bluuebunny/crossref_metadata_2025_split huggingface dataset:
Theory-assisted optical ray tracing to extract cavitation-bubble shapes from experiment
Authors: Koch Max , Rosselló Juan M. , Lechner Christiane , Lauterborn Werner , Eisener Julian , Mettin Robert 
Published: March 2021

AbstractExperimental analysis of cavitation bubble dynamics typically uses optical imaging and photographic recording. However, the images are often severely affected by distortions and shadows due to refraction and total reflection of the illuminating light at the liquid–gas interface of the bubble. Optical ray tracing may become a powerful tool for the analysis process by assisting in the comparison of experiments to numerical two-phase flow simulations. The novelty of the present approach consists in digitizing almost the complete experimental arrangement with all its optically relevant elements and objects—including a numerical model of the yet unknown bubble—and numerically photographing the scene via ray tracing. The method is applied to the jetting dynamics of single bubbles collapsing at a solid wall. Here, ray tracing can help in the interpretation of raw experimental data concerning the complex bubble interface deformations and internal structures during the collapse. The precise shape of the highly dynamical bubbles can be inferred, thus ray tracing provides a correction method for velocity values of the liquid jets. Strong evidence is found for the existence of an ultra-short-time, fast jet, exceeding velocities known to date in the field.Graphic abstract
Quenched local limit theorem for random walks among time-dependent ergodic degenerate weights
Authors: Andres Sebastian , Chiarini Alberto , Slowik Martin 
Published: March 2021

AbstractWe establish a quenched local central limit theorem for the dynamic random conductance model on $${\mathbb {Z}}^d$$

Z

d

only assuming ergodicity with respect to space-time shifts and a moment condition. As a key analytic ingredient we show Hölder continuity estimates for solutions to the heat equation for discrete finite difference operators in divergence form with time-dependent degenerate weights. The proof is based on De Giorgi’s iteration technique. In addition, we also derive a quenched local central limit theorem for the static random conductance model on a class of random graphs with degenerate ergodic weights.
A solution framework for linear PDE-constrained mixed-integer problems
Authors: Gnegel Fabian , Fügenschuh Armin , Hagel Michael , Leyffer Sven , Stiemer Marcus 
Published: March 2021

AbstractWe present a general numerical solution method for control problems with state variables defined by a linear PDE over a finite set of binary or continuous control variables. We show empirically that a naive approach that applies a numerical discretization scheme to the PDEs to derive constraints for a mixed-integer linear program (MILP) leads to systems that are too large to be solved with state-of-the-art solvers for MILPs, especially if we desire an accurate approximation of the state variables. Our framework comprises two techniques to mitigate the rise of computation times with increasing discretization level: First, the linear system is solved for a basis of the control space in a preprocessing step. Second, certain constraints are just imposed on demand via the IBM ILOG CPLEX feature of a lazy constraint callback. These techniques are compared with an approach where the relations obtained by the discretization of the continuous constraints are directly included in the MILP. We demonstrate our approach on two examples: modeling of the spread of wildfire and the mitigation of water contamination. In both examples the computational results demonstrate that the solution time is significantly reduced by our methods. In particular, the dependence of the computation time on the size of the spatial discretization of the PDE is significantly reduced.
Energy flow characteristics of friction-induced nonlinear vibrations in a water-lubricated bearing-shaft coupled system
Authors: Qin Li , Qin Hongling , Xing Jing Tang 
Published: March 2021

