bluuebunny/crossref_metadata_2025 huggingface dataset:
Locally Resonant Effective Phononic Crystals for Subwavelength Vibration Control of Torsional Cylindrical Waves
Authors: Arretche Ignacio , Matlack Kathryn H.
Published: October 2021

Locally resonant materials allow for wave propagation control in the subwavelength regime. Even though these materials do not need periodicity, they are usually designed as periodic systems since this allows for the application of the Bloch theorem and analysis of the entire system based on a single unit cell. However, geometries that are invariant to translation result in equations of motion with periodic coefficients only if we assume plane wave propagation. When wave fronts are cylindrical or spherical, a system realized through tessellation of a unit cell does not result in periodic coefficients and the Bloch theorem cannot be applied. Therefore, most studies of periodic locally resonant systems are limited to plane wave propagation. In this article, we address this limitation by introducing a locally resonant effective phononic crystal composed of a radially varying matrix with attached torsional resonators. This material is not geometrically periodic but exhibits effective periodicity, i.e., its equations of motion are invariant to radial translations, allowing the Bloch theorem to be applied to radially propagating torsional waves. We show that this material can be analyzed under the already developed framework for metamaterials. To show the importance of using an effectively periodic system, we compare its behavior to a system that is not effectively periodic but has geometric periodicity. We show considerable differences in transmission as well as in the negative effective properties of these two systems. Locally resonant effective phononic crystals open possibilities for subwavelength elastic wave control in the near field of sources.
Fe2O3-WO3 and Fe2O3-CuO nanoheterostructures by XPS
Authors: Maccato Chiara , Bigiani Lorenzo , Barreca Davide , Gasparotto Alberto
Published: October 2021

The detrimental effects of gaseous nitrogen oxides (NOx, with x = 1 and 2) on both human health and the environment have triggered efforts aimed at the development of solar-activated photocatalysts for their efficient removal. In this regard, Fe2O3-WO3 and Fe2O3-CuO nanoheterostructures were prepared by a two-step vapor phase route. In particular, chemical vapor deposition (CVD) of β-Fe2O3, a scarcely investigated iron(III) oxide polymorph, was followed by radio frequency-sputtering of WO3 or CuO under mild conditions. The adopted strategy enabled the obtainment of nanoheterostructures with a peculiar pyramidal morphology and a uniform dispersion of CuO or WO3 onto the pristine iron(III) oxide. In this work, the chemical composition of the target systems was investigated by means of x-ray photoelectron and x-ray excited-Auger electron spectroscopies. In addition to the identification of elemental chemical states, the reported results confirmed the formation of pure and O-deficient systems, in which the direct interplay between the single components opens the door to air purification using the developed systems as photocatalysts.
Native listeners rely on rhythmic cues when deciding on the nativeness of speech
Authors: Pellegrino Elisa , Schwab Sandra , Dellwo Volker
Published: October 2021

Foreign-accented speech typically deviates segmentally and suprasegmentally from native-accented speech. Two experiments were conducted to investigate the role of amplitude envelope (ENV), segment duration (DUR), and speech rate (SR) on Italian listeners' ability to identify native-accented Italian in utterances produced by Zurich German speakers. In experiment 1, listeners judged in a two-alternative forced-choice perception task which of the two stimuli in a trial they perceived as more native-like. Stimuli in each trial only varied in ENV and DUR, which were retrieved either from a native Italian speaker [first language (L1) donor] or from a German speaker of Italian [second language (L2) donor]. Results revealed that listeners make use of both DUR and ENV to identify the more native-like stimuli, but the effect of ENV was more subtle. In experiment 2, SR differences (resulting from native and non-native segment duration differences in experiment 1) were normalized for. It was found that this drastically reduced the effect of segment durations in terms of perceived nativeness; however, the ENV effect still remained. This was not the case in a control group of listeners without competence in Italian. Though effects were subtle, the study shows that ENV cues contribute to the percept of nativeness in L2 speech.
Modeling three-dimensional underwater acoustic propagation over multi-layered fluid seabeds using the equivalent source method
Authors: He Tengjiao , Mo Shiqi , Fang Erzheng , Wang Mingguang , Zhang Rui
Published: October 2021

This paper develops an efficient three-dimensional (3D) underwater acoustic propagation model with multi-layered fluid seabeds based on the equivalent source method (ESM). It solves the Helmholtz equation exactly by a superposition of fields generated by equivalent sources. A linear system coupling ESM equations is derived by imposing boundary conditions and solved iteratively using the generalized minimum residual method. Unlike a direct ESM solver, matrix–vector products in each iteration are evaluated by a pre-corrected fast Fourier transformation (PFFT), significantly reducing the numerical cost and enabling efficient solution of 3D large-scale propagation. Moreover, sound speed profiles can be taken into account by dividing the water column into sub-layers, each of which requires an individual PFFT procedure using an FFT subgrid scheme. Simulations of propagation over a Gaussian canyon validate the PFFT-accelerated ESM (PFFT-ESM). The capability of the PFFT-ESM for 3D scattering problems is demonstrated by further presenting the Gaussian canyon simulations with corrugated surface waves.
Cryptic vocal behavior of foraging humpback whales on feeding grounds in West Greenland
Authors: Videsen Simone K. A. , Simon Malene , Johnson Mark , Madsen Peter Teglberg , Christiansen Fredrik
Published: October 2021

