bluuebunny/crossref_metadata_2025_split huggingface dataset:
Experimentelle Untersuchungen und numerische Verifizierung zum Frischbetondruck bei geneigten Schalungssystemen
Authors: Freund Björn , Proske Tilo , Graubner Carl‐Alexander 
Published: November 2014

AbstractModerne Massivbauwerke weisen als Gestaltungselement immer häufiger geneigte Betonbauteile auf. Bei der Herstellung von Ingenieurbauwerken, wie Kühltürmen oder Faulbehältern, kommen ebenfalls geneigte Schalungen zum Einsatz. Hinsichtlich der Dimensionierung von Schalungssystemen stellt der Frischbetondruck die maßgebliche Einwirkung dar. Die existierende Norm zum Frischbetondruck DIN 18218 enthält bisher keine Angaben für geneigte Schalungen. Daher wird in der Baupraxis bei geneigten Schalungen oftmals der hydrostatische Frischbetondruck angesetzt, was u. U. zu einer Überdimensionierung des Schalungssystems bzw. zu einer unnötigen Verlangsamung der zulässigen Betoniergeschwindigkeit und somit zu einer längeren Herstellzeit führt. Die durchgeführten Untersuchungen zeigen, dass der Frischbetondruck bei geneigten Schalungen mit konstanter Bauteildicke kleiner ausfällt als bei lotrechten Schalungen. Bestätigt wird dies durch numerische Analysen.Experimental investigation and numerical verification of the pressure of fresh concrete on inclined formwork systemsModern concrete structures have often inclined concrete components as their design elements. Inclined formwork is also used for the construction of other engineering structures such as cooling towers and digesters. The pressure of fresh concrete determines the dimensioning of formwork systems and the possible rate of casting. DIN 18218 as the available code for calculation of fresh concrete pressure does not contain any provisions for inclined formwork. Thus, in construction practice, the hydrostatic pressure is often used as the design value. This can lead to an over‐dimensioning of the formwork system or to an unnecessary reduction of pouring rate. The results of current investigation show that the pressure of fresh concrete on the inclined formwork with a constant thickness is lower than on the vertical one.
Ermüdungsverhalten von Beton unter zyklischer Beanspruchung aus dem Betrieb von Windenergieanlagen
Authors: Roggendorf Thomas , Goralski Claus 
Published: November 2014

AbstractDa hinsichtlich der Nachweisführung für die charakteristischen Bereiche einer Windenergieanlage (WEA) unter Ermüdungsbeanspruchung aus der Bemessungspraxis verschiedene offene Punkte bekannt sind, wurde im Auftrag des Deutschen Instituts für Bautechnik (DIBt) der Sachstandsbericht “Ermüdungsverhalten von Beton unter zyklischer Beanspruchung aus dem Betrieb von Windkraftanlagen” [1] erstellt. Ziel der durchgeführten Untersuchungen war die Schaffung einer objektiven Bewertungsgrundlage zur Einstufung der derzeitigen Nachweiskonzepte für zyklische Beanspruchungen aus dem Betrieb von WEA. Dazu wurden theoretische und experimentelle Untersuchungen, die als Grundlage für die in bestehenden Regelwerken verankerten Ansätze dienen, zusammengestellt und bewertet. Darüber hinaus wurden weiterführende Bemessungsansätze aus der Literatur dargestellt und verglichen. Es folgten eigene Vergleichsberechnungen zur Ermüdungsfestigkeit an für WEA spezifischen Beispielen. Basierend auf diesen Untersuchungen wurden abschließend unter Berücksichtigung der speziellen Beanspruchungsszenarien für Bauteile von WEA der weitere Forschungsbedarf aufgezeigt und Empfehlungen für Modellversuche erarbeitet. Im vorliegenden Bericht werden die Untersuchungen und wesentliche Ergebnisse kurz zusammengefasst.Concrete fatigue behaviour under cyclic loading from the operation of wind turbine generatorsWhen it comes to the verification of characteristic sections in the structures for wind turbine generators under cyclic loading, various questions are known in the current design practice. Thus, the German building authorities “Deutsches Institut für Bautechnik (DIBt)” commissioned the status report “Concrete fatigue behaviour under cyclic loading from the operation of wind turbine generators” [1]. The intention of the investigations was to establish an objective criterion for the assessment of current design principles for cyclic loading from the operation of wind turbine generators. For this purpose, theoretical and experimental examinations providing a basis for the present approaches in existing codes and regulations were assembled and evaluated. In addition, advanced design approaches from literature were summarised and compared. Following this, comparative calculations concerning the resistance against concrete fatigue for typical impacts from wind turbine generators were performed. Based on these examinations and in consideration of the particular loading scenarios of structures for wind turbine generators, the need for further research was identified and recommendations for theoretical and experimental investigations were developed. The investigations and significant results are summarised in the present report.
Hierarchically Organized Silica–Titania Monoliths Prepared under Purely Aqueous Conditions
Authors: Flaig Sylvia , Akbarzadeh Johanna , Dolcet Paolo , Gross Silvia , Peterlik Herwig , Hüsing Nicola 
Published: November 2014

