bluuebunny/crossref_metadata_2025_split huggingface dataset:
Neuartige Methode zum Ermüdungsnachweis bestehender Straßenbrücken mittels Monitoring – Anwendungsbeispiel einer Straßenbrücke in der Schweiz
Authors: Touilbi Abdelhak , Brühwiler Eugen 
Published: February 2022

AbstractDer Regelermüdungsnachweis für Straßenbrücken nach Eurocode kann mit dem aus einem Einzelfahrzeug bestehenden Ermüdungslastmodell ELM3 und den sogenannten Schadensäquivalenzfaktoren λi geführt werden, ohne das aufwendige Ermüdungslastmodell ELM4 mit mehreren Fahrzeugtypen anwenden zu müssen. Allerdings unterliegt dieser Regelnachweis Einschränkungen. So können beispielsweise Brücken mit Stützweiten oder Einflusslinienlängen außerhalb des Intervalls [10 m – 80 m] nicht nachgewiesen werden. Darüber hinaus wird ein messdatengestützter Ermüdungsnachweis vorgestellt. Dabei kann der Schadenäquivalenzfaktor λ1 für Monitoringdaten berechnet und ausgewertet werden. Aufbauend auf dem vorliegenden Regelermüdungsnachweis nach Eurocode wird in diesem Beitrag eine Methode zum Ermüdungsnachweis vorgeschlagen, die auf der Tragwerksantwort der zu untersuchenden Bauwerke fußt. Mithilfe dieser Methode lässt sich der Schadenäquivalenzfaktor λ1 für beliebige Einflusslinienlängen und Monitoringspektren ohne Einschränkungen ermitteln.
Fault clustering by small‐entropy nonnegative matrix factorizations
Authors: Jia Qilong 
Published: February 2022

AbstractFault clustering attempts to partition a set of faulty samples into several clusters, allowing the exploration of the underlying pattern of faults. Nonnegative matrix factorizations (NMFs) are good candidates for fault clustering since they are inherently capable of data clustering and variants of the ‐means algorithm. However, NMFs always show poor performance in real‐world clustering applications for their naive data clustering mechanism. To improve the clustering performance of the existing NMFs and solve the fault clustering problem, this paper proposes a new type of NMFs, called small‐entropy nonnegative matrix factorizations (SENMFs). SENMFs impose a small amount of entropy on the cluster probability distribution of each sample to avoid ambiguous clustering results. Moreover, the algorithm for SENMFs is convergent in theory. We selected three types of faulty samples of the penicillin fermentation process for fault clustering. The case study results showed that SENMFs exceed the state‐of‐the‐art NMFs and ‐means in terms of fault clustering performance.
Covalently cross‐linked hydrogels: Mechanisms of nonlinear viscoelasticity
Authors: Kamkar Milad , Janmaleki Mohsen , Erfanian Elnaz , Sanati‐Nezhad Amir , Sundararaj Uttandaraman 
Published: February 2022

AbstractGelatin‐based hydrogels have been widely used in tissue engineering, three‐dimensional cell culture, drug delivery, and cell therapy. The mechanical behaviour of hydrogels combined with their chemical properties determines their functionality and efficacy. With respect to the mechanical behaviour of hydrogels, the vast majority of publications have reported their linear viscoelastic response. However, for practical conditions in the body, these materials experience large deformations beyond the linear viscoelastic limit. Herein, to mimic practical conditions and to evaluate the mechanical response of the hydrogels subjected to large deformations, we report inter‐ and intra‐cycle nonlinear viscoelastic behaviour of a gelatin methacryloyl (GelMA) hydrogel with different concentrations of the hydrogel precursor (10%–20% [w/v]) under large amplitude oscillatory shear deformation. To achieve this, we used a novel technique by chemically bonding the hydrogels to treated glass slides, which were attached to the oscillating metal plates using a double‐sided tape to alleviate any error arising from wall slip during rheological measurements. The results show that the elasticity of the covalently cross‐linked hydrogels at large deformations obeys a nonlinear force‐extension law and that the viscous intra‐cycle nonlinearity at moderate deformations stems from the dual cross‐linked (DC; i.e., physical and chemical) nature of the GelMA hydrogel. It was also shown that viscoelastic parameters can be tuned by the concentration of the hydrogel precursor, that is, yield stress increased from 2.6–7.1 kPa, critical strain amplitude decreased from γ0 = 100%–70%, and the onset of inter‐cycle nonlinearity shifted from γ0 = 50%–20% upon increasing the concentration of the hydrogel precursor. These insights have important implications for the rational development of hydrogel‐based biomaterials to design biocompatible scaffolds in tissue engineering applications.
Erschließung geothermischer Lagerstätten mittels Hochdruck‐Wasserstrahl Bohrtechnik
Authors: Hahn Simon , Polat Berker , Jamali Shahin , Wittig Volker , Bracke Rolf 
Published: February 2022