Male humpback whales (Megaptera novaeangliae) sing in mating aggregations in the form of song displays, but much less is known about how both sexes use sound on their feeding grounds. Here, we test different hypotheses about the function of vocalizations in 14 foraging humpback whales tagged with sound and movement recording Dtags in Greenland. We show that this population of foraging humpback whales have an overall low call rate of 11.9 calls h−1 (inter-quartile range = 12.1) with no support for the hypotheses that they employ sound in the localization or manipulation of prey nor in the coordination of lunge feeding. The calls had a mean received level of 135 ± 5dB re 1 μPa, which is some 30 dB lower than maximum levels of song recorded on similar deployed tags, suggesting a much smaller active space of these vocalizations. This reduced active space might, in concert with low call rates, serve to mitigate eavesdropping by predatory killer whales or conspecifics competing for the same prey resources. We conclude that feeding humpback whales in Greenland produce low level, infrequent calls suggesting that calling is not a prerequisite for successful feeding, but likely serves to mediate within group social interactions.
Analogs of Marinopyrrole A Show Enhancement to Observed
In Vitro
Potency against Acute Toxoplasma gondii Infection
Authors: Martens Matthew C. , Liu Yan , Sanford Austin G. , Wallick Alexander I. , Warner Rosalie C. , Li Rongshi , Davis Paul H.
Published: October 2021

The apicomplexan parasite
Toxoplasma gondii
is the causative agent of toxoplasmosis, a globally distributed infection with severe clinical consequences for immunocompromised individuals and developing fetuses. There are few available treatments, and these are associated with potentially severe adverse effects.
Pharmacokinetics/Pharmacodynamics of Caspofungin in Plasma and Peritoneal Fluid of Liver Transplant Recipients
Authors: Pressiat Claire , Ait-Ammar Nawel , Daniel Matthieu , Hulin Anne , Botterel Françoise , Levesque Eric
Published: October 2021

The weaker diffusion of echinocandins in the peritoneal fluid (PF) could promote
Candida
-resistant isolates. The aim of this study was to analyze the pharmacokinetics (PK)/pharmacodynamics (PD) of caspofungin in plasma and PF samples from liver transplant recipients.
In Vitro
Susceptibility of Typhoidal, Nontyphoidal, and Extended-Spectrum-β-Lactamase-Producing
Salmonella
to Ceftolozane/Tazobactam
Authors: Teng Jade L. L. , Chan Elaine , Dai Asher C. H. , Ng Gillian , Li Tsz Tuen , Lai Christopher , Wu Alan K. L. , Lau Susanna K. P. , Woo Patrick C. Y.
Published: October 2021

Both typhoidal and nontyphoidal salmonellae are included in the top 15 drug-resistant threats described by the U.S. Centers for Disease Control and Prevention.
In Vitro
Activity of Ceftibuten/VNRX-5236 against Urinary Tract Infection Isolates of Antimicrobial-Resistant
Enterobacterales
Authors: Karlowsky James A. , Hackel Meredith A. , Sahm Daniel F.
Published: October 2021

Ceftibuten/VNRX-7145 is a cephalosporin/boronate β-lactamase inhibitor combination under development as an oral treatment for complicated urinary tract infections caused by
Enterobacterales
producing serine β-lactamases (Ambler class A, C, and D).
In vivo
, VNRX-7145 (VNRX-5236 etzadroxil) is cleaved to the active inhibitor, VNRX-5236. We assessed the
in vitro
activity of ceftibuten/VNRX-5236 against 1,066 urinary isolates of
Enterobacterales
from a 2014–2016 global culture collection.
Phage Activity against Planktonic and Biofilm Staphylococcus aureus Periprosthetic Joint Infection Isolates
Authors: Totten Katherine M. C. , Patel Robin
Published: October 2021

We recently reported the successful treatment of a case of periprosthetic joint infection (PJI) with phage. Phage activity against bacteria causing PJI has not been systematically evaluated.
The Workings of a Renal Unit
Authors: Hedger N. A.
Published: October 2021

This article describes the work of a large Regional Renal Unit. A background to the structure and logistics of such a unit is given along with the type of patients it receives and therapies it can offer. Renal Replacement Therapy (RRT) is briefly described, as are the problems associated with it. The aim is to de-mystify the workings of a renal unit and to provide some advice concerning its use by non-nephrologists.
Royal British Legion War Grave Pilgrimages: A Medical Escort’s Perspective
Authors: Richardson J. C.
Published: October 2021

The Royal British Legion organises pilgrimages to nearly all parts of the world where British servicemen and servicewomen and their allies fought and died. The Pilgrimage Department has taken thousands of widows, other relatives, veterans and friends to visit the grave of a loved one or comrade buried overseas. The parties of pilgrims are escorted by Service medical officers and nurses of the Regular and Reserve Armed Forces. The role of the medical escort is described.
Middle term results of a cementless threaded self-tapping acetabular cup
Authors: Pandit H. G. , Hand C. J. , Ramos J. L. , Pradham N. S. , Boyd N. A.
Published: October 2021