AbstractHierarchically organized silica–titania monoliths were synthesized under purely aqueous conditions by applying a new ethylene glycol‐modified single‐source precursor, such as 3‐[3‐{tris(2‐hydroxyethoxy)silyl}propyl]acetylacetone coordinated to a titanium center. The influence of the silicon‐ and titanium‐containing single‐source precursor, the novel glycolated organofunctional silane, and the addition of tetrakis(2‐hydroxyethyl)orthosilicate on the formation of the final porous network was investigated by SEM, TEM, nitrogen sorption, and SAXS/WAXS. In situ SAXS measurements were performed to obtain insight into the development of the mesoporous network during sol–gel transition. IR‐ATR, UV/Vis, XPS, and XAFS measurements showed that up to a Si/Ti ratio of 35:1, well‐dispersed titanium centers in a macro‐/mesoporous SiO2 network with a specific surface area of up to 582 m2 g−1 were obtained. An increase in Ti content resulted in a decrease in specific surface area and a loss of the cellular character of the macroporous network. With a 1:1 Si/Ti ratio, silica–titania powders with circa 100 m2 g−1 and anatase domains within the SiO2 matrix were obtained.
Divergent Total Synthesis of the Tricyclic Marine Alkaloids Lepadiformine, Fasicularin, and Isomers of Polycitorols by Reagent‐Controlled Diastereoselective Reductive Amination
Authors: In Jinkyung , Lee Seokwoo , Kwon Yongseok , Kim Sanghee 
Published: November 2014

AbstractWe describe a flexible and divergent route to the pyrrolo‐/pyrido[1,2‐j]quinoline frameworks of tricyclic marine alkaloids via a common intermediate formed by the ester–enolate Claisen rearrangement of a cyclic amino acid allylic ester. We have synthesized the proposed structure of polycitorols and demonstrated that the structure of these alkaloids requires revision. In addition to asymmetric formal syntheses, stereoselective and concise total syntheses of (−)‐lepadiformine and (−)‐fasicularin were also accomplished from simple, commercially available starting materials in a completely substrate‐controlled manner. The key step in these total syntheses was the reagent‐dependent stereoselective reductive amination of the common intermediate to yield either indolizidines 55 a or 55 b. Aziridinium‐mediated carbon homologation of the hindered C‐10 group to the homoallylic group facilitated the synthesis.
Two‐dimensional (2D) Supramolecular Coordination at Liquid/Solid Interfaces Studied by Scanning Tunneling Microscopy
Authors: Xu Jing , Zeng Qingdao 
Published: November 2014

AbstractIn this review, supramolecular coordination processes on two‐dimensional (2D) surfaces or interfaces observed by scanning tunneling microscopy (STM) are discussed. Four parts are mainly involved, which include (1) recognition of Fe3+ through functional molecular networks, (2) K+‐induced switching of valinomycin, (3) supramolecular coordination happened in a nano‐reactor, (4) reversible 2D supramolecular spring driven by coordination. The direct insight of the coordination phenomena provided by STM supplements our knowledge of its mechanism. Since different building blocks can be connected into a whole part through coordination, the understanding of its mechanism will be beneficial to the future design of molecular devices.
A closed‐form equation approach to multi‐port/multi‐zone behavioral modeling of GaN FET Amplifiers
Authors: Crespo‐Cadenas Carlos , Reina‐Tosina Javier , Madero‐Ayora María J. , Allegue‐Martínez Michel 
Published: November 2014

