bluuebunny/crossref_metadata_2025_split huggingface dataset:
Phosphoramides: Synthesis, Spectroscopy, and X‐ray Crystallography
Authors: Gholivand Khodayar , Shariatinia Zahra , Oroujzadeh Nasrin 
Published: August 2013

ABSTRACTA series of new phosphoramides with general formula RP(O)X2, where R = amino/p‐methylphenoxy and X = amine, were synthesized and characterized by 1H, 13C, 31P nuclear magnetic resonance (NMR), and infrared (IR) spectroscopy and elemental analysis. The 31P{1H} NMR spectra show that among compounds 7–9 containing 2‐, 3‐, and 4‐aminopyridinyl moieties, respectively, the shielding order of the P atom decreases as 7 > 9 > 8. Also, the structure of compound 7 was determined by X‐ray crystallography. In this structure, repeated noncentrosymmetric dimers are formed by two strong intermolecular N(1)‐H(1N)…N(2) and N(3)‐H(3N)…O(1) hydrogen bonds. Taking into account weak intermolecular C(17)‐H(17C)…N(4), C(17)‐H(17E)…N(4), C(2)‐H(2A)…O(2), and also weak aromatic C—H…C interactions, a three‐dimensional polymeric chain is created in the crystalline network. The density functional theory calculations at B3LYP, B3PW91, and M06 levels using the 6–31+G** basis set were in good agreement with the X‐ray crystallography data.
Synthesis and Spectral Characterization of Some Novel Phosphonyl‐ and Phosphoryl Pyrazole Compounds
Authors: Ali Tarik E. 
Published: August 2013

ABSTRACT1,3‐Diphenyl‐1H‐pyrazole‐4‐carbaldehyde (1) reacted with aniline, 2‐substituted anilines, and P,P‐dimethylphosphinic hydrazide in the presence of diethyl phosphite to give acyclic α‐aminophosphonate 2, cyclic α‐aminophosphonates 4–6, and α‐hydrazinophosphonate 7, respectively. Also, treatment of aldehyde 1 with cyanoaceto‐hydrazide, acetophenone, and malononitrile afforded the condensation products 8, 16, and 21, respectively, which in turn, reacted with diethyl phosphite and P,P‐dimethylphosphinic hydrazide. The reaction of diethyl phosphite with the hydrazone 8 and chalcone 16 yielded the novel phosphorus heterocycles 13 and 18, respectively, while its reaction with the dicyanoarylidene 21 produced the dicyanopyrazolyl phosphonate 22. On the other hand, treatment of the hydrazone 8 with P,P‐dimethylphosphinic hydrazide gave the unexpected P,P‐dimethylphosphinic hydrazone 15, which reacted with diethyl phosphite forming α‐hydrazinophosphonate 7. Furthermore, the interesting N‐phosphoryl pyrazoles 20 and 24 were resulted in good yield via cycloaddition of P,P‐dimethylphosphinic hydrazide to the chalcone 16 and dicyanoarylidene 21, respectively. Structures of all newly synthesized compounds were confirmed by considering the data of IR spectroscopy, MS, and 1H‐, 13C‐, and 31P‐NMR spectroscopy, as well as that of elemental analyses.
Projected risks to groundwater‐dependent terrestrial vegetation caused by changing climate and groundwater abstraction in the Central Perth Basin, Western Australia
Authors: Barron Olga , Froend Ray , Hodgson Geoff , Ali Riasat , Dawes Warrick , Davies Phil , McFarlane Don 
Published: August 2013

AbstractThe effect of potential climate change on groundwater‐dependent vegetation largely depends on the nature of the climate change (drying or wetting) and the level of current ecosystem dependence on groundwater resources. In south‐western Australia, climate projections suggest a high likelihood of a warmer and drier climate. The paper examines the potential environmental impacts by 2030 at the regional scale on groundwater‐dependent terrestrial vegetation (GDTV) adapted to various watertable depths, on the basis of the combined consideration of groundwater modelling results and the framework for GDTV risk assessment. The methodology was tested for the historical period from 1984 to 2007, allowing validation of the groundwater model results' applicability to such an assessment. Climate change effects on GDTV were evaluated using nine global climate models under three greenhouse gas emission scenarios by applying the climate projections to groundwater models. It was estimated that under dry climate scenarios, GDTV is likely to be under high and severe risk over more than 20% of its current habitat area. The risk is also likely to be higher under an increase in groundwater abstraction above current volumes. The significance of climate change risk varied across the region, depending on both the intensity of the change in water regime and the sensitivity of the GDTV to such change. Greater effects were projected for terrestrial vegetation dependent on deeper groundwater (6–10 m). Copyright © 2013 John Wiley & Sons, Ltd.
Field investigation and modelling of coupled stream discharge and shallow water‐table dynamics in a small Mediterranean catchment (Sardinia)
Authors: Niedda Marcello , Pirastru Mario 
Published: August 2013

