bluuebunny/crossref_metadata_2025_split huggingface dataset:
Synthesis of Trifluoromethylated Quinoxaline‐Based Polymers for Photovoltaic Applications
Authors: Putri Sella Kurnia , Kim Yun Hwan , Whang Dong Ryeol , Kim Joo Hyun , Chang Dong Wook 
Published: July 2018

AbstractA series of quinoxaline‐based conjugated polymers, in which the electron‐donating benzodithiophene (BDT) unit is linked to the electron‐accepting 6,7‐difluorinated quinoxaline (DFQ) derivatives by a thiophene bridge, is synthesized. To investigate their effects on the intrinsic properties of polymers, strong electron‐withdrawing trifluoromethyl (CF3) groups were incorporated into the meta‐position of the phenyl ring at the 2,3‐positions of the DFQ unit of the reference polymer, labelled PEhB‐FQx, to yield the target polymer PEhB‐FQxCF3. In addition, the 2‐ethylhexyloxy substituents on the BDT donor in PEhB‐FQxCF3 are changed to the more planar 2‐ethylhexyl thiophene units to produce another target polymer PThB‐FQxCF3. Owing to the significant contributions of the CF3 moiety, PEhB‐FQxCF3 exhibits quite discernible optical and electrochemical properties along with significant enhancement in photovoltaic performances compared to the reference polymer PEhB‐FQx. Furthermore, the incorporation of the alkylthienyl side chains on the BDT moiety confers on the resultant PThB‐FQxCF3 to possess the maximum power conversion efficiency of 7.26% with an open circuit voltage of 0.88 V, short‐circuit current density of 12.20 mA cm−2, and fill factor of 67.80%.
Highly Conducting Polythiophene Thin Films with Less Ordered Microstructure Displaying Excellent Thermoelectric Performance
Authors: Zhang Jiajia , Song Guangjie , Qiu Lin , Feng Yanhui , Chen Jie , Yan Jie , Liu Liyao , Huang Xing , Cui Yutao , Sun Yimeng , Xu Wei , Zhu Daoben 
Published: July 2018

AbstractPolythiophene (PTh) with highly regular molecular structure is synthesized as nearly amorphous thin films by electrochemical methods in a BFEE/DTBP mixed medium (BFEE = boron fluoride ethyl ether; DTBP = 2,6‐di‐tert‐butypyridine). The doping level and film morphology of PTh are modulated through adjusting the current density applied during the polymerization process. A combined analysis with solid‐state NMR, FT‐IR, and Raman spectra reveals the molecular structural regularity of the resulted PTh films, which leads to the highest electrical conductivity up to 700 S cm−1 for films obtained under an optimized current density of 1 mA cm−2. By applying the self‐heating 3ω‐method, thermal conductivities are measured along the in‐plane direction. A highly reduced Lorenz number of 6.49 × 10−9 W Ω K−2 and low lattice thermal conductivity of 0.21 W m−1 K−1 were extracted based on the analyses of the electrical and thermal conductivities according to the Wiedemann–Franz Law; the former is about one‐third of the Sommerfeld value. Finally, the maximized ZT value can reach up to 0.10 under room temperature, which shows that the highly conducting polymers with less ordered structure is the practical direction for developing organic thermoelectric materials.
Benzene‐d6 and toluene‐d8 as guest molecules in micropores of a layered zirconium phosphonate: 2H, 13C{1H}, and 31P{1H} solid‐state NMR, deuterium NMR relaxation, and molecular motions
Authors: Contreras Aida R. , Bakhmutov Vladimir I. , Elliott Douglas W. , Clearfield Abraham 
Published: July 2018

