bluuebunny/crossref_metadata_2025_split huggingface dataset:
Peculiarities of cosmic ray modulation in the solar minimum 23/24
Authors: Alania M. V. , Modzelewska R. , Wawrzynczak A. 
Published: May 2014

AbstractWe study changes of the galactic cosmic ray (GCR) intensity for the ending period of the solar cycle 23 and the beginning of the solar cycle 24 using neutron monitors experimental data. We show that an increase of the GCR intensity in 2009 is generally related with decrease of the solar wind velocity U, the strength B of the interplanetary magnetic field (IMF), and the drift in negative (A < 0) polarity epoch. We present that temporal changes of rigidity dependence of the GCR intensity variation, before reaching maximum level in 2009 and after it, do not noticeably differ from each other. The rigidity spectrum of the GCR intensity variations calculated based on neutron monitors data (for rigidities > 10 GV) is hard in the minimum and near‐minimum epoch. We do not recognize any nonordinary changes in the physical mechanism of modulation of the GCR intensity in the rigidity range of GCR particles to which neutron monitors respond. We compose 2‐D nonstationary model of transport equation to describe variations of the GCR intensity for 1996–2012 including the A > 0 (1996–2001) and the A < 0 (2002–2012) periods; diffusion coefficient of cosmic rays for rigidity 10–15 GV is increased by ~ 30% in 2009 (A < 0) comparing with 1996 (A > 0). We believe that the proposed model is relatively realistic, and obtained results are satisfactorily compatible with neutron monitors data.
Technique for measuring and correcting the Taylor microscale
Authors: Chuychai P. , Weygand J. M. , Matthaeus W. H. , Dasso S. , Smith C. W. , Kivelson M. G. 
Published: May 2014

AbstractWe discuss and develop methods to estimate and refine measurements of the Taylor microscale from discrete data sets. To study how well a method works, we construct a time series of discrete data with a known power spectrum and Taylor scale, but with various truncations of the resolution that eliminate higher frequencies in a controlled fashion. We compute the second‐order structure function and correlation function, assuming that the unresolved dissipation range spectrum has various values of spectral index. A series of Taylor scale estimates are obtained from parabolic fits to subsets of the correlation function data, and these are extrapolated to the limit of zero separation. The error in this procedure, for finite time resolution sampling, depends on the spectral index in the dissipation range. When the spectral form is known, we can compute a correction factor that improves the estimate of the Taylor microscale value determined from the extrapolation method and band‐limited data. Application of this technique to spacecraft observations of solar wind fluctuations is illustrated.
Mixed‐phase cloud radiative properties over Ross Island, Antarctica: The influence of various synoptic‐scale atmospheric circulation regimes
Authors: Scott Ryan C. , Lubin Dan 
Published: May 2014

AbstractSpectral downwelling shortwave irradiance measurements made beneath overcast stratiform cloud decks at Ross Island, Antarctica (77.5°S, 167°E), are used in conjunction with discrete ordinates‐based radiative transfer simulations to examine how mixed‐phase clouds influence shortwave irradiance at the surface during austral spring‐summer. From 10 October 2012 until 4 February 2013, an Analytical Spectral Devices (ASD, Inc.) spectroradiometer deployed at the Arrival Heights (77.82°S, 166.65°E) laboratory of McMurdo Station measured in 1 min averages the downwelling spectral hemispheric (direct plus diffuse) irradiance spanning visible (VIS) and near‐infrared regions of the solar spectrum, from 350 to 2200 nm. Conservative‐scattering cloud optical depth τc is retrieved in the interval 1022–1033 nm, where the albedo of the snow‐covered surface is lower than at VIS wavelengths. The impact of liquid versus mixed‐phase cloud properties on the surface shortwave energy budget is discerned using irradiances in the 1.6 μm window. Five case studies employ NASA A‐Train satellite and ancillary meteorological data sets to investigate the macrophysical, microphysical, and shortwave radiative characteristics of clouds possessing distinct meteorological histories. Cloud systems within marine air masses arriving at Ross Island after transiting the West Antarctic ice sheet (WAIS) and the Ross Ice Shelf are radiatively dominated by the ice phase. In contrast, moist marine air moving directly onshore from the Ross Sea brings low clouds with a stronger influence of liquid water. Deep cyclonic disturbances over the Ross Sea are seen to be limited in their ability to deliver significant moisture as far south as Ross Island, where clouds are mainly optically thin.
Simulating water markets with transaction costs
Authors: Erfani Tohid , Binions Olga , Harou Julien J. 
Published: May 2014