AbstractHigh‐pressure water jet drilling technologies are widely used in the drilling industry. Especially in geothermal and hard rock applications, jet drilling is, however, confronted with several limitations like lateral length, hole size, steerability and jetability of the reservoir rock. The application of jet drilling technologies in the field can only be estimated based on the experience of the operator and surface experiments imitating downhole conditions. To predict a successful jetting operation in the field, a modelling framework has been developed, which considers operational and technical parameters as well as reservoir rock specifications. The framework consists of calibrated models describing downhole hydraulics and mechanics during the jetting operation and estimates the required technical equipment to successfully penetrate the reservoir rock and the maximum achievable lateral length for various hole configurations. The modelling framework is applied on a theoretical case study.
Geomechanische Reservoircharakterisierung in Bayern im Rahmen der Geothermie‐Allianz Bayern
Authors: Potten Martin , Bohnsack Daniel , Käsling Heiko , Thuro Kurosch 
Published: February 2022

AbstractTo increase the use of geothermal energy in Bavaria, the subsurface, which serves as a reservoir, must be explored as precisely as possible. In the projects of the Geothermal‐Alliance Bavaria, the most promising areas for geothermal exploration in Bavaria were characterised based on an extensive geomechanical laboratory testing program which was carried out on both drill cores and analogue samples from quarries. In the North Alpine Foreland Basin (SE Germany), the geomechanical test results on Upper Jurassic carbonate rocks show a high heterogeneity. On the contrary, in the Franconian Basin (NE Bavaria) the geomechanical properties of granite analogues are rather homogenous. For the numerical simulation of the borehole stability, the determined parameters from ultrasonic‐ and compression tests serve as input parameters for different scenarios. For both locations, the determination of the failure depth around the borehole and the stress distribution in the near‐field of the borehole were accomplished. In the North Alpine Foreland Basin, the borehole stability decreases with increasing depth. For all scenarios in NE Bavaria, the borehole stability is very low. In the future, the determined parameter ranges will allow to validate already existing models and to develop new ones. This will enable a better knowledge of the sedimentary and crystalline reservoirs and a more effective use of geothermal energy in Bavaria.
Strukturdominierte Reaktion des geothermischen Reservoirs während Stützmitteleintrag in Geretsried, Bayern
Authors: Backers Tobias , Kahnt René , Stockinger Georg 
Published: February 2022

AbstractAs a source of sustainable, renewable, and clean energy, deep geothermal systems increasingly gain importance for the energy transition. In Germany, the North Alpine Foreland Basin is the success story for hydrothermal systems. Besides successful projects in the Munich area, recent attempts to establish successfully operating geothermal wells southwards, e.g., in Geretsried, failed due to a lack of permeability of the rock mass. Subsequent research in Geretsried found that all existing discontinuities are low to non‐productive. The current project ZoKrateS, rethinking the Geretsried reservoir being a petrothermal play, bypasses these limitations by stimulating the existing fractures, and trying to keep them conductive by embedding proppants that prevent full closure. Four detached sections of the well GEN‐1ST‐A1 were subject to individual stages of stimulation. These four sections have been stimulated by placing proppants at injection pressures below the in‐situ least principal stress at no microseismic activity. After injection the communication between well and formation appeared to be increased. Although data processing is still ongoing, linear correlations between cumulative injected volume and quasi‐static pressure may be interpreted as channel flow within highly disturbed rock masses at intersections of faults. The high elasticity of these sections enables even low pressure to cause discontinuity opening below the least principal stress.
Einsatz einer Knautschzone bei der Sanierung des Gotschnatunnels, Klosters (CH)
Authors: Tschötschel Marco , Balthaus Hansgeorg , Beeler Patrick , Schwalt Markus , Seith Oliver 
Published: February 2022