AbstractFor the first time, pore spaces in the Zr (IV) phosphonate (1) as a representative of layered metal (IV) phosphonate materials have been investigated by studying mobility of guest molecules, benzene‐d6, and toluene‐d8. Guest molecules located in micropores of 1 have been characterized by solid‐state 13C{1H} and 2H NMR spectra in static samples with varying temperatures. At moderately low temperatures, the benzene and toluene molecules experience fast isotropic reorientations and show the motionally averaged liquid‐like carbon and deuterium line shapes in the NMR spectra. At lower temperatures, two anisotropic motional modes have been found for benzene molecules by analyzing the 2H NMR line shapes: the well‐known in‐plane C6 rotation and composite motions. Interpretation of the variable‐temperature 2H T1 relaxation times identifies the composite motions as 120° flips around the C6 axis perpendicular to the molecular plane and the rotations around the molecular para‐C‐C axis. The data obtained resulted in the idealized (cylinder‐shaped) model of micropores in compound 1 with the diameter of 20–30 Å. Furthermore, the activation energy of 20.1 kJ/mol determined for the benzene motions classifies the molecule–surface interactions as weak but enough for absorption.
Posterior vaginal compartment repairs: Does vaginal vault (level I) fixation significantly improve the vaginal introital (level III) repair?
Authors: Haylen Bernard T. , Wong Audris , Kerr Stephen 
Published: July 2018

IntroductionLimited data exist associating vaginal vault and introital defects before and after posterior repairs (PR). We hypothesize: (i) a positive association between the size of vaginal vault and introital defects preoperatively; and (ii) a positive association between the reduction of these defects postoperatively if vault fixation (sacrospinous colpopexy—SSC) is used with the PR.MethodsIn a cross‐sectional study of 300 consecutive PRs, the following were measured pre‐ and immediately postoperatively: (i) from POP‐Q: genital hiatus (GH—Level III); (ii) from PR‐Q: perineal gap (PG—Level III), posterior vaginal vault descent (PVVD—Level I). The data for introital defects (GH, PG) were separated according to the need for vault fixation using a SSC due to a larger vaginal defect (PVVD over 5 cm).ResultsMean (SD) preoperative GH and PG were both significantly larger in the SSC versus no SSC group: GH (3.73 [0.94] vs 3.36 [0.83] cm, P = 0.01); PG (2.91 [1.0] vs 2.61 [0.91] cm, P = 0.05). SSC performed with the PR (84%); not performed (16%) cases. The mean (SD) postoperative reduction in GH (antero‐posterior) was significantly (29%—P = 0.002) greater—1.1 (0.69) cm (29.5%) in the SSC group and 0.77 (0.49) cm (22.9%) in the no SSC group. The decrease in the PG (transverse) was greater by 11% (0.05).ConclusionsLevels I and III defects are associated with PRs; preoperatively larger vaginal vault (PVVD over 5 cm) and larger introital defects (GH, PG). Postoperatively, vault fixation resulted in significantly greater reduction in the introital defects.SummaryVaginal vault fixation (SSC) significantly improves the vaginal introital repair.
Are There Hidden Costs Associated With Conducting Layoffs? The Impact of Reduction‐in‐Force and Layoff Notices on Teacher Effectiveness
Authors: Strunk Katharine O. , Goldhaber Dan , Knight David S. , Brown Nate 
Published: July 2018

AbstractFew studies examine employee responses to layoff‐induced unemployment risk; none that we know of quantify the impact of job insecurity on individual employee productivity. Using data from the Los Angeles Unified School District (LAUSD) and Washington State during the Great Recession, we provide the first evidence about the impact of the layoff process on teacher productivity. In both sites we find that teachers impacted by the layoff process are less productive than those who do not face layoff‐induced job threat. LAUSD teachers who are laid off and then rehired to return to the district are less productive in the two years following the layoff. Washington teachers who are given a reduction‐in‐force (RIF) notice and are then not laid off have reduced effectiveness in the year of the RIF. We argue that these results are likely driven by impacts of the layoff process on teachers’ job commitment and present evidence to rule out alternate explanations.
Noise in the Operating Room Distracts Members of the Surgical Team. An Observational Study
Authors: Keller Sandra , Tschan Franziska , Semmer Norbert K. , Holzer Eliane , Candinas Daniel , Brink Mark , Beldi Guido 
Published: July 2018

