A constitutive equation for graphene based on density functional theory

AbstractAn anisotropic strain energy function is proposed for tensile loading in graphene that provides a nonlinear, hyperelastic constitutive equation. In the proposed function, the energy depends on the principal invariants of the right Cauchy–Green tensor and the strains in the zigzag and armchair directions. The use of the zigzag and armchair strains gives the model the ability to account for anisotropic behavior at moderate deformations. The constitutive law parameters are determined by a least squares fit to the energies predicted by density functional theory (DFT) calculations, and a good match is obtained to the DFT results for zigzag and armchair graphene sheets with various loading combinations. The law is applied in a continuum calculation of nanoindentation of a graphene membrane. The force–deflection predicted with this model show excellent agreement with analogous experimental results, thus providing a strong link between DFT calculations and nanoexperiments

Comprehensive Solution to Scattering by Bianisotropic Objects of Arbitrary Shape

This paper presents a method of moments (MoM) solution for the problems of electromagnetic scattering by inhomogeneous three- dimensional bianisotropic scatterers of any shape. The electromagnetic response of bianisotropy has been described by the constitutive relations of the most general form composed of four 3 X 3 matrices or tensors. The volume equivalence principle is used to obtain a set of mixed potential formulations for a proper description of the original scattering problem. Here, the total fields are separated into the incident fields and the scattered fields. The scattered fields are related to the electric and magnetic potentials which are excited by electric and magnetic bound charges and polarization currents. The body of the scatterer is meshed through the use of tetrahedral cells with face-based functions used to expand unknown quantities. At last, the Galerkin test method is applied to create a method of moments (MoM) matrix from which the numerical solution is obtained. Implemented in a MATLAB program, the numerical formulation is evaluated and verified for various types of scatterers. The results are compared with those of previous work, and a good agreement is observed. Finally, a scattering from a two-layered dispersive chiroferrite sphere is presented as the most general example

Blind Video Quality Assessment at the Edge

Owing to the proliferation of user-generated videos on the Internet, blind video quality assessment (BVQA) at the edge attracts growing attention. The usage of deep-learning-based methods is restricted by their large model sizes and high computational complexity. In light of this, a novel lightweight BVQA method called GreenBVQA is proposed in this work. GreenBVQA features a small model size, low computational complexity, and high performance. Its processing pipeline includes: video data cropping, unsupervised representation generation, supervised feature selection, and mean-opinion-score (MOS) regression and ensembles. We conduct experimental evaluations on three BVQA datasets and show that GreenBVQA can offer state-of-the-art performance in PLCC and SROCC metrics while demanding significantly smaller model sizes and lower computational complexity. Thus, GreenBVQA is well-suited for edge devices

Household Catastrophic Medical Expenses in Eastern China: Determinants and Policy Implications

Background: Much of research on household catastrophic medical expenses in China has focused on less developed areas and little is known about this problem in more developed areas. This study aimed to analyse the incidence and determinants of catastrophic medical expenses in eastern China. Methods: Data were obtained from a health care utilization and expense survey of 11,577 households conducted in eastern China in 2008. The incidence of household catastrophic medical expenses was calculated using the method introduced by the World Health Organization. A multi-level logistic regression model was used to identify the determinants. Results: The incidence of household catastrophic medical expenses in eastern China ranged from 9.24% to 24.79%. Incidence of household catastrophic medical expenses was lower if the head of household had a higher level of education, labor insurance coverage, while the incidence was higher if they lived in rural areas, had a family member with chronic diseases, had a child younger than 5 years old, had a person at home who was at least 65 years old, and had a household member who was hospitalized. Moreover, the impact of the economic level on catastrophic medical expenses was non-linear. The poorest group had a lower incidence than that of the second lowest income group and the group with the highest income had a higher incidence than that of the second highest income group. In addition, region was a significant determinant. Conclusions: Reducing the incidence of household catastrophic medical expenses should be one of the priorities of health policy. It can be achieved by improving residents’ health status to reduce avoidable health services such as hospitalization. It is also important to design more targeted health insurance in order to increase financial support for such vulnerable groups as the poor, chronically ill, children, and senior populations

Evidence for the disky origin of luminous Virgo dwarf ellipticals from the kinematics of their globular cluster systems

