Destructive Effects Research Articles

Analysis of destructive effect of Zn on carbon brick and way of Zn into carbon brick

Analysis of destructive effect of Zn on carbon brick and way of Zn into carbon brick

Criterion of construction and strategy of functioning of information and telecommunication system with protection against destructive effects

The creation of information and telecommunication systems with the integration of information transmission, reception and processing functions determines the need to find technical solutions to ensure its security and protection while increasing the intensity of information processes, improving technologies for unauthorized access to information areas and creating destructive effects. Joint fulfillment of requirements for information security and maintaining operational properties of the system, which regulate efficiency, efficiency and resource intensity of information exchange, is achieved in accordance with a minimum-margin rule, the essence of which is to find the maximum possible information losses and determine a strategy for achieving minimum values of these losses. Within the framework of the used approach, the best solution is to establish a set of parameters of transmitting and receiving devices and information processing means with the lowest loss value of the target function of information exchange under the most dangerous and effective destructive effects. Goal – justification of the criterion for construction and strategy of functioning of the information and telecommunication system with protection against destructive effects. The criterion of construction and strategy of operation of the information and telecommunication system are justified in order to achieve the best probabilistic-time indicators of information exchange with a balanced set of measures to ensure security and information protection in case of destructive impacts. Due to the variety and variability of the conditions for the manifestation of destabilizing factors, the parameters and reconfiguration schemes of telecommunication channels, as well as the operating modes of information processing devices, were established while achieving the effectiveness of meeting the information needs of subscribers according to the optimality criterion and setting indicators of the efficiency and resource consumption of the system according to the suitability criterion. Possibilities and options for adaptive, situational and reflective control of the information and telecommunication system in the interests of rational distribution of the information resource to achieve target functions and the use of technologies for ensuring security and protecting information from destructive influences are investigated. Automatic control of the system is at the stage of prohibiting destructive effects on the information area by maintaining components in states that most fully correspond to the goals and objectives of information exchange. Situational control of information security during transmission and reception, used, as a rule, at an early stage of implementation of the conflict component in the information process, is based on the identification of destabilizing factors based on the results of classification of current states and neutralization of threats due to the restructuring of the system operation regulations carried out. Reflexive control, the strategy of which is based on prediction and evaluation of changes in the parameters of information processes under destructive effects, is in the form of transferring components of the information and telecommunication system to the state of its own information equilibrium, which helps to maximize the target function of information exchange while minimizing the performance indicators of destructive effects carried out. Due to the expediency of consistent implementation of the above control strategies in assessing the degree of occurrence of threats to the information process, the vector of parameters of information objects and telecommunication channels must from the conditions for neutralizing the full set of predicted destabilizing factors be determined. A reasonable criterion for building an information and telecommunication system makes it possible to jointly search for technical solutions for creating receiving and transmitting devices and information processing means in order to achieve maximum performance indicators of information exchange under established limitations of efficiency and resource intensity. The developed rule for selecting the strategy for controlling components of the information and telecommunication system establishes time-frequency and space-energy distributions of information processes necessary to meet the information needs of subscribers when transmitting, receiving and processing information in different conditions for the manifestation of destructive threats. The obtained results form a methodological basis for building information and telecommunication systems with protection of information coming through their channels with increasing requirements for target functions of information exchange and strengthening system restrictions due to improvement of technologies for unauthorized access to information areas and creation of destructive effects.

Xenophobia: a hindrance factor to South Africa’s ambition of becoming a developmental state

The prevalence of xenophobic violence toward foreigners has hindered South Africa’s ambition to become a developmental state since 2007, when the concept of a “democratic developmental state” was first endorsed during the African National Congress (ANC) conference in Polokwane. This ambition has also been thwarted by the inability of the post-apartheid regime to provide adequate and sustainable services to the citizens. Xenophobia has disrupted economic growth and has contributed to poor service delivery in local municipalities, thus leading to social protests. The developmental state depends mainly on a solid balance of economic growth and human development. It also leans on the capacity of the state to establish policies that address poverty and promote the expansion of solid economic opportunities. In this endeavor, migrants increase economic growth and make it sustainable, increase productivity, and promote the labor market. They also promote the labor force and human capital, economic growth, and public finance, thus enabling the realization of a developmental state. However, xenophobia has limited migrants’ contributions to economic growth and social well-being in South Africa. It has destructive effects on South Africa’s economic structure and growth, thus affecting the delivery of adequate services that would enhance its ability to achieve a developmental state. The paper recommends that there is a need for South Africa to understand that xenophobia affects economic growth and the service delivery framework. To address the prevalence of xenophobia and achieve its ambition of a developmental state, South Africa needs to hasten its responses to curb xenophobia and integrate migrants into economic opportunities. The paper adopted a qualitative research methodology and conceptual and document analysis techniques to collect data that enabled the achievement of the above assertions.

