bluuebunny/crossref_metadata_2025_split huggingface dataset:
Stable boundary‐layer regimes at Dome C, Antarctica: observation and analysis
Authors: Vignon Etienne , van de Wiel Bas J. H. , van Hooijdonk Ivo G. S. , Genthon Christophe , van der Linden Steven J. A. , van Hooft J. Antoon , Baas Peter , Maurel William , Traullé Olivier , Casasanta Giampietro 
Published: January 2017

Investigation of meteorological measurements along a 45 m tower at Dome C on the high East Antarctic Plateau revealed two distinct stable boundary layer (SBL) regimes at this location. The first regime is characterized by strong winds and continuous turbulence. It results in full vertical coupling of temperature, wind magnitude and wind direction in the SBL. The second regime is characterized by weak winds, associated with weak turbulent activity and very strong temperature inversions reaching up to 25 K in the lowest 10 m. Vertical temperature profiles are generally exponentially shaped (convex) in the first regime and ‘convex–concave–convex’ in the second.The transition between the two regimes is particularly abrupt when looking at the near‐surface temperature inversion and it can be identified by a 10 m wind‐speed threshold. With winds under this threshold, the turbulent heat supply toward the surface becomes significantly lower than the net surface radiative cooling. The threshold value (including its range of uncertainty) appears to agree with recent theoretical predictions from the so‐called ‘minimum wind speed for sustainable turbulence’ (MWST) theory.For the quasi‐steady, clear‐sky winter cases, the relation between the near‐surface inversion amplitude and the wind speed takes a characteristic ‘S’ shape. Closer analysis suggests that this relation corresponds to a ‘critical transition’ between a steady turbulent and a steady ‘radiative’ regime, with a dynamically unstable branch in the transition zone. These fascinating characteristics of the Antarctic boundary layer challenge present and future numerical models to represent this region in a physically correct manner.
Halogen bond versus hydrogen bond: The many‐body interactions approach
Authors: Domagała Małgorzata , Lutyńska Aneta , Palusiak Marcin 
Published: January 2017

AbstractThe analysis of interrelation between halogen bond and hydrogen bond in the (RX)(HNC)(HCN) complexes (R = CH3, CF3and X = Cl, Br, I) was performed on the basis of DFT calculations. Both two‐body additive contributions and three‐body nonadditive contributions to the total interaction energy were discussed. QTAIM was used for topological analysis of electron density. Additionally, QTAIM analysis of electron density was performed for both two‐ and three‐body complexes. The electron charge transfer in trimers showed the dual character of the fragment with halogen atom involved into the investigated interactions—it acts as Lewis acid and Lewis base, depending on the type of interaction considered. The effect of cooperativity of X‐ and H‐bonding was assessed on the basis of many‐body interaction energy and electron density analysis. Additionally, an alternative two‐body model with the same situation (in the context of intermolecular interactions) is investigated. The anti‐cooperative effect was found also for this model.
Roads, value, and dispossession in Baja California Sur, Mexico
Authors: Anderson Ryan 
Published: January 2017

AbstractThis article utilizes theories of value and space, along with Harvey's notion of “accumulation by dispossession,” to critically investigate the histories and social effects of the commodification of place on the East Cape of Baja California Sur, Mexico. The article defines value as the product of specific social relations and examines how places are created, valued, commodified, and co‐opted in the development process. The actual process of co‐optation, however, is highly contingent on the development of infrastructure, particularly roads, which play a vital yet ambivalent role in shaping how different people not only access but also value the East Cape.
Drivers and deterrents of entrepreneurial enterprise in the risk‐prone Global South
Authors: Lundy Brandon D. , Patterson Mark , O'Neill Alex 
Published: January 2017

AbstractThrough the case of Guinea‐Bissau, this article considers how small‐scale, often cross‐border entrepreneurs mitigate risk and establish resilient businesses able to cope with ongoing political and economic shocks. Nineteen interviews and 153 surveys were conducted over two months with business leaders and regulators within the commercial centers and markets of Guinea‐Bissau to assess entrepreneurial profiles and activities. Findings show that small‐scale private investment from the Global South is increasing. Through thematic analysis, 18 different drivers of foreign business and 23 impediments to foreign entrepreneurship and investment were identified within this risk‐prone environment. Limited assets imply limited opportunities, suggesting a need to mobilize all available resources to achieve entrepreneurial success. The implications of this research are that resiliency for these foreign investors has improved and risks are mitigated through established social capital that can be converted into financial capital, linked social–business networks across borders, microenvironmental knowledge, and maintaining relatively small businesses able to fly “under the radar.” In understanding foreign entrepreneurs' motives, the social and structural undergirding of South–South investment is exposed.
Don't mix Paxil, Viagra, and Xanax: What financiers' jokes say about inequality
Authors: Souleles Daniel 
Published: January 2017