We report evidence for dynamically significant rotation in the globular cluster systems of two luminous Virgo dwarf ellipticals, VCC1261 and VCC1528. Including previous results for VCC1087, the globular cluster systems of all three Virgo dwarf ellipticals studied in detail to date exhibit v_rot/sigma > 1. Taking the rotation seen in the globular clusters as maximal disk rotation, we find all three dEs lie on the r-band Tully-Fisher relation. We argue that these data support the hypothesis that luminous dEs are the remnants of transformed disk galaxies. We also obtained deep, longslit data for the stars in VCC1261 and VCC1528. Both these galaxies show rapid rotation in their inner regions, with spatial scales of ~0.5 kpc. These rotation velocities are similar to those seen in the GC systems. Since our longslit data for Virgo dEs extend out to 1-2 effective radii (typical of deep observations), whereas the globular clusters extend out to 4--7 effective radii, we conclude that non-detections of rotation in many luminous dEs may simply be due to a lack of radial coverage in the stellar data, and that globular clusters represent singularly sensitive probes of the dynamics of dEs. Based on these data, we suggest that gas disks are significant sites of globular cluster formation in the early universe.Comment: To appear in the AJ, corrected typographical errors in Table 1, added a referenc

Comprehensive Solution to Scattering by Bianisotropic Objects of Arbitrary Shape

This paper presents a method of moments (MoM) solution for the problems of electromagnetic scattering by inhomogeneous three- dimensional bianisotropic scatterers of any shape. The electromagnetic response of bianisotropy has been described by the constitutive relations of the most general form composed of four 3 £ 3 matrices or tensors. The volume equivalence principle is used to obtain a set of mixed potential formulations for a proper description of the original scattering problem. Here, the total ¯elds are separated into the incident ¯elds and the scattered ¯elds. The scattered ¯elds are related to the electric and magnetic potentials which are excited by electric and magnetic bound charges and polarization currents. The body of the scatterer is meshed through the use of tetrahedral cells with face-based functions used to expand unknown quantities. At last, the Galerkin test method is applied to create a method of moments (MoM) matrix from which the numerical solution is obtained. Implemented in a MATLAB program, the numerical formulation is evaluated and veri¯ed for various types of scatterers. The results are compared with those of previous work, and a good agreement is observed. Finally, a scattering from a two-layered dispersive chiroferrite sphere is presented as the most general example

On-chip, High-sensitivity Temperature Sensors Based on Dye-doped Solid-state Polymer Microring Lasers

We developed a chip-scale temperature sensor with a high sensitivity of 228.6 pm/°C based on a rhodamine 6G (R6G)-doped SU-8 whispering-gallery mode microring laser. The optical mode was largely distributed in a polymer core layer with a 30 μm height that provided detection sensitivity, and the chemically robust fused-silica microring resonator host platform guaranteed its versatility for investigating different functional polymer materials with different refractive indices. As a proof of concept, a dye-doped hyperbranched polymer (TZ-001) microring laser-based temperature sensor was simultaneously developed on the same host wafer and characterized using a free-space optics measurement setup. Compared to TZ-001, the SU-8 polymer microring laser had a lower lasing threshold and a better photostability. The R6G-doped SU-8 polymer microring laser demonstrated greater adaptability as a high-performance temperature-sensing element. In addition to the sensitivity, the temperature resolutions for the laser-based sensors were also estimated to be 0.13 °C and 0.35 °C, respectively. The rapid and simple implementation of micrometer-sized temperature sensors that operate in the range of 31 – 43 °C enables their potential application in thermometry

Managing knowledge to promote sustainability in Australian transport infrastructure projects

To deliver tangible sustainability outcomes, the infrastructure sector of the construction industry needs to build capacities for the creation, application and management of ever increasing knowledge. This paper intends to establish the importance and key issues of promoting sustainability through knowledge management (KM). It presents a new conceptual framework for managing sustainability knowledge to raise the awareness and direct future research in the field of transport infrastructure, one of the fast growing sectors in Australia. A holistic KM approach is adopted in this research to consider the potential to "deliver the right information to the right person at the right time" in the context of sustainable development of infrastructure. A questionnaire survey among practitioners across the nation confirmed the necessity and identified priority issues of managing knowledge for sustainability. During infrastructure development, KM can help build much needed industry consensus, develop capacity, communicate decisions, and promote specific measures for the pursuit of sustainability. Six essential elements of the KM approach and their priority issues informed the establishment of a conceptual KM framework. The transport infrastructure sector has come to realise that development must not come at the expense of environmental and social objectives. In practice however, it is facing extensive challenges to deliver what has been promised in the sustainability agenda. This research demonstrates the importance of managing sustainability knowledge, integration of various stakeholders, facilitation of plans and actions and delivery of tangible benefits in real projects, as a positive step towards meeting these challenges

