bluuebunny/crossref_metadata_2025 huggingface dataset:
Multiscale analysis of heterogeneous materials in boundary representation
Authors: Praster Maximilian , Reichel Rainer , Klinkel Sven
Published: November 2019

This paper deals with a numerical method for modeling heterogeneous materials with nonlinear behavior. Many novel high‐performance materials consist of different components. In the frame of nonlinear behavior the resulting macroscopic material properties cannot be determined without great experimental effort. In order to simulate the nonlinear material behavior, a nested finite element method (FE2) is used. An accompanying homogenization is performed for each load step. The material behavior is determined from the represented volume element (RVE) on the heterogeneous micro structure. The present approach is dealing with a discretization method of the heterogeneous structure. It based on the geometrical data of the interface boundary of the different constituents. A quad‐tree algorithm, in combination with a trimming algorithm is used for the mesh generation. Based on the geometrical data it yields an initial mesh for the analysis. Within the algorithm a staircase approximation of voids or inclusions is circumvented. However, the resulting mesh yields polygonal elements with an arbitrary number of nodes on the element boundary. To this end a novel polygonal element formulation is provided. It is based on the scaled boundary finite element method (SBFEM). The basic idea is to scale the boundary representation in relation to a scaling center. In contrast to SBFEM the present method makes us of an approximation of the displacement response in scaling direction. This enables the analysis of geometrical and material‐related nonlinear problems in solid mechanics. The interpolation at the boundary in circumferential direction is independent of the interpolation in scaling direction. This allows for novel refinement strategies, where e.g. p‐refinement is only applied for the interior element domain. The internal degrees of freedom are eliminated by static condensation. It leads to an element formulation with an arbitrary number of nodes at the element boundary. Thus, the present element is perfectly suited for a quad‐tree meshing algorithm of the RVE. Its hierarchical, tree‐like data structure makes it very useful for adaptive mesh refinements of complex geometries and regions with localized gradients. The classical hanging‐nodes problem for standard elements is omitted by the present element formulation. Some numerical examples show the capability of the formulation with respect to the numerical homogenization of heterogeneous materials.
Thermo‐mechanical fluid‐structure interaction for thermal buckling
Authors: Martin Katharina , Reese Stefanie
Published: November 2019

Aerothermodynamical loads cause buckling and plastic deformation of thin‐walled structures under boundary conditions, which restrict the structural movement. We present the numerical computation of a loosely coupled fluid‐structure interaction for thermal buckling. The task of the research is to provide a mechanical model which incorporates the correct material behaviour and is suitable for thermal panel buckling. For this, an elasto‐viscoplastic material model with non‐linear isotropic hardening is used, which also includes nonlinearly temperature dependent material parameters. This material model is implemented into a user material in Abaqus FEA. The structural computation is coupled with the fluid computation within the fluid‐structure interaction code ifls from the TU Braunschweig. For the fluid solver TAU from the DLR is used.
On the fracture behavior of vitreous two‐dimensional silica
Authors: Bamer Franz , Ebrahem Firaz , Stratmann Jan , Markert Bernd
Published: November 2019

In this paper, we present an athermal mechanical investigation of a two‐dimensional silica glass. We generate the network artificially using a Monte Carlo bond switch algorithm and compare our network with experimental results. Using an athermal quasistatic mechanical deformation method, we show that the two‐dimensional network glass reveals ductile fracture behavior, whereas the crystalline polymorph behaves purely brittle.
On the implementation of rate‐independent gradient‐enhanced crystal plasticity theory
Authors: Fohrmeister Volker , Klinge Sandra , Mosler Jörn
Published: November 2019

In the present work, classical local crystal plasticity is reformulated using incremental energy minimization. The resulting constrained optimization problem is efficiently solved by a nonlinear complementary problem, which additionally solves the problem of determination of the set of active slip systems. The model is extended to a nonlocal, gradient‐enhanced, formulation by employing and adapting the micromorphic approach. By doing so, the implementation of the gradient‐enhanced model is almost identical to that of the original local one, with the exception of additional balance equations.
Stress response of 2D silica under quasi‐static tension
Authors: Ebrahem Firaz , Bamer Franz , Markert Bernd
Published: November 2019

We use classical molecular dynamics simulations to generate topologically different models of vitreous 2D silica, all of which are subjected to quasi‐static tensile loading until fracture occurs. We demonstrate the effects of structural disorder on the material behaviour of 2D silica. For each sample, we determine the network structure by identifying the relative count of single rings and so‐called ring triplets each of which composed of three adjacent rings that share a common corner. In each sample, we spatially detect the first local atomic‐scale rearrangement during deformation and correlate it to the ring triplet involved.
Robust efficient global optimisation via adaptive surrogate refinement
Authors: Le Carrer Noémie , Moens David , Faes Matthias
Published: November 2019

Through the combination of a given surrogate model (e.g. Kriging) and a procedure allowing to compute the local optima of a given black‐box function (e.g. tuned Particle swarm optimization), our algorithm produces refined estimates of the global optima of a multidimensional black‐box model. A confidence ellipsoid computed in a Bayesian way is associated to each estimate, and shown to be reliable. The setting is tested on the 2‐dimensional Branin function. Results outperform those given by two state‐of‐the‐art non‐parallelised efficient global optimisation methods.
Contact Line Advection using the Level Set Method
Authors: Fricke Mathis , Marić Tomislav , Bothe Dieter
Published: November 2019