AbstractIn the semi‐arid Mediterranean environment, the rainfall–runoff relationships are complex because of the markedly irregular patterns in rainfall, the seasonal mismatch between evaporation and rainfall, and the spatial heterogeneity in landscape properties. Watersheds often display considerable non‐linear threshold behavior, which still make runoff generation an open research question. Our objectives in this context were: to identify the primary processes of runoff generation in a small natural catchment; to test whether a physically based model, which takes into consideration only the primary processes, is able to predict spatially distributed water‐table and stream discharge dynamics; and to use the hydrological model to increase our understanding of runoff generation mechanisms. The observed seasonal dynamics of soil moisture, water‐table depth, and stream discharge indicated that Hortonian overland‐flow was negligible and the main mechanism of runoff generation was saturated subsurface‐flow. This gives rise to base‐flow, controls the formation of the saturated areas, and contributes to storm‐flow together with saturation overland‐flow. The distributed model, with a 1D scheme for the kinematic surface‐flow, a 2D sub‐horizontal scheme for the saturated subsurface‐flow, and ignoring the unsaturated flow, performed efficiently in years when runoff volume was high and medium, although there was a smoothing effect on the observed water‐table. In dry years, small errors greatly reduced the efficiency of the model. The hydrological model has allowed to relate the runoff generation mechanisms with the land‐use. The forested hillslopes, where the calibrated soil conductivity was high, were never saturated, except at the foot of the slopes, where exfiltration of saturated subsurface‐flow contributed to storm‐flow. Saturation overland‐flow was only found near the streams, except when there were storm‐flow peaks, when it also occurred on hillslopes used for pasture, where soil conductivity was low. The bedrock–soil percolation, simulated by a threshold mechanism, further increased the non‐linearity of the rainfall–runoff processes. Copyright © 2013 John Wiley & Sons, Ltd.
PRACTICAL ASPECTS OF IRRIGATION OF BIOSALINE CROPS WITH SALINE WATER VIEWED FROM A LAND AND WATER USE PERSPECTIVE
Authors: Croon Frank W. 
Published: August 2013

ABSTRACTThe potential for using saline water for the irrigation of salt‐tolerant or biosaline crops, as a way to reduce the dependence of agriculture on limited freshwater resources, is analysed in this paper. In theory, saline water irrigation is possible provided high leaching ratios are applied; in practice this is only possible and sustainable where soils have a high infiltration capacity and drainability, provided the infrastructure (i) can handle the high volumes of leaching water; (ii) is salt resistant, (iii) is virtually seepage free (to prevent salinization of surrounding areas) and (iv) the highly saline drainage water can be safely disposed of. Specialized management is required to monitor salinity and prevent and correct errors and damage; this results in costly infrastructure and operation and maintenance.Most biosaline crops are low‐value crops. Therefore saline water irrigation for dry foot crops will often not be commercially feasible. In the case of wet foot crops the conditions for soils, infrastructure and management are less strict and less costly. Irrigation with saline water of wet foot crops could therefore be feasible in certain areas. The most promising biosaline inundated crops are biomass and fibre crops as a raw material for pulp, energy or particle boards. Copyright © 2013 John Wiley & Sons, Ltd.
Comment on “Empirical relationship between electron precipitation and far‐ultraviolet auroral emissions from DMSP observations” by Sotirelis et al.
Authors: Knight H. , Strickland D. 
Published: August 2013

AbstractSotirelis et al. (2013), which reported on comparisons of Defense Meteorological Satellite Program (DMSP) F16 Special Sensor Ultraviolet Spectrographic Imager (SSUSI) Lyman‐Birge‐Hopfield short and long (LBHS and LBHL) far ultraviolet (FUV) radiances with Special Sensor J/5 (SSJ/5) in situ particle fluxes, overlooked comparable comparisons of observations made by the same two instruments reported in Knight et al. (2008, 2012). The results are compared, and it is found that the statistical ratio of SSUSI LBHL to SSJ/5 electron energy flux reported by Soterelis et al. is a factor of ~2 greater than would be expected based on Knight et al. (2008, 2012). This difference is mainly caused by a SSUSI calibration change.
The shape of Enceladus as explained by an irregular core: Implications for gravity, libration, and survival of its subsurface ocean
Authors: McKinnon William B. 
Published: August 2013