Abstract
Based on the energy flow theory of nonlinear dynamical system, the stabilities, bifurcations, possible periodical/chaotic motions of nonlinear water-lubricated bearing-shaft coupled systems are investigated in this paper. It is revealed that the energy flow characteristics around the equlibrium point of system behaving in the three types with different friction-paramters. (a) Energy flow matrix has two negative and one positive energy flow factors, constructing an attractive local zero-energy flow surface, in which free vibrations by initial disturbances show damped modulated oscillations with the system tending its equlibrium state, while forced vibrations by external forces show stable oscillations. (b) Energy flow matrix has one negative and two positive energy flow factors, spaning a divergence local zero-energy flow surface, so that the both free and forced vibrations are divergence oscillations with the system being unstable. (c) Energy flow matrix has a zero-energy flow factor and two opposite factors, which constructes a local zero-energy flow surface dividing the local phase space into stable, unstable and central subspace, and the simulation shows friction self-induced unstable vibrations for both free and forced cases. For a set of friction parameters, the system behaves a periodical oscillation, where the bearing motion tends zero and the shaft motion reaches a stable limit circle in phase space with the instant energy flow tending a constant and the time averaged one tending zero. Numerical simulations have not found any possible chaotic motions of the system. It is discovered that the damping matrices of cases (a), (b) and (c) respectively have positive, negative and zero diagonal elements, resulting in the different dynamic behavour of system, which gives a giderline to design the water-lubricated bearing unit with expected performance by adjusting the friction parameters for applications.

Graphic Abstract
Unsteady Effects on NOx Measurements in Pulse Detonation Combustion
Authors: Hanraths Niclas , Bohon Myles D. , Paschereit Christian Oliver , Djordjevic Neda 
Published: March 2021

AbstractEmission measurements from unsteady combustion systems such as Pulse Detonation Combustion (PDC) are challenging due to the inherently large variations in pressure, temperature, composition, and flow velocity of the exhaust gas. Comparison of experimental data is additionally complicated by differences in operating conditions and gas sampling setup between different facilities. Qualitative considerations with regard to the sampling process from PDC, based on one-dimensional simulations, indicate a systematic influence of the sampling setup and extraction process on the resulting concentration measurements. Therefore, operating frequency, sample time, fill time, as well as PDC outlet and probe geometry were varied experimentally in order to assess the degree to which each of these parameters impact the resulting measured $${\rm NO}_{\rm x}$$

NO
x

in order to better inform researchers of these effects when making measurements. It was shown that measured $${\rm NO}_{\rm x}$$

NO
x

emissions can vary significantly depending on the choice of these parameters and therefore care must be exercised in order to reduce the influence of the sampling technique when aiming for comparable results.
Assessing population collapse of Drupella spp. (Mollusca: Gastropoda) 2 years after a coral bleaching event in the Republic of Maldives
Authors: Saponari L. , Dehnert I. , Galli P. , Montano S. 
Published: March 2021

AbstractCorallivory causes considerable damage to coral reefs and can exacerbate other disturbances. Among coral predators, Drupella spp. are considered as delayer of coral recovery in the Republic of Maldives, although little information is available on their ecology. Thus, we aimed to assess their population structure, feeding behaviour and spatial distribution around 2 years after a coral bleaching event in 2016. Biological and environmental data were collected using belt and line intercept transects in six shallow reefs in Maldives. The snails occurred in aggregations with a maximum of 62 individuals and exhibited a preference for branching corals. Yet, the gastropods showed a high plasticity in adapting feeding preferences to prey availability. Drupella spp. were homogenously distributed in the study area with an average of 9.04 ± 19.72 ind/200 m2. However, their occurrence was significantly different at the reef scale with the highest densities found in locations with higher coral cover. The impact of Drupella spp. appeared to be minimal with the population suffering from the loss of coral cover. We suggest that monitoring programs collect temporal- and spatial-scale data on non-outbreaking populations or non-aggregating populations to understand the dynamics of predation related to the co-occurrence of anthropogenic and natural impacts.
Electrical conductivity determination of semiconductors by utilizing photography, finite element simulation and resistance measurement
Authors: Wang Rui , Moos Ralf 
Published: March 2021

AbstractA new method is developed to measure precisely and reliably the electrical conductivity of a block-shaped semiconductor specimen using four-wire technique with electrodes in arbitrary shape and position. No effort for accurate electrode preparation is necessary anymore. This method may be especially applied to measure the conductivity of ceramics at high temperatures, when typical spring-contacts or clamp-contacts are not possible and instead wound wires are used for electrically contacting the specimen. The method comprises the following: An image of the specimen is processed to a 3D model. By applying a finite element simulation on this 3D model, a form factor (also called geometry factor) that considers the effect of the non-infinitesimally small electrodes is calculated. Together with the measured resistance (preferably in four-wire technique), the actual conductivity of the sample is derived. Experimental results confirmed the validity of the proposed method. As a limitation of the method, the conductivity of the specimen should be within the range of 0.01 Sm−1 and 106 Sm−1.
Micro dynamics and macro stability in inventor networks
Authors: Fritsch Michael , Kudic Muhamed 
Published: March 2021

