization to arbitrary order and guarantees a computational cost that scales as O(p3) for Cartesian multipole interactions of order p.
Magnetoresistance effects and spin-valve like behavior of an arrangement of two MnAs nanoclusters
Authors: Fischer M. , Elm M. T. , Sakita S. , Hara S. , Klar P. J.
Published: January 2015

We report on magnetotransport measurements on a MnAs nanocluster arrangement consisting of two elongated single-domain clusters connected by a metal spacer. The arrangement was grown on GaAs(111)B-substrates by selective-area metal organic vapor phase epitaxy. Its structural properties were investigated using scanning-electron microscopy and atomic-force microscopy, while its magnetic domain structure was analyzed by magnetic-force microscopy. The magnetoresistance of the arrangement was investigated at 120 K for two measurement geometries with the magnetic field oriented in the sample plane. For both geometries, discrete jumps of the magnetoresistance of the MnAs nanocluster arrangement were observed. These jumps can be explained by magnetic-field induced switching of the relative orientation of the magnetizations of the two clusters which affects the spin-dependent scattering in the interface region between the clusters. For a magnetic field orientation parallel to the nanoclusters' elongation direction a spin-valve like behavior was observed, showing that ferromagnetic nanoclusters may be suitable building blocks for planar magnetoelectronic devices.
Effect of electrostatic interactions on the velocity fluctuations of settling microspheres
Authors: Sugita K. , Norisuye T. , Nakanishi H. , Tran-Cong-Miyata Q.
Published: January 2015

In general, the sedimentation velocities of microparticles in liquids are not uniform due to long-ranged hydrodynamic interactions. Although the velocity fluctuations have been extensively studied experimentally, numerically, and theoretically, the effect of charges of microparticles on the velocity fluctuations is not yet reported. This is probably due to some difficulties in the detection of optical signals from the micron-sized particles dispersed in water where the refractive index is more or less different, leading to serious scattering and attenuation of visible light. So far, since the dynamic ultrasound scattering technique was a good candidate to observe micron- and nano-sized particles in optically opaque systems, we investigated the velocity fluctuations ΔV of microparticles in water. In this study, we show that the velocity fluctuations of charged silica particles exhibit anomalous rise in the concentration dependence of ΔV and show that such a behavior can be suppressed by adding a small amount of salt.
Gd5(Si,Ge)4 thin film displaying large magnetocaloric and strain effects due to magnetostructural transition
Authors: Hadimani Ravi L. , Silva Joao H. B. , Pereira Andre M. , Schlagel Devo L. , Lograsso Thomas A. , Ren Yang , Zhang Xiaoyi , Jiles David C. , Araújo Joao P.
Published: January 2015

Magnetic refrigeration based on the magnetocaloric effect is one of the best alternatives to compete with vapor-compression technology. Despite being already in its technology transfer stage, there is still room for optimization, namely, on the magnetic responses of the magnetocaloric material. In parallel, the demand for different magnetostrictive materials has been greatly enhanced due to the wide and innovative range of technologies that emerged in the last years (from structural evaluation to straintronics fields). In particular, the Gd5(SixGe1−x)4 compounds are a family of well-known alloys that present both giant magnetocaloric and colossal magnetostriction effects. Despite their remarkable properties, very few reports have been dedicated to the nanostructuring of these materials: here, we report a ∼800 nm Gd5Si2.7Ge1.3 thin film. The magnetic and structural investigation revealed that the film undergoes a first order magnetostructural transition and as a consequence exhibits large magnetocaloric effect (−ΔSmMAX ∼ 8.83 J kg−1 K−1, ΔH = 5T) and giant thermal expansion (12000 p.p.m). The thin film presents a broader magnetic response in comparison with the bulk compound, which results in a beneficial magnetic hysteresis reduction. The ΔSmMAX exhibited by the Gd5(Si,Ge)4 thin film makes it a promising candidate for micro/nano magnetic refrigeration area.
Dynamical cancellation of pulse-induced transients in a metallic shielded room for ultra-low-field magnetic resonance imaging
Authors: Zevenhoven Koos C. J. , Dong Hui , Ilmoniemi Risto J. , Clarke John
Published: January 2015

Pulse-induced transients such as eddy currents can cause problems in measurement techniques where a signal is acquired after an applied preparatory pulse. In ultra-low-field magnetic resonance imaging, performed in magnetic fields typically of the order of 100 μT, the signal-to-noise ratio is enhanced in part by prepolarizing the proton spins with a pulse of much larger magnetic field and in part by detecting the signal with a Superconducting QUantum Interference Device (SQUID). The pulse turn-off, however, can induce large eddy currents in the shielded room, producing an inhomogeneous magnetic-field transient that both seriously distorts the spin dynamics and exceeds the range of the SQUID readout. It is essential to reduce this transient substantially before image acquisition. We introduce dynamical cancellation (DynaCan), a technique in which a precisely designed current waveform is applied to a separate coil during the later part and turn off of the polarizing pulse. This waveform, which bears no resemblance to the polarizing pulse, is designed to drive the eddy currents to zero at the precise moment that the polarizing field becomes zero. We present the theory used to optimize the waveform using a detailed computational model with corrections from measured magnetic-field transients. SQUID-based measurements with DynaCan demonstrate a cancellation of 99%. Dynamical cancellation has the great advantage that, for a given system, the cancellation accuracy can be optimized in software. This technique can be applied to both metal and high-permeability alloy shielded rooms, and even to transients other than eddy currents.
Liquid metal actuated ejector vacuum system
Authors: Tang Jianbo , Zhou Yuan , Liu Jing , Wang Junjie , Zhu Wenxiu
Published: January 2015

An ejector vacuum system using nontoxic room-temperature liquid metal as actuating fluid was fabricated and experimentally demonstrated. With physical merits of high density, fluidity, and ultralow vapor pressure, the liquid metal could serve as a high momentum density carrier fluid. The main performance parameters of the liquid metal actuated ejector were thus found to be significantly improved by orders superior as compared with that of water actuating system. Under oxidation protection, an ultimate vacuum pressure of 170 Pa was achieved and capacity of evacuating a 500 ml nitrogen reservoir from atmospheric pressure to 480 Pa within 96 s was obtained.