AbstractDuring the renovation of the Gotschna Tunnel from 2019 to 2020, prefabricated elements made of Compex were used for the first time as a deformable yielding zone in the invert zone. The client, construction management, construction company and supplier of the compressible elements worked closely together to implement the design specifications. Consequently, the expectations of the special building material in terms of the production quality of the prefabricated elements and handling on the construction site were more than met. The parties involved in the construction thus see potential for further applications and further developments of Compex.
Groundwater recharge over the past 100 years: Regional spatiotemporal assessment and climate change impact over the Saguenay‐Lac‐Saint‐Jean region, Canada
Authors: Boumaiza Lamine , Walter Julien , Chesnaux Romain , Lambert Mélanie , Jha Madan Kumar , Wanke Heike , Brookfield Andrea , Batelaan Okke , Galvão Paulo , Laftouhi Nour‐Eddine , Stumpp Christine 
Published: February 2022

AbstractProper knowledge of potential groundwater recharge (PGR) and its spatiotemporal distribution are essential for sustainable groundwater management, especially within the context of climate change. Here, a robust GIS‐based water budget framework was developed to estimate PGR at a regional scale and map its spatial distribution. This framework is demonstrated over the Saguenay‐Lac‐Saint‐Jean region (13 200 km2) of Quebec (Canada). The PGR mapping process was based on a model incorporating water budget components. The vertical inflows (VI) include water amounts from rainfall and snowmelt, whereby the latter was assessed using HYDROTEL model. VI were combined with the maximum and minimum temperatures to estimate actual evapotranspiration (AET), while the surface runoff (RuS) was assessed using the curve number method. Field observations of annual variation in temperatures and the water budget components, over a period of 100 years (1910–2009), were used to provide a comprehensive overview of the effects of climate change on PGR. The last 10 years of the observation period (i.e., 2000–2009) indicate that 6% of the study area has PGR rates of 35%–50%. PGR rates of 20%–35% occur in 58% of the study area, while 36% have PGR of 5%–20%. The trend analysis of temperature time series reveals an average of 1.1 ± 0.6°C increase over 100 years. Also, an increase in the water budget components is observed. Despite the increasing trends of RuS and AET, PGR still showed an increasing trend with an average increase of 0.7 ± 0.4 mm/year over the past 100 years. This observation indicates that the increase in VI was enough to compensate for the increases in AET and RuS. This finding of an increasing PGR in the study area provides useful information for future studies focusing on predicting long‐term PGR evolution and for the development of efficient long‐term groundwater management strategies.
Identifying factor‐augmented vector autoregression models via changes in shock variances
Authors: Yamamoto Yohei , Hara Naoko 
Published: February 2022

SummaryThis study proposes a method to identify factor‐augmented vector autoregression models without imposing uncorrelatedness or any timing restrictions among observed and unobserved factors in the vector autoregression system. To this end, we utilize changes in unconditional shock variances following Rigobon (2003). The proposed method can incorporate both observed and unobserved factors in the structural vector autoregression system and allows the contemporaneous matrix to be fully unrestricted. We derive the asymptotic distribution of the impulse response estimator and consider a bootstrap inference method. We also provide two diagnostic tools: a test for the identification condition and a class of overidentifying restrictions tests. A Monte Carlo experiment shows that the asymptotic and bootstrap methods yield a satisfactory coverage rate when the shock of an observed factor is analyzed, although the bootstrap method is more accurate. We apply the proposed method to an empirical example for the effects of U.S. monetary policies on asset prices. A contractionary monetary policy shock induces positive and hump‐shaped interest rate responses along the maturity dimension and negative but insignificant stock price responses.
Physicochemical properties and sensory evaluation of a bean‐based composite soup flour
Authors: Kambabazi Marie‐Rose , Okoth Michael Wandayi , Ngala Sophia , Njue Lucy , Vasanthakaalam Hilda 
Published: February 2022