Investigation of purge angle on the air inhomogeneity reduction and energy efficiency improvement of the desiccant wheel dehumidification system

ABSTRACT The rotary desiccant wheel dehumidification system has been extensively applied to achieve deep dehumidification in the modern environment with low humidity ratio. The effect of mixing destruction caused by the temperature and humidity inhomogeneity on the thermodynamic performance of the desiccant wheel deep dehumidification (DWDD) system has not been thoroughly illustrated. This research aims to reduce the mixing destruction and improve the overall energy efficiency of the DWDD system. Numerical analyses were carried out to investigate the mixing destruction characteristics of the deep dehumidification process. The results revealed that the mixing exergy destruction gradually becomes a prominent factor as regeneration temperature and humidity ratio increase under deep dehumidification, and there is a significant temperature and humidity ratio gradient in the transition angles from the regeneration side to the process side. The purge angle is regulated to reduce the average temperature and humidity ratio on the process side and lower the air inhomogeneity. The exergy efficiency of the desiccant wheel can be improved from 44.8% to 73.9% at the regeneration humidity ratio of 20 g/kg under the effective purge angle of 30°, indicating a considerable enhancement of exergy efficiency under the effective purge angle at a high regeneration humidity ratio.

A 7.62 mm energetic bullet filled with PTFE-Mg-based reactive materials for anti-drone application

To counter thin and lightweight targets such as drone swarms, a specialized design of 7.62 mm energetic bullets has been developed. These bullets utilize reactive materials as the core encased in a copper jacket, offering the advantages of impact-induced energy release, multiple damage, and lightweight. The study involved the preparation of three energetic bullets using the reactive materials (different ratio of PTFE-Mg-Bi2O3 and PTFE-Mg-Bi2O3-W) and systematically evaluating their destructive effect. The results showed that three energetic bullets (EB-A, EB-B, and EB-W) successfully penetrated two-layer stacked 2 mm 50# cold-rolled steel targets, and the respective reaction durations observed during the penetration process were 4.1, 3.5, and 9.2 ms. After armor-piercing, energetic bullets released an amount of chemical energy and produced fragmentation, deflagration reactions, and overpressure destructive effects. To further investigate the damage mechanism of the three reactive material-filled bullets, a detailed analysis of PTFE-Mg-based reactive material, such as reaction energy, burning rate, combustion temperature field, reaction overpressure, was conducted. Our work provides a comprehensive understanding of energy release performance of the reactive materials and damage behavior of the energetic bullets.

Review of Mining and Sanitation Waste Water Management and Their Contribution to Water Contamination in Zambia

This research digs into the convoluted topography of water contamination in Zambia's Copperbelt Province, with an emphasis on the important contributions of mining and sewage effluent. This report provides major conclusions about the origins, types, and effects of contaminants in the region's water bodies based on a thorough review of current research and empirical evidence. Mining activities emerge as a major source of water pollution, with effluent contaminated with heavy metals, sulphates, and other compounds that pose serious hazards to aquatic ecosystems and public health. Despite efforts to improve wastewater treatment, shortcomings persist, resulting in the leakage of toxic effluent into neighboring waterways. Similarly, sewage wastewater contributes to contamination by including faecal coliforms, nutrients, oils, and heavy metals. The effects of water contamination are far-reaching, as indicated by increasing pollutant concentrations in stream sediments and downstream bodies. Aquatic life suffers from habitat destruction, diminished biodiversity, and negative health effects, while communities relying on these water supplies face increased health risks. Given these issues, the paper analyses potential solutions and recommendations for effective wastewater management, with a focus on interdisciplinary collaboration, technical innovation, and regulatory enforcement. Initiatives fostering recycling, resource recovery, and the implementation of advanced treatment technology hold promise for minimizing water pollution and maintaining sustainable water management practices in the Copperbelt Province.

