Periodic Systems Research Articles

The Impact of COVID-19 pandemic on addictive behaviors: an integrative review

Addictive behaviors and their impacts have been widely explored. Going through a pandemic moment requires further research since crisis situations involve higher propensity to dependency. The aim of this integrative review was to identify studies that have been conducted so as to explore behaviors related to brain’s reward system in a pandemic period, which include substance addiction, internet addiction, gaming and other overusing behaviors. In order to accomplish our objective an integrative search was conducted in CAPES periodicals. Some inclusion and exclusion criteria were used to select the studies and in total (N=12) were explored independently. The results showed that there is an increasingly concern about health care systems, especially for those addicted to substances who need daily support, since addictions habits may have also increased. Behavioral addictions also increased and were exploited in some studies, especially those related to technologies, such as gaming and smartphone usage.

The Impact of Divorce Cooling-Off Period on Registered Divorces: Evidence from China

The divorce rate in China has continued to rise since the 21st century. In order to reduce impulsive divorces, the divorce cooling-off period (DCOP) system was established in the Civil Code of China. The aim of this research is to examine the impact of the DCOP on registered divorces. Data from the Ministry of Civil Affairs, National Bureau of Statistics, civil affairs departments, and statistical bureaus of 31 provinces, the 2018 to 2023 editions of the China Statistical Yearbook, and the China Civil Affairs Statistical Yearbook were utilized in this work. The event study analysis reveals that the number of registered divorces decreased significantly in China after the DCOP provision’s enforcement. The ordinary least squares model indicates an average annual decrease of about 2.6 million registered divorces when the DCOP provision takes effect, and the DCOP plays a decisive role in this decrease, which suggests that the DCOP system has achieved its original intention. This research not only highlights the important role of the DCOP in reducing registered divorces but also provides insights on how to improve the DCOP system and promote the stability of marriage.

Coupled Perturbed Approach to Dual Basis Sets for Molecules and Solids. II: Energy and Band Corrections for Periodic Systems

Coupled Perturbed Approach to Dual Basis Sets for Molecules and Solids. II: Energy and Band Corrections for Periodic Systems

Feasibility and challenges in sustaining a community based surveillance system in post-Ebola Sierra Leone

BackgroundIn outbreak-prone settings, community-based surveillance (CBS) systems can alert health authorities to respond in a timely manner where suspected cases of disease are being reported. After the 2014–2016 Ebola outbreak, the WHO and other stakeholders supported the establishment of CBS in Sierra Leone, for which community health workers (CHW) were trained to collect and report symptoms data of 11 priority health conditions in their communities. Our study objective was to assess feasibility and challenges to sustain CBS in a low resource setting as part of a World Bank evaluation of Sierra Leone’s Ministry of Health and Sanitation’s (MoHS) CBS and electronic Integrated Disease Surveillance & Response (eIDSR) systems.MethodsIn 2019 we conducted a mixed methods assessment consisting of a household incidence survey, health facility survey, household case verification survey, a costing analysis, and in-depth interviews and focus group discussions with key stakeholders of the CBS system in eight chiefdoms of 4 purposefully selected districts in Sierra Leone. The study period for primary data collection was February through April 2019. We also conducted secondary data analysis of surveillance data in DHIS2 of all 32 chiefdoms.ResultsIn districts where CBS was ‘fully functional’, the number and type of CBS alerts corresponded to the number and type of diseases reported through facility based eIDSR system in the same period. However under-reporting of diarrhea and measles suspects from the community still appeared to occur, and reporting deteriorated when primary health care staff including CHWs reported the stoppage of stipends. The annual budget impact for CBS was estimated at 4.4 million USD in 2018. The majority of costs were made at community level (73%) compared to regional (0.3%), primary health unit (21%), district (4%) and national (2%) level. The most important costs drivers were training of CHWs (59% of total costs) and salaries (including stipends of the CHWs) of human resources (15%). Barriers included sustainable financing of human resources, internet connectivity, as well as limited trainings and supportive supervision, and unsupported transportation costs for CHWs and peer supervisors (PS). CHWs and community members reported that communities are more willing to share information about health issues compared to the pre-CBS implementation period.ConclusionsThe similarity between CBS and IDSR reports support the possibility that CBS increases the sensitivity of disease surveillance to the level of the community, which would enable local authorities to take early prevention measures when and where impact will be the greatest. Qualitative interviews suggest that CBS has improved the interface between the community and primary level of the health system. However if the barriers to sustainability are left unaddressed, opportunities for CBS to prevent disease outbreaks will go unrealized.