AbstractBackgroundNoise pollution in operation rooms may distract the surgical team members. In particular during phases of high task complexity, noise can jeopardize concentration. Phases of high complexity are related to task specificities and may thus be different for different members of the surgical team.Study designNoise exposure was measured during 110 open abdominal surgeries. Distinguishing three phases (opening, main phase, and closing), noise was related to self‐report of distraction levels by main and secondary surgeons, scrub nurses and anesthetists.ResultsNoise pollution was higher than recommended levels for concentrated work. Adjusted for duration, surgical type, and difficulty of the surgery, results showed that second surgeons are more likely distracted when noise pollution was high in the main phase; and anesthetists are more likely distracted when noise pollution was high during the closing phase. Main surgeons’ and scrub nurses’ concentration was not impaired by measured noise levels.ConclusionsIn phases with higher concentration demands, noise pollution was particularly distracting for second surgeons and anesthetist, corresponding to their specific task demands (anesthetists) and experience (second surgeons). Reducing noise levels particularly in the main and closing phase of the surgery may reduce concentration impairments.
Vertical flight path segments sets for aircraft flight plan prediction and optimisation
Authors: Dancila B. D. , Botez R. M. 
Published: July 2018

ABSTRACTThe paper presents a method for constructing a set of vertical flight path segments, that would compose an aircraft's vertical flight envelope, by using an aircraft performance model. This method is intended to be used for aircraft flight plan prediction and optimisation algorithms. The goal is to reduce the volume of recurring segment performance computations currently required for flight plan prediction or optimisation. The method presented in this paper applies to a free-flight scenario. The flight-path segments composing the vertical flight envelope belong to one of the unrestricted climb, constant-speed level flight, step-climb and continuous descent segments, performed at the consigned climb, cruise and descent speed schedules and at the consigned air temperature values. The method employs an aircraft model using linear interpolation tables. Nine test scenarios were utilised to assess the performances of the resulting flight envelopes as a function of the number of cruise altitudes and descent flight paths. The set of evaluated performance parameters includes the range of total flight times and still-air flight distances, and the vertical profiles describing the minimum and maximum flight times, and still-air flight distances. The advantages of the proposed method are multiple. First, it eliminates the need for repetitive aircraft performance computations of identical vertical flight plan segments, and provides the means for quick retrieval of the corresponding performance data for use in the construction of a full flight plan. Second, the vertical flight path look-up structure and the vertical flight-path graph describe a set of vertical flight paths that consider an aircraft's and flight plan's configuration parameters and cover its maximum flight envelope. Third, the look-up structure and the graph provide the means for rapid and clear identification of the available options for constructing a flight-plan segment, as well as for detecting the points associated with changes in the flight phases, including climb, cruise, step-climb and descent.
Guest Editors’ Introduction: Philosophical Approaches to Leadership Ethics II: Perspectives on the Self and Responsibility to Others
Authors: Ciulla Joanne B. , Knights David , Mabey Chris , Tomkins Leah 
Published: July 2018

ABSTRACT:This article introduces the second of two special issues on philosophical approaches to leadership ethics. In this issue, the articles draw on the works of Plato, Niccolò Machiavelli, Michel Foucault, and Jürgen Habermas to explore questions in leadership ethics concerning leaders’ self-knowledge and self-constitution and their responsibilities to their followers. The articles in this issue demonstrate the potential of philosophy to deepen our understanding of leadership and ethics.
The consumption pattern of 28 species of carabid beetles (Carabidae) to a weed seed,Viola arvensis
Authors: Deroulers P. , Bretagnolle V. 
Published: July 2018

AbstractSeedbank control has been the cornerstone of agricultural management practices. Regulating weeds by using their predators, as a weed control strategy, may be a prerequisite of decreasing herbicide use, and has thus attracted much research investigating the possible contribution of both vertebrates and invertebrates as weed seed predators. Carabid beetles are considered as one of the most important invertebrate seed predators in agroecosystems. We aimed at investigating carabid beetle preferences to a single prey type, seeds ofViola arvensis. We measured the consumption of seeds in 28 species of carabid beetles, under controlled experimental conditions. Two main tribes are identified in tested species,Harpaliniwith 12 species andPterostichiniwith ten species. We found no relationships between species body mass andViola’s seed consumption, nor with the ratio between mandible length and labrum width (ML/LW). However, trends became significant with the ratio ML/LW when restricting these analyses to species that ate at least five seeds. In addition, we detected a positive and significant relationship between consumption rate and occurrence in trapping sessions over the last 3 years. These results are in favor of weed seeds control by carabids. Clear limits of this study are the use of a single seed species and under control conditions. This experimentation calls for additional studies to check for consistencies in consumption against seed species.
Natural factors regulating mustard aphid dynamics in cabbage
Authors: Fidelis E.G. , Farias E.S. , Silva R.S. , Lopes M.C. , Silva N.R. , Picanço M.C. 
Published: July 2018