Regulation of the formation of osteoclastic actin rings by proline-rich tyrosine kinase 2 interacting with gelsolin

Osteoclast activation is important for bone remodeling and is altered in multiple bone disorders. This process requires cell adhesion and extensive actin cytoskeletal reorganization. Proline-rich tyrosine kinase 2 (PYK2), a major cell adhesion–activated tyrosine kinase in osteoclasts, plays an important role in regulating this event. The mechanisms by which PYK2 regulates actin cytoskeletal organization and osteoclastic activation remain largely unknown. In this paper, we provide evidence that PYK2 directly interacts with gelsolin, an actin binding, severing, and capping protein essential for osteoclastic actin cytoskeletal organization. The interaction is mediated via the focal adhesion–targeting domain of PYK2 and an LD motif in gelsolin's COOH terminus. PYK2 phosphorylates gelsolin at tyrosine residues and regulates gelsolin bioactivity, including decreasing gelsolin binding to actin monomer and increasing gelsolin binding to phosphatidylinositol lipids. In addition, PYK2 increases actin polymerization at the fibroblastic cell periphery. Finally, PYK2 interacts with gelsolin in osteoclasts, where PYK2 activation is required for the formation of actin rings. Together, our results suggest that PYK2 is a regulator of gelsolin, revealing a novel PYK2–gelsolin pathway in regulating actin cytoskeletal organization in multiple cells, including osteoclasts

Association of Early Interventions With Birth Outcomes and Child Linear Growth in Low-Income and Middle-Income Countries:Bayesian Network Meta-analyses of Randomized Clinical Trials

Importance:The first 1000 days of life represent a critical window for child development. Pregnancy, exclusive breastfeeding (EBF) period (0-6 months), and complementary feeding (CF) period (6-24 months) have different growth requirements, so separate considerations for intervention strategies are needed. No synthesis to date has attempted to quantify the associations of interventions under multiple domains of micronutrient and balanced energy protein and food supplements, deworming, maternal education, water sanitation, and hygiene across these 3 life periods with birth and growth outcomes. Objective: To determine the magnitude of association of interventions with birth and growth outcomes based on randomized clinical trials (RCTs) conducted in low-income and middle-income countries (LMICs) using Bayesian network meta-analyses. Data Sources: MEDLINE, Embase, and Cochrane databases were searched from their inception up to August 14, 2018. Study Selection: Included were LMIC-based RCTs of interventions provided to pregnant women, infants (0-6 months), and children (6-24 months). Data Extraction and Synthesis: Two independent reviewers used a standardized data extraction and quality assessment form. Random-effects network meta-analyses were performed for each life period. Effect sizes are reported as odds ratios (ORs) and mean differences (MeanDiffs) for dichotomous and continuous outcomes, with 95% credible intervals (CrIs). This study calculated probabilities of interventions being superior to standard of care by at least a minimal clinically important difference. Main Outcomes and Measures. The study compared ORs on preterm birth and MeanDiffs on birth weight for pregnancy, length for age (LAZ) for EBF, and height for age (HAZ) for CF. Results: Among 302 061 participants in 169 randomized clinical trials, the network meta-analyses found several nutritional interventions that demonstrated greater association with improved birth and growth outcomes compared with standard of care. For instance, compared with standard of care, maternal supplements of multiple micronutrients showed reduced odds for preterm birth (OR, 0.54; 95% CrI, 0.27-0.97) and improved mean birth weight (MeanDiff, 0.08 kg; 95% CrI, 0.00-0.17 kg) but not LAZ during EBF (MeanDiff, −0.02; 95% CrI, −0.18 to 0.14). Supplementing infants and children with multiple micronutrients showed improved LAZ (MeanDiff, 0.20; 95% CrI, 0.03-0.35) and HAZ (MeanDiff, 0.14; 95% CrI, 0.02-0.25). The study found that pregnancy interventions generally had higher probabilities of a minimal clinically importance difference than the interventions for the EBF or CF in the first 1000 days of life. Conclusions and Relevance: These analyses highlight the importance of intervening early for child development, during pregnancy if possible. Results of this study suggest that there is a need to combine interventions from multiple domains and test for their effectiveness as a package