Fine‐Tuning of Elastic Properties by Modifying Ordering of Parallel Nanolayer Inclusions in Hard Sphere Crystals

It is known that changes on the microscopic, structural level of materials exert changes on their macroscopic properties, in particular elastic ones. This approach can be used to alter the elastic properties of materials. However, it is not easy to predict the impact of a particular change in the structure of crystals. The recent studies show that depending on the size, shape, and orientation of inclusions used, the resulting elastic properties may differ. Inclusions may enhance, weaken, or eliminate the auxetic properties in a hard sphere model. This study is focused on the influence of the spatial distribution of planar inclusions within the hard sphere crystal and its impact on its elastic properties. Periodic systems containing two nanolayer inclusions in the representative volume element, oriented orthogonally to ‐direction and in various spatial ordering, are considered. It has been shown that introducing layer inclusions causes the deterioration of auxetic properties in the ‐direction. However, the latter weakly depends on the spatial ordering of the inclusion layers. Moreover, changes in the size of the inclusion particles, combined with different ordering of the inclusion layers, can be used to coarsely and finely tune the elastic properties of the model crystal.

Nonlinear dynamics of the complex periodic coupled system via a proportional generalized fractional derivative

Nonlinear dynamics of the complex periodic coupled system via a proportional generalized fractional derivative

ПРОЄКТНА ТЕХНОЛОГІЯ ЯК ЗАСІБ ФОРМУВАННЯ ПРОФЕСІЙНО-МЕТОДИЧНИХ КОМПЕТЕНЦІЙ БАКАЛАВРА СЕРЕДНЬОЇ ОСВІТИ (ХІМІЯ)

The purpose of the article is to find out the possibilities of using project technology in the educational process on a competency-based basis by students of higher education. The article clarifies the essence and task of applying project methods in professional pedagogical training. The peculiarities and practical value of the project method for the formation of professional competences of future chemistry teachers are revealed. Literary sources on the use of project methods in educational institutions of various levels were analyzed. The stages of creating practice-oriented projects are indicated: preparatory (theoretical), adaptation, search, activity (practical), final. The relationship between project activities of bachelors and the formation of their professional competence is shown. An approximate extended plan of the methodical project is given. The role of pedagogical practice in the acquisition of professional and methodical competences in the application of the project "Methodology and technology for studying the topic "The structure of the atom" developed by student-interns is outlined. Periodic law and periodic system of chemical elements" in the 8th grade. Considerable attention is paid to the protection of pedagogical practice, which examines the results of implementing the developed project into the educational process by future chemistry teachers. The requirements regarding the readiness of future teachers to carry out the educational process in chemistry are taken into account when reporting on the completion of pedagogical practice. It was found that the project technology is an invariant component in the educational process in the training of specialists in the specialty of Secondary Education (Chemistry) and ensures the integration of scientific-theoretical and practical (acquiring experience) training of the future chemistry teacher. Involvement of students in the development of long-term and personal projects ensures the full formation of professional competencies in accordance with the requirements of the educational and professional program «Secondary Education (Chemistry)».