AbstractFrom a macro perspective, inventor networks tend to generate remarkably stable structures over time. At the same time, we observe highly dynamic processes at the micro level, in terms of inventor entries and exits as well as formations and terminations of collaborative relationships between them. In order to explain this—at least at the first glance—contradicting pattern, we investigate processes at the intermediate network level. Our analysis draws upon co-patenting data for the entire population of West German inventors in the field of laser technology research from the onset of the technology in the early 1960s over a period of 45 years. Our findings suggest that the key factor for maintaining structural stability of networks is that directly linked partners of inventors with stabilizing properties—so-called ‘key players’—take over this function in a subsequent period. We show that processes at the intermediate network level provide new insights on the co-existence of micro fluidity and macro stability in complex adaptive systems.
Effect of Nanog overexpression on the metastatic potential of a mouse melanoma cell line B16-BL6
Authors: Saito Mikako , Kishi Ryota , Sasai Tomoko , Hatakenaka Tomohiro , Matsuki Nahoko , Minagawa Seiya 
Published: March 2021

AbstractNanog, a marker and regulator of the undifferentiated state in embryonic stem cells were anticipated to be an effective enhancer of cancer metastasis. We have developed a Nanog overexpressing mouse melanoma cell line B16-BL6 (BL6). BL6 was well recognized as a cell line with a high metastatic potential. In vitro tests revealed the enhancement of cell proliferation, wound healing activity, and matrix metalloproteinase 9 (MMP9) activity. Nanog-induced up- or down-regulated genes were comprehensively analyzed by transcriptome sequencing using Nanog+BL6 and wild-type BL6. Principally, up-regulated genes were involved in vesicle-aided glucose transport and oxidative phosphorylation, while down-regulated genes were associated with immunosuppression and apoptosis. A marked finding was that TGF-β1 was down-regulated, because TGF-β1 has been well discussed about its suppressive/progressive dual role in cancer. In vivo test showed that the number and volume of metastatic colonies of BL6 to lung were as high as 115 colonies/lung and 5.6 mm3/lung. Under this condition, Nanog overexpression caused a progressive effect (150 colonies/lung, p = 0.25; 9.2 mm3/lung, p = 0.13) rather than a suppressive effect on the metastasis. In this study, the effectiveness of Nanog overexpression in enhancing the metastatic potential of melanoma cell lines has been demonstrated for the first time.
Advancing the Water Footprint into an Instrument to Support Achieving the SDGs – Recommendations from the “Water as a Global Resources” Research Initiative (GRoW)
Authors: Berger Markus , Campos Jazmin , Carolli Mauro , Dantas Ianna , Forin Silvia , Kosatica Ervin , Kramer Annika , Mikosch Natalia , Nouri Hamideh , Schlattmann Anna , Schmidt Falk , Schomberg Anna , Semmling Elsa 
Published: March 2021

AbstractThe water footprint has developed into a widely-used concept to examine water use and resulting local impacts caused during agricultural and industrial production. Building on recent advancements in the water footprint concept, it can be an effective steering instrument to support, inter alia, achieving sustainable development goals (SDGs) - SDG 6 in particular. Within the research program “Water as a Global Resource” (GRoW), an initiative of the Federal Ministry for Education and Research, a number of research projects currently apply and enhance the water footprint concept in order to identify areas where water is being used inefficiently and implement practical optimization measures (see imprint for more information). With this paper, we aim to raise awareness on the potential of the water footprint concept to inform decision-making in the public and private sectors towards improved water management and achieving the SDGs.
Reliability-based design and implementation of crow search algorithm for longitudinal dispersion coefficient estimation in rivers
Authors: Ghaemi Alireza , Zhian Tahmineh , Pirzadeh Bahareh , Hashemi Monfared Seyedarman , Mosavi Amir 
Published: March 2021