Protection of Reinforced Concrete Columns from Pounding-Induced Effects in Adjacent Buildings

The pounding damage is one of the most common seismic damages observed after past earthquakes in adjacent reinforced concrete (RC) buildings having insufficient gap in-between. Particularly in highly populated regions, there are numerous adjacent RC buildings, in which pounding can cause severe damage or total collapse. Many previous reconnaissance reports following earthquakes have emphasized severe column damage due to pounding with the slab of adjacent building. In this paper, a retrofitting method is presented to reduce the seismic damage caused by pounding on existing RC structural elements in cases where collision is unavoidable. Pounding effects are investigated by using 4- and 7-story RC buildings with unequal floor elevations. As a retrofitting solution for pounding, steel columns and neoprene rubber pads are placed at the mid-height of the story so that the pounding takes place between the neighboring slab and added steel columns instead of existing RC columns. The mid-column pounding of existing RC buildings with and without retrofitting are numerically investigated. In the numerical model, buildings are connected by link elements to reproduce the pounding in-between. Nonlinear response history analyses are performed using 11 different real ground-motion records. Pounding forces, peak floor accelerations, inter-story drift ratios, story shear force distributions, and plastic hinge distributions are obtained and compared for each of the pounding conditions. The analysis results revealed that the proposed retrofitting method protects the existing RC columns from brittle type of shear failure and reduces the destructive effects of pounding.

Research on electronics hardening technology of integrated electronic system of lunar exploration Cubesat

In the lunar exploration CubeSat mission, the complex space environment and limited onboard resources place higher requirements on the anti-radiation design of the integrated electronic system. By analyzing the destructive effects of the deep space radiation environment and the failure mechanism of components, a hardening scheme for the integrated electronic system of lunar exploration CubeSat is proposed. A variety of measures are taken to target the key components and circuit parts in the integrated electronic system that are susceptible to radiation damage. A prototype verification system for anti-radiation hardening technology was designed and system-level testing was carried out. Research results show that adopting effective radiation-resistant hardening technology can significantly improve the safety and reliability of CubeSat integrated electronic systems in deep space environments.

Experimental investigation of partial and cloud cavitation control on a hydrofoil using bio-inspired riblets

We experimentally investigated a passive cavitation control approach to control partial and cloud cavitation on a National Advisory Committee for Aeronautics 0015 hydrofoil. For this approach, we implemented two different kinds of mesoscale bio-inspired riblets, known as scalloped riblets and sawtooth riblets, on the suction side of the hydrofoil near its leading edge. We studied the dynamics of partial and cloud cavitation on the hydrofoil with and without two kinds of riblets using a high-speed camera. In addition, we performed hydro-acoustic measurements to analyze the effects of this passive control on the cavitation induced noise in the wake of the hydrofoils. We considered flows at Reynolds numbers 0.5 × 106 and 0.6 × 106 with the hydrofoils at angles of attack of 8° and 10°. Results revealed that the cloud cavitation shedding on the hydrofoil suction surface was mitigated significantly due to the reduction in the re-entrant jet momentum. Also, the influence of tip vortex cavitation was reduced on the modified hydrofoils. Furthermore, the large-scale cavitation induced noise for the unmodified hydrofoil was located mostly at lower frequency in the range of 30 Hz, which was similar to the cavity shedding frequency. The small-scale vortex-induced noise concentrated at relative higher frequency between 100 and 120 Hz. The noise reduction in this study was achieved by scalloped and sawtooth riblets at low frequency domain and for some cases at higher frequency range by manipulating of the cavitation oscillation mechanism and elimination of a large-scale cavitation structure. This study provided new insight into controlling the destructive effects of cavitation using bio-inspired riblets, which should be relevant for various engineering applications.

Orbital angular momentum spectrum of model partially coherent beams in turbulence

The use of partial coherence has been extensively studied as a potential solution to mitigate the destructive effects of atmospheric turbulence in optical applications involving the free space propagation of light. However, in OAM-based optical systems, reducing coherence leads to the broadening of the orbital angular momentum (OAM) spectrum, consequently increasing the cross-talk between adjacent modes. In this paper, we have investigated three fundamental classes of partially coherent OAM beams under the influence of turbulence. The aim is to identify a distinct type of partially coherent beam (PCB) in which the reduction in coherence results in higher resistance of the OAM spectrum against atmospheric disturbances. It is demonstrated that, for a specific propagation distance, we can prepare a PCB in which the benefits of reducing coherence outweigh its drawbacks.