In this work, we consider the geometrical problem of the numerical advection of a hypersurface by a prescribed velocity field in the special case when the hypersurface intersects the domain boundary. This problem emerges from the discretization of continuum models for dynamic wetting. The kinematic evolution equation [1], [2] expresses the fundamental relationship between the rate of change of the contact angle and the structure of the transporting velocity field. We employ a simple version of the Level Set method to numerically solve the hyperbolic transport equation for the interface in two dimensions. The results are validated against an analytic solution of the kinematic evolution equation. Full access to the data and C++‐implementations is provided via an open research data repository [3].
Anisotropic Stiffness Degradation in Biaxial Tensile Testing of SMC
Authors: Lang Juliane , Schemmann Malte , Böhlke Thomas
Published: November 2019

Biaxial tensile tests allow the investigation of damage evolution in sheet molding compound under biaxial stress states. This is of particular interest due to the different damage phenomena in composite materials. A key challenge is to find a suitable specimen design, because typical cruciform specimens fail in the arms before damage occurs in the area of interest which is the area of the biaxial stress state in the center area of the specimen. A specimen was found which enables the observation of anisotropic stiffness degradation which is one phenomenon of damage. In this proceedings the results of the experiments are presented.
Crack deflection in short fiber reinforced composites: Theory and experiment
Authors: Judt Paul , Ricoeur Andreas
Published: November 2019

In the past decades different crack growth and crack deflection criteria have been proposed, e.g. the maximum hoop stress criterion [1], the minimum strain energy density criterion [2] or the maximum energy release rate criterion [3]. These criteria were extended concerning phenomena such as crack path instability [4,5] and the anisotropy of fracture parameters [4]. Another approach for the prediction of crack growth and deflection angle is based on the Jk‐integral [6], assuming the crack to grow into the direction of the J‐vector [7]. The resulting deflection angles coincide well with those from other criteria in the case of small mixed‐mode ratios KII/KI or deflection angles, respectively. One challenge is the accurate calculation of the second coordinate J2 [8] and the appropriateness of this approach has been shown [9]. Nevertheless, in the cases of anisotropic crack resistance parameters, large mode‐II loading or unstable crack paths, the classical J‐vector criterion fails.

In this paper, an extended J‐vector criterion is introduced providing the crack growth direction in the case of anisotropic fracture parameters and elastic constants [9,10]. The theory is validated by experimental results for different anisotropy ratios and orientations.
On the development of continuum material models for 2D materials from Density Functional Theory data
Authors: Shirazian Farzad , Hu Ming , Sauer Roger A.
Published: November 2019

A multiscale framework is presented for the development of continuum models for 2D materials. The framework consists of four steps. First the 2D material is studied by performing a set of Density Functional Theory (DFT) simulations. A continuum model consistent with the material properties is then developed. The continuum model is calibrated based on the generated DFT data. Finally, the model is validated from new DFT data. The generation of DFT results and the calibration of the continuum model are discussed in this paper and a numerical example of a pressurized square phosphorus sheet is presented. The framework has previously been applied to graphene and single layer blue phosphorus.
Optimal control of district heating networks
Authors: Linn Dominik , Mohring Jan , Siedow Norbert
Published: November 2019

Standard models for district heating networks usually lead to a high number of coupled nonlinear and algebraic equations, which makes an optimal control of such networks a difficult task. We present an iterative algorithm, in which we separately resolve the high dimensional equality constraints, leaving us with a series of low dimensional quadratic programs with linear inequality constraints, which can be solved by established methods.
Computer simulations in lectures in mathematics and in the natural sciences: learning‐theoretical aspects
Authors: Gunesch Roland
Published: November 2019

This article presents an overview of results from the mathematics education literature about the usefulness of using computer simulations in lectures in mathematics and in the natural sciences. Therefore, it justifies (some) established teaching practices in mathematics lectures. This arcitle discusses some key differences between computer simulations used for scientific research and simulations used for teaching. We describe some aspects of learning theory which are useful for analyzing computer simulations of mathematical phenomena.
Reduction of nonlinear dynamical systems excited by random loads
Authors: Dostal Leo
Published: November 2019

The presented research deals with methods for the study of complex interactions between noise and nonlinearities in dynamical systems. Practical applications of this research are beginning to appear across the spectrum of mechanics; for example vibration absorbers, ship dynamics, energy harvesting, and variable speed machining processes. In the presented approach perturbed Hamiltonian systems are considered, which are damped and excited by an absolutely regular non‐white Gaussian process. Analytical and semi‐analytical solutions to the corresponding nonlinear stochastic differential equations (SDE) are determined. The approach is based on a limit theorem by Khashminskii, from which a class of methods has been derived known as stochastic averaging. In the presented approach Homoclinic orbits, which divide the phase space of the corresponding Hamiltonian flow into different regions, are mapped to a graph in the one degree of freedom case. For two degree of freedom systems this procedure results in a mapping to a book, and so on for higher degrees of freedom. From the drift and diffusion of the resulting averaged process, probability density functions and first passage times are obtained.
Space‐Time Isogeometric Analysis of Parabolic Diffusion Problems in Moving Spatial Domains
Authors: Kyas Svetlana , Langer Ulrich , Repin Sergey
Published: November 2019