Various designs of acetabular cup are available for cementless fixation in patients undergoing total hip arthroplasty. Conflicting results have been reported in the literature about the middle to long term outcomes with the use of these cups. We present our experience of a design of self-tapping threaded acetabular cup with metal backing (the ACSYS acetabular cup). This is a study of 41 hips with average follow up of 6.43 years. Functional grading of the hips was very satisfactory and none of the patients needed revision for aseptic loosening. No case of significant cup migration or osteolysis was noted. The paper also reviews the literature.
Heat strain in Royal Navy helicopter aircrew
Authors: House J. R
Published: October 2021

A review of the literature on heat strain and aircrew and a questionnaire survey of Royal Navy aircrew have been completed. Aircrew appreciate, some 50% from first hand experience, that heat strain can reduce their operational endurance and performance. They are at greatest risk of developing it in the pre-flight period, especially when wearing Nuclear, Biological, or Chemical (NBC) protective equipment. Several techniques they use to reduce this risk are described. Some may be of particular assistance in the field should air conditioned facilities be unavailable. However, opportunities to improve the thermal environment within the aircraft on the ground and in flight are limited as the heat generated within it and high levels of solar radiation impinging on it severely challenge air conditioning units, themselves constrained by weight and size. Other demands placed on protective clothing offer little potential to increase the rate at which aircrew can lose accumulated heat. It is concluded that an appropriate micro-climate cooling system worn next to the skin may be required to achieve truly significant reductions in heat strain. Research at the Institute of Naval Medicine has identified liquid cooling techniques which may be suitable for aircrew in all but the smallest helicopters.

Any views expressed are those of the author and do not necessarily represent those of the Department.
Normative blood pressure response to exercise stress testing in children and adolescents
Authors: Clarke Melanie M , Zannino Diana , Stewart Natalie P , Glenning Jonathan P , Pineda-Guevara Salvador , Kik Jolien , Mynard Jonathan P , Cheung Michael M H
Published: October 2021

Objective

To describe normative values for blood pressure (BP) response to maximal exercise in children/adolescents undergoing a treadmill stress test.

Methods

From a retrospective analysis of medical records, patients who had undergone a Bruce protocol exercise stress test, with (1) normal cardiovascular system and (2) a body mass index percentile rank below 95% were included for analysis. Sex, age, height, weight, resting and peak heart rate, resting and peak systolic blood pressure (SBP), test duration, stage of Bruce protocol at termination, reason for undergoing the test and reason for termination of test were collected. Percentiles for exercise-induced changes in SBP were constructed by age and height for each sex with the use of quantile regression models.

Results

648 patients with a median age of 12.4 years (range 6–18 years) were included. Typical indications for stress testing were investigation of potential rhythm abnormalities, syncope/dizziness and chest pain and were deemed healthy by an overseeing cardiologist. Mean test duration was 12.6±2.2 min. Reference percentiles for change in SBP by sex, age and height are presented.

Conclusion

The presented reference percentiles for the change in SBP for normal children and adolescents will have utility for detecting abnormally high or low BP responses to exercise in these age groups.
Metallo-beta-lactamase-producing Escherichia coli in the sewage of Mexico City: where do they come from?
Authors: Lüneberg Kathia , Amábile-Cuevas Carlos F. , Mucito-Varela Eduardo , Martínez Leticia , Salinas Eva , López-Vidal Yolanda , Siebe Christina , Rosas Irma
Published: October 2021

While monitoring the presence of antibiotic resistance in municipal wastewater bacteria from Mexico City, five Escherichia coli isolates were found to be resistant to carbapenems, antibiotics of “last resort” used mostly in hospitals. Further analysis revealed that these carbapenem-resistant isolates carried the gene encoding a metallo-beta-lactamase, NDM-5. The gene was found to be beared by a large, ∼145 kb conjugative plasmid, which also carries putative genes encoding resistance to sulfonamides, trimethoprim, tetracycline, ciprofloxacin, and chloramphenicol (although no phenotypic chloramphenicol resistance was detected) and quaternary-ammonium compounds. The plasmid also carried gene mobility determinants, such as integron integrase and two transposases. In addition to the direct public health threat posed by the presence of such multi-resistant organisms in wastewater released into the environment and used for crop irrigation; it is particularly concerning that carbapenem-resistant E. coli is rather rare in Mexican hospitals (<1%), but was found in small, 100 mL samples of municipal wastewater. This suggests that these organisms are under-reported by clinical microbiology laboratories, underlining the usefulness of wastewater monitoring, or that there is an unknown source of such carbapenem-resistant organisms that are being dumped into the wastewater. The source of these bacteria must be assessed and controlled to prevent further spread of this multi-resistance plasmid among other environmental and clinical microorganisms.
Sensitivity to triple Higgs couplings via di-Higgs production in the 2HDM at $$e^+e^-$$ colliders
Authors: Arco F. , Heinemeyer S. , Herrero M. J.
Published: October 2021

