bluuebunny/crossref_metadata_2025_split huggingface dataset:
Viscoelasticity of Maxwell's model and non‐Newtonian viscosity revisited
Authors: Hoffmann H.‐J. 
Published: February 2018

AbstractThe viscosity of fluids and melts is an important characteristic to steer processes and reactions of materials, to use lubricants and to fabricate diverse products of glass. To steer such fabrication processes reliably and free of failures one necessarily needs to understand and use the true data of the viscosity. The forces applied to measure the viscosity act also to accelerate parts of the samples and particularly to deform them elastically. To evaluate the viscosity one must necessarily consider such ‘side reactions’. Cylindrical samples under longitudinal deformation are demonstrated to deform rather elastically than by viscous flow upon application of the load, e. g. Neglecting this effect the ’viscosity’ apparently decreasing with increasing load may be misinterpreted as non‐Newtonian viscosity. In fact, it represents the change from viscous to elastic behaviour with decreasing time interval of the application of force. Furthermore, production of entropy during deformation for measurement has to be taken into account adequately. The sample warms up during heavy deformation. If the viscosity depends strongly on the temperature, one must take into account that temperature and viscosity change with the intensity of the load. Then the so called ’shear thinning’ is rather ’sheer heating’. This is demonstrated quantitatively with data of the viscosity as a function of the load, which have recently been published using capillary rheometers.
Texture analysis of T1‐w and T2‐w MR images allows a quantitative evaluation of radiation‐induced changes of internal obturator muscles after radiotherapy for prostate cancer
Authors: Scalco Elisa , Rancati Tiziana , Pirovano Ileana , Mastropietro Alfonso , Palorini Federica , Cicchetti Alessandro , Messina Antonella , Avuzzi Barbara , Valdagni Riccardo , Rizzo Giovanna 
Published: February 2018

PurposeTo investigate the potential of texture analysis applied on T2‐w and postcontrast T1‐w images acquired before radiotherapy for prostate cancer (PCa) and 12 months after its completion in quantitatively characterizing local radiation effect on the muscular component of internal obturators, as organs potentially involved in urinary toxicity.MethodsT2‐w and postcontrast T1‐w MR images were acquired at 1.5 T before treatment (MRI1) and at 12 months of follow‐up (MRI2) in 13 patients treated with radiotherapy for PCa. Right and left internal obturator muscle contours were manually delineated upon MRI1 and then automatically propagated on MRI2 by an elastic registration method. Planning CT images were coregistered to both MRIs and dose maps were deformed accordingly. A high‐dose region receiving >55 Gy and a low‐dose region receiving <55 Gy were identified in each muscle volume. Eighteen textural features were extracted from each region of interest and differences between MRI1 and MRI2 were evaluated.ResultsA signal increase was highlighted in both T2‐w and T1‐w images in the portion of the obturators near the prostate, i.e., in the region receiving medium‐high doses. A change in the spatial organization was identified, as an increase in homogeneity and a decrease in contrast and complexity, compatible with an inflammatory status. In particular, the region receiving medium‐high doses presented more significant or, at least, stronger differences.ConclusionsTexture analysis applied on T1‐w and T2‐w MR images has demonstrated its ability in quantitative evaluating radiation‐induced changes in obturator muscles after PCa radiotherapy.
Spectral resolution and high‐flux capability tradeoffs in CdTe detectors for clinical CT
Authors: Hsieh Scott S. , Rajbhandary Paurakh L. , Pelc Norbert J. 
Published: February 2018