This paper addresses locally stabilized space‐time isogeometric (IgA) schemes for parabolic diffusion problems in moving spatial domains. It generalizes the results of our preceding works for problems in fixed spatial domains. We present functional a posteriori error estimates and study adaptive numerical procedures based on them and on truncated hierarchical B‐splines.
DNAJB1‐PRKACA–positive metastatic fibrolamellar carcinoma with unknown primary in a pediatric patient
Authors: Balbeur Samuel , Dumortier Adeline , Mergen Julien , Libbrecht Louis , Torbenson Michael , Boulanger Cecile , de Ville de Goyet Maelle , Van Damme An , Brichard Bénédicte
Published: November 2019

Fibrolamellar carcinoma (FLC) is a rare variant of hepatocellular carcinoma, occurring in children and young adults without underlying liver disease. The diagnosis is based on morphological characteristics of the tumor, supplemented by immunohistochemistry and/or genetic testing. Recently, the presence of a characteristic DNAJB1‐PRKACA fusion gene has been associated with FLC. Herein, we report a case of FLC presenting as peritoneal carcinomatosis in a 14‐year‐old female. Interestingly, no liver tumor was seen on imaging, and an alternative possibility is that the tumor arose outside the liver as a hepatoid carcinoma with fibrolamellar features.
Intravenous immunoglobulin therapy enhances suppressive regulatory T cells and decreases innate lymphoid cells in children with immune thrombocytopenia
Authors: Wang Shih‐Chung , Yang Kuender D. , Lin Ching‐Yuang , Huang Alex Y. , Hsiao Chien‐Chou , Lin Ming‐Tsan , Tsai Yi‐Giien
Published: November 2019

Background

This study aimed to investigate the relationship between CD4+ regulatory T cells (Tregs) and innate lymphoid cells (ILCs) in children with primary immune thrombocytopenia (ITP) undergoing high‐dose intravenous immunoglobulin (IVIG) therapy.

Methods

We enrolled a cohort of 30 children with newly diagnosed ITP and 30 healthy controls and collected blood samples for levels of Tregs, ILCs, relevant cytokines, and Treg suppression assay at the diagnosis, two days, four weeks, and one year (only platelet count) after high‐dose IVIG treatment. IVIG partial responders was defined by a platelet count less than 100 × 109/L at 12 months after IVIG treatment.

Results

Children with newly diagnosed ITP exhibited elevated levels of ILC1, ILC2, ILC3, Th17, myeloid dendritic cells (DCs), plasmacytoid DCs, and serum IFN‐γ and IL‐17A levels, accompanied by a decrease in IL‐10‐producing Tregs. High‐dose IVIG therapy reversed these aberrations. Platelet counts positively correlated with Tregs (rho = 0.72) and negatively correlated with both ILC1 (rho = −0.49) and ILC3 (rho = −0.60) (P < 0.05). Significantly lower Tregs and higher ILC1, ILC3, DCs, and serum IL‐17A levels were noted in the partial responders (n = 8) versus responders (n = 22; P < 0.05). We found that Tregs suppressed proliferation of ILCs and CD4+ T cells in CD25‐depleted peripheral PBMCs and enhanced the apoptosis of CD4+CD45RO+ T cells in vitro following IVIG therapy.

Conclusions

Effective high‐dose IVIG therapy for children with newly diagnosed ITP appears to result in the induction of Tregs, which suppresses ILC proliferation in vitro and is associated with platelet response.
Brain‐derived neurotrophic factor levels in pediatric sickle cell disease
Authors: Lance Eboni I. , Barron‐Casella Emily , Everett Allen D. , Casella James F.
Published: November 2019

Background

Children with sickle cell disease (SCD) have an increased risk of neurological complications, particularly stroke and silent cerebral infarction (SCI). Brain‐derived neurotrophic factor (BDNF) is a nerve growth factor associated with neuronal survival, synaptic plasticity, elevated transcranial Doppler (TCD) velocities and increased risk of stroke in patients with SCD. The objective of this study was to analyze plasma BDNF protein levels in children with SCD participating in the Silent Cerebral Infarct Transfusion Multi‐Center Clinical Trial (SIT Trial), comparing plasma samples of children with SCD and SCI to plasma samples from children with SCD without SCI, as well as healthy pediatric control participants.

Procedure

Entry, exit, and longitudinal blood samples were collected from 190 SIT Trial participants with SCD and healthy pediatric controls over time. BDNF levels were measured by enzyme‐linked immunosorbent assay. Sample collection was not optimized for measurements of BDNF, but factors affecting BDNF levels were accounted for in analyses.

Results

BDNF levels were significantly higher in children with SCD in comparison to healthy pediatric control subjects. BDNF levels significantly increased over time in SCD participants. BDNF levels did not show any significant associations with the presence or absence of SCI or new/progressive SCI/stroke or TCD velocities.