Constrained solutions of generalized coupled discrete-time periodic matrix equations with application in state observer design for linear periodic systems

PurposeIt is desired to provide a diversified iterative scheme for solving the constrained solutions of the generalized coupled discrete-time periodic (GCDTP) matrix equations from the perspective of optimization.Design/methodology/approachThe paper considers generalized reflexive solutions of the GCDTP matrix equations by applying the Jacobi gradient-based iterative (JGI) algorithm, which is an extended variant of the gradient-based iterative (GI) algorithm.FindingsThrough numerical simulation, it is verified that the efficiency and accuracy of the JGI algorithm are better than some existing algorithms, such as the GI algorithm in Hajarian, the RGI algorithm in Sheng and the AGI algorithm in Xie and Ma.Originality/valueIt is the first instance in which the GCDTP matrix equations are solved applying the JGI algorithm.

Electron transfer mediated activation of periodate by contaminants to generate 1O2 by charge-confined single-atom catalyst.

The electron transfer process (ETP) is able to avoid the redox cycling of catalysts by capturing electrons from contaminants directly. However, the ETP usually leads to the formation of oligomers and the reduction of oxidants to anions. Herein, the charge-confined Fe single-atom catalyst (Fe/SCN) with Fe-N3S1 configuration was designed to achieve ETP-mediated contaminant activation of the oxidant by limiting the number of electrons gained by the oxidant to generate 1O2. The Fe/SCN-activate periodate (PI) system shows excellent contaminant degradation performance due to the combination of ETP and 1O2. Experiments and DFT calculations show that the Fe/SCN-PI* complex with strong oxidizing ability triggers the ETP, while the charge-confined effect allows the single-electronic activation of PI to generate 1O2. In the Fe/SCN + PI system, the 100% selectivity dechlorination of ETP and the ring-opening of 1O2 avoid the generation of oligomers and realize the transformation of large-molecule contaminants into small-molecule biodegradable products. Furthermore, the Fe/SCN + PI system shows excellent anti-interference ability and application potential. This work pioneers the generation of active species using ETP's electron to activate oxidants, which provides a perspective on the design of single-atom catalysts via the charge-confined effect.

Periodic systems have new classes of synchronization stability

The master stability function is a robust and useful tool for determining the conditions of synchronization stability in a network of coupled systems. While a comprehensive classification exists in the case in which the nodes are chaotic dynamical systems, its application to periodic systems has been less explored. By studying several well-known periodic systems, we establish a comprehensive framework to understand and classify their properties of synchronizability. This allows us to define five distinct classes of synchronization stability, including some that are unique to periodic systems. Specifically, in periodic systems, the master stability function vanishes at the origin, and it can therefore display behavioral classes that are not achievable in chaotic systems, where it starts, instead, at a strictly positive value. Moreover, our results challenge the widely held belief that periodic systems are easily put in a stable synchronous state, showing, instead, the common occurrence of a lower threshold for synchronization stability. Published by the American Physical Society 2024

Application of one-dimensional periodic layers with elastomeric seismic isolators for three-dimensional isolation

Three-dimensional (3D) seismic isolation is an appealing idea to protect structures and their components from earthquake-induced horizontal and vertical ground motions. Past attempts to develop 3D isolation systems were ineffective due to their complexity and reliability issues. One-dimensional periodic material-based isolation systems (1D-PIS) have been extensively researched for applications as raft foundations due to their simple and construction-friendly unit cell designs. These systems aim to attenuate seismic excitations in both horizontal and vertical directions. However, the effectiveness of 1D-PIS in mitigating 3D excitations may be limited due to the potential mismatch between the frequency content of horizontal and vertical vibrations. The present study proposes to combine a conventional horizontal isolation system with a 1D-PIS in the vertical direction to achieve a simple, passive, and efficient three-dimensional isolation system for structures and components. The 1D-PIS is strengthened by incorporating steel shims within the rubber layers and implementing steel casings at its periphery, enabling its utilization as an isolated system. Small-scale experimental and numerical investigations were conducted on strengthened 1D-PIS to study its isolation characteristics in the vertical directions. The study reveals that infinite boundary conditions required for the efficacy of 1D-PIS were achieved through lateral restraint provided by steel shims and steel casings. Notably, the individual isolation characteristics of the conventional and the 1D-PIS are not compromised in the combined isolation system. Nonlinear time history analysis on a prototype combined isolation system confirms its effectiveness in attenuating the seismic response under simultaneous horizontal and vertical ground motions.