AbstractThis article makes use of theories of humor and play to analyze a corpus of jokes private equity investors tell about the work that they do. Private equity investors, at the time of a field project I conducted from spring 2012 through summer 2014, managed about US$3.5 trillion in mostly other people's money, to buy and sell whole companies as investments. By just about any measure, they're wealthy and powerful (they have lots of resources and can make many other people do things). I suggest that analyzing private equity investors' jokes and laughter allows us a way to understand what they think about the wealth and power they cultivate and the inequality they enable. I further suggest that private equity investors, in many ways, are ambivalent about the justification for their social status. In turn, my analysis and observations offer a critique of too rigid theories about the nature of present social inequality.
One–pot Reaction for the Convenient Synthesis of Functionalized 2‐Oxaspiro[bicyclo[2.2.1]heptane‐2,3′‐indolines]
Authors: Sun Jing , Yang Mr. Ren‐Yin , Yan Chao‐Guo 
Published: January 2017

AbstractAn efficient synthetic protocol for functionalized 2‐oxaspiro[bicyclo[2.2.1]heptane‐2,3′‐indolines] was successfully developed by one‐pot two‐step reaction of phenacyl bromides, malononitrile and 3‐methyleneoxindolines in ethanol in the presence of triethylamine. On the other hand, the similar three‐component reaction of phenacyl bromides, ethyl cyanoacetate and 3‐methyleneoxindolines afforded functionalized spiro[cyclopentane‐1,3′‐indoline] derivatives.
Gel–based Controlled Synthesis of Silver Nanoparticles and Their Applications in Catalysis, Sensing and Environmental Remediation
Authors: Bala Sukhen , Mondal Raju 
Published: January 2017

AbstractWe report herein a novel gel‐based method of generating silver nanoparticles (AgNPs) for various applications. An unorthodox pyridyl‐pyrazole basedchelatinglow molecular mass gelator was used for controlled synthesis of multifunctional AgNPs. The resultant fiber networks of gel itself act as template for AgNPs formation when a threshold concentration of Ag salts is exceeded. It is noteworthy here that existence of such threshold condition for AgNP formation is strategically important but under explored. The as‐synthesized AgNPs exhibit efficient catalytic activity of the reduction of 4‐nitrophenol and Methylene blue.The as‐synthesized AgNPs shows highly selective sensing ability of toxic Hg2+ ion in ppm level. Furthermore, our system also offers a unique two‐in‐one environmental remediation through sequestration‐cum‐reduction of toxic hexavalent Cr.
Silver Patterned Supramolecular Liquid Crystalline Gels as Electrochemical Sensor of Tyrosine
Authors: K.Narayanan Rohini , Sadanandhan Neethu K. , Devaki Sudha J. 
Published: January 2017

AbstractHere, we have prepared silver nanoparticle patterned functional liquid crystalline gels (SFLAG) through self‐assembly process. The surface plasmon energy of SFLAGs were observed at ∼ 420 nm and FCC lattices of silver particles were confirmed with XRD. Formation of liquid crystalline gel phase was studied by microscopic techniques and rheology. Enhancement in the conductance of SFLAG modified glassy carbon electrode (SFLAG/GCE) was studied with electrochemical impedance spectroscopy. Finally its application is demonstrated as an electrochemical sensor for the oxidation of tyrosine using electrochemical techniques such as cyclic voltammetry, differential pulse voltammetry and chronoamperometry with a high current response and lower detection limit (10 nM). Electrochemical sensor performances such as interference of various analytes, selectivity, repeatability, storage stability and the real sample analysis with human blood serum were performed. All these excellent properties of SFLAG/GCE can be exploited as an electrochemical sensor for the analytical detection of tyrosine which is a biomarker for the early detection of cancer.
Ion‐Dependent Modulation of Self‐Healing Hydrogels
Authors: Basak Shibaji , Singh Ishwar , Kraatz Heinz‐Bernhard 
Published: January 2017