AbstractA bean‐based composite soup flour (CSF) containing red kidney beans, sweet potatoes, amaranth leaves, and carrots was developed using Nutrisurvey software to choose four nutritious CSFs, which were then subjected to sensory evaluation to select the most preferred CSF by mothers with young children. The top‐ranked bean‐based CSF was then analyzed for energy, proximate composition, and selected mineral/vitamin content. Additionally, swelling capacity, water and oil absorption capacity, emulsion activity/stability, foaming capacity/stability, gelatinization temperature, and least gelatinization concentration were determined. The optimum quality CSF was composed of 70% red kidney beans, 15% amaranth leaves, 10% sweet potatoes, and 5% carrots. The compositional and energy analysis showed that the selected CSF had 20.58% protein, 59% carbohydrates, 2.93% fat, 3.38% fiber, 8.95% moisture, 5.08% ash, and 344.9 kcal/100 g energy. The mineral and vitamins contents of CSF per 100 g were 216.2, 1.14, 3.83, and 32.83 mg for calcium, zinc, iron, and magnesium, respectively; 3.55 mg for vitamin A; and 166.36 mg vitamin C. Vitamins B2, B5, B6, B9, and B12 were 0.57, 3.53, 0.27, 0.07, and 0.02 mg/100 g, respectively. Functional properties determined were 31.5 ml (swelling capacity), 70.5% (water absorption capacity), 28% (oil absorption capacity), 25%, 18% (emulsion activity), 18% (emulsion stability), 15% (foam capacity), 33.4% (foam stability), 88.5°C (gelatinization temperature), and 10% (least gelation concentration). Consumption of the formulated CSF can nearly meet the dietary reference intake (DRI) of children aged 1–3 years in determined nutrients except for fiber. The developed bean‐based CSF can be used to improve dietary diversity and reduce malnutrition especially for young children.
On the 2‐Wasserstein distance for self‐similar measures on the unit interval
Authors: Brawley Easton , Doyle Mason , Niedzialomski Robert 
Published: February 2022

AbstractWe obtain a lower and an upper bound for the 2‐Wasserstein distance between self‐similar measures associated to two increasing non‐overlapping linear contractions of the unit interval. We use a method of approximation of the measures via iterations of the Hutchinson operator on a delta Dirac measure. This allows us to obtain explicit estimates for the 2‐Wasserstein distance between the approximating measures. We use these bounds to obtain the bounds for the distance between the self‐similar measures.
Slip resistance of bolted joints with slotted holes
Authors: Dörre M. , Glienke R. , Schwarz M. , Henkel K.‐H. 
Published: February 2022

AbstractGleitfest vorgespannte Schraubenverbindungen kommen überall dort zum Einsatz, wo zyklische Beanspruchungen auf Schraubenverbindungen wirken und aus Ermüdungsfestigkeitsgründen reibschlüssig übertragen werden müssen. Die Bemessung sowie die Nachweisführung dieser Verbindungen sind weitestgehend durch bestehende Normen und Regelwerke zu realisieren. Allerdings bestehen für Langlöcher sowie übergroße Rundlöcher nach wie vor offene Fragestellungen in der Nachweisführung. Diese werden notwendig um Fertigungstoleranzen kostengünstig auszugleichen. Im Rahmen eines öffentlich geförderten Forschungsprojektes (AiF‐Nr.: 18608BR) wurde u. a. der Fragestellung größerer Nennlochspiele und deren Einfluss auf die Tragwirkung hochfest vorgespannter Schraubverbindungen nachgegangen [1]. Dazu wurden die verschiedenen Regelwerke vergleichend gegenübergestellt. Anschließend wurden experimentelle Untersuchungen zum Einfluss der Lochgeometrie auf den Gleitwiderstand durchgeführt. Aus den Erkenntnissen wurden schlussendlich Empfehlungen für den Konstruktions‐ und Berechnungsingenieur abgeleitet.
Research on the enhancement of signal‐to‐noise ratio by radio frequency white noise in compact dense‐pattern multipass cell for trace gas detection
Authors: Tian Xing , Cheng Gang , Chen Jiajin , Liu Kun 
Published: February 2022

AbstractThe number of reflections is increased as much as possible in the optical multi‐pass absorption cell to improve the effective optical path, but easily affected by light overlap resulting in light path interference. We present a novel strategy for suppressing the optical interference and improving the signal‐to‐noise ratio (SNR) with the radio frequency (RF) bandwidth‐limited white noise. A linear output spectral response of the intensity with the CH4 concentration between 50 ppmv and 180 ppmv with a distributed feedback laser (DFB) at 1.653 μm was observed. The results show that the addition of RF noise effectively increases the laser line width and improves the SNR. About 3.6 gain in the SNR has been achieved using the RF noise, which led to a minimum detectable concentration of 0.03 ppmv (SNR = 1573). This performance level can reduce the difficulty of light adjustment and is very suitable for applications to trace gas sensing in harsh environment.
An insight into tapioca and wheat starch gelatinization mechanisms using TD‐NMR and complementary techniques
Authors: Rakhshi Elham , Cambert Mireille , Diascorn Yves , Lucas Tiphaine , Rondeau‐Mouro Corinne 
Published: February 2022