System Tautochronic Path for Pendulum Vibration Absorber Based on Simple Harmonic Oscillator Transformation

Abstract Centrifugal pendulum vibration absorbers (CPVAs) are essentially collections of pendulums attached to a rotating component or components within a mechanical system for the purpose of mitigating the typical torsional surging that is inherent to internal combustion engines and electric motors. The dynamic stability and performance of CPVAs are highly dependent on the motion path defined for their pendulous masses. Assemblies of absorbers are tuned by adjusting these paths such that the pendulums respond to problematic orders (multiples of average rotation speed) in a way that smooths the rotational accelerations arising from combustion or other nonuniform rotational acceleration events. For most motion paths, pendulum tuning indeed shifts as a function of the pendulum response amplitude. For a given motion path, the tuning shift that occurs as pendulum amplitude varies produces potentially undesirable dynamic instabilities. Large amplitude pendulum motion that mitigates a high percentage of torsional oscillation while avoiding instabilities brought on by tuning shift introduces complexity and hazards into CPVA design processes. Therefore, identifying pendulum paths whose tuning order does not shift as the pendulum amplitude varies, so-called tautochronic paths, may greatly simplify engineering design processes for generating high-performing CPVAs. To illustrate this new approach and results, a tautochronic cutout shape producing constant period system motion is obtained for a simplified problem involving a mass sliding in the cutout of a larger mass that is free to translate horizontally without friction in a constant gravitational field, where the translating base mass replaces the rotating rotor in the centrifugal field.

The edge states of one-dimensional spin-$\frac{1}{2}$-like noninteracting periodic systems under the most compactly supported Wannier-type functions

Abstract A hallmark of topological insulators is topologically protected edge states, which are determined by topological invariants defined under Bloch functions. Of course, not all edge states are stable, and they are independent of topological invariants. And in a recent study, it was found that even stable protected gapless edge states cannot be explained by topological invariants in two-dimensional (2D) systems. Motivated by this idea, we carried out a thorough study in one-dimensional (1D) spin-$\frac{1}{2}$-like noninteracting periodic systems and found that all edge states can be explained by the most compactly supported Wannier-type functions (MCWTFs). All the answers are contained in the flat-band Hamiltonian defined by MCWTFs. Edge states can be obtained by solving special equations using the parameters of MCWTFs. Symmetries are the special solutions of these equations, and we have proved the relationship between zero-energy edge states and symmetry analytically in partial cases, which was only a well-known result in the past. By solving the equations, we also find that not all zero-energy edge states are determined by symmetry, which is beyond the current framework. Through numerical verification, we show that these zero-energy edge states, like those protected by symmetry, are not affected by the energy spectrum of the system, so they are only related to the Bloch functions. We also derive special properties of zero-energy edge states protected by chiral symmetry from the perspective of MCWTFs, which are consistent with the previous literature. Finally, we do a test in the 2D case and find the connection between the Chern number and the Wannier functions. Our results show that compared with topological invariants, the origin of the edge state can be understood more comprehensively from the perspective of Wannier functions.

Parametric Instability of Alfvén Waves and Wave Packets in Periodic and Open Systems

The parametric decay instability of Alfvén waves has been widely studied, but few investigations have examined wave packets of finite size and the effect of different boundary conditions on the growth rate. In this paper, we perform a linear analysis of circular and arc-polarized wave trains and wave packets in periodic and open boundary systems in a low-β plasma. We find that both types of wave are 3–5 times more stable in open boundary conditions compared to periodic. Additionally, once the wave packet width ℓ becomes smaller than the system size L, the growth rate decreases nearly with a power law γ ∝ ℓ/L. This study demonstrates that the stability of a pump wave cannot be separated from the laboratory settings, and that the growth rate of daughter waves depends on the conditions downstream and upstream of the pump wave and on the fraction of volume it fills. Our results can explain simulations and experiments of localized Alfvén waves. They also suggest that Alfvénic fluctuations in the solar wind, including sharp impulses known as switchbacks, can be more stable than traditional theory suggests depending on wind conditions.