AbstractA peptide based gelator has been reported that forms supramolecular hydrogels in presence of divalent metal ions through metal‐ligand interaction. These hydrogels are multi‐stimuli responsive and self‐healing in nature. The rheology studies show that the mechanical strength and healing properties are highly dependent on metal ions and mechanical strength of these hydrogels could be tune by applying appropriate metal ions. It has been found that the mechanical and healing properties also depend on the counter anion used. Furthermore, the water suppression 1H NMR study in hydrogel state was performed to probe the hydrogen bonding interaction between gelator to gelator and gelator to water molecules in real‐time.
Ultrafast Vibrational Spectroscopy of Aqueous Solution of Methylamine from First Principles MD Simulations
Authors: Biswas Sohag , Mallik Bhabani S. 
Published: January 2017

AbstractWe performed Car‐Parrinello molecular dynamics (CPMD) simulations of deuterated aqueous solution of methylamine (MA) to investigate the structure, dynamics and time dependent vibrational spectra of water molecules in the first solvation shell. Our results show that the hydrogen bond of DOD…ND2 is the dominant interaction between ND2 and D2O as compared to the D2O…D2N. The hydrogen bond involving DOD…ND2 has longer lifetime (2.6 ps) than both D2O…D2N (1.1 ps) and water‐water hydrogen bonds. The residence time of water molecule inside the first solvation shell of ND2 is 5.72 ps. The vibrational spectral diffusion of water molecules in the first hydration shell of the amine nitrogen of methylamine proceeds with three time scales. A short‐time relaxation originates from dynamics of amine‐water hydrogen bonds without breaking (90 fs), and a slower relaxation (∼1.8 ps) is due to the breaking of amine‐water hydrogen bonds. Another longer time constant (∼7 ps) is due to the escape dynamics of water molecules from the first hydration shell of the amine group.
An Investigation of Interfacial and Photoelectrochemical Performance of Thermally Prepared C,N‐codoped TiO2 Photoanodes for Water Splitting
Authors: Venkatkarthick Radhakrishnan , Davidson Donald Jonas , Vasudevan Subramanyan , Sozhan Ganapathy , Ravichandran Subbiah 
Published: January 2017

AbstractIn the present study, C,N‐codoped TiO2 (C,N‐TiO2) thin film photoanodes are prepared by a thermal treatment of titanium substrates embedded in various materials such as aluminosilicates (zeolite) or alumina particles and heat treated at 5000 C for 3 h in a carbon contaminated muffle furnace. The prepared C,N‐codoped TiO2 photoanodes showed a significant water oxidation with the highest photo currents of about 100 μA cm−2 at zero bias versus (Ag/AgCl) using alumina as reactant medium under a standard 1 SUN illumination of solar simulator when compared to pure TiO2 (∼25μA cm−2) in 1 M KOH electrolyte. The C,N‐codoped TiO2 photoanode showed stable photocurrent for about 10 hours in the long term stability test. The physico‐chemical properties of the prepared C,N‐codoped TiO2 thin film sample was examined by Scanning electron microscopy, Energy dispersive X‐rays, X‐ray diffractions, X‐ray photoelectron spectroscopy, UV‐visible diffuse reflectance spectroscopy and electrochemical impedance measurements for light harvesting (photo absorption) characteristics. It is found that the C,N‐codoped TiO2 exhibited strong absorption to visible‐light region and improved electron donor density than pure TiO2 from UV‐Vis absorbance spectra and Mott‐Schottky analysis, respectively. The enhanced photoelectrochemical performance of the C,N‐codoped TiO2 could be ascribed to the strong visible light absorption through band gap reduction and suppression of electrons‐holes recombination process.
Piperidine Promoted Direct Sulfenylation of 2‐Naphthol with Aryl Thiols under Aqueous Conditions
Authors: Xiao Fuhong , Tian Jingxin , Xing Qiaoyan , Huang Huawen , Deng Guo‐Jun , Liu Yuejin 
Published: January 2017

AbstractAn efficient and convenient method has been developed for the preparation of aryl sulfides via a piperidine promoted direct sulfenylation of naphthols with arylthiols under aqueous conditions. This synthetic strategy features environmental friendliness, easy operation, and mild reaction conditions.
Extraction of the Very High Tunneling Current and Extremely Stable Emission Current from GdB6/W‐Tip Source Synthesized Using Arc Plasma
Authors: Suryawanshi Sachin R. , Kanhe Nilesh , Mathe Vikas L. , Phase Deodatta M. , Late Dattatray J. , More Mahendra A. 
Published: January 2017