SummaryIn this paper, a systematic method for the simulation of weakly and mildly nonlinear GaN FET amplifiers is reported. The core of the proposal is a third‐order Volterra‐based behavioral model with multi‐spectral and multi‐node capabilities that is formally derived from a circuit‐level representation. Starting with the equivalent circuit of a typical FET device with thermal power feedback and fading memory, described in terms of its large‐signal functions, closed‐form expressions for the kernels at the gate, drain and thermal nodes are developed up to the third order. The use of these kernels allows the calculation of the responses in the dc, first‐, second‐ and third‐harmonic zones, which are shown to be dependent on the frequency response of the amplifier circuit terminating impedances and thermal filter. The simulation approach has been applied to calculate the nonlinear response of a typical power amplifier circuit, showing the ability of the proposed approach to provide an accurate prediction of multi‐spectral, multi‐node, multi‐bias characteristics, including AM/AM‐AM/PM conversion, spectral regrowth, intermodulation, and temperature rise, under diverse input signal waveforms and bandwidths. These results have been successfully compared with commercial CAD tools based on harmonic balance or envelope simulation. Copyright © 2014 John Wiley & Sons, Ltd.
Neuro‐ and social‐cognitive clustering highlights distinct profiles in adults with anorexia nervosa
Authors: Renwick Beth , Musiat Peter , Lose Anna , DeJong Hannah , Broadbent Hannah , Kenyon Martha , Loomes Rachel , Watson Charlotte , Ghelani Shreena , Serpell Lucy , Richards Lorna , Johnson‐Sabine Eric , Boughton Nicky , Treasure Janet , Schmidt Ulrike 
Published: November 2014

ABSTRACTObjectiveThis study aimed to explore the neuro‐ and social‐cognitive profile of a consecutive series of adult outpatients with anorexia nervosa (AN) when compared with widely available age and gender matched historical control data. The relationship between performance profiles, clinical characteristics, service utilization, and treatment adherence was also investigated.MethodConsecutively recruited outpatients with a broad diagnosis of AN (restricting subtype AN‐R: n = 44, binge‐purge subtype AN‐BP: n = 33 or Eating Disorder Not Otherwise Specified‐AN subtype EDNOS‐AN: n = 23) completed a comprehensive set of neurocognitive (set‐shifting, central coherence) and social‐cognitive measures (Emotional Theory of Mind). Data were subjected to hierarchical cluster analysis and a discriminant function analysis.ResultsThree separate, meaningful clusters emerged. Cluster 1 (n = 45) showed overall average to high average neuro‐ and social‐ cognitive performance, Cluster 2 (n = 38) showed mixed performance characterized by distinct strengths and weaknesses, and Cluster 3 (n = 17) showed poor overall performance (Autism Spectrum disorder (ASD) like cluster). The three clusters did not differ in terms of eating disorder symptoms, comorbid features or service utilization and treatment adherence. A discriminant function analysis confirmed that the clusters were best characterized by performance in perseveration and set‐shifting measures.DiscussionThe findings suggest that considerable neuro‐ and social‐cognitive heterogeneity exists in patients with AN, with a subset showing ASD‐like features. The value of this method of profiling in predicting longer term patient outcomes and in guiding development of etiologically targeted treatments remains to be seen. © 2014 Wiley Periodicals, Inc. (Int J Eat Disord 2015; 48:26–34)
Gonadal hormones modulate the responsiveness to local β‐blocker‐induced antinociception in the temporomandibular joint of male and female rats
Authors: Fávaro‐Moreira N.C. , Okoti L.W. , Furini R. , Tambeli C.H. 
Published: November 2014