AbstractThis paper presents an optimization model to simulate short‐term pair‐wise spot‐market trading of surface water abstraction licenses (water rights). The approach uses a node‐arc multicommodity formulation that tracks individual supplier‐receiver transactions in a water resource network. This enables accounting for transaction costs between individual buyer‐seller pairs and abstractor‐specific rules and behaviors using constraints. Trades are driven by economic demand curves that represent each abstractor's time‐varying water demand. The purpose of the proposed model is to assess potential hydrologic and economic outcomes of water markets and aid policy makers in designing water market regulations. The model is applied to the Great Ouse River basin in Eastern England. The model assesses the potential weekly water trades and abstractions that could occur in a normal and a dry year. Four sectors (public water supply, energy, agriculture, and industrial) are included in the 94 active licensed water diversions. Each license's unique environmental restrictions are represented and weekly economic water demand curves are estimated. Rules encoded as constraints represent current water management realities and plausible stakeholder‐informed water market behaviors. Results show buyers favor sellers who can supply large volumes to minimize transactions. The energy plant cooling and agricultural licenses, often restricted from obtaining water at times when it generates benefits, benefit most from trades. Assumptions and model limitations are discussed.
Application of multiobjective optimization to scheduling capacity expansion of urban water resource systems
Authors: Mortazavi‐Naeini Mohammad , Kuczera George , Cui Lijie 
Published: May 2014

AbstractSignificant population increase in urban areas is likely to result in a deterioration of drought security and level of service provided by urban water resource systems. One way to cope with this is to optimally schedule the expansion of system resources. However, the high capital costs and environmental impacts associated with expanding or building major water infrastructure warrant the investigation of scheduling system operational options such as reservoir operating rules, demand reduction policies, and drought contingency plans, as a way of delaying or avoiding the expansion of water supply infrastructure. Traditionally, minimizing cost has been considered the primary objective in scheduling capacity expansion problems. In this paper, we consider some of the drawbacks of this approach. It is shown that there is no guarantee that the social burden of coping with drought emergencies is shared equitably across planning stages. In addition, it is shown that previous approaches do not adequately exploit the benefits of joint optimization of operational and infrastructure options and do not adequately address the need for the high level of drought security expected for urban systems. To address these shortcomings, a new multiobjective optimization approach to scheduling capacity expansion in an urban water resource system is presented and illustrated in a case study involving the bulk water supply system for Canberra. The results show that the multiobjective approach can address the temporal equity issue of sharing the burden of drought emergencies and that joint optimization of operational and infrastructure options can provide solutions superior to those just involving infrastructure options.
Hydraulic and thermal effects of in‐stream structure‐induced hyporheic exchange across a range of hydraulic conductivities
Authors: Menichino Garrett T. , Hester Erich T. 
Published: May 2014