PurposePhoton‐counting detectors using CdTe or CZT substrates are promising candidates for future CT systems but suffer from a number of nonidealities, including charge sharing and pulse pileup. By increasing the pixel size of the detector, the system can improve charge sharing characteristics at the expense of increasing pileup. The purpose of this work is to describe these considerations in the optimization of the detector pixel pitch.MethodsThe transport of x rays through the CdTe substrate was simulated in a Monte Carlo fashion using GEANT4. Deposited energy was converted into charges distributed as a Gaussian function with size dependent on interaction depth to capture spreading from diffusion and Coulomb repulsion. The charges were then collected in a pixelated fashion. Pulse pileup was incorporated separately with Monte Carlo simulation. The Cramér–Rao lower bound (CRLB) of the measurement variance was numerically estimated for the basis material projections. Noise in these estimates was propagated into CT images. We simulated pixel pitches of 250, 350, and 450 microns and compared the results to a photon counting detector with pileup but otherwise ideal energy response and an ideal dual‐energy system (80/140 kVp with tin filtration). The modeled CdTe thickness was 2 mm, the incident spectrum was 140 kVp and 500 mA, and the effective dead time was 67 ns. Charge summing circuitry was not modeled. We restricted our simulations to objects of uniform thickness and did not consider the potential advantage of smaller pixels at high spatial frequencies.ResultsAt very high x‐ray flux, pulse pileup dominates and small pixel sizes perform best. At low flux or for thick objects, charge sharing dominates and large pixel sizes perform best. At low flux and depending on the beam hardness, the CRLB of variance in basis material projections tasks can be 32%–55% higher with a 250 micron pixel pitch compared to a 450 micron pixel pitch. However, both are about four times worse in variance than the ideal photon counting detector. The optimal pixel size depends on a number of factors such as x‐ray technique and object size. At high technique (140 kVp/500 mA), the ratio of variance for a 450 micron pixel compared to a 250 micron pixel size is 2126%, 200%, 97%, and 78% when imaging 10, 15, 20, and 25 cm of water, respectively. If 300 mg/cm2 of iodine is also added to the object, the variance ratio is 117%, 91%, 74%, and 72%, respectively. Nonspectral tasks, such as equivalent monoenergetic imaging, are less sensitive to spectral distortion.ConclusionsThe detector pixel size is an important design consideration in CdTe detectors. Smaller pixels allow for improved capabilities at high flux but increase charge sharing, which in turn compromises spectral performance. The optimal pixel size will depend on the specific task and on the charge shaping time.
Infant multiple breath washout using a new commercially available device: Ready to replace the previous setup?
Authors: Kentgens Anne‐Christianne , Guidi Marisa , Korten Insa , Kohler Lena , Binggeli Severin , Singer Florian , Latzin Philipp , Anagnostopoulou Pinelopi 
Published: February 2018

AbstractIntroductionMultiple breath washout (MBW) is a sensitive test to measure lung volumes and ventilation inhomogeneity from infancy on. The commonly used setup for infant MBW, based on ultrasonic flowmeter, requires extensive signal processing, which may reduce robustness. A new setup may overcome some previous limitations but formal validation is lacking.AimWe assessed the feasibility of infant MBW testing with the new setup and compared functional residual capacity (FRC) values of the old and the new setup in vivo and in vitro.MethodsWe performed MBW in four healthy infants and four infants with cystic fibrosis, as well as in a Plexiglas lung simulator using realistic lung volumes and breathing patterns, with the new (Exhalyzer D, Spiroware 3.2.0, Ecomedics) and the old setup (Exhalyzer D, WBreath 3.18.0, ndd) in random sequence.ResultsThe technical feasibility of MBW with the new device‐setup was 100%. Intra‐subject variability in FRC was low in both setups, but differences in FRC between the setups were considerable (mean relative difference 39.7%, range 18.9; 65.7, P = 0.008). Corrections of software settings decreased FRC differences (14.0%, −6.4; 42.3, P = 0.08). Results were confirmed in vitro.ConclusionMBW measurements with the new setup were feasible in infants. However, despite attempts to correct software settings, outcomes between setups were not interchangeable. Further work is needed before widespread application of the new setup can be recommended.
A Flexible High‐Performance Photoimaging Device Based on Bioinspired Hierarchical Multiple‐Patterned Plasmonic Nanostructures
Authors: Lee Yoon Ho , Lee Tae Kyung , Kim Hongki , Song Inho , Lee Jiwon , Kang Saewon , Ko Hyunhyub , Kwak Sang Kyu , Oh Joon Hak 
Published: February 2018

AbstractIn insect eyes, ommatidia with hierarchical structured cornea play a critical role in amplifying and transferring visual signals to the brain through optic nerves, enabling the perception of various visual signals. Here, inspired by the structure and functions of insect ommatidia, a flexible photoimaging device is reported that can simultaneously detect and record incoming photonic signals by vertically stacking an organic photodiode and resistive memory device. A single‐layered, hierarchical multiple‐patterned back reflector that can exhibit various plasmonic effects is incorporated into the organic photodiode. The multiple‐patterned flexible organic photodiodes exhibit greatly enhanced photoresponsivity due to the increased light absorption in comparison with the flat systems. Moreover, the flexible photoimaging device shows a well‐resolved spatiotemporal mapping of optical signals with excellent operational and mechanical stabilities at low driving voltages below half of the flat systems. Theoretical calculation and scanning near‐field optical microscopy analyses clearly reveal that multiple‐patterned electrodes have much stronger surface plasmon coupling than flat and single‐patterned systems. The developed methodology provides a versatile and effective route for realizing high‐performance optoelectronic and photonic systems.
Zur Einführung der BIM‐Methode in den Planungsund Herstellungsprozess
Authors: Grawe Wigand , Wichers Michael 
Published: February 2018