AbstractHerein, we report the one step arc plasma synthesis of the GdB6 (Gadolinium hexaboride) nanoparticles and its field emission (FE) characteristics on tungsten point substrate (GdB6/W). The SEM / TEM analysis revealed the GdB6 nanoparticles on W point substrate exhibit irregular shaped, grainy, dense, course morphology, i. e. uniformly covering the entire tip substrate surface. For GdB6/W point source, the values of the turn‐on and threshold fields, defined as field required to draw an emission current density ∼1 mA/cm2 and ∼100 mA/cm2, respectively are found to be ∼ 2.2 and ∼2.7 V/μm, for anode‐cathode separation of ∼1 mm. Interestingly, a very high emission current density of ∼3.5 A/cm2 has been drawn from the GdB6/W point emitter at relatively lower applied field of ∼6.4 V/μm. The field enhancement factor found to be ∼10,250. The GdB6/W point electron source exhibits a good emission current stability at ∼10 mA for a period of 6 hr. The emission current stability is enumerated in terms of standard deviation and its magnitude has been measured to be only 1.72 % with respect to the average value. The superlative field emission characteristics signify the GdB6/W point electron source as potential candidates for vacuum micro/nanoelectronics device applications.
Mobile Gates Driven by Intermolecular Hydrogen Bonding
Authors: Zhang Rui‐Lian , Guan Ya‐Lan , Xiao Mi , Xiao Xin‐Cai 
Published: January 2017

AbstractA novel family of mobile gates is reported. The proposed gates were fabricated with polyacrylamide (PAAM) microspheres solution and the immobilizing‐ poly(acrylic acid) (PAAC) membrane using their intermolecular hydrogen bonding. Under the range of the molar ratio of the amide groups and carboxylic acid groups being from 26 to 38, the system showed off when PAAM microspheres combined with PAAC at the temperatures being lower than upper critical solution temperature (UCST) of PAAM‐PAAC while displayed on when PAAM microspheres were far away PAAC at the temperatures being higher than the UCST. The results of the optical microscopy images and reversible thermoresponsive release experiments display that the gates had satisfactorily reversibility and renewability. The proposed mobile gates provide a new mode of behavior for drug delivery systems and other chemical purification.
Mesoporous Tantalum Oxide Photocatalyst: Structure and Activity Evaluation
Authors: Seisenbaeva Gulaim A. , Cojocaru Bogdan , Jurca Bogdan , Tiseanu Carmen , Nedelec Jean‐Marie , Kessler Vadim G. , Parvulescu Vasile I. 
Published: January 2017

AbstractMesoporous nanostructured pure tantalum pentoxide and Eu‐doped Ta2O5 were produced by facile and reproducible one‐pot procedure not involving structure directing agents. The as‐produced material is poorly crystalline and catalytically inactive. Photoluminescence behavior of the doped oxide indicates that it is formed by quick nucleation of pure Ta2O5, leaving the Eu‐dopant only on the surface of the formed material. Further thermal treatment leads to crystallization and structural transformation as revealed by in situ X‐Ray Diffraction (XRD) and Rietveld refinement used to identify and quantify the emerging phases as well as Diffuse Reflectance UV‐vis Spectroscopy (DR‐UV‐Vis) and Raman Spectroscopy studies. The thermally induced transformation results in generation of surface oxygen vacancies that provide the material with pronounced photocatalytic activity in selective oxidation of aromatic amine compounds. The processes of generation and curing of the vacancies have been followed and quantified by temperature programmed oxidation and reduction and photoluminescence studies, offering in depth insight into the reaction mechanism.
Pd nanoparticles Incarcerated in Aluminium Oxy‐Hydroxide: An Efficient and Recyclable Heterogeneous Catalyst for Selective Knoevenagel Condensation
Authors: Göksu Haydar , Gültekin Emine 
Published: January 2017

AbstractKnoevenagel condensation between aryl aldehyde derivatives with malononitrile was successfully achieved using commercially available Pd/AlO(OH) nanoparticles (0.5 wt% Pd) in an aqueous medium. All benzylidenemalononitrile (BMN) derivatives were obtained promptly (8‐60 min) with high selectivity and yields of over 99 % in a mixture of H2O/MeOH (v/v=1/2) at room temperature. Moreover, when benzoyl chloride derivatives were utilized instead of aryl aldehyde derivatives, medium amounts of the expected products were yielded. Before the reaction and after five reuses, characterization of the Pd/AlO(OH) nanoparticles was carried out via X‐ray diffraction and scanning electron microscopy analysis. The BMN derivative characterization was accomplished using the 1H NMR and 13C NMR spectra. In order to optimize the reaction conditions, the parametric effects of the solvent type and catalyst amount were examined. Consequently, the PdAlO(OH) NPs were used for the first time in the Knoevenagel condensation. A novel, practical and eco‐friendly process was developed for Knoevenagel condensation in the presence of Pd/AlO(OH) nanoparticles.
Tri–tert‐Butanolamine as an Organic Promoter in Nucleophilic Fluorination
Authors: Shinde Sandip S. , Khonde Nilesh S. , Kumar Pradeep 
Published: January 2017