Conclusions

Plasma BDNF levels are elevated and increase over time in children with SCD. Additional studies with more longitudinal samples are needed to address the reasons for those increased levels.
Outcomes following proton therapy for Ewing sarcoma of the cranium and skull base
Authors: Kharod Shivam M. , Indelicato Daniel J. , Rotondo Ronny L. , Mailhot Vega Raymond B. , Uezono Haruka , Morris Christopher G. , Bradfield Scott , Sandler Eric S. , Bradley Julie A.
Published: November 2019

Purpose

Despite the dosimetric advantages of proton therapy, little data exist on patients who receive proton therapy for Ewing sarcoma of the cranium and skull base. This study reports local disease control and toxicity in such patients.

Materials/methods

We reviewed 25 patients (≤21 years old) with nonmetastatic Ewing sarcoma of the cranium and skull base treated between 2008 and 2018. Treatment toxicity was graded per the Common Terminology Criteria for Adverse Events v4.0. The Kaplan‐Meier product limit method provided estimates of disease control and survival.

Results

Median patient age was 5.9 years (range, 1–21.7). Tumor subsites included the skull base (48%), non‐skull‐base calvarial bones (28%), paranasal sinuses (20%), and nasal cavity (4%). All patients underwent multiagent alkylator‐ and anthracycline‐based chemotherapy; 16% underwent gross total resection (GTR) before radiation. Clinical target volume (CTV) 1 received 45 GyRBE and CTV2 received 50.4 GyRBE following GTR or 54–55.8 GyRBE following biopsy or subtotal resection. Median follow‐up was 3.7 years (range, 0.26–8.3); no patients were lost. The 4‐year local control, disease‐free survival, and overall survival rates were 96%, 86%, and 92%, respectively. Two patients experienced in‐field recurrences. One patient experienced bilateral conductive hearing loss requiring aids, two patients developed intracranial vasculopathy, and 6 patients required hormone replacement therapy for neuroendocrine deficits. None developed a secondary malignancy.

Conclusion

Proton therapy is associated with a favorable therapeutic ratio in children with large Ewing tumors of the cranium and skull base. Despite its high conformality, we observed excellent local control and no marginal recurrences. Treatment dosimetry predicts limited long‐term neurocognitive and neuroendocrine side effects.
Incidence of chromosomal anomalies in fetuses with isolated right aortic arch: A meta‐analysis
Authors: Luo Qingyi , Chen Jian , Zhang Yu , Li Jianhua , Su Xuan , Wang Qinghui , Ding Yunchuan
Published: November 2019

Objective

Right aortic arch (RAA) can be associated with chromosomal anomalies. However, the incidence of chromosomal anomalies when RAA is isolated (iRAA), ie, not associated with intracardiac anomalies, varies between different studies (0%‐28.5%). We have performed a meta‐analysis to allow a more accurate prenatal counselling.

Methods

We searched PubMed, Embase, and Web of Science for articles related to chromosomal anomalies among iRAA fetuses until April 2019. A total of 22 relevant studies, including 670 fetuses, were selected in the final meta‐analysis.

Results

The results revealed that the overall rates of chromosomal anomalies and 22q11.2 deletion in iRAA fetuses were 7.5% (95% confidence interval [CI], 4.7%‐10.8%) and 4.3% (95% CI, 2.6%‐6.4%), respectively, while the rates were lower in iRAA without extracardiac anomalies, 4.7% (95% CI, 1.1%‐10.8%) and 2.4% (95% CI, 0.5%‐5.7%). The rate of chromosomal or copy number variants including 22q11.2 deletion identified by chromosomal microarray analysis (CMA) in iRAA fetuses was 8.2% (95% CI, 5.0%‐12.1%) and 3.7% (95% CI, 1.7%‐6.6%), respectively, compared with 5.1% (95% CI, 2.5%‐8.4%) and 2.4% (95% CI, 0.7%‐5.1%) identified by traditional karyotyping.

Conclusions

A considerable proportion of iRAA cases have associated chromosomal anomalies and prevalence of associated 22q11.2 deletion, and CMA is recommended if invasive prenatal testing is performed.
Proteomics of Long‐Lived Mammals
Authors: Tombline Gregory , Gigas Jonathan , Macoretta Nicholas , Zacher Max , Emmrich Stephan , Zhao Yang , Seluanov Andrei , Gorbunova Vera
Published: November 2019

Mammalian species differ up to 100‐fold in their aging rates and maximum lifespans. Long‐lived mammals appear to possess traits that extend lifespan and healthspan. Genomic analyses have not revealed a single pro‐longevity function that would account for all longevity effects. In contrast, it appears that pro‐longevity mechanisms may be complex traits afforded by connections between metabolism and protein functions that are impossible to predict by genomic approaches alone. Thus, metabolomics and proteomics studies will be required to understand the mechanisms of longevity. Several examples are reviewed that demonstrate the naked mole rat (NMR) shows unique proteomic signatures that contribute to longevity by overcoming several hallmarks of aging. SIRT6 is also discussed as an example of a protein that evolves enhanced enzymatic function in long‐lived species. Finally, it is shown that several longevity‐related proteins such as Cip1/p21, FOXO3, TOP2A, AKT1, RICTOR, INSR, and SIRT6 harbor posttranslational modification (PTM) sites that preferentially appear in either short‐ or long‐lived species and provide examples of crosstalk between PTM sites. Prospects of enhancing lifespan and healthspan of humans by altering metabolism and proteoforms with drugs that mimic changes observed in long‐lived species are discussed.
Myofascial Pain Syndrome: A Narrative Review Identifying Inconsistencies in Nomenclature
Authors: Phan Vy , Shah Jay , Tandon Hannah , Srbely John , DeStefano Secili , Kumbhare Dinesh , Sikdar Siddhartha , Clouse Allison , Gandhi Amar , Gerber Lynn
Published: November 2019