AbstractMit dem Anspruch der durchgängigen Nutzung eines digitalen Gebäudemodells über den gesamten Lebensdauerzyklus eines Bauwerks, beginnend mit den ersten Entwürfen, über die Planung und Ausführung bis hin zur Nutzung und Verwaltung, war die Idee des Building Information Modeling (BIM) geboren. Die daraus resultierende Umstrukturierung der Planungsabläufe fordert von allen Planungsbeteiligten einen Paradigmenwechsel und damit die Bereitschaft, vorhandene Planungsstrukturen zu verlassen. Das Zusammenfügen der einzelnen Fachbeiträge zu einem Gesamtmodell stellt die Planer vor technische als auch menschliche Herausforderungen. Erkenntnisse, die sich im Rahmen der Einführung für die Praxis zeigen können, sollen diskutiert und erläutert werden. BIM steht somit nicht nur für eine neue Planungskultur, sondern auch für ein neues Miteinander der Planungsbeteiligten.
Ermittlung der Sicherheitselemente bei der verformungsorientierten Bemessung von hybriden Trägern
Authors: Geißler Karsten , Korpas Gregor 
Published: February 2018

AbstractFür Hybridträger, die zunehmend auch in Baukonstruktionen häufiger eingesetzt werden, stellt sich die Frage nach den erforderlichen Sicherheitsfaktoren für die Werkstoffe und die Verbundfuge. Die für die Einzelwerkstoffe bekannten Sicherheitsfaktoren erfassen das Problemfeld des hybriden Trägers nicht bzw. ggf. nur zufällig. Im vorliegenden Beitrag wird zunächst eine neue Methode zur Berechnung hybrider Träger mit nachgiebiger Verbundfuge vorgestellt. Dabei wird das gesamte Dehnungsverhalten bis zum Grenzzustand der Tragfähigkeit betrachtet. Wegen der aus der Nachgiebigkeit der Verbundfuge resultierenden Spannungsumlagerungen im Gesamtquerschnitt ergeben sich andere Wichtungen für die Querschnittsteile. Mit streuenden Eingangsparametern können eine probabilistische Auswertung vorgenommen und die Bemessungswerte für die einzelnen Werkstoffeigenschaften einschließlich der Verbundfuge bestimmt werden.Allgemein ergibt sich, dass die Bemessungswerte der Einzelwerkstoffe – neben ihren eigenen Streuungen – auch von der Bedeutung der Querschnittsteile innerhalb des Hybridträgers maßgeblich beeinflusst werden. Die Tragfähigkeit des Hybridträgers und die Wichtung bzw. die Bemessungswerte der Einzelwerkstoffe sind stark abhängig von der Nachgiebigkeit der Verbundfuge.
Einflussfaktoren auf die Vorspannkraft von Schrauben mit Durchmessern bis M72 in Ringflanschverbindungen
Authors: Schwedler Michael , Dörfeldt Stefan , Lüddecke Falk , Seidel Marc , Thiele Marc 
Published: February 2018

AbstractBei Monopfahlgründungen von Offshore‐Windenergieanlagen wird die Verbindung zwischen Monopfahl und Übergangsstück als geschraubter Ringflansch ausgeführt. Die zunehmende Leistungsfähigkeit der Windenergieanlagen führt zu immer größeren Schnittgrößen in diesem Anschluss. In der Folge erhöhen sich nicht nur die Querschnittsabmessungen, sondern es kommen auch zunehmend größere Schrauben zum Einsatz. Da die einschlägigen Regelwerke zur Bemessung dieser Verbindungen nicht für Schrauben der Größen M64 oder M72 konzipiert wurden, stellt sich die Frage der Übertragbarkeit auf solche Anwendungsfälle. Im Rahmen des Aufsatzes werden Einflüsse diskutiert, die eine Herabsetzung der Schraubentragfähigkeit verursachen könnten. Diese Einflüsse, vornehmlich geometrische Imperfektionen, werden systematisch untersucht und ergänzend in praxisrelevanten Beispielen bewertet. Die somit gewonnenen Erkenntnisse werden für die abschließende Beurteilung der großen Schrauben in Ringflanschverbindungen herangezogen.
Konsequent Digital
Authors: Peter Boris , Helbig Thorsten , Oppe Matthias 
Published: February 2018