AbstractTo provide evidence for previously proposed assumptions concerning starch gelatinization sub‐mechanisms, a more detailed investigation was carried out using multiscale analysis of a starch type selected for its marked difference. Tapioca starch was chosen due to its cohesive/springy properties and its growing use in the food industry. Time‐domain nuclear magnetic resonance (TD‐NMR) was used to investigate the leaching of material, water absorption and crystallite melting in hydrated tapioca starch (45%). The interpretation of T2 mass intensity evolutions, especially those of the (intra‐ and extra‐granular) aqueous phases, was discussed drawing on complementary techniques such as microscopy, Rapid Visco Analyser (RVA), differential scanning calorimetry (DSC) and swelling factor (SF) and solubility index (SI) measurements. Results show that the T2 assignments usually proposed in the literature are dependent on starch origin. The differences in T2 evolutions (value and mass intensity) observed between wheat and tapioca starches at intermediate hydration levels could be linked to the different gelatinization behaviour of tapioca starch involving the latter's higher granule rupture level, higher gelatinization temperature and greater swelling power above its gelatinization temperature.
Neighbor Q‐learning based consensus control for discrete‐time multi‐agent systems
Authors: Zhu Xiaoxia , Yuan Xin , Dong Lu , Wang Yuanda , Sun Changyin 
Published: February 2022

AbstractThe neighbor Q‐learning based consensus control algorithm is developed for discrete‐time multi‐agent systems in this article. To realize the proposed algorithm, a new actor‐critic architecture is employed for each agent. The critic network of each agent approximates its Q‐function while the actor network produces control signal by minimizing the Q‐function. Considering the distribution metrics of the systems, the neighbors' Q‐functions of each agent are applied to the update procedure of the critic network to stabilize the learning process and avoid the overestimation problem. The convergence properties and stability analysis for the proposed algorithm are provided. Different discount factors corresponding to various topology structures are discussed in the convergence analysis section. The accurate system model is nonessential for the algorithm which is too intricate to build up for practical systems. Finally, three simulation examples including different discount factors are conducted to demonstrate the effectiveness of the consensus control algorithm.
Assessing the inter‐rater and intra‐rater reliability of the Physical Therapy Competence Assessment for Airway Suctioning (PT‐CAAS)
Authors: Miller Erin , Brooks Dina , O’Brien Kelly K. , Beavers Lindsay , Stratford Paul , Nonoyama Mika , Mori Brenda 
Published: February 2022

AbstractBackground and PurposeThe Physical Therapy Competence Assessment for Airway Suctioning (PT‐CAAS) is a recently developed measure to assess the clinical competence of physiotherapists who perform airway suctioning with adults. The purpose of this study was to assess the inter‐rater and intra‐rater reliability of the PT‐CAAS.MethodsScoring rules were developed through expert consultation. Reliability was then assessed using nine videos of suctioning performed in a simulated learning environment. A repeated measures design was used, with two replicate sets of measurements made by each participant for all videos. Data were analyzed using a repeated measures model for the concurrent assessment of inter‐rater and intra‐rater reliability. Participants were physiotherapists with suctioning experience.ResultsTwenty physiotherapists completed initial scoring and re‐scoring for all nine videos; their data were included in the analysis. Intraclass correlation coefficients (ICCs) for inter‐rater reliability ranged from 0.569 [lower one‐sided 95% confidence interval (CI): 0.395; standard error of measurement (SEM): 0.963] for infection control to 0.759 (lower one‐sided 95% CI: 0.612; SEM: 0.722) for post‐suctioning assessment and care. The inter‐rater ICC for overall performance was 0.752 (lower one‐sided 95% CI: 0.602; SEM: 0.660). ICCs for intra‐rater reliability ranged from 0.759 (lower one‐sided 95% CI: 0.197; SEM 0.721) for infection control to 0.860 (lower one‐sided 95% CI: 0.544; SEM: 0.550) for post‐suctioning assessment and care. The intra‐rater ICC for overall performance was 0.867 (lower one‐sided 95% CI: 0.559; SEM: 0.483).DiscussionEvidence of moderate to good inter‐rater and good intra‐rater reliability was found; however, the results should be interpreted with caution given the wide CIs and relatively large SEMs. Improved assessor training and assessments of reliability using a larger sample size are recommended.