There is currently confusion surrounding the phenotype of and diagnostic criteria for myofascial pain syndrome (MPS) in the published literature. This narrative literature review investigated whether there is consensus regarding the descriptive terminology used for MPS and the trend of MPS publications over time. The phrase “myofascial pain syndrome” was used to search PubMed and Web of Science, returning 923 articles. Of these, we included only full‐text, primary research articles containing “myofascial pain syndrome” in the title, reducing the total articles reviewed to 167. We identified 116 descriptors and categorized them under one of five clusters that shared similar findings and are commonly associated with MPS: “trigger points,” “muscle,” “pain,” “nervous system,” and “fascia.” The frequency of the clinical criteria of Travell and Simons was tabulated. Terms pertaining to the clusters “trigger points,” “muscle,” or “pain” appeared in approximately 90% of the articles; “nervous system” in 46%; and “fascia” in 20%. Only 42% used the criteria of Travell and Simons. Most articles (122) included a combination of three or four clusters to describe MPS. In addition, MPS publications have doubled since 2010 compared to the prior decade. The publication patterns, determined by changes in which specialty journals articles on MPS have been published, have shifted from investigational to intervention studies. This may have been influenced by heterogeneity in the usage of MPS terminology. This underscores the lack of a reliable MPS diagnosis and limits human subjects research. Improved consistency in terminology is needed to establish consensus within the field and to inform future research studying the pathophysiology of MPS.
Ultra‐High Fidelity Laser‐Induced Air Shock from Energetic Materials
Authors: Biss Matthew M. , Brown Kathryn E. , Tilger Christopher F.
Published: November 2019

Recent interest in the implementation of the Laser‐induced Air Shock from Energetic Materials (LASEM) technique prompted an investigation using ultra‐high‐speed imaging diagnostics to provide early‐time (sub‐μs) shock‐wave‐radius‐versus‐time data necessary to accurately determine the characteristic laser‐induced‐shock velocity (y‐intercept) for high explosives (HE) of interest. Ultra‐high‐speed focused‐shadowgraphy images were collected from nanosecond‐pulsed laser‐ablated samples of HE similar to those in the published literature. Shadowgraphy images were collected using interframe times ranging from 50–750 ns, with exposure times of 5 ns. Acquired shock‐wave‐radius‐versus‐time data permitted a high‐fidelity assessment of the shock wave velocity produced at the characteristic radius of the generated laser‐plasma pulse. The resulting data from eight different HE indicated that early‐time energy contributions and the resulting laser‐induced shock velocity profiles produced from ablation of the HE material were indistinguishable amongst the explosives tested for the majority of the time domain characterized (0–12 μs).
Effect of DGTN Content on Mechanical and Thermal Properties of Modified Single‐Base Gun Propellant Containing NQ and RDX
Authors: Wang Yongqiang , Yang Huiqun , Han Jinchao , Gao Kangjian
Published: November 2019

In order to improve the mechanical properties of nitroguanidine (NQ) base modified single‐base gun propellant, five kinds of propellants with different contents (0 %, 1 %, 2 %, 3 %) were prepared to study the effect of diglycerol tetranitrate (DGTN) content on the mechanical properties and thermal behaviors of the gun propellant. The impact strength and compress strength were tested by simple beam impact testing machine and universal materials testing machine, respectively. The thermal stability and thermal characteristic were tested by vacuum stability test (VST) and differential scanning calorimetry (DSC). Experimental data on comparative study indicates that the mechanical properties of gun propellant can be improved for addition of DGTN. The gun propellant has a better comprehensive mechanical property containing 2 % DGTN. Compared with the blank sample, the impact strength and compression ratio of the propellant increased by 11.36 % and 28 % respectively, and the compression strength decreased by 1.9 %. The vacuum stability results determined that the thermal stability of the five propellants is evaluated to be eligible and increases with the increase of DGTN content. The enthalpy of activation and free energy of activation of propellant increased for the addition of DGTN, the entropy of activation and enthalpy of activation decreased with the increase of DGTN content.
Fire behaviors of vertical and horizontal polymethyl methacrylate slabs under autoignition conditions
Authors: Huang Dongmei , Wang Chaoyi , Shen Yiming , Lin Peng , Shi Long
Published: November 2019