AbstractIn Teilbereichen der Planung und Ausführung bestehen im Stahlbau bereits seit vielen Jahren geschlossene Prozessketten im Sinne der „closed BIM‐Methode”. Durch computerunterstützte Fertigungsmethoden gewonnene Freiheitsgrade konnten architektonisch und technisch genutzt werden. Die konsequente Weiterentwicklung der digitalen Prozessketten im Stahlbau ermöglicht eine wirtschaftliche und qualitativ hochwertige Umsetzung äußerst komplexer Bauwerksgeometrien innerhalb kürzester Zeit. Dieser Artikel erläutert die konsequente Weiterentwicklung digitaler Planungsmethoden im Stahlbau anhand von Projektbeispielen.
Derivation of the characteristic water pressure resistance of combined steel pile walls
Authors: Just Adrian , Kuhlmann Ulrike , El Boueiz Perla , Prüm Cécile 
Published: February 2018

AbstractWorld trade is steadily increasing, leading to a high demand for economic solutions for quay walls. The combined steel pile wall is the most common steel construction solution. The primary elements are king piles, while intermediate piles function as secondary elements. The design of these secondary elements is governed by section 5.5.2 of EN 1993‐5 [9]. The test‐based method described in section 5.5.2(5) and (6) is used to generate the characteristic water pressure resistance values of the different combinations of I‐shaped king and Z‐shaped intermediate piles, each in different steel grades, which are given in the product catalogue of ArcelorMittal [1]. The test series executed and the subsequent setting‐up and validation of a numerical model are presented in detail in this paper. A numerical model was used for a parametric study. The different failure modes observed in this parametric study are presented. A statistical evaluation according to Annex D of EN 1990 [6] and Annex C of EN 1993‐1‐5 [8] leads to characteristic resistance values.
Buckling design of axially compressed steel silos on discrete supports
Authors: Jansseune Arne , Belis Jan , De Corte Wouter 
Published: February 2018

AbstractThis paper compares the buckling strengths derived from a validated shell‐based FEM model of discretely supported axially compressed silos with the interaction curves given in EN 1993‐1‐6 for axial compression. The buckling strengths were numerically determined for a wide range of geometries and yield strengths, considering two configuration types of discretely supported steel silos: with engaged columns and partial‐height U‐shaped longitudinal stiffeners. For these types, remarkably good correspondence was found between the numerical results of discretely supported steel silos and the interaction curves for uniformly compressed cylindrical steel silos, although unconservative in many cases.
Code‐Meshing and Writing Instruction in Multilingual Classrooms
Authors: Lee Alice Y. , Handsfield Lara J. 
Published: February 2018

AbstractClassrooms act as linguistic sieves when they continue to accept only dominant forms of English as the “correct” and “appropriate” language choice for all students. Students who speak other languages, such as African American Language or Spanish, are often encouraged to use those languages on the playground or at home but not in “official” spaces. This article interrogates such language practices by considering code‐meshing as an instructional approach that invites multiple languages within the classroom. The authors highlight the choices of teachers who encourage code‐meshing in their writing practices and offer pedagogical suggestions that can help teachers broaden their incorporation of all students' languages.
Procedural and obstetric outcomes after embryo reduction vs fetal reduction in multifetal pregnancy
Authors: Kim M. S. , Choi D. H. , Kwon H. , Ahn E. , Cho H. Y. , Baek M. J. , Shin J. E. , Moon M. J. 
Published: February 2018