AbstractEnceladus' global shape is not consistent with a simultaneously hydrostatic and fully differentiated body, but its geophysical hyperactivity strongly implies that it is differentiated. Enceladus' surface conforms to a triaxial shape, consistent with relaxation to a global geoid, but its rocky core need not be hydrostatic. A modestly irregular core, either in terms of topography or density, and dynamically aligned, would act to enhance the global geoid. Explaining the full global shape of Enceladus requires ~10 km of excess core polar flattening and ~4 km of excess core equatorial distortion, for a uniform density core. The stresses associated with this excess topography can be sustained indefinitely, but because the rocky core is not hydrostatic, Enceladus' degree‐2 gravity coefficients J2 and C22 will not conform to the hydrostatic ratio of 10/3 (testable by Cassini gravity). Notably, core polar axes could be depressed by up to 4–6 km with respect to internal isobars. Such a topographic variation could help preserve polar ocean remnants. For example, if Enceladus' ocean undergoes secular freezing, it will first ground near the tidal axes. Polar seas would be the last to freeze, and survival of a south polar sea may be one reason why Enceladus' activity today is concentrated at high southern latitudes. Isostatic variations in the thickness or density of a floating ice shell may also contribute to Enceladus' nonhydrostatic shape, but a strength‐supported, nonisostatic icy lithosphere is argued here to be unlikely, given Enceladus' record of regional high heat flows, faulting, and viscous relaxation.
On Rooted Packings, Decompositions, and Factors of Graphs
Authors: Lonc Zbigniew , Petryshyn Nataliya 
Published: August 2013

AbstractIn this article, we study so‐called rooted packings of rooted graphs. This concept is a mutual generalization of the concepts of a vertex packing and an edge packing of a graph. A rooted graph is a pair , where G is a graph and . Two rooted graphs and are isomorphic if there is an isomorphism of the graphs G and H such that S is the image of T in this isomorphism. A rooted graph is a rooted subgraph of a rooted graph if H is a subgraph of G and . By a rooted ‐packing into a rooted graph we mean a collection of rooted subgraphs of isomorphic to such that the sets of edges are pairwise disjoint and the sets are pairwise disjoint. In this article, we concentrate on studying maximum ‐packings when H is a star. We give a complete classification with respect to the computational complexity status of the problems of finding a maximum ‐packing of a rooted graph when H is a star. The most interesting polynomial case is the case when H is the 2‐edge star and S contains the center of the star only. We prove a min–max theorem for ‐packings in this case.
Exact stability conditions in upwinding‐scheme FDTD for the Boltzman transport equation
Authors: Chamanara Nima , Caloz Christophe 
Published: August 2013

SUMMARYAn in‐depth stability analysis of the FDTD method under the upwinding scheme for the Boltzmann transport equation (BTE) under the relaxation time approximation is provided. Both time forward and time backward difference equations are considered. In the time forward differencing case, a sufficient stability condition is derived for the BTE with variable coefficients, and a necessary and sufficient condition is derived for the BTE with constant coefficients. In the time backward differencing case, it is shown that the differencing equations are unconditionally stable. It is shown numerically that the previously reported stability conditions in the literature are not accurate. Copyright © 2013 John Wiley & Sons, Ltd.
Double‐viewing‐zone integral imaging 3D display without crosstalk based on a tilted barrier array
Authors: Tang Song , Wang Ya‐Zhou , Deng Huan , Ji Chao‐Chao , Wang Qiong‐Hua 
Published: August 2013

AbstractWe propose an integral imaging (II) three‐dimensional (3D) display using a tilted barrier array and a stagger microlens array. The tilted barrier array consists of two orthogonally polarized sheets. In the stagger microlens array, the center of the microlens has p/2 shift with the elemental image along the horizontal direction, where p is the pitch of the microlens. The proposed II 3D display produces two different viewing zones and each of them is almost equal to that of the conventional II 3D display, and it has no crosstalk. We verify the feasibility of the proposed II 3D display in the simulation results.
Assessment of dispersive liquid–liquid microextraction for the simultaneous extraction, preconcentration, and derivatization of Hg2+ and CH3Hg+ for further determination by GC–MS
Authors: Soares Bruno M. , Pereira Ederson R. , Maciel Juliana V. , Vieira Augusto A. , Duarte Fabio A. 
Published: August 2013