The impact of initial fabric anisotropy on cyclic liquefaction behavior with polygonal particles using the discrete element method (DEM)

Liquefaction is one of the most significant phenomena that can occur in soil during an earthquake. The destructive effects of this phenomenon on earth structures have captured the attention of many geotechnical engineers. Additionally, the gradual increase in pore water pressure during the cyclic loading induced by the propagation of earthquake waves, known as cyclic liquefaction, is a crucial factor that might lead to the complete loss of shear strength in soils. A better understanding of cyclic liquefaction is essential for improving earthquake hazard analysis and mitigating structural damage. Factors influencing liquefaction behavior include particle size, particle grading, and soil fabric. By “soil fabric,” we refer to the arrangement and positioning of particles with each other, particle shape, and the shape of voids among particles. This research aims to focus on the effects of fabric anisotropy on cyclic liquefaction of granular soils with angular particles. To carry out this investigation, the discrete element method has been employed. In the discrete element method, the geometry of particles and, generally, the soil fabric can be considered. In this research, specimens with varying particle orientation angles were produced and subjected to cyclic loading tests under undrained conditions. By examining the stress paths of specimens during cyclic loading, it is observed that the initial fabric and inherent anisotropy significantly influence the behavior of the specimens. Inherent anisotropy leads to varying numbers of cycles required for the initial liquefaction of each specimen. Furthermore, it is observed that as the particle orientation angle increases, the localization of axial strains shifts from tensile to compressive directions. The effect of inherent anisotropy plays a substantial role in the initial liquefaction (ru = 1). If the liquefaction of specimens is of interest at lower values of ru, the effect of inherent anisotropy can be disregarded.

Important-Data-Based DoS Attack Mechanism and Resilient H∞ Filter Design for Networked T-S Fuzzy Systems.

This article is concerned with the security problems for networked Takagi-Sugeno (T-S) fuzzy systems with asynchronous premise constraints. The primary objective of this article is twofold. First, a novel important-data-based (IDB) denial-of-service (DoS) attack mechanism is proposed from the perspective of the adversary for the first time to reinforce the destructive effect of the DoS attacks. Different from most existing DoS attack models, the proposed attack mechanism can utilize the information of packets, evaluate the importance degree of packets, and only attack the most "important" ones. As such, a larger system performance degradation can be expected. Second, corresponding to the proposed IDB DoS mechanism, a resilient H∞ fuzzy filter is designed from the defender's point of view to alleviate the negative effect of the attack. Furthermore, since the defender does not know the attack parameter, an algorithm is designed to estimate it. In a word, a unified attack-defense framework is developed in this article for networked T-S fuzzy systems with asynchronous premise constraints. With the help of the Lyapunov functional method, sufficient conditions are successfully established to compute the desired filtering gains and ensure the H∞ performance of the filtering error system. Finally, two examples are exploited to demonstrate the destructiveness of the proposed IDB DoS attack and the usefulness of the developed resilient H∞ filter.

Investigation of the Highway Between Isparta-Ağlasun (Burdur) in Terms of Mass Movement Sensitivity

In our country, mass-ground movements such as landslides, rockfalls and avalanches are the most common types of disasters after earthquakes in terms of their destructive effects. The aim of the study is to determine the susceptibility of mass movements on sloping surfaces along the Isparta-Ağlasun road route. The study area includes approximately 41 kilometres of highway route between Isparta city centre and Ağlasun districts and its surroundings. Steep slopes on the road, loose soil properties in places, and torrential rains cause frequent rock falls, slope debris and mud flows on the study area. It is extremely important to identify the areas susceptible to ground movements along the route in order to take necessary precautions and prevent future loss of life and property. For this purpose, the parameters that are thought to cause mass movements along the road route were evaluated together with Geographical Information Systems programme and Analytical Hierarchy Method and the areas sensitive to low-medium-high and very high mass movements along the route were determined. The sensitivity map obtained was supported by field observations. With this study, areas sensitive to mass movements along the route were mapped and a database was created to help local administrators and planners.