Rainstorm Flood Risk Assessment of Urban Metro System in Different Operating Periods: A Case Study of the Central Urban Area of Tianjin, China

Rainstorm Flood Risk Assessment of Urban Metro System in Different Operating Periods: A Case Study of the Central Urban Area of Tianjin, China

Capture and catalytic conversion of CO2 from marine and offshore applications – A review

Abstract This contribution examines recent advances in modeling fluid dynamics and capture/conversion of CO2 from marine and offshore applications in packed-bed columns/trickle-bed reactors subjected to static inclination, externally-induced rolling and heaving motions. Breaking the axial symmetry of the two-phase flow once the packed bed system is tilted results in a significant decrease in process performance, the extent of which is determined by the magnitude of the tilt and the column/reactor diameter. Only the conversion of CO2 from marine engine emissions on-board large cargo ships via catalytic cycloaddition of CO2 to styrene oxide in multiphase large-diameter trickle-bed reactors increases slightly with increasing reactor inclination. Under the externally induced column/reactor oscillations, CO2 capture/conversion performance shifts toward the steady-state solution of the vertical column/reactor as the asymmetry between the two inclined positions decreases. Oscillating (between two inclined symmetrical positions) and heaving packed-bed columns/trickle-bed reactors generate an oscillating performance around the steady-state solution of the vertical static position, which is driven by the amplitude and period of the angular and heaving motions via the continuous evolution of the intensity of the reverse secondary flow and by the magnitude of the reactor/column diameter. The catalytic conversion of CO2 captured from marine emissions via an integrated process coupling reverse water-gas shift reaction and methanol synthesis in a fixed-bed reactors network system shows a remarkable enhancement with the addition of H2O adsorbent to the reaction systems in the sorption-enhanced process periods.

Healthcare Internet of Things system implementations for COVID-19 prevention

BackgroundIn response to the widespread transmission of COVID-19 in Australia, healthcare facilities implemented stringent infection control measures, and mandatory and manual screening procedures were introduced to ensure the safety of patients and healthcare staff. However, these necessary measures resulted in imbalances within the healthcare system, a shortage of front-line workers and impacts on patient experience and wait times. The prioritization of infection control measures shifted resources away from routine care, causing delays in accessing necessary healthcare services.Methods and FindingsTo address these challenges, we developed and implemented an Internet of Things (IoT) Smart Screening eGate solution in partnership with a large metropolitan children’s hospital in Australia. This solution integrated a contactless health self-service web app, thermal camera, and physical barrier to automate the COVID-19 health screening and data recording process. During the 3-month pilot period, we deployed the eGate at multiple entrances to the hospital, and monitored the number of users of the system in different periods. We also used a framework of formative evaluation to classify user design challenges within limited resources and improved the design of the eGate to enhance its effectiveness. Our findings show that the IoT eGate solution improved the efficiency of the screening process and reduced the workload and exposure risks of front-line staff and anyone who required access to the hospital. By automating the screening process, we reduced the need for manual screening and minimized contact between individuals, thus reducing the risk of potentially infected.ConclusionIn conclusion, our pilot study demonstrated the potential of IoT technologies in improving the efficiency and safety of medical facilities during pandemics and provided a series of recommendations for the translation of IoT technologies for medical facilities, including the importance of co-design and collaboration with stakeholders, user-centered design, and ongoing monitoring and evaluation.