AbstractBackgroundWe have previously demonstrated that blockade of β‐adrenoreceptors (β‐AR) located in the temporomandibular joint (TMJ) of rats suppresses formalin‐induced TMJ nociceptive behaviour in both male and female rats, but female rats are more responsive. In this study, we investigated whether gonadal hormones modulate the responsiveness to local β‐blocker‐induced antinociception in the TMJ of rats.MethodsCo‐administration of each of the selective β1 (atenolol), β2 (ICI 118.551) and β3 (SR59230A)‐AR antagonists with equi‐nociceptive concentrations of formalin in the TMJ of intact, gonadectomized and hormone‐treated gonadectomized male and female rats.ResultsAtenolol, ICI 118.551 and SR59230A significantly reduced formalin‐induced TMJ nociception in a dose response fashion in all groups tested. However, a lower dose of each β‐AR antagonist was sufficient to significantly reduce nociceptive responses in gonadectomized but not in intact and testosterone‐treated gonadectomized male rats. In the female groups, a lower dose of β1‐AR antagonist was sufficient to significantly reduce nociceptive responses in gonadectomized but not in intact or gonadectomized rats treated with progesterone or a high dose of oestradiol; a lower dose of β2‐AR antagonist was sufficient to significantly reduce nociceptive responses in gonadectomized but not in intact and gonadectomized rats treated with low or high dose of oestradiol.ConclusionGonadal hormones may reduce the responsiveness to local β‐blocker‐induced antinociception in the TMJ of male and female rats. However, their effect depends upon their plasma level, the subtype of β‐AR and the dose of β‐blockers used.
Nostalgia counteracts self‐discontinuity and restores self‐continuity
Authors: Sedikides Constantine , Wildschut Tim , Routledge Clay , Arndt Jamie 
Published: November 2014

AbstractNostalgia is a resource that functions, in part, as a response to self‐discontinuity and a source of self‐continuity. We tested and supported this regulatory role of nostalgia in the tradition of establishing a causal chain. In Study 1, we examined the naturalistic association between events precipitating self‐discontinuity and nostalgia. Self‐discontinuity, especially when stemming from negative life events, was associated with higher proneness to nostalgia. In Study 2, we experimentally induced negative self‐discontinuity (i.e. relatively disruptive), positive self‐discontinuity (i.e. relatively non‐disruptive) or self‐continuity (i.e. neutral non‐disruptiveness) and subsequently assessed state levels of nostalgia. Only negative self‐discontinuity evoked heightened nostalgia. In Study 3, we experimentally induced nostalgia (versus ordinary autobiographical recollection) and assessed self‐continuity. Nostalgia augmented self‐continuity. In Study 4, we experimentally induced nostalgia (versus ordinary autobiographical recollection versus positive autobiographical recollection) and assessed self‐continuity. Again, nostalgia augmented self‐continuity and did so above and beyond positive affect. Here, we ruled out demand characteristics as a rival hypothesis. Taken together, the findings clarify the role of nostalgia in the dynamic between self‐discontinuity and self‐continuity and elucidate the restorative properties of nostalgia for the self‐system. Copyright © 2014 John Wiley & Sons, Ltd.
Maximum likelihood TOA and OTDOA estimation with first arriving path detection for 3GPP LTE system
Authors: Xu W. , Huang M. , Zhu C. , Dammann A. 
Published: November 2014

AbstractThe US Federal Communications Commission (FCC) has mandated wireless network operators and mobile devices to provide accurate location information for E‐911. Requirements for time of arrival (TOA) and time difference of arrival (TDOA) measurements have been specified in 3GPP LTE Rel. 9 to ensure accurate user equipment (UE) positioning even under bad conditions (e.g. with channel quickly varying and SNR being as low as −13 dB). To fulfil these requirements, it is vital to accurately estimate the first signal arriving path. In this work, we first derive ‐ without any approximation ‐ the Cramér–Rao lower bound (CRLB) of the LTE TOA and TDOA measurements based on the different pilots, which is shown to be as low as a few metres for SNR = −13 dB. The achievable performance of the LTE system is compared with the FCC and 3GPP requirements, and the impact of mobile multipath channels on the measurements is analysed. Then, we describe practical low‐complexity methods for LTE TOA and TDOA measurements with enhanced first arriving path detection. The maximum likelihood based correlation profile is used as detection metric. After grossly determining the signal region by a moving window, three methods, namely, peak detection, SNR‐based threshold and adaptive threshold based on noise floor and metric peak value are employed to estimate the first arriving path. Simulation results show that the proposed adaptive threshold‐based method can meet all 3GPP requirements under various realistic mobile channels, and can in some cases achieve a performance close to the CRLB. Copyright © 2014 John Wiley & Sons, Ltd.
Comparative anatomy of the stem, leaf and inflorescence basal axis of Polianthes L. (Asparagaceae, Agavoideae) species
Authors: Solano Eloy , Terrazas Teresa , González‐Becerril Alma 
Published: November 2014