An important task at future colliders is the investigation of the Higgs-boson sector. Here the measurement of the triple Higgs coupling(s) plays a special role. Based on previous analyses, within the framework of Two Higgs Doublet Models (2HDM) type I and II, we define and analyze several two-dimensional benchmark planes, that are over large parts in agreement with all theoretical and experimental constraints. For these planes we evaluate di-Higgs production cross sections at future high-energy $$e^+e^-$$

e
+

e
-

colliders, such as ILC or CLIC. We consider two different channels for the neutral di-Higgs pairs $$h_i h_j=hh,hH,HH,AA$$

h
i

h
j

=
h
h
,
h
H
,
H
H
,
A
A

: $$e^+e^- \rightarrow h_i h_j Z$$

e
+

e
-

→

h
i

h
j

Z

and $$e^+e^- \rightarrow h_i h_j \nu {{\bar{\nu }}}$$

e
+

e
-

→

h
i

h
j

ν

ν

¯

. In both channels the various triple Higgs-boson couplings contribute substantially. We find regions with a strong enhancement of the production channel of two SM-like light Higgs bosons and/or with very large production cross sections involving one light and one heavy or two heavy 2HDM Higgs bosons, offering interesting prospects for the ILC or CLIC. The mechanisms leading to these enhanced production cross sections are analyzed in detail. We propose the use of cross section distributions with the invariant mass of the two final Higgs bosons where the contributions from intermediate resonant and non-resonant BSM Higgs bosons play a crucial role. We outline which process at which center-of-mass energy would be best suited to probe the corresponding triple Higgs-boson couplings.
The Soret coefficients of the ternary system water/ethanol/triethylene glycol and its corresponding binary mixtures
Authors: Schraml M. , Bataller H. , Bauer C. , Bou-Ali M. M. , Croccolo F. , Lapeira E. , Mialdun A. , Möckel P. , Ndjaka A. T. , Shevtsova V. , Köhler W.
Published: October 2021

Thermodiffusion in ternary mixtures is considered prototypic for the Soret effect of truly multicomponent systems. We discuss ground-based measurements of the Soret coefficient along the binary borders of the Gibbs triangle of the highly polar and hydrogen bonding ternary DCMIX3-system water/ethanol/triethylene glycol. All three Soret coefficients decay with increasing concentration, irrespective of the choice of the independent component, and show a characteristic sign change as a function of temperature and/or composition. With the exception of triethylene glycol/ethanol at high temperatures, the minority component always migrates toward the cold side. All three binaries exhibit temperature-independent fixed points of the Soret coefficient. The decay of the Soret coefficient with concentration can be related to negative excess volumes of mixing. The sign changes of the Soret coefficients of the binaries allow to draw far-reaching conclusions about the signs of the Soret coefficients of the corresponding ternary mixtures. In particular, we show that at least one ternary composition must exist, where all three Soret coefficients vanish simultaneously and no steady-state separation is observable.

Graphic abstract
Land Cover Image Segmentation Based on Individual Class Binary Masks
Authors: Somasunder Sathyanarayanan , Shih Frank Y.
Published: October 2021

Remote sensing techniques have been developed over the past decades to acquire data without being in contact of the target object or data source. Their application on land-cover image segmentation has attracted significant attention during recent years. With the help of satellites, scientists and researchers can collect and store high-resolution image data that can be further be processed, segmented, and classified. However, these research results have not yet been synthesized to provide coherent guidance on the effect of variant land-cover segmentation processes. In this paper, we present a novel model that augments segmentation using smaller networks to segment individual classes. The combined network is trained on the same data but with the masks, combined and trained using categorical cross entropy. Experimental results show that the proposed method produces the highest mean IoU (Intersection of Union) as compared against several existing state-of-the-art models on the DeepGlobe dataset.
A Hybrid Artificial Bee Colony Algorithm to Solve a New Minimum Exposure Path Problem with Various Boundary Conditions for Wireless Sensor Networks
Authors: Ye Miao , Cai Yue , Qiu Hongbing , Wang Junyi , Deng Xiaofang
Published: October 2021

The original minimum exposure path (MEP) problem in WSNs (wireless sensor networks) requires the starting point and ending point of a moving target to be fixed, thus limiting the evaluation of coverage quality relative to the locations of these points. To resolve this issue, a minimum exposure path problem with various boundaries (VB-MEP) is proposed in this paper. Because the corresponding graph model cannot be established, the original classical methods (grid method and Voronoi diagram method) used to solve the minimum exposure path problem are no longer effective for the VB-MEP problem. This paper first transforms the problem into a hybrid optimization problem with constraint conditions and then considers the characteristics of the transformed mathematical optimization model with high dimensionality, unfixed dimensionality and high nonlinearity so that the deterministic optimization methods are no longer applicable. A hybrid artificial colony solution algorithm that incorporates the actual characteristics of the problem is designed, and a convergence analysis and a proof of the designed algorithm are given. Through simulation experiments based on large-scale node distribution scenarios, it is found that the designed hybrid optimization model with constraints and hybrid artificial bee colony solution algorithm can effectively solve the proposed VB-MEP problem.
Coastline Extraction from GF-3 SAR Images Using LKDACM and GMM Algorithms
Authors: Liu Dongsheng , Han Ling
Published: October 2021

Coastline detection using a Gaussian Mixture Model (GMM) applied to synthetic aperture radar (SAR) imagery is usually inaccurate due to the inherent noise of SAR data. In addition, the traditional active counter model is sensitive to the initial position of the contour line and requires a large number of iterations to converge to a solution. In this study, we first used the GMM algorithm to segment the SAR images and obtain a coarse land and sea segmentation map. This map is then used as the initial position for a subsequent active contour model. The K distribution was introduced into the local statistical active contour model to better model the SAR image. The Gaussian distribution-based local active contour model and the algorithm detailed in this paper were used to perform coastline extraction experiments on four SAR images. Four GF-3 SAR images with different modes were collected to validate the efficiency of the proposed method. The experimental results show that the coastline extraction methods from SAR images based on the GMM algorithm and the K distribution-based local statistical active contour model (LKDACM) overcame the shortcomings of the traditional active contour model to accurately and quickly detect coastlines, thus enabling the detection of coastline changes.
A New Method for Surface-to-Air Video Detection and Tracking of Airborne Vehicles
Authors: Pakfiliz Ahmet Güngör
Published: October 2021