AbstractLipaphis erysimi (L.) Kaltenbach (Hemiptera: Aphididae) is one of the most important pests of brassica crops, mainly causing losses due to sap sucking, toxin injection and viral transmission. Knowledge about the main natural factors that regulate populations of this pest, as well as its critical mortality stage, is crucial for the development of integrated pest management of L. erysimi. Here, we determined the critical stage and key mortality factors for L. erysimi in cabbage using an ecological life table. Causes of mortality at each stage of L. erysimi development were monitored daily in the field for seven seasons. From the experimental data, we determined the key factor and critical stage of mortality through correlation and regression analyses. The nymphal stage, especially first instar nymphs, was critical for L. erysimi mortality. The key mortality factors were, in descending order of importance, physiological disturbances and predation by Syrphidae, Coccinellidae and Solenopsis ants. Therefore, control measures should target early stages of L. erysimi and the use of cabbage cultivars that have negative effects against L. erysimi may be a promising strategy for its management. Our results may be useful for plant geneticists who could develop new cabbage cultivars based on these findings. In addition, conservation measures of the main predators of L. erysimi may contribute to the natural control of this pest.
The Social History of Early Roman Coinage
Authors: Bernard Seth 
Published: July 2018

AbstractFiscal explanations often given for Rome's first coins fail to account for the shape of monetary development. Nothing in the mid-republican budget matches the small scale and sporadic production of Roman coins during the early third century, or coinage's rapid expansion in the lead-up to the Second Punic War. Instead, I locate early Roman coinage within a broader reconfiguration of wealth and political power during the early phases of imperial expansion. Coins facilitated the exchange of wealth in the absence of strong social ties; conquest opened up Roman society to vast wealth of this order while also sparking debate about wealth's integration into the political community. Archaeological and textual evidence permits us to trace the contested and uneven development of elite accommodation to impersonal wealth during the third century. This context, I argue, offers the best explanation for Rome's initial coins.
Transfer and Interference in Amygdaloid Kindling in Cats
Authors: Wake Akira , Wada Juhn A. 
Published: July 2018

SummaryExamination of the effects of primary site kindling upon the development
of secondary site amygdaloid kindling in cats showed that the former exerts powerful positive as well as negative after effects upon the latter. The
positive after effect appears to be directed towards establishing a linkage
between the secondary site and the Stage 6 generalized convulsive mechanism. The negative after effects were strikingly similar to those observed in animals with forebrain bisection subjected to amygdaloid kindling, suggesting that it is primarily directed towards functional accessibility of the cerebral structures interconnected by the forebrain commissure. The similarity of the findings in animals with anterior neocortical lesions supports such an assumption. The transient nature of the negative after effects was indicated by the development of a ‘normal’ clinical ictal pattern from the secondary site when it occurred spontaneously. Secondary site kindling exerted similar but less prominent negative after effects when the primary site was re-tested. Stage 6 seizure was elicited upon the first trial, however.
Myopathy Associateci with Amyloid Angiopathy
Authors: Bruni Joseph , Bilbao Juan M. , Pritzker Kenneth P. H. 
Published: July 2018

SummaryA 38-year-old patient with the clinical picture of a progressive myopathy resembling limb girdle muscular dystrophy is presented. Muscle biopsy showed amyloid deposits in the walls of small endomysial blood vessels. There was no clinical or physiological evidence of peripheral nerve involvement, no plasma cell dyscrasia and no generalized amyloidosis. There was no muscle fiber hypertrophy, inflammation or neurogenic change. There was no response to steroid therapy.The etiopathogenesis of this amyloid angiopathy is undetermined. The extensive vessel involvement with amyloid deposition and the absence of changes indicative of muscular dystrophy or inflammatory myopathy leads us to favor an ischemic basis for this patient’s myopathy.
Through the Looking Glass: A Psychologist's Experience of Depression
Authors: Manning Martha 
Published: July 2018