AbstractIn‐stream structure‐induced hyporheic exchange and associated thermal dynamics affect stream ecosystems. Their importance is controlled by spatial variability of sediment hydraulic conductivity (K). We calibrated a computational fluid dynamics (CFD) model of surface and groundwater hydraulics near a channel‐spanning weir (represents log dams, boulder weirs) to field data and varied K from 10−7 to 10−2 m/s (silt to gravel). Surface water stopped cresting the weir for K > 10−3 m/s. Non‐Darcy hyporheic flow was also prevalent for K > 10−3 m/s, and velocity errors using non‐CFD models ranged up to 32.2%. We also modeled weir‐induced heat transport during summer. As K increased from 10−7 to 10−3 m/s, weir‐induced hyporheic heat advection steadily increased. Cooling and buffering along hyporheic flow paths decreased with increasing K, particularly above K = 10−5 and 10−4 m/s, respectively. Vertical heat conduction between surface water and groundwater near the weir decreased with increasing K, particularly for K > 10−5 m/s. Conduction between hyporheic flow paths and adjacent groundwater helped cool hyporheic flow. Downstream surface water cooling by hyporheic advection increased steadily with K as increases in hyporheic flow overwhelmed decreases in cooling along hyporheic flow paths. Yet such effects were small (0.016°C) even at K = 10−3 m/s. The largest thermal effect of weir‐induced exchange was therefore spatial expansion of subsurface diel variability (particularly for K > 10−5 m/s) which affects benthic habitat and chemical reactions. The specific values of K where such trend shifts occur is likely variable among streams based on flow conditions, but we expect the presence of such trend shifts to be widespread.
Physical and observable characteristics of cloud‐to‐ground lightning over the Pearl River Delta region of South China
Authors: Liu Yonglin , Chan L. Y. , Lin Qinhao , Feng Wanxing , Bi Xinhui , Chen Jiahong , Tao Hantao , Wang Xinming , Chen Duohong , Sheng Guoying , Fu Jiamo 
Published: May 2014

AbstractCloud‐to‐ground (CG) lightning characteristic parameters deduced from the lightning location system (LLS) for five differing microenvironmental areas relative to megacity, city, municipal town, hilly suburban area, and mountainous rural area conditions were examined in our 2009–2011 Pearl River Delta (PRD) study. Our LLS data analysis showed that there were high variation of lightning characteristics and phenomenal changes among these areas. As a supplement to the usual study of physical characteristics, an observation‐based methodology had been developed to study the lightning behavior, while the respective thunderstorms were traversing through these observation areas. Special features and phenomenal changes related to the lightning characteristic parameters, such as observable lightning stroke days (OLSDs) and observable lightning stroke frequency and density for an OLSD, were also addressed. Microenvironmental variation due to change in topography, degree of urbanization, urban effect, and thunderstorm strength was found to affect the spatial distribution of lightning stroke and the severity of lightning activities over the observation areas. This approach increases our understanding of lightning in subtropical China. It also tells us more about the behavior of lightning while the thunderstorm traverses through an observation area. This information is lacking in previous studies.
Using injury severity to improve occupational injury trend estimates
Authors: Sears Jeanne M. , Bowman Stephen M. , Hogg‐Johnson Sheilah 
Published: May 2014

BackgroundHospitalization‐based estimates of trends in injury incidence are also affected by trends in health care practices and payer coverage that may differentially impact minor injuries. This study assessed whether implementing a severity threshold would improve occupational injury surveillance.MethodsHospital discharge data from four states and a national survey were used to identify traumatic injuries (1998–2009). Negative binomial regression was used to model injury trends with/without severity restriction, and to test trend divergence by severity.ResultsTrend estimates were generally biased downward in the absence of severity restriction, more so for occupational than non‐occupational injuries. Restriction to severe injuries provided a markedly different overall picture of trends.ConclusionsSeverity restriction may improve occupational injury trend estimates by reducing temporal biases such as increasingly restrictive hospital admission practices, constricting workers' compensation coverage, and decreasing identification/reporting of minor work‐related injuries. Injury severity measures should be developed for occupational injury surveillance systems. Am. J. Ind. Med. 57:928–939, 2014. © 2014 Wiley Periodicals, Inc.
Occupational cadmium exposure‐associated oxidative stress and erythrocyte fragility among jewelry workers in India
Authors: Moitra Subhabrata , Brashier Bill B. , Sahu Subhashis 
Published: May 2014