Detection process of airborne targets may be thought simple because of the incompatible nature of aircraft, choppers, UAVs, and drones regarding clear sky background. When changes in the background are considered, brightness variation of the sky complicates the process. Changes in the shapes and types of clouds add another challenge to the process. Tracking process directly depends on the detection process and type of the data stream. The practical systems used for video detection and tracking of airborne targets are manual, and manual structures have some drawbacks compared to automatic structures. For video surveillance, guidance, regional security, and defense applications in dense environments, automatic detection and tracking process may be an obligation rather than preference. In this study, an automatic detection and tracking algorithm for video streams of airborne targets is proposed. A land-based moving camera captures the video data, and not only the flying objects but probably also the camera are in motion. Although the detection and tracking of moving objects via moving sensors is a relatively arduous task, this is the prevalent case in real-life scenarios. Video detection and tracking systems have one or more moving video sensors, while one or more flying air vehicles are in operation area. The proposed algorithm includes an image processing stage for detection and a tracking stage for initiation and continuation. An assessment study has been conducted for the actual video data and found that the proposed method yields successful results for detection, track formation, and continuation processes.
Rescaled Einstein–Hilbert gravity: Inflation and the Swampland criteria
Authors: Oikonomou V. K. , Giannakoudi Ifigeneia , Gitsis Achilles , Revis Konstantinos-Rafail
Published: October 2021

In this work, we shall study a class of [Formula: see text] gravity models which during the inflationary era, which is the large curvature regime, result to an effective inflationary Lagrangian that contains a rescaled Einstein–Hilbert term [Formula: see text] in the presence of a canonical minimally coupled scalar field. The dimensionless parameter [Formula: see text] is chosen to take values in the range [Formula: see text] and the main motivation for studying these rescaled Einstein–Hilbert [Formula: see text] gravities, is the fact that the rescaled action may render an otherwise incompatible canonical scalar field theory with the Swampland criteria, to be compatible with the Swampland criteria and specifically the distance conjecture and the de Sitter conjecture, without considering the refined de Sitter conjecture however. As we will show, by studying a large number of inflationary potentials appearing in the 2018 Planck collaboration paper for the constraints on inflation, the simultaneous compatibility with both the Planck constraints and the aforementioned two Swampland criteria is achieved for some models, and the main characteristic of the models for which this is possible is the small value that the parameter [Formula: see text] must take.
ELECTROCHEMICAL CORROSION BEHAVIOR AND MICROSTRUCTURAL CHARACTERIZATION OF HVOF SPRAYED INCONEL718-Al2O3COMPOSITE COATINGS
Authors: VASUDEV HITESH , PRASHAR GAURAV , THAKUR LALIT , BANSAL AMIT
Published: October 2021

In the current experimental study, grey cast iron (CI) substrate was coated with Inconel718-Al2O3based composite coating with a high-velocity oxy-fuel technique. The effect of changing the Al2O3content (10, 20 and 30 wt.%) on the microstructure, hardness, porosity and electrochemical corrosion performance of Inconel (INC718) coating was studied. Investigations on the corrosion behavior of uncoated and HVOF-coated substrates were carried out at room temperature at 3.5[Formula: see text]wt.% sodium chloride solution (NaCl) with the help of the potentiodynamic polarization approach. The surface morphologies and compositions of HVOF as-sprayed and electrochemically corroded coatings were studied through SEM and EDS techniques. The various phases existing in the INC718 and Al2O3feedstock powders and HVOF-deposited composite coatings were determined by XRD analysis. The microhardness of INC718-based coatings was found to be increased with the increase in Al2O3content. The highest average microhardness value of about [Formula: see text]HV[Formula: see text] was observed in INC718-30[Formula: see text]wt.% Al2O3coating. The deposited coatings exhibited an increased porosity level with the increased amount of Al2O3contents. However, the coating with 10[Formula: see text]wt.% Al2O3content exhibited the maximum corrosion resistance. Its improved corrosion performance is attributed to low porosity levels, which causes the penetrating pathways of Cl−ions to be blocked completely.
APPLICATION OF POLARIZED RESONANCE SYNCHRONOUS SPECTROSCOPY IN CHARACTERIZING THE COMPLEX OPTICAL BEHAVIOR OF CdTe QUANTUM DOTS
Authors: DIAO NA , YANG CONGLING , WU SHAOGUI , WANG JIAYANG , WU PEIZE
Published: October 2021