In this study, horizontal and vertical black polymethyl methacrylate (PMMA) samples were investigated experimentally and theoretically under 25‐70 kW/m2 heat flux with autoignition conditions. An empirical model was developed to predict the autoignition time, where the significance of this model is to unify the prediction for both horizontal and vertical samples. Both horizontal and vertical samples show similar phenomena, such as burning stages and no higher than 2 cm sample expansion. It is obtained that the vertical samples show averagely 21% lower CO yield and also longer ignition time than those of the horizontal samples, while the CO2 yield increases about 24%. However, the vertical samples show a relatively high fire risk. This can be reflected by higher surface temperature, bigger average heat release rate (HRR) and mass loss rate (MLR), higher peak MLR, longer bubbling stage, higher CO2 yield, where the differences become even bigger under a higher external heat flux. A linear relationship was found between the average HRR of vertical and horizontal samples, and also between the ignition temperature and external heat flux for both orientated samples. The research outcomes provide a practical basis and guide for the risk assessment of combustible materials under both vertical and horizontal orientation.
Acanthopanax senticosus polysaccharide regulates the intestinal homeostasis disruption induced by toxic chemicals in Drosophila
Authors: Zhang Hong , Wang Sihong , Jin Li Hua
Published: November 2019

The intestinal epithelium provides the first line of defense against pathogens and toxic compounds. The ingestion of toxic compounds causes an enhanced epithelial cell death and an excessive proliferation of intestinal stem cells, eventually resulting in the disruption of gut homeostasis. In this study, Drosophila gut inflammation model induced by toxic compounds was exploited to analyze the ameliorative effect of Acanthopanax senticosus polysaccharide on the disruption of gut homeostasis. As a result, it was found that A. senticosus polysaccharide can significantly increase the survival rate of Drosophila adults as well as reduce the excessive proliferation and differentiation of intestinal stem cells through epidermal growth factor receptor, jun‐N‐terminal kinase, and Notch signaling pathways under the exposure to toxic compounds dextran sodium sulfate. Moreover, the polysaccharide effectively decreased the epithelial cell death and the accumulation of reactive oxygen species and antimicrobial peptides induced by sodium dodecyl sulfate. In addition, it was found that A. senticosus polysaccharide can extend the lifespan of only female flies but not male flies. In conclusion, A. senticosus polysaccharide has an obvious protective effect on the gut homeostasis of Drosophila melanogaster.
Integrated multiresponse parameter and tolerance design with model parameter uncertainty
Authors: Han Yunxia , Ma Yizhong , Ouyang Linhan , Wang Jianjun , Tu Yiliu
Published: November 2019

Integrated parameter and tolerance design is a cost‐effective method to multiresponse quality improvement. However, previous methods usually ignore model parameter uncertainty, dispersion effect, or correlation among responses. This may lead to the obtained optimal solutions far from the true optimal values of parameters and tolerances. To address the problem, a novel integrated parameter and tolerance design method is proposed to solve correlated multiple response problems under consideration of model parameter uncertainty, the location and dispersion effects of the quality loss, and the tolerance costs simultaneously. As there usually exists uncertainty in the quality loss and tolerance costs, multiobjective optimization is adopted to seek for the robust optimal solutions. The effectiveness and robustness of the proposed method are illustrated with a practical example and a random simulation example. The results show that the proposed method provides more reasonable results in quality improvement and cost reduction than those of the existing methods.
Isolated laryngeal sarcoidosis
Authors: Ahmadi Aslan , Dehghani Firouzabadi Fatemeh , Dehghani Firouzabadi Mohammad , Roomiani Maryam
Published: November 2019

To improve diagnosis and treatment of laryngeal sarcoidosis, we present a rare case of upper airway obstruction of unclear aetiology, with life‐threatening complication.The patient was a 19‐year boy who presented with progressive severe dyspnoea for eight months. After extensive diagnostic evaluations with no conclusive diagnosis, biopsy showed non‐caseating granulomatous inflammation consistent with laryngeal sarcoidosis that was treated with a CO2 laser attached to a microscope. The laser was also used to resect epiglottitis, false focal cords, and aryepiglottic fold completely due to supraglottic swelling with a thick oedematous epiglottis. A 1.5‐ms pulse‐duration CO2 laser attached to a microscope is an effective technique of treating laryngeal sarcoidosis and preventing its hazardous complication. Beneficial effects of this method are not only an immediate improvement of the symptoms, but also this method decreases the need for long‐term medical therapy with its side effects or avoid tracheostomy due to upper airway obstruction.
Green entrepreneurship inclination among the younger generation: An avenue towards a green economy
Authors: Soomro Bahadur Ali , Ghumro Ikhtiar Ali , Shah Naimatullah
Published: November 2019

The current study sought to predict the inclination toward green entrepreneurship among the younger generation. The study employed a deductive approach by collecting cross‐sectional data. Bachelor and Master's degree students in business management and entrepreneurship courses comprised the respondents. The study analyzed 284 usable survey questionnaires in its final estimation. The results obtained by employing structural equation modeling (SEM) show the positive and significant impact of sustainability orientation and sustainability education on the green entrepreneurship inclination. In contrast, the nonsignificant effect of self‐efficacy on green entrepreneurship inclination is detected among respondents. The study's findings would support the government, policy makers, and university authorities in developing a tailor‐made awareness program through building a curriculum that could offer greater inclination toward green and sustainable education. The outcomes may lead to providing a better living place for future generations worldwide.
Whole‐Genome Regulation for Yeast Metabolic Engineering
Authors: Jiang Shuangying , Si Tong , Dai Junbiao
Published: November 2019