Noise filter using a periodic system of dual Helmholtz resonators

This study investigates noise reduction using a periodic arrangement of dual Helmholtz resonators and explores the introduction of defects within this periodic structure. The transfer matrix method was employed to carry out theoretical research. The computations of the interface response function approach results are verified, and consistent outcomes are demonstrated. The simulation results highlight the distinctive dual resonance frequencies of dual Helmholtz resonators. By differentiating dual Helmholtz resonators from traditional Helmholtz resonators, prospective applications for low-frequency noise reduction are envisioned. In this contribution, introducing defects in the middle of perfect dual Helmholtz resonators adds more value to the acoustic filter. In particular, the first neck and cavity of the defective dual Helmholtz resonator. This study shows that introducing a 2D-defect into identical dual Helmholtz resonators can improve the transmission of defect modes by taking advantage of the advantageous interaction of the resonant modes. In such arrangements, the entire structure functioned as a potent selective filter.

Structural and energetic properties of cluster models of anatase-supported single late transition metal atoms: a density functional theory benchmark study.

Single-atom catalytic systems constitute an intriguing research topic due to their inherently different chemical behavior as compared to classic heterogeneous catalysts. In this study, cluster systems representing single late transition metal atoms adsorbed on anatase were constructed starting from previously generated periodic models and subjected to a density functional theory (DFT) benchmark study. The ability of different density functional approximations representing all rungs of the Jacob's Ladder classification to accurately describe bond lengths and adsorption energies was assessed for these clusters with the aim of revealing the functional that allows to retain the structural characteristics of the initial periodic system, while also delivering reliable energetics. In this regard, our results indicate that optimisation of the clusters with the meta-GGA functionals TPSS or RevTPSS provides the lowest mean unsigned error and root-mean-square deviations with respect to the periodic models. Moreover, these functionals and, to a slightly lesser degree, PW91 were also found to provide adsorption energies that are statistically the least deviating from the CCSD(T) reference data. More complex hybrid functionals appear to be performing less well. Cluster geometries were determined at the Kohn-Sham DFT level using the LANL2DZ basis set for the transition metals and the Pople 6-31G(d) basis set for O and H. The density functional approximations considered were SVWN, PBE, BP86, BLYP, PW91, TPSS, RevTPSS, M06L, M11L, B3LYP, PBE0, M06, M06-2X, MN15, ωB97X-D, CAM-B3LYP, M11, and MN12-SX. Reference adsorption energies of the metals on the support cluster were obtained at the CCSD(T)/LANL2TZ (transition metals)/6-311 + + G(d,p)//RevTPSS/LANLD2DZ (transition metals)/6-31G*. Besides the above-mentioned functionals, energy calculations using the double-hybrid functionals, DSDPBEP86, PBE0-DH, and B2PLYP, were also performed. All adsorption energy calculations were carried out on the RevTPSS geometries.

Multiple Circular Polarizations Coexisting with Bound States in the Continuum Without Breaking Symmetry

AbstractBound states in the continuum (BICs) have been engineered in periodic photonic systems to achieve diverse polarization behavior in momentum space. By breaking C2z symmetry of photonic crystal slabs (PhCS), purely circular polarization, which hold significant potential for applications in topological physics and chiral optics, can be achieved near the BICs. In this study, the intriguing phenomenon of BICs on the degenerate band of PhCS with a triangular lattice featuring cylindrical holes are investigated. Unlike previous studies that mainly focused on BICs on non‐degenerate photonic bands, this research reveals a sophisticated interplay between BICs and Dirac points on the more intricate degenerate photonic band. This interaction gives birth to two pairs of purely circular polarizations with opposite chirality, even without breaking any symmetry of the PhCS. Additionally, It is find that by further breaking the σz mirror symmetry of the PhCS, these purely circular polarization states can be significantly amplified. This findings not only enrich the polarization responses of high‐Q photonic devices but also enables the modulation of chiral light, laying the groundwork for the creation of high‐quality optical devices with precisely engineered polarization properties.