Quantum dots (QDs) are a kind of excellent nano fluorescent materials with complex optical properties. They are simultaneous photon absorber, emitter and scatterer, making it difficult to comprehensively and accurately understand their optical behaviors using conventional methods. Existing studies almost concentrated on their photon absorption and fluorescence features while few studies focused on their light scattering, on-resonance fluorescence (ORF), and so on. In this work, we report a study of the complex optical activities of CdTe QDs using a polarized resonance synchronous spectroscopy (PRS2), combined with Ultraviolet-visible (UV-vis) spectroscopy and fluorescence polarization technologies. This work reveals the complicated optical behaviors of CdTe QDs under the conditions of different ligand functionalization, concentration, incubation time, solvent polarity and provides information including scattering, ORF, UV-vis absorbance spectra, UV-vis extinction, absorption, and scattering cross-section spectra, Stokes-shifted fluorescence (SSF) depolarization and scattering to extinction ratio (SER), etc. Furthermore, we explored the mechanism of QDs as a fluorescent sensor to detect trace Hg2+ from the perspective of light scattering. The observation suggested that the binding of Hg2+ to the QDs leads to their aggregation, which might also contribute to the fluorescence quenching of QDs. Our work is critical for developing a comprehensive understanding of the optical properties of QDs and provides useful information for their actual applications.
Routing in IoT Lossy Networks: Potential Issues and Proposed Changes
Authors: Jeridi Mohamed Hechmi , Elmadssia Sami , Ezzedine Tahar
Published: October 2021

The specificities of the Internet of Things (IoT) require innovative methods to perform routing, owing to the resource limitations of network nodes. The IPv6 routing protocol for low-power and lossy networks ( RPL), as one of these pioneering methods, performs a variety of routing measurements to meet the requirements of some IoT applications, but, does not solve the problems of sudden and intense data traffic caused by the particularity of the other ones. Indeed, it has been observed that such unexpected and excessive data traffic leads to routing instability and traffic congestion in the IoT network. In order to overcome the mentioned shortcomings, we propose a common solution using the mobility of some nodes to reduce system instability and alleviate congestion on the network, to be named: use of mobile node for the Instability & Congestion Alleviation in IoT networks (mob-ICA). Therefore, our contribution consists in overcoming network instability by dynamically regulating the message transmission period to choose the parent nodes according to the speed and direction of the mobile nodes and in reducing congestion by using these nodes to locally create alternative paths to the parental node
Recovery analysis for block ℓp − ℓ1 minimization with prior support information
Authors: Zhang Jing , Zhang Shuguang
Published: October 2021

This paper provides a new theoretical support for block sparse recovery. By embedding prior support information into the block [Formula: see text] minimization with [Formula: see text], we establish a sufficient condition on block [Formula: see text]-restricted isometry property (RIP) to guarantee the stable and robust recovery of block sparse signals, as well as obtain a corresponding upper bound estimate of the error. The obtained result not only generalizes the existing ones, but also shows that the block [Formula: see text] minimization with prior support information behaves robust and stable recovery performance under weaker condition than the analogous one for the block [Formula: see text] minimization if more than [Formula: see text] of the support information is accurate.
Homogenization and Correctors for Stochastic Hyperbolic Equations in Domains with Periodically Distributed Holes
Authors: Mohammed Mogtaba , Khan Waseem Asghar
Published: October 2021

The goal of this paper is to present new results on homogenization and correctors for stochastic linear hyperbolic equations in periodically perforated domains with homogeneous Neumann conditions on the holes. The main tools are the periodic unfolding method, energy estimates, probabilistic and deterministic compactness results. The findings of this paper are stochastic counterparts of the celebrated work [D. Cioranescu, P. Donato and R. Zaki, The periodic unfolding method in perforated domains, Port. Math. (N.S.) 63 (2006) 467–496]. The convergence of the solution of the original problem to a homogenized problem with Dirichlet condition has been shown in suitable topologies. Homogenization and convergence of the associated energies results recover the work in [M. Mohammed and M. Sango, Homogenization of Neumann problem for hyperbolic stochastic partial differential equations in perforated domains, Asymptot. Anal. 97 (2016) 301–327]. In addition to that, we obtain corrector results.
Refinement of some partition identities of Merca and Yee
Authors: Mahanta Pankaj Jyoti , Saikia Manjil P.
Published: October 2021

Recently, Merca and Yee proved some partition identities involving two new partition statistics. We refine these statistics and generalize the results of Merca and Yee. We also correct a small mistake in a result of Merca and Yee.
The spectrum and metric dimension of Indu–Bala product of graphs
Authors: Banerjee Subarsha
Published: October 2021

Given a connected graph [Formula: see text], the distance Laplacian matrix [Formula: see text] is defined as [Formula: see text], and the distance signless Laplacian matrix [Formula: see text] is defined as [Formula: see text], where [Formula: see text] is the transmission matrix of [Formula: see text] and [Formula: see text] is the distance matrix of [Formula: see text]. The Indu–Bala product of two graphs [Formula: see text] and [Formula: see text], denoted by [Formula: see text], was introduced in (G. Indulal and R. Balakrishnan, Distance spectrum of Indu–Bala product of graphs,  AKCE Int. J. Graph Comb. 13(3) (2016) 230–234). In this paper, we first obtain the distance Laplacian spectrum of [Formula: see text] in terms of Laplacian spectra of [Formula: see text] and [Formula: see text]. We then obtain the distance signless Laplacian spectrum of [Formula: see text] in terms of signless Laplacian spectra of [Formula: see text] and [Formula: see text]. We construct pair of graphs which are distance Laplacian co-spectral as well as pair of graphs which are distance signless Laplacian co-spectral. We further find the metric dimension of [Formula: see text] in terms of metric dimensions of [Formula: see text] and [Formula: see text]. Finally, we provide a problem for future research.
Electronic Structure of Pyrochlore Iridate Pr2Ir2O7: Interplay Between Spin-Orbit Coupling and Hubbard Potential
Authors: Bendjeda S. , Zaoui A. , Djermouni M. , Kacimi S. , Boularaf A. , Kadiri A.
Published: October 2021