AbstractThe longitudinal dispersion coefficient (LDC) of river pollutants is considered as one of the prominent water quality parameters. In this regard, numerous research studies have been conducted in recent years, and various equations have been extracted based on hydrodynamic and geometric elements. LDC’s estimated values obtained using different equations reveal a significant uncertainty due to this phenomenon’s complexity. In the present study, the crow search algorithm (CSA) is applied to increase the equation’s precision by employing evolutionary polynomial regression (EPR) to model an extensive amount of geometrical and hydraulic data. The results indicate that the CSA improves the performance of EPR in terms of R2 (0.8), Willmott’s index of agreement (0.93), Nash–Sutcliffe efficiency (0.77), and overall index (0.84). In addition, the reliability analysis of the proposed equation (i.e., CSA) reduced the failure probability (Pf) when the value of the failure state containing 50 to 600 m2/s is increasing for the Pf determination using the Monte Carlo simulation. The best-fitted function for correct failure probability prediction was the power with R2 = 0.98 compared with linear and exponential functions.
A Regularized LSTM Method for Predicting Remaining Useful Life of Rolling Bearings
Authors: Liu Zhao-Hua , Meng Xu-Dong , Wei Hua-Liang , Chen Liang , Lu Bi-Liang , Wang Zhen-Heng , Chen Lei 
Published: March 2021

AbstractRotating machinery is important to industrial production. Any failure of rotating machinery, especially the failure of rolling bearings, can lead to equipment shutdown and even more serious incidents. Therefore, accurate residual life prediction plays a crucial role in guaranteeing machine operation safety and reliability and reducing maintenance cost. In order to increase the forecasting precision of the remaining useful life (RUL) of the rolling bearing, an advanced approach combining elastic net with long short-time memory network (LSTM) is proposed, and the new approach is referred to as E-LSTM. The E-LSTM algorithm consists of an elastic mesh and LSTM, taking temporal-spatial correlation into consideration to forecast the RUL through the LSTM. To solve the over-fitting problem of the LSTM neural network during the training process, the elastic net based regularization term is introduced to the LSTM structure. In this way, the change of the output can be well characterized to express the bearing degradation mode. Experimental results from the real-world data demonstrate that the proposed E-LSTM method can obtain higher stability and relevant values that are useful for the RUL forecasting of bearing. Furthermore, these results also indicate that E-LSTM can achieve better performance.
Emergency room comprehensive assessment of demographic, radiological, laboratory and clinical data of patients with COVID-19: determination of its prognostic value for in-hospital mortality
Authors: Gatti Marco , Calandri Marco , Biondo Andrea , Geninatti Carlotta , Piatti Clara , Ruggirello Irene , Santonocito Ambra , Varello Sara , Bergamasco Laura , Bironzo Paolo , Boccuzzi Adriana , Brazzi Luca , Caironi Pietro , Cardinale Luciano , Cavallo Rossana , Riccardini Franco , Limerutti Giorgio , Veltri Andrea , Fonio Paolo , Faletti Riccardo 
Published: March 2021