AbstractThe genus Polianthes belongs to Asparagaceae, subfamily Agavoideae (APG III, 2009) and is endemic to Mexico, spanning the states of Chihuahua and Tamaulipas in the north, and extending to the state of Oaxaca in the south. Its species are perennial, herbaceous plants with corms and bulbs. Their leaves are green or glaucous, linear or lanceolate. Inflorescences are in racemes or spikes with narrow and widely infundibuliform flowers, varying in color from white to red. The fruit is a capsule with black seeds. The number of species of Polianthes varies depending on the criteria to classify them. For example, in the first revision for the genus, Rose (1903) recognized 12 species. According to Espejo and López (1992), the genus has 15 species, whereas GarcíaMendoza and Galván (1995) reported 12 species, and Solano and Feria (2007) recognized 14 species and three varieties. (© 2013 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Latent classes of course in Alzheimer's disease and predictors: the Cache County Dementia Progression Study
Authors: Leoutsakos Jeannie‐Marie S. , Forrester Sarah N. , Corcoran Christopher D. , Norton Maria C. , Rabins Peter V. , Steinberg Martin I. , Tschanz Joann T. , Lyketsos Constantine G. 
Published: November 2014

ObjectiveSeveral longitudinal studies of Alzheimer's disease (AD) report heterogeneity in progression. We sought to identify groups (classes) of progression trajectories in the population‐based Cache County Dementia Progression Study (N = 328) and to identify baseline predictors of membership for each group.MethodsWe used parallel‐process growth mixture models to identify latent classes of trajectories on the basis of Mini‐Mental State Exam (MMSE) and Clinical Dementia Rating sum of boxes scores over time. We then used bias‐corrected multinomial logistic regression to model baseline predictors of latent class membership. We constructed receiver operating characteristic curves to demonstrate relative predictive utility of successive sets of predictors.ResultsWe fit four latent classes; class 1 was the largest (72%) and had the slowest progression. Classes 2 (8%), 3 (11%), and 4 (8%) had more rapid worsening. In univariate analyses, longer dementia duration, presence of psychosis, and worse baseline MMSE and Clinical Dementia Rating sum of boxes were associated with membership in class 2, relative to class 1. Lower education was associated with membership in class 3. In the multivariate model, only MMSE remained a statistically significant predictor of class membership. Receiver operating characteristic areas under the curve were 0.98, 0.88, and 0.67, for classes 2, 3, and 4 relative to class 1.ConclusionsHeterogeneity in AD course can be usefully characterized using growth mixture models. The majority belonged to a class characterized by slower decline than is typically reported in clinical samples. Class membership could be predicted using baseline covariates. Further study may advance our prediction of AD course at the population level and in turn shed light on the pathophysiology of progression. Copyright © 2014 John Wiley & Sons, Ltd.
Atypical antipsychotic drug use and falls among nursing home residents in Winnipeg, Canada
Authors: Bozat‐Emre Songul , Doupe Malcolm , Kozyrskyj Anita L. , Grymonpre Ruby , Mahmud Salaheddin M. 
Published: November 2014

ObjectiveThe purpose of this study is to assess whether atypical antipsychotic drug (AAD) use is associated with increased risk of falling among older (≥65 years) nursing home (NH) residents.MethodsWe conducted a nested case–control study using Resident Assessment Instrument Minimum Data Set 2.0 (RAI‐MDS©) for NHs to identify falls, and population‐based administrative healthcare databases to measure drug use and other study covariates. Cases (n = 626) were NH residents in Winnipeg, Canada, who had a fall between 1 April 2005 and 31 March 2007, and were matched to four controls on age, sex, and length of NH stay (n = 2388).ResultsWhile the odds of falling were statistically greater for AAD users versus nonusers (OR = 1.6, 95% CI 1.1–2.3), this association was type and dose dependent. Compared to nonusers, the odds of falling were greater for high‐dose (>150 mg/day) quetiapine users and for high‐dose (>2 mg/day) risperidone users. On the other hand, olanzapine (regardless of dose), low‐dose quetiapine, and low‐dose risperidone use were not associated with increased fall risk. Furthermore, the effect of AAD use, in general, on the risk of falling was significantly greater for people with wandering problems (OR = 1.8, 95% CI 1.1–3.1).ConclusionsOur findings suggest greater risk of falling with high‐dose quetiapine use and with high‐dose risperidone use among NH residents. In addition, the effect of AAD use was greater for people who frequently wander. Further research is needed to confirm these findings, and to address other important unanswered questions about the safest dose and duration of AAD use. Copyright © 2014 John Wiley & Sons, Ltd.