AbstractTri‐tert‐butanol amine acts as promoter with alkali metal salts in the nucleophilic fluorination of alkylsulfonates. It significantly enhances the reactivity of alkali metal salts with minimum formation of side‐products (alkene, ether, and alcohol) compared to other catalysts in fluorination reaction. The synergism of tert‐alcohol and amine moiety plays a pivotal role in fluorination.
Building Light‐Emitting Metal‐Organic Frameworks by Post‐Synthetic Modification
Authors: Abdelhameed Reda M. , Ananias Duarte , Silva Artur M. S. , Rocha João 
Published: January 2017

AbstractLn3+‐bearing Metal‐Organic Frameworks (MOFs) are attracting much attention because of their unique luminescence properties and the possibility of fine‐tuning the metal coordination spheres by post‐synthetic modification (PSM). Here, we report PSM of the well‐known IRMOF‐3 by reaction with methyl 3‐chloro‐3‐oxopropanoate and pyridine‐2,6‐dicarbonyl dichloride affording, respectively, IRMOF‐3‐CM and IRMOF‐3‐PY. 1H NMR of the digested modified samples showed ca. 100 % conversion of the amino group. The pendant groups of PSM IRMOF‐3 were subsequently used to coordinate Eu+3 and Tb3+ and the luminescence properties of the materials studied.
Catalytic Conversion of Carbohydrates to Methyl Lactate Using Isolated Tin Sites in SBA‐15
Authors: Pang Jifeng , Zheng Mingyuan , Li Xinsheng , Song Lei , Sun Ruiyan , Sebastian Joby , Wang Aiqin , Wang Junhu , Wang Xiaodong , Zhang Tao 
Published: January 2017

AbstractA series of Sn‐SBA‐15 catalysts were synthesized using a post‐synthetic metal implantation method for converting carbohydrates to methyl lactate. The tin species were highly dispersed and isolatedly grafted in the framework of SBA‐15 under the tin salt concentration between 2 and 25 wt%. They solely provided a large number of Lewis acid sites, which showed robust activity for carbohydrates conversion in contrast to the performance of tin dioxide domains or particles. Over a Sn‐SBA‐15 catalyst (Si/Sn molar=150), the Lewis acid density was 45.9 μmol/g, and methyl lactate yield reached a high value of 57.0 % from inulin conversion in methanol at 433 K for 20 h, without the formation of methyl levulinate by‐product. The Sn‐SBA‐15 catalysts were rather stable under reaction conditions, and cycled at least for 4 times without deactivation.
Effect of Reduction Protocol of Pd Catalysts on Product Distribution in Furfural Hydrogenation
Authors: Date Nandan S. , Biradar Narayan S. , Chikate Rajeev C. , Rode Chandrashekhar V. 
Published: January 2017

AbstractSingle step conversion of furfural to ring hydrogenation and decarbonylation products, 2‐methyltetrahydrofuran (2‐MeTHF) and tetrahydrofuran (THF) in high selectivity was achieved by controlling the particle size of Pd/C catalyst. The particle size variation of Pd/C catalysts in the range of 3.8 to 22 nm could be achieved by employing different reducing agents. Of particular interest was the NaBH4 reduced catalyst (Pd−B/C), which gave the lowest crystallite size of 4.8 nm due to incorporation of B into the inner lattices of Pd−Pd. This phase was evidenced by a characteristic XRD peak of Pd−B at 2θ=38.85 O as well as a shift of (111) peak (40.07 O) of Pd towards the lower value (39.8 O). As compared to formaldehyde reduced catalyst (Pd−F/C), Pd−B/C catalyst completely suppressed the formation of furfuryl alcohol to give > 65 % selectivity to 2‐MeTHF and THF. At 180 OC, almost equal distribution of side chain hydrogenation and ring opening products, 2‐MF (45 %) and PeDO (37 %), respectively, was observed while, higher temperature clearly favoured ring hydrogenation and decarbonylation reactions to give 2‐MeTHF and THF.