As the most thoroughly investigated eukaryotic microorganism, Saccharomyces cerevisiae is widely used as a cell factory for producing valuable compounds. Currently, strain construction and optimization still cost a vast amount of capital and time to achieve industrially relevant parameters. To efficiently excavate the genetic factors required for desired traits, many high‐throughput genome engineering tools are developed. This review focuses on the genome‐wide approaches that are applied in yeast. Through multiplex genome editing and/or transcription regulation, these tools generate cell populations with great genetic diversity, enabling identification of the critical factors and synergistic interactions in a short time.
Toward scalable cloud data center simulation using high‐level architecture
Authors: Elahi Bukhtawar , Malik Asad Waqar , Rahman Anis U. , Khan Muazzam A.
Published: November 2019

Existing simulators are designed to simulate a few thousand nodes due to the tight integration of modules. Thus, with limited simulator scalability, researchers/developers are unable to simulate protocols and algorithms in detail, although cloud simulators provide geographically distributed data centers environment but lack the support for execution on distributed systems. In this paper, we propose a distributed simulation framework referred to as CloudSimScale. The framework is designed on top of highly adapted CloudSim with communication among different modules managed using IEEE Std 1516 (high‐level architecture). The underlying modules can now run on the same or different physical systems and still manage to discover and communicate with one another. Thus, the proposed framework provides scalability across distributed systems and interoperability across modules and simulators.
Release Kinetics and Antimicrobial Properties of Iodinated Species Liberated from Physically and Chemically Modified Starch Granules
Authors: Tran Melissa , Castro Jordan , O'Brien Katherine R. , Pham Candace , Bird Terry H. , Iovine Peter M.
Published: November 2019

Herein, the preparation of iodine‐loaded high amylose starch (HAS) granules and their utility as slow release reservoirs for the delivery of antimicrobial iodinated species are described. Several varieties of HAS granules are studied including those that are physically or chemically modified. Granules are impregnated with iodinated species, resulting in stained materials that are bench stable. Mass gain after staining with Lugol's solution range from 5 to 18 wt% depending on the type of starch granule. Release kinetics for both chemically and physically modified iodinated granules show an initial burst phase followed by a tapering of iodinated species release. A two‐step granule pretreatment protocol is developed that significantly alters the release of iodinated species relative to granules that are untreated. Microbiological data indicate that even after 2 weeks, unmodified and lyophilized iodinated granules release sufficient quantities of antimicrobial iodine to completely kill planktonic Escherichia coli and Staphylococcus aureus. Pretreated lyophilized granules also show complete killing power at 3.5 weeks. Although increasing the temperature from 25 to 37 °C does not alter the release characteristics, the addition of salt significantly inhibits release.
TGF‐β1 mediated Smad signaling pathway and EMT in hepatic fibrosis induced by Nano NiO in vivo and in vitro
Authors: Zhang Qiong , Chang Xuhong , Wang Haibing , Liu Yunlan , Wang Xiaoxia , Wu Minmin , Zhan Haibing , Li Sheng , Sun Yingbiao
Published: November 2019

Nickel oxide nanoparticles (Nano NiO) bears hepatotoxicity, while whether it leads to liver fibrosis remains unclear. The aim of this study was to establish the Nano NiO‐induced hepatic fibrosis model in vivo and investigate the roles of transforming growth factor β1 (TGF‐β1) in Smad pathway activation, epithelial‐mesenchymal transition (EMT) occurrence, and extracellular matrix (ECM) deposition in vitro. Male Wistar rats were exposed to 0.015, 0.06, and 0.24 mg/kg Nano NiO by intratracheal instilling twice a week for 9 weeks. HepG2 cells were treated with 100 μg/mL Nano NiO and TGF‐β1 inhibitor (SB431542) to explore the mechanism of collagen formation. Results of Masson staining as well as the elevated levels of type I collagen (Col‐I) and Col‐III suggested that Nano NiO resulted in hepatic fibrosis in rats. Furthermore, Nano NiO increased the protein expression of TGF‐β1, p‐Smad2, p‐Smad3, alpha‐smooth muscle actin (α‐SMA), matrix metalloproteinase9 (MMP9), and tissue inhibitors of metalloproteinase1 (TIMP1), while decreased the protein content of E‐cadherin and Smad7 in rat liver and HepG2 cells. Most importantly, Nano NiO‐triggered the abnormal expression of the abovementioned proteins were all alleviated by co‐treatment with SB431542, implying that TGF‐β1‐mediated Smad pathway, EMT and MMP9/TIMP1 imbalance were involved in overproduction of collagen in HepG2 cells. In conclusion, these findings indicated that Nano NiO induced hepatic fibrosis via TGF‐β1‐mediated Smad pathway activation, EMT occurrence, and ECM deposition.
Developing a Vision of Leadership Educator Professional Practice
Authors: Priest Kerry L. , Jenkins Daniel M.
Published: November 2019

This chapter explores leadership education as a professional role and developmental journey, and proposes a framework of leadership educator professional development.
Exploring and Enhancing Leader, Educator, and Leadership Educator Professional Identities
Authors: Seemiller Corey , Crosby Barbara C.
Published: November 2019