Driving to the symposium, the vague anxiety and discomfort I had heen experiencing for the past few days finally culminated in the realization that 7 years ago that day, I awoke from my first night as an inpatient at a psychiatric unit.Since then and because of that, I've learned a great deal about depressive and manic-depressive illness. I've learned about stigma and shame. I've learned about the devastation that the violence we benignly call “mood disorder” wreaks on families. I have been awed by the array of treatments we've found to ease the suffering, and humbled by the fact that we still have a long way to go. I have become painfully aware of how unenlightened the world still is about psychiatric illness, and saddened by the cruel irony that the only thing more stigmatizing than suffering from a psychiatric illness is seeking treatment for it.
Geomechanical Sensitivities of Injection‐Induced Earthquakes
Authors: Levandowski Will , Weingarten Matthew , Walsh Rall 
Published: July 2018

AbstractWastewater reinjection increases pore fluid pressure and can make faults frictionally unstable, triggering earthquakes. Little is known, however, about how regional geomechanical properties influence the likelihood that disposal will induce seismicity. We investigate the impact of preinjection conditions on the proportion of possible fault orientations destabilized by a specified pore pressure increase. Stress state is the most important factor, with 7 times as many planes unstable in extension than contraction—indeed, normal or strike‐slip faulting environments characterize most injection‐induced seismicity—and additional fivefold increases in transitional stress states. Geomechanical susceptibility depends inversely on overburden density and depth, consistent with the shallow hypocenters of most induced events. The coefficient of friction and initial pore pressure have little impact: Faults initially below hydrostatic pressure can slip during gravity‐fed injection. Combining these factors, site‐specific geomechanical analyses could determine 300‐fold variations in the likelihood of induced seismicity before disposal, offering a proactive way to manage hazard.
Mapping Saturn's Nightside Plasma Sheet Using Cassini's Proximal Orbits
Authors: Sergis N. , Achilleos N. , Guio P. , Arridge C. S. , Sorba A. M. , Roussos E. , Krimigis S. M. , Paranicas C. , Hamilton D. C. , Krupp N. , Mitchell D. G. , Dougherty M. K. , Balasis G. , Giannakis O. 
Published: July 2018

AbstractBetween April and the end of its mission on 15 September, Cassini executed a series of 22 very similar 6.5‐day‐period proximal orbits, covering the mid‐latitude region of the nightside magnetosphere. These passes provided us with the opportunity to examine the variability of the nightside plasma sheet within this time scale for the first time. We use Cassini particle and magnetic field data to quantify the magnetospheric dynamics along these orbits, as reflected in the variability of certain relevant plasma parameters, including the energetic ion pressure and partial (hot) plasma beta. We use the University College London/Achilleos‐Guio‐Arridge magnetodisk model to map these quantities to the conjugate magnetospheric equator, thus providing an equivalent equatorial radial profile for these parameters. By quantifying the variation in the plasma parameters, we further identify the different states of the nightside ring current (quiescent and disturbed) in order to confirm and add to the context previously established by analogous studies based on long‐term, near‐equatorial measurements.
Inferring Compressible Fluid Dynamics From Vent Discharges During Volcanic Eruptions
Authors: Méndez Harper J. S. , Cimarelli C. , Dufek J. , Gaudin D. , Thomas R. J. 
Published: July 2018

AbstractObservations at numerous volcanoes reveal that eruptions are often accompanied by continual radio frequency (CRF) emissions. The source of this radiation, however, has remained elusive until now. Through experiments and the analysis of field data, we show that CRF originates from proximal discharges driven by the compressible fluid dynamics associated with individual volcanic explosions. Blasts produce flows that expand supersonically, generating regions of weakened dielectric strength in close proximity to the vent. As erupted material—charged through fragmentation, friction, or other electrification process—transits through such a region, pyroclasts remove charge from their surfaces in the form of small interparticle spark discharges or corona discharge. Discharge is maintained as long as overpressured conditions at the vent remain. Beyond describing the mechanism underlying CRF, we demonstrate that the magnitude of the overpressure at the vent as well as the structure of the supersonic jet can be inferred in real time by detecting and locating CRF sources.