ABSTRACTObjectiveTo compare the obstetric outcome and incidence of procedure‐related adverse events after embryo reduction (ER) vs fetal reduction (FR), in multifetal pregnancies undergoing reduction to twins or singletons.MethodsWe analyzed retrospectively data from multifetal pregnancies that underwent transvaginal ER (n = 181) at a mean gestational age of 7.6 weeks or transabdominal FR (n = 115) at a mean gestational age of 12.9 weeks between December 2006 and January 2017. FR was performed after a detailed fetal anomaly scan. The two groups were compared with respect to obstetric outcomes, such as incidence of miscarriage, early or late preterm delivery, maternal complications and fetal loss, and procedure‐related adverse events, including incidence of subchorionic hematoma and procedure‐related fetal loss.ResultsCompared with pregnancies that underwent ER, the incidence of procedure‐related fetal loss was lower in the FR group (7.2% vs 0.9%; P = 0.039; odds ratio (OR), 0.12; 95% CI, 0.02–0.89). Mean gestational age at delivery for twins was 34.2 weeks in the ER group and 35.7 weeks in the FR group (P = 0.014). Compared with the ER group, the FR group had lower miscarriage (8.8% vs 2.6%; P = 0.045; OR, 0.28; 95% CI, 0.08–0.97) and overall fetal loss (13.3% vs 5.2%; P = 0.031; OR, 0.36; 95% CI, 0.14–0.91) rates.ConclusionsThe FR procedure is, overall, a better and safer approach to reducing morbidity and mortality in multifetal pregnancies. Spontaneous demise of one fetus may occur after ER, and FR has the advantage that chorionic villus sampling and ultrasound screening for increased nuchal translucency and anatomical defects can be conducted before the procedure. The ER approach is still reasonable when a patient's religious or other ethical concerns are of primary importance. Copyright © 2018 ISUOG. Published by John Wiley & Sons Ltd.
Imaging in gynecological disease (13): clinical and ultrasound characteristics of endometrioid ovarian cancer
Authors: Moro F. , Magoga G. , Pasciuto T. , Mascilini F. , Moruzzi M. C. , Fischerova D. , Savelli L. , Giunchi S. , Mancari R. , Franchi D. , Czekierdowski A. , Froyman W. , Verri D. , Epstein E. , Chiappa V. , Guerriero S. , Zannoni G. F. , Timmerman D. , Scambia G. , Valentin L. , Testa A. C. 
Published: February 2018

ABSTRACTObjectiveTo describe the clinical and ultrasound characteristics of ovarian pure endometrioid carcinomas.MethodsThis was a retrospective multicenter study of patients with a histological diagnosis of pure endometrioid carcinoma. We identified 161 patients from the International Ovarian Tumor Analysis (IOTA) database who had undergone preoperative ultrasound examination by an experienced ultrasound examiner between 1999 and 2016, and another 78 patients from the databases of the departments of gynecological oncology in the participating centers. All tumors were described using IOTA terminology. In addition, one author reviewed all available ultrasound images and described them using pattern recognition.ResultsMedian age of the 239 patients was 55 years (range, 19–88 years). On ultrasound examination, two (0.8%) endometrioid carcinomas were described as unilocular cysts, three (1.3%) as multilocular cysts, 37 (15.5%) as unilocular‐solid cysts, 115 (48.1%) as multilocular‐solid cysts and 82 (34.3%) as solid masses. Median largest tumor diameter was 102.5 mm (range, 20–300 mm) and median largest diameter of the largest solid component was 63 mm (range, 9–300 mm). Papillary projections were present in 70 (29.3%) masses. Most cancers (188 (78.7%)) were unilateral. In 49 (20.5%) cases, the cancer was judged by the pathologist to develop from endometriosis. These cancers, compared with those without evidence of tumor developing from endometriosis, more often manifested papillary projections on ultrasound (46.9% (23/49) vs 24.7% (47/190)), were less often bilateral (8.2% (4/49) vs 24.7% (47/190)) and less often associated with ascites (6.1% (3/49) vs 28.4% (54/190)) and fluid in the pouch of Douglas (24.5% (12/49) vs 48.9% (93/190)). Retrospective analysis of available ultrasound images using pattern recognition revealed that many tumors without evidence of tumor developing from endometriosis (36.3% (41/113)) had a large central solid component entrapped within locules, giving the tumor a cockade‐like appearance.ConclusionsEndometrioid cancers are usually large, unilateral, multilocular‐solid or solid tumors. The ultrasound characteristics of endometrioid carcinomas developing from endometriosis differ from those without evidence of tumor developing from endometriosis, the former being more often unilateral cysts with papillary projections and no ascites. Copyright © 2018 ISUOG. Published by John Wiley & Sons Ltd.