AbstractBackgroundCadmium‐induced pulmonary and renal target organ effects are well‐established although its association with oxidative stress and associated hematological effects for human toxicity remain understudied.MethodsIn a population of cadmium‐exposed male jewelry manufacturing workers (n = 32) and referents without direct exposure (n = 21), all with urinary cadmium quantification, we measured plasma antioxidant enzymes (catalase, superoxide dismutase), lipid peroxidation (malondialdehyde), erythrocyte fragility, and surface irregularity of the erythrocyte membrane.ResultsCompared to referents, exposed workers manifested significantly lower plasma antioxidant enzymes, and increased malondialdehyde and erythrocyte fragility (for all, P < 0.01). Consistent with the exposure subcategories, activities of superoxide dismutase and catalase were reduced and lipid peroxidation and erythrocyte fragility were enhanced (P < 0.01 for all) in terms of Cd‐effect indicating a strong impact on hematological system and oxidative stress.ConclusionCd exposure contributes to oxidative stress and related erythrocyte effects thus making the hematological system another end‐organ target for chronic Cd toxicity. Am. J. Ind. Med. 57:1064–1072, 2014. © 2014 Wiley Periodicals, Inc.
How Does a Coordinated Radical Ligand Affect the Spin Crossover Properties in an Octahedral Iron(II) Complex?
Authors: Schmitz Markus , Seibel Manuel , Kelm Harald , Demeshko Serhiy , Meyer Franc , Krüger Hans‐Jörg 
Published: May 2014

AbstractThe influence of a coordinated π‐radical on the spin crossover properties of an octahedral iron(II) complex was investigated by preparing and isolating the iron(II) complex containing the tetradentate N,N′‐dimethyl‐2,11‐diaza[3.3](2,6)pyridinophane and the radical anion of N,N′‐diphenyl‐acenaphtene‐1,2‐diimine as ligands. This spin crossover complex was obtained by a reduction of the corresponding low‐spin iron(II) complex with the neutral diimine ligand, demonstrating that the reduction of the strong π‐acceptor ligand is accompanied by a decrease in the ligand field strength. Characterization of the iron(II) radical complex by structural, magnetochemical, and spectroscopic methods revealed that spin crossover equilibrium occurs above 240 K between an S=1/2 ground state and an S=3/2 excited spin state. The possible origins of the fast spin interconversion observed for this complex are discussed.
Structural Basis of Chitin Oligosaccharide Deacetylation
Authors: Andrés Eduardo , Albesa‐Jové David , Biarnés Xevi , Moerschbacher Bruno M. , Guerin Marcelo E. , Planas Antoni 
Published: May 2014

AbstractCell signaling and other biological activities of chitooligosaccharides (COSs) seem to be dependent not only on the degree of polymerization, but markedly on the specific de‐N‐acetylation pattern. Chitin de‐N‐acetylases (CDAs) catalyze the hydrolysis of the acetamido group in GlcNAc residues of chitin, chitosan, and COS. A major challenge is to understand how CDAs specifically define the distribution of GlcNAc and GlcNH2 moieties in the oligomeric chain. We report the crystal structure of the Vibrio cholerae CDA in four relevant states of its catalytic cycle. The two enzyme complexes with chitobiose and chitotriose represent the first 3D structures of a CDA with its natural substrates in a productive mode for catalysis, thereby unraveling an induced‐fit mechanism with a significant conformational change of a loop closing the active site. We propose that the deacetylation pattern exhibited by different CDAs is governed by critical loops that shape and differentially block accessible subsites in the binding cleft of CE4 enzymes.
Adsorption of a silicone‐based surfactant on polyethylene and polypropylene surfaces and its tribologic performance
Authors: Song Junlong , Li Yan , Cheng Qiang 
Published: May 2014

ABSTRACTAqueous silicone‐based surfactants are widely used in the processing of synthetic fibers in textile industries since they enhance a number of functional and processing properties. In this paper the interactions between silicone‐based surfactants and textile‐relevant surfaces (polyethylene and polypropylene) were investigated by quartz crystal microbalance with dissipation and the tribologic performance was evaluated by lateral force microscopy. Our results showed that the more hydrophobic polypropylene surface had higher affinity with silicone‐based lubricants than polyethylene surface. These adsorbed layers provided lubricity in textile materials when subject to shear forces and offered protection to wear and abrasion. This is explained by the fact that the hydrophobic groups in the surfactant molecules interact more effectively with the polypropylene surface via hydrophobic forces. This information will ultimately help to further our understanding on lubrication phenomena in fiber processing. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014, 131, 40838.
A physical strategy for the preparation of isotactic polypropylene spheres with microsphere and bead–string spherulite morphologies
Authors: Jin Jing , Du Jiang , Chen Hongyu , Marchand Gary , Walton Kim , Han Charles C. 
Published: May 2014