AbstractMortality risk in COVID-19 patients is determined by several factors. The aim of our study was to adopt an integrated approach based on clinical, laboratory and chest x-ray (CXR) findings collected at the patient’s admission to Emergency Room (ER) to identify prognostic factors. Retrospective study on 346 consecutive patients admitted to the ER of two North-Western Italy hospitals between March 9 and April 10, 2020 with clinical suspicion of COVID-19 confirmed by reverse transcriptase-polymerase reaction chain test (RT-PCR), CXR performed within 24 h (analyzed with two different scores) and recorded prognosis. Clinical and laboratory data were collected. Statistical analysis on the features of 83 in-hospital dead vs 263 recovered patients was performed with univariate (uBLR), multivariate binary logistic regression (mBLR) and ROC curve analysis. uBLR identified significant differences for several variables, most of them intertwined by multiple correlations. mBLR recognized as significant independent predictors for in-hospital mortality age > 75 years, C-reactive protein (CRP) > 60 mg/L, PaO2/FiO2 ratio (P/F) < 250 and CXR “Brixia score” > 7. Among the patients with at least two predictors, the in-hospital mortality rate was 58% against 6% for others [p < 0.0001; RR = 7.6 (4.4–13)]. Patients over 75 years had three other predictors in 35% cases against 10% for others [p < 0.0001, RR = 3.5 (1.9–6.4)]. The greatest risk of death from COVID-19 was age above 75 years, worsened by elevated CRP and CXR score and reduced P/F. Prompt determination of these data at admission to the emergency department could improve COVID-19 pretreatment risk stratification.
Therapy options for adrenal insufficiency and recommendations for the management of adrenal crisis
Authors:   On Behalf of Endo ERN (MTG1), Nowotny Hanna , Ahmed S. Faisal , Bensing Sophie , Beun Johan G. , Brösamle Manuela , Chifu Irina , Claahsen van der Grinten Hedi , Clemente Maria , Falhammar Henrik , Hahner Stefanie , Husebye Eystein , Kristensen Jette , Loli Paola , Lajic Svetlana , Reisch Nicole 
Published: March 2021

AbstractAdrenal insufficiency (AI) is a life-threatening condition requiring life-long glucocorticoid (GC) substitution therapy, as well as stress adaptation to prevent adrenal crises. The number of individuals with primary and secondary adrenal insufficiency in Europe is estimated to be 20–50/100.000. A growing number of AI cases are due to side effects of GC treatment used in different treatment strategies for cancer and to immunotherapy in cancer treatment. The benefit of hormone replacement therapy is evident but long-term adverse effects may arise due to the non-physiological GC doses and treatment regimens used. Given multiple GC replacement formulations available comprising short-acting, intermediate, long-acting and novel modified-release hydrocortisone as well as subcutaneous formulations, this review offers a concise summary on the latest therapeutic improvements for treatment of AI and prevention of adrenal crises. As availability of various glucocorticoid formulations and access to expert centers across Europe varies widely, European Reference Networks on rare endocrine conditions aim at harmonizing treatment and ensure access to specialized patient care for individual case-by-case treatment decisions. To improve the availability across Europe to cost effective oral and parenteral formulations of hydrocortisone will save lives.
Urologic, lymphedema, pelvic pain and gastrointestinal symptoms increase after radiotherapy in patients with primary uterine tumors: a prospective longitudinal Swedish cohort study
Authors: Holmqvist A. , Axelsson A. , Mikivier R. , Redelius K. , Odelram Wiréen U. , Uppugunduri S. 
Published: March 2021

Abstract
Purpose
Radiotherapy (RT) causes an inflammatory reaction of the tissue which leads to fibrosis and reduced functioning of the pelvic organs. Few studies have shown significant relationships between side effects and RT in uterine tumors. Here, the urological, lymphedema, pelvic pain and gastrointestinal (GI) symptoms were studied before and after RT in patients with primary uterine tumors using the EORTC QLQ-EN24, specifically designed for uterine cancer patients.

Methods
This prospective cohort study comprised patients with primary uterine tumors who received pelvic radiotherapy (RT). A total of 43 patients were included from May 2014 to February 2019. Patients completed the questionnaires for global health status and functioning before the start of RT and at 3 and 12 months after RT.

Results
We found a significant worsening of the urological symptoms 3 months after RT which persisted up to 12 months after RT compared to baseline values prior to start of RT (p = 0.007). An exacerbation of the urinary symptoms was seen in patients with vaginal brachytherapy/boost compared to patients with pelvic RT at 12 months after RT (p = 0.053). The severity of lymphedema symptoms increased from RT start to 12 months after RT (p = 0.019) and the pelvic pain were higher at 3 months after RT compared to before RT (p = 0.004). Also, the level of GI symptoms was significantly higher 12 months after RT compared to the RT start (p < 0.001).

Conclusions
The urologic, lymphedema, pelvic pain and GI symptoms all increase after RT.