We have investigated the electronic structure of pyrochlore iridate Pr2Ir2O7 compound with Fd-3m space group using first-principle density functional theory calculations. [Formula: see text] calculations show that the PrAFM–IrNM state in Pr2Ir2O7 compound is energetically more favorable than the other phases. Combining of the interaction of electronic correlation (U) and spin-orbit coupling (SO) leads to three different phases for this material. (1) An anti-ferromagnetic metal is found by the [Formula: see text] ([Formula: see text][Formula: see text]eV) approximation without taking into account the spin orbit interaction. (2) A metal-semimetal transition appears, when the spin-orbit coupling is applied. (3) A semi-conductor characteristic with a narrow gap increases slightly by varying the Hubbard potential of nonmagnetic Ir atoms from 0.5[Formula: see text]eV to 1.5[Formula: see text]eV. The effect of the spin orbit (SO) coupling and the interaction (U) clearly influences the Fermi region of the calculated band structures and densities of states of this system. The hydrostatic pressure effect on the energy gap has shown a further advantage in predicting the desired gap value for this kind of materials. The optical properties, including the dielectric function, refractive index, reflectivity and real part of optical conductivity, are calculated for radiation up to 8[Formula: see text]eV. Overall, however, for both [Formula: see text] values of Pr2Ir2O7, the compound shows similar optical characteristics.
A novel finite element algorithm for predicting the elastic properties of wood fibers
Authors: Charupeng N. , Kunthong P.
Published: October 2021

Wood fibers are industrially attractive low-cost natural materials that offer good mechanical properties. It is, however, extremely difficult to experimentally determine the elastic properties of single wood fibers due to the structural complexity and variability of basic properties. We propose a three-step finite element (FE)-modeling algorithm to predict the elastic constants of a single wood fiber. The model is based on calculating the elastic constants of the fiber in three consecutive length scales including nanostructure of cellulose microfibrils (25–30[Formula: see text]nm), ultrastructure in the fiber wall layers (2–3[Formula: see text][Formula: see text]m) and single wood fibers (30–40[Formula: see text][Formula: see text]m). The results for a given set of parameters are compared to previous studies with good agreement. The work exhibits its novelty through the model’s robustness and potential for industrial applications. It merely requires three essential inputs — chemical composition and bulk density of fiber and microfibril angle of [Formula: see text] wall layer, but is capable of predicting reasonably accurately the elastic constants of a wood fiber completely without any required model preprocessing or meshing like common commercial FE method software packages. Furthermore, the validated model is used to perform a parametric study. We have found that cellulose content has positive correlations with almost all the elastic parameters — relatively strong for [Formula: see text] and [Formula: see text], but weaker for [Formula: see text]. Lignin and hemicellulose have the greatest influence on [Formula: see text] and [Formula: see text]. The bulk density of fiber is shown to affect all elastic constants except the longitudinal elastic modulus.
Molybdenum Carbonyl Complexes with Benzimidazole Derivatives Against SARS-CoV-2 by Molecular Docking and DFT/TDDFT Methods
Authors: Üstün Elvan , Düşünceli Serpil Demir , Coşkun Feyzullah , Özdemir İsmail
Published: October 2021

Benzimidazole derivative molecules attract attention of scientists due to their bioactivities. The dramatic changes in recorded activities according to the type and position of the substituents motivate synthesis and analysis of new molecules. Commercial benzimidazole-based molecules have been used in therapeutic procedures. It is known that the activities of metal complexes with benzimidazole derivative ligands have different activities when compared to the benzimidazole main structure. Nowadays, one of the most important health problems is COVID-19, which caused the pandemic that we are still experiencing. Although vaccine studies are important to overcome acute problems, regarding the possible post-vaccination adverse effects, the need for new drugs against the virus is obvious. Considering the urgency and the limited facilities during the pandemic, preliminary in silico studies of candidate molecules are essential. In this study, {[bis-(N-benzylbenzimidazole)] tetracarbonylmolybdenum}, {[bis-(N-4-chlorobenzylbenzimidazole)] tetracarbonylmolybdenum} and {[bis-(N-4-methoxybenzylbenzimidazole)] tetracarbonylmolybdenum} were synthesized and characterized. The optimization and the structural analysis of these molecules were performed by DFT/TDDFT methods. The molecules were docked into SARS coronavirus main peptidase (PDB ID: 2gtb), COVID-19 main protease in complex with Z219104216 (PDB ID: 5r82), COVID-19 main protease in complex with an inhibitor N3 (PDB ID: 6lu7) and Papain-like protease of SARS-CoV-2 (PDB ID: 6w9c) crystal structures for evaluation of their anti-viral activity.
Dynamic Computational Models and Simulations of the Opioid Crisis: A Comprehensive Survey
Authors: Shojaati Narjes , Osgood Nathaniel D.
Published: October 2021