ABSTRACTThis study mainly focuses on the formation of isotactic polypropylene (iPP) blend morphologies with microspheres and distinct bead–string spherulites. iPP microspheres have been prepared by a simple and convenient strategy through either an isothermal or a nonisothermal crystallization process based on the macrophase‐separated structure in molten state of iPP/olefin block copolymer (OBC) blend. The dimension of the iPP spheres can be adjusted easily from about 1 µm to >10 µm by controlling the compatibility and annealing conditions. It was found that any of the following three parameters, the molecular structure of OBC (particularly the octene content), molecular weight of iPP, and annealing condition can be rescaled with others in controlling the dimension of the iPP microspheres. The mechanism of the formation of iPP microspheres was studied in detail. Surprisingly, the typical spinodal decomposition morphology with interconnected or thin sheet structure is the precursor of these microspheres. During the subsequent annealing process, it breaks up and further coarsens into spherical structure. In addition, distinct spherulites with a bead–string substructure have been obtained during the isothermal crystallization. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014, 131, 40863.
Changes in habitat use patterns by bottlenose dolphins over a 10‐year period render static management boundaries ineffective
Authors: Hartel Elizabeth F. , Constantine Rochelle , Torres Leigh G. 
Published: May 2014

ABSTRACT

Bottlenose dolphins (Tursiops truncatus) in northern New Zealand range widely and their coastal distribution increases their risk of exposure to a variety of threats.
Marine protected areas (MPAs) are increasingly used to protect species but there is a paucity of studies examining their efficacy.
In the Bay of Islands, New Zealand (35°14'S, 174°06'E), dolphin distribution and habitat use patterns were examined between two time periods: 1996–2000 and 2007–2010. In addition, dolphin use of tourism exclusion zones designed to protect the dolphins were assessed.
Spatial distribution was analysed using kernel densities and Mantel tests.
Broad‐scale distribution patterns remained constant between the two periods but fine‐scale dolphin distribution patterns shifted considerably.
The exclusion zones that were established based on results from the 1996–2000 study were rarely used in 2007–2010, and therefore no longer provided dolphins protection from tourism.
This research demonstrates the plasticity in dolphin habitat use patterns through time and the importance of re‐evaluating the efficacy of static protected areas, especially for wide‐ranging species.
Copyright © 2014 John Wiley & Sons, Ltd.
H∞ Fault Detection for Two‐Dimensional T‐S Fuzzy Systems in FM Second Model
Authors: Wang Lanning , Wang Weiqun 
Published: May 2014

AbstractThis paper investigates the H∞ fault detection problem for two‐dimensional (2D) Takagi‐Sugeno (T‐S) fuzzy systems in a Fornasini‐Marchesini second (FM II) state‐space model. Our aim is to develop fault detection filters for the 2D T‐S fuzzy system both in the non‐fuzzy case and the fuzzy case. Attention is focused on the design of the above two kinds of fault detection filters, which guarantee the fault detection system to be asymptotically stable and to have a prescribed H∞ performance. Sufficient conditions are derived for the existence of such filters in terms of linear matrix inequalities (LMIs), and the corresponding filter synthesis problem then is solved both of the kinds of fault detection filters. Numerical examples are used to demonstrate the effectiveness of the proposed method. Moreover, simulation results show that, under the conditions of reaching the same optimal H∞ performance level and feasible region, the fault detection filter we designed for the fuzzy case has better sensitivity to the fault signal than the one designed for the non‐fuzzy case.
A Novel Multi‐Step Model Predictive Control for Multi‐Input Systems
Authors: Zhang Langwen , Wang Jingcheng 
Published: May 2014

AbstractIn this paper, a novel control scheme, known as multi‐step model predictive control (MPC), is presented for multi‐input systems. To reduce computational complexity, only one or several control inputs are optimized at each time interval. A multi‐step MPC scheme for nominal multi‐input systems is presented. A set invariance condition for polytopic uncertain systems is identified, and the invariant set is determined by solving a linear matrix inequality optimisation problem. Based on the set invariance condition, a min‐max multi‐step robust MPC algorithm is proposed for the polytopic uncertain systems. Two examples are carried out to demonstrate the effectiveness of the proposed algorithms.