This work reports the development of a dispersive liquid–liquid microextraction method for the simultaneous extraction, preconcentration, and derivatization of Hg2+ and CH3Hg+ species from water samples for further determination by GC–MS. Some parameters of the proposed method, such as volume and type of disperser and extraction solvent, and Na[B(C6H5)4] concentration were investigated using response surface methodology. Suitable recoveries were obtained using 80 μL C2Cl4 (as extraction solvent), 1000 μL ethanol (as disperser solvent), and 300 μL 2.1 mmol/L Na[B(C6H5)4] (as derivatizing agent). Accuracy was evaluated in terms of recovery and ranged from 87 to 99% with RSD values <7%. In addition, a certified reference material of water (NIST 1641d) was analyzed and agreed with the certified value about 107% (for Hg2+), with RSD values <8.5%. LODs were 0.3 and 0.2 μg/L, with enrichment factors of 112 and 115 for Hg2+ and CH3Hg+, respectively. The optimized method was applied for the determination of Hg2+ and CH3Hg+ in tap, well, and lake water samples.
The effect of cooling press on the encapsulation properties of crystalline photovoltaic modules: residual stress and adhesion
Authors: Li Heng‐Yu , Perret‐Aebi Laure‐Emmanuelle , Chapuis Valentin , Ballif Christophe , Luo Yun 
Published: August 2013

AbstractA high‐quality encapsulation process is crucial to ensuring the performance and long‐term reliability of photovoltaic (PV) modules. In crystalline Si technology‐based modules, poly (ethylene‐co‐vinyl acetate) (EVA) is the most widely used PV encapsulant. Its encapsulation process is usually performed in a flat‐bed vacuum bag laminator. In certain types of laminators, cooling press can be applied to the module cooling process after the module encapsulation, leading to a much higher cooling rate (~100 °C/min) than conventional natural cooling due to the application of water cooling circulation and mechanical pressure on the modules. In this work, the effect of the cooling press on the encapsulation properties of PV modules with EVA as the encapsulant are assessed on the aspects of residual stress in the modules, peeling strength between glass and EVA, and the resulting EVA gel content after encapsulation. The results show that the cooling press influences the encapsulation properties of PV modules. In particular by applying the cooling press after encapsulation, the residual normal stress in the Si solar cell in the encapsulated module after cooling can be reduced by as much as 22 ± 2 to 27 ± 3% depending on the EVA gel content, whereas the peeling strength between front glass and EVA is increased by ~ 10%. This work should help the further optimization of PV module encapsulation processes aimed at improving module encapsulation quality. Copyright © 2013 John Wiley & Sons, Ltd.
Electrospun Microfibrous Membranes with Atmospheric‐Pressure Plasma Surface Modification for the Application in Dye‐Sensitized Solar Cells
Authors: Huang Chun , Lin Pin‐Jen , Tsai Ching‐Yuan , Juang Ruey‐Shin 
Published: August 2013

AbstractElectrospun poly(vinylidenefluoride‐co‐hexafluoropropylene) (PVDF‐HFP) microfibrous membrane was modified by cyclonic atmospheric‐pressure plasma in this work. The gas‐phase temperature of plasma state was <90°C, indicating that this plasma could treat electrospun PVDF‐HFP membrane without heat damages. Surface properties of the plasma‐modified electrospun PVDF‐HFP membranes were examined by the static contact angle (CA) analysis. It was observed that such cyclonic atmospheric‐pressure plasma was useful in electrospun PVDF‐HFP membrane surface modification; for example, the water CA was reduced from 137 to <30° with only 1 min treatment time. Field‐emission scanning electron microscopy was used to determine the changes in surface features of the electrospun PVDF‐HFP membrane after plasma treatment. A dye‐sensitized solar cell (DSSC) fabricated with the plasma‐modified electrospun PVDF‐HFP membrane electrolyte revealed good conversion efficiency. This work proved that surface modification of the electrospun PVDF‐HFP microfibrous membrane by cyclonic atmospheric‐pressure plasma was an innovative method for DSSC applications.
Controller design for nonlinear systems using the Contoured Robust Controller Bode plot
Authors: Taylor J. D. , Messner William 
Published: August 2013