This chapter discusses the distinction and intersections of leader and educator identities, and offers reflective exercises for exploring, developing, and deepening one's professional leadership educator identity.
Leadership Education: Advancing a Community of Practice
Authors: Endersby Lisa , Jenkins Daniel M. , Priest Kerry L.
Published: November 2019

This chapter offers reflection and recommendations for advancing leadership education as a community of practice through the lenses of identity, agency, and responsibility.
Empire of Riches: Visions of Dutch Commercial Imperialism, c. 1600–1750
Authors: Weststeijn Arthur
Published: November 2019

This chapter uncovers the intellectual roots of the exceptionalist narrative of the Dutch empire as a trading empire. It shows how this narrative originated in the humanist culture of the Dutch Republic around 1600 and became ingrained in elite and popular culture in the following decades. Analysing texts, imagery and urban architecture, Weststeijn argues that the idea of a non-territorial commercial empire gained weight because of its dominant manifestations in the Dutch public sphere around 1650 and in the visual culture of the European Enlightenment, which celebrated Dutch commercial imperialism as a Company-Republic. The dominance of this representation of empire in terms of a corporate instead of a national entity explains why the concept of a ‘Dutch empire’ never became an ideological construct.
Understanding Digital Earth
Authors: Liu Zhen , Foresman Tim , van Genderen John , Wang Lizhe
Published: November 2019

In the two decades since the debut of the Digital Earth (DE) vision, a concerted international effort has engaged in nurturing the development of a technology framework and harnessing applications to preserve the planet and sustain human societies. Evolutionary threads can be traced to key historic and multidisciplinary foundations, which were presciently articulated and represented at the first International Symposium on Digital Earth hosted by the Chinese Academy of Sciences in 1999. Pioneering groups in government, industry, and academia have cultivated this fertile futuristic conceptual model with technological incubation and exploratory applications. An array of space-age developments in computers, the internet and communications, Earth observation satellites, and spatially oriented applications sparked an innovative discipline. The Beijing Declaration on Digital Earth is recognized for its role in promulgating the series of International Symposia on Digital Earth to promote understanding of the impacts of DE technology and applications on behalf of humankind. Combinations of industrial, academic, and government organizations have rapidly advanced the technological components necessary for implementing the DE vision. Commercial leaders such as Google have accelerated the influence of DE for large segments of society. Challenges remain regarding requisite collaboration on international standards to optimize and accelerate DE implementation scenarios. This chapter provides an overview of the DE initiative and basic framework, the global response to DE, the evolution of DE, its relationship to key global science initiatives, and the response to global challenges.
Artificial Intelligence
Authors: Guérin Eric , Aydin Orhun , Mahdavi-Amiri Ali
Published: November 2019

In this chapter, we provide an overview of different artificial intelligence (AI) and machine learning (ML) techniques and discuss how these techniques have been employed in managing geospatial data sets as they pertain to Digital Earth. We introduce statistical ML methods that are frequently used in spatial problems and their applications. We discuss generative models, one of the hottest topics in ML, to illustrate the possibility of generating new data sets that can be used to train data analysis methods or to create new possibilities for Digital Earth such as virtual reality or augmented reality. We finish the chapter with a discussion of deep learning methods that have high predictive power and have shown great promise in data analysis of geospatial data sets provided by Digital Earth.
Geospatial Information Visualization and Extended Reality Displays
Authors: Çöltekin Arzu , Griffin Amy L. , Slingsby Aidan , Robinson Anthony C. , Christophe Sidonie , Rautenbach Victoria , Chen Min , Pettit Christopher , Klippel Alexander
Published: November 2019

In this chapter, we review and summarize the current state of the art in geovisualization and extended reality (i.e., virtual, augmented and mixed reality), covering a wide range of approaches to these subjects in domains that are related to geographic information science. We introduce the relationship between geovisualization, extended reality and Digital Earth, provide some fundamental definitions of related terms, and discuss the introduced topics from a human-centric perspective. We describe related research areas including geovisual analytics and movement visualization, both of which have attracted wide interest from multidisciplinary communities in recent years. The last few sections describe the current progress in the use of immersive technologies and introduce the spectrum of terminology on virtual, augmented and mixed reality, as well as proposed research concepts in geographic information science and beyond. We finish with an overview of “dashboards”, which are used in visual analytics as well as in various immersive technologies. We believe the chapter covers important aspects of visualizing and interacting with current and future Digital Earth applications.
Transformation in Scale for Continuous Zooming
Authors: Li Zhilin , Yan Haowen
Published: November 2019

This chapter summarizes the theories and methods in continuous zooming for Digital Earth. It introduces the basic concepts of and issues in continuous zooming and transformation in scale (or multiscale transformation). It presents the theories of transformation in scale, including the concepts of multiscale versus variable scale, transformation in the Euclidean space versus the geographical space, and the theoretical foundation for transformation in scale, the Natural Principle. It addresses models for transformations in scale, including space-primary hierarchical models, feature-primary hierarchical models, models of transformation in scale for irregular triangulation networks, and the models for geometric transformation of map data. It also discusses the mathematical solutions to transformations in scale (including upscaling and downscaling) for both raster (numerical and categorical data) and vector (point set data, line data set and area data) data. In addition, some concluding remarks are provided.