The emergence of interface states in graphene/transition metal dichalcogenides heterostructure with lateral interface

The relative strength of different proximity spin-orbit couplings in graphene on transition metal dichalcogenides (TMDC) can be tuned via the metal composition in the TMDC layer. While Gr/MoSe$_2$, has a normal gap, proximity to WSe$_2$ instead leads to valley-Zeeman-driven inverted bands. Although the $\mathbb{Z}_2$ index vanishes, these systems enable a concentration-dependent topological crossover with band gap closure when graphene is stacked on a composite or alloyed TMDC layer. This is due to a nonzero Berry curvature at the individual valleys and a change of the valley Chern index at a critical composition ratio. Therefore, inherently, we also expect that stacked heterostructures of graphene on composite TMDC layers should host localised boundary modes due to the presence of Gr/WSe$_2$- and Gr/MoSe$_2$-like domains with opposite valley Chern indices. In this study, we show that a Gr/(Mo-W)Se$_2$ heterostructure with a lateral interface in the TMDC layer can indeed host topologically protected in-gap propagating modes, similar to those at the border of commensurate AB and BA domains in biased minimally-twisted bilayer graphene. However, the stability of these modes depends crucially on the system size. We demonstrate that the electronic behaviour of Gr/(Mo-W)Se$_2$ heterostructures evolves from a homogeneous effective medium to a superposition of domain-localised bands and zero-energy branch crossings as the domain size in the alloyed TMDC layer is increased.Comment: 10 pages and 4 figure

Constellation Queries over Big Data

A geometrical pattern is a set of points with all pairwise distances (or, more generally, relative distances) specified. Finding matches to such patterns has applications to spatial data in seismic, astronomical, and transportation contexts. For example, a particularly interesting geometric pattern in astronomy is the Einstein cross, which is an astronomical phenomenon in which a single quasar is observed as four distinct sky objects (due to gravitational lensing) when captured by earth telescopes. Finding such crosses, as well as other geometric patterns, is a challenging problem as the potential number of sets of elements that compose shapes is exponentially large in the size of the dataset and the pattern. In this paper, we denote geometric patterns as constellation queries and propose algorithms to find them in large data applications. Our methods combine quadtrees, matrix multiplication, and unindexed join processing to discover sets of points that match a geometric pattern within some additive factor on the pairwise distances. Our distributed experiments show that the choice of composition algorithm (matrix multiplication or nested loops) depends on the freedom introduced in the query geometry through the distance additive factor. Three clearly identified blocks of threshold values guide the choice of the best composition algorithm. Finally, solving the problem for relative distances requires a novel continuous-to-discrete transformation. To the best of our knowledge this paper is the first to investigate constellation queries at scale

Staggered Quantum Walks With Superconducting Microwave Resonators

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)The staggered quantum walk is a model defined by the product of local operators associated with two or more independent graph tessellations. This model is versatile, encompasses several well-known discrete-time quantum walks, and inherits interesting features of the continuous-time quantum walk. We propose an implementation of the staggered quantum walk model with superconducting microwave resonators, where the required local operations are provided by the nearest neighbor interaction of the resonators coupled through superconducting quantum interference devices. The tunability of the interactions makes this system an excellent toolbox for this class of quantum walks. We focus on the one-dimensional case and discuss its generalization to a more general class known as triangle-free graphs.9514CNPq [PDJ 165941/2014-6, 303406/2015-1, 474143/2013-9]FAPESP through the Research Center in Optics and Photonics (CePOF)Faperj [26/102.350/2013]Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP

ACADEMIC LIBRARY USERS’ EXPERIENCE: A REVIEW ON RELATED CONCEPTS AND EMPIRICAL IMPLICATION

In order to answer the questions raised to guide this study, there is need to review previous literature that relates to variables understudied. Also, to operationally define key concepts used for this study to ensure clarity of the concepts. Literature review shows a vibrant section and significant untouched materials to structure the infrastructure of a precise subject component in whichever category of a research study. It is conducted to obtain a clear consideration about the precise area of study. The literature review is arranged developing themes directly drawn from the literature, chronologically and thematically in this study. Researchers followed literature Review as the main methodology to review the existing empirical knowledge to build conceptual content to support for the proposed research directions. The findings provide the insights on how empirical findings being shared in literature reviews connecting the concept of Band Citizenship behavior and related concepts and implications. Based on the discussion, postulate the future research directions in line with the empirical knowledge gaps found within.  Article visualizations