SUMMARYIn this paper, we develop the Contoured Robust Controller Bode (CRCBode) plot and demonstrate its use in the design of robust controllers for nonlinear single‐input single‐output (SISO) systems. The CRCBode plot shows contours (level sets) of a robust performance quantity on the Bode magnitude and phase plots of the controller. An iterative frequency domain loop‐shaping design approach is employed to eliminate all intersections of the controller frequency response with certain ‘forbidden regions,’ indicating that a standard SISO robust stability and performance criterion is satisfied. Nonlinearities are accounted for by avoiding the maximum forbidden regions over a structured uncertainty set consisting of linearizations of the system dynamics about several operating points. We demonstrate this technique by designing and experimentally verifying a flow‐rate controller for a butterfly‐valve based liquid cooling system, which is robust to valve nonlinearities and flow disturbances. Finally, we compare this compensator with one generated using an automated H ∞  synthesis algorithm and discuss the advantages of the CRCBode approach. Copyright © 2013 John Wiley & Sons, Ltd.
The Effects of Writing‐to‐Learn Activities on Elementary Students’ Conceptual Understanding: Learning About Force and Motion Through Writing to Older Peers
Authors: CHEN YING‐CHIH , HAND BRIAN , McDOWELL LEAH 
Published: August 2013

ABSTRACTThis quasi‐experimental and pre/posttest study was designed to examine whether fourth‐grade students who engaged in collaboratively writing letters to 11th‐grade students performed better on tests of conceptual understanding of a unit on force and motion than students who did not. The participants included 835 fourth‐grade students and 416 11th‐grade students from four elementary schools and one high school in the United States. Students in treatment groups were asked to write three letters for exchange at the beginning/during/completion of an 8‐week teaching unit about force and motion. The structure of writing was based on three components of arguments: question, claim, and evidence. A comparison of the pre‐ and posttest results indicated that students who engaged in collaborative letter‐writing tasks performed better than students who did not. The pre‐ and posttest results also showed that female, special, low socioeconomic status, and gifted students benefited the most from the collaborative letter‐writing tasks. Through the letter‐writing exchange activities, the fourth‐grade students were supported and encouraged to learn difficult concepts by the 11th‐grade students. The more the 11th graders asked the fourth graders for explanation and clarification of the concepts in the letters, the more the fourth‐grade students learned. Two factors related to argumentative writing were identified as predictors of success on students’ achievement tests: overall cohesiveness, with an emphasis on embedding multiple modal representations in the text and the strength of the relationship between claims and evidence. This study suggests that there is a pedagogical need to build support structures to help students understand the role of audience, the function of multiple modal representations, and the quality of evidence for supporting knowledge claims in argumentative writing, as this could lead to a better understanding of scientific concepts. © 2013 Wiley Periodicals, Inc. Sci Ed 97:745–771, 2013
Transforming Misconceptions: Using Transformative Experience to Promote Positive Affect and Conceptual Change in Students Learning About Biological Evolution
Authors: HEDDY BENJAMIN C. , SINATRA GALE M. 
Published: August 2013

ABSTRACTTeaching and learning about complex scientific content, such as biological evolution, is challenging in part because students have a difficult time seeing the relevance of evolution in their everyday lives. The purpose of this study was to explore the effectiveness of the Teaching for Transformative Experiences in Science (TTES) model (Pugh, 2002) for facilitating conceptual change and positive affect in college students learning about evolution. Fifty‐five undergraduates experienced instruction on six key evolution concepts (adaptation, variation, inheritance, speciation, domestication, and extinction). Instruction enhanced with the TTES model was compared to a conceptual change intervention, using refutation text and discussion. Outcomes were assessed using the Evolutionary Reasoning Scale (Shtulman, 2006), the Transformative Experience Survey (Pugh, Linnenbrink‐Garcia, Koskey, Stewart, & Manzey, 2010a), and the Evolution Emotions Survey. The results showed that the group that experienced the TTES model showed higher levels of transformative experience and greater conceptual change than the comparison group. In addition, the treatment group showed an increase in enjoyment of the evolution content over the course of instruction. Implications for transformative experience as a conceptual change pedagogical technique are discussed. © 2013 Wiley Periodicals, Inc. Sci Ed 97:723–744, 2013