Opioids have been shown to temporarily reduce the severity of pain when prescribed for medical purposes. However, opioid analgesics can also lead to severe adverse physical and psychological effects or even death through misuse, abuse, short- or long-term addiction, and one-time or recurrent overdose. Dynamic computational models and simulations can offer great potential to interpret the complex interaction of the drivers of the opioid crisis and assess intervention strategies. This study surveys existing studies of dynamic computational models and simulations addressing the opioid crisis and provides an overview of the state-of-the-art of dynamic computational models and simulations of the opioid crisis. This review gives a detailed analysis of existing modeling techniques, model conceptualization and formulation, and the policy interventions they suggest. It also explores the data sources they used and the study population they represented. Based on this analysis, direction and opportunities for future dynamic computational models for addressing the opioid crisis are suggested.
Pointer-Based Divergence Analysis for OpenCL 2.0 Programs
Authors: Wang Shao-Chung , Yu Lin-Ya , Her Li-An , Hwang Yuan-Shin , Lee Jenq-Kuen
Published: October 2021

A modern GPU is designed with many large thread groups to achieve a high throughput and performance. Within these groups, the threads are grouped into fixed-size SIMD batches in which the same instruction is applied to vectors of data in a lockstep. This GPU architecture is suitable for applications with a high degree of data parallelism, but its performance degrades seriously when divergence occurs. Many optimizations for divergence have been proposed, and they vary with the divergence information about variables and branches. A previous analysis scheme viewed pointers and return values from functions as divergence directly, and only focused on OpenCL 1.x. In this article, we present a novel scheme that reports the divergence information for pointer-intensive OpenCL programs. The approach is based on extended static single assignment (SSA) and adds some special functions and annotations from memory SSA and gated SSA. The proposed scheme first constructs extended SSA, which is then used to build a divergence relation graph that includes all of the possible points-to relationships of the pointers and initialized divergence states. The divergence state of the pointers can be determined by propagating the divergence state of the divergence relation graph. The scheme is further extended for interprocedural cases by considering function-related statements. The proposed scheme was implemented in an LLVM compiler and can be applied to OpenCL programs. We analyzed 10 programs with 24 kernels, with a total analyzed program size of 1,306 instructions in an LLVM intermediate representation, with 885 variables, 108 branches, and 313 pointer-related statements. The total number of divergent pointers detected was 146 for the proposed scheme, 200 for the scheme in which the pointer was always divergent, and 155 for the current LLVM default scheme; the total numbers of divergent variables detected were 458, 519, and 482, respectively, with 31, 34, and 32 divergent branches. These experimental results indicate that the proposed scheme is more precise than both a scheme in which a pointer is always divergent and the current LLVM default scheme.
Glaucoma Assessment from Fundus Images with Fundus to OCT Feature Space Mapping
Authors: Gaddipati Divya Jyothi , Sivaswamy Jayanthi
Published: October 2021

Early detection and treatment of glaucoma is of interest as it is a chronic eye disease leading to an irreversible loss of vision. Existing automated systems rely largely on fundus images for assessment of glaucoma due to their fast acquisition and cost-effectiveness.
Optical Coherence Tomographic
(
OCT
) images provide vital and unambiguous information about nerve fiber loss and optic cup morphology, which are essential for disease assessment. However, the high cost of OCT is a deterrent for deployment in screening at large scale. In this article, we present a novel CAD solution wherein both OCT and fundus modality images are leveraged to learn a model that can perform a mapping of fundus to OCT feature space. We show how this model can be subsequently used to detect glaucoma given an image from only one modality (fundus). The proposed model has been validated extensively on four public andtwo private datasets. It attained an AUC/Sensitivity value of 0.9429/0.9044 on a diverse set of 568 images, which is superior to the figures obtained by a model that is trained only on fundus features. Cross-validation was also done on nearly 1,600 images drawn from a private (OD-centric) and a public (macula-centric) dataset and the proposed model was found to outperform the state-of-the-art method by 8% (public) to 18% (private). Thus, we conclude that fundus to OCT feature space mapping is an attractive option for glaucoma detection.
Finding Fair and Efficient Allocations for Matroid Rank Valuations
Authors: Benabbou Nawal , Chakraborty Mithun , Igarashi Ayumi , Zick Yair
Published: October 2021

In this article, we present new results on the fair and efficient allocation of indivisible goods to agents whose preferences correspond to
matroid rank functions
. This is a versatile valuation class with several desirable properties (such as monotonicity and submodularity), which naturally lends itself to a number of real-world domains. We use these properties to our advantage; first, we show that when agent valuations are matroid rank functions, a socially optimal (i.e., utilitarian social welfare-maximizing) allocation that achieves envy-freeness up to one item (EF1) exists and is computationally tractable. We also prove that the Nash welfare-maximizing and the leximin allocations both exhibit this fairness/efficiency combination by showing that they can be achieved by minimizing any symmetric strictly convex function over utilitarian optimal outcomes. To the best of our knowledge, this is the first valuation function class not subsumed by additive valuations for which it has been established that an allocation maximizing Nash welfare is EF1. Moreover, for a subclass of these valuation functions based on maximum (unweighted) bipartite matching, we show that a leximin allocation can be computed in polynomial time. Additionally, we explore possible extensions of our results to fairness criteria other than EF1 as well as to generalizations of the above valuation classes.