EXAMINES ACADEMIC LIBRARY USERS’ EXPERIENCE TOWARDS LIBRARY PATRONAGE IN STATE UNIVERSITIES IN SRI LANKA

Libraries and information centers are service units held with the responsibility of providing varied information services based on a number of resources. It covers tangible assets, namely library building, equipment, furniture, information resources and staff. The intangible element has been the information services provided by the libraries. The tangible assets and intangible services of libraries are changing greatly due to the development and changes in the area of information technology. The purpose of this study is to empirically investigate to accomplish the relationship between Service Quality dimensions, customer experience (CE) library patronage (LP) and library user attitude (LUA) in the context of university library service quality in Sri Lanka. In addition, it investigates the mediating effect of customer experience in the relationship between dimensions of library service quality and the library patronage.  Article visualizations

A novel approach to prevent graphene oxide re-aggregation during the melt compounding with polymers

The technology for the preparation of polymer-GO nanocomposites was investigated by studying the structure-properties relationships of two different systems, based on PA6 and EVA, fabricated by using different preparation methods, i.e. melt mixing, wet phase inversion, and the combination of the two. The morphology of nanocomposites resulted dramatically influenced by the technique adopted and showed to be the critical variable affecting the physical properties of the materials. Finally, the mechanical and dynamic-mechanical of the nanocomposites were improved by using the hybrid technique combining the two procedures

Historical Evolution from Measuring Service Quality to Library User Experience:: A Conceptual Review of Related Concepts

Experience reflects customers’ overall assessment of value rather than in relation to expectations, highlighting the importance of these perceptual attributes. These attributes reflect customers’ higher-order objectives leading to purchasing behavior better than technical aspects of service do, the latter subject to frequent changes due to technology and competition. Therefore perceptual attributes are more stable as the focus of evaluation of experience SERVQUAL focuses largely upon customers’ assessment of the service process and human interactions Individual components of a service encounter may be assessed as ‘good quality’, but that does not automatically mean that the overall experience is judged high quality, nor does measuring the components of service quality ensure that customers achieve their desired outcomes

The effects of alpha-lipoic acid supplementation on glucose control and lipid profiles among patients with metabolic diseases: A systematic review and meta-analysis of randomized controlled trials

Abstract Objective This systematic review and meta-analysis of randomized controlled trials (RCTs) was performed to summarize the effect of alpha-lipoic acid (ALA) supplementation on glycemic control and lipid profiles among patients with metabolic diseases. Methods We searched the following databases till October 2017: MEDLINE, EMBASE, Web of Science and Cochrane Central Register of Controlled Trials. The relevant data were extracted and assessed for quality of the studies according to the Cochrane risk of bias tool. Data were pooled using the inverse variance method and expressed as standardized mean difference (SMD) with 95% confidence intervals (95% CI). Heterogeneity between studies was assessed by the Cochran Q statistic and I-squared tests (I2). Twenty-four studies were included in the meta-analyses. Results The findings of this meta-analysis showed that ALA supplementation among patients with metabolic diseases significantly decreased fasting glucose (SMD -0.54; 95% CI, −0.89, –0.19; P = 0.003), insulin (SMD –1.01; 95% CI, −1.70, −0.31; P = 0.006), homeostasis model assessment of insulin resistance (SMD -0.76; 95% CI, −1.15, –0.36; P < 0.001) and hemoglobin A1c (SMD –1.22; 95% CI, −2.01, –0.44; P = 0.002), triglycerides (SMD –0.58; 95% CI, −1.00, −0.16; P = 0.006), total- (SMD –0.64; 95% CI, −1.01, −0.27; P = 0.001), low density lipoprotein-cholesterol (SMD –0.44; 95% CI, −0.76, −0.11; P = 0.008). We found no detrimental effect of ALA supplementation on high density lipoprotein-cholesterol (HDL-cholesterol) levels (SMD 0.57; 95% CI, −0.14, 1.29; P = 0.11). Conclusions Overall, the current meta-analysis demonstrated that ALA administration may lead to an improvement in glucose homeostasis parameters and lipid profiles except HDL-cholesterol levels. Keywords: Meta-analysis Lipid profiles Glycemic control Alpha-lipoic acid