Genetic architecture of the toxicological response to eucalyptol and citronellal in Drosophila melanogaster

The excessive and indiscriminate use of synthetic insecticides has led to environmental pollution, wildlife destruction, and adverse effects on human health, while simultaneously giving rise to resistance in insect pest populations. This adaptive trait is expressed through various mechanisms, such as changes in the cuticle, heightened activities of detoxifying enzymes, and alterations in the sites of action that reduce their affinity for insecticides. In this context, we associate variation in toxicological response with genomic variation, to identify genetic polymorphisms underlying the different steps of the insect (genotype)-response (phenotype)-insecticide (environment) interaction. Under this framework, our objective was to investigate the genetic factors involved in the toxicological response of D. melanogaster lines when exposed to citronellal and eucalyptol vapors (monoterpenes of plant origin). We quantified KT50 in adult males, representing the time necessary for half of the exposed individuals to be turned upside down (unable to walk or fly). Since the genomes of all lines used are completely sequenced, we perform a Genome Wide Association Study to analyze the genetic underpinnings of the toxicological response. Our investigation enabled the identification of 656 genetic polymorphisms and 316 candidate genes responsible for the overall phenotypic variation. Among these, 162 candidate genes (77.1%) exhibited specificity to citronellal, 45 (21.4%) were specific to eucalyptol, and 3 candidate genes (1.5%) namely CG34345, robo2, and Ac13E, were implicated in the variation for both monoterpenes. These suggest a widespread adaptability in the response to insecticides, encompassing genes influenced by monoterpenes and those orchestrating resistance to the toxicity of these compounds.

Streptococcus salivarius ameliorates the destructive effect on the epithelial barrier by inhibiting the growth of Prevotella melaninogenica via metabolic acid production.

Oral lichen planus (OLP) is one of the most common oral mucosal diseases, exhibiting a higher prevalence in women than men, but its pathogenesis is still unclear. Current research suggests that microbial dysbiosis may play an important role in the pathogenesis of OLP. Our previous research has found that the increase of Prevotella melaninogenica and decrease of Streptococcus salivarius have been identified as a potential pathogenic factor in OLP. Consequently, the objective of this study is to examine whether S. salivarius can counteract the detrimental effects of P. melaninogenica on the integrity of the epithelial barrier function. Epithelial barrier disruption was induced by P. melaninogenica in human keratinocytes (HaCaT cells). HaCaT cells were pretreated with S. salivarius(MOI=20) or cell-free supernatant for 3h, followed by treatment with P. melaninogenica (MOI=5) for 3h. The epithelial barrier integrity of HaCaT cells was detected by FD4 permeability. The mRNA level of tight junction protein was detected by quantitative real-time polymerase chain reaction (PCR). Immunofluorescence and Western Blot were used to detect the protein expression of zonula occludin-1 (ZO-1). The serial dilution-spotting assay was applied to monitor the viability of P. melaninogenica at the end of 8 and 24h incubation. Challenge by P. melaninogenica decreased the levels of tight junction proteins, including occludin, ZO-1, and claudin in HaCaT cells. S. salivarius or its cell-free supernatant inhibited the down-regulation of ZO-1 mRNA and protein expression levels induced by P. melaninogenica and thus improved the epithelial barrier function. The inhibitory effect of the cell-free supernatant of S. salivarius on the growth of P. melaninogenica is associated with metabolic acid production rather than with bacteriocins and hydrogen peroxide. These results suggest that live S. salivarius or its cell-free supernatant significantly ameliorated the disruption of epithelial tight junctions induced by P. melaninogenica, likely through the inhibition of P. melaninogenica growth mediated by metabolic acid production.

The gendered costs of stigma: How experiences of conflict‐related sexual violence affect civic engagement for women and men

AbstractA common understanding emphasizes the destructive effects of conflict‐related sexual violence (CRSV) on social cohesion and community life. Stressing the agency of survivors, we present an alternative argument. Our theory predicts that survivors seek to counteract the stigma attached to CRSV by contributing to the community in the form of civic engagement. Drawing on three original surveys from Democratic Republic of Congo (DRC), Liberia, and Sri Lanka and relying on list experiments to reduce underreporting bias, we find that survivors of CRSV indeed show increased levels of civic engagement. This civic effect is consistent across the three contexts and very likely causal. We also rule out an alternative mechanism based on posttraumatic growth and dispel concerns that increased civic engagement comes at the expense of decreased intergroup relations. However, looking at sex differences, our results are more sobering. While in line with our prediction, they do not support the optimistic notion that survivors' mobilization results in female empowerment and the closing of existing gender gaps in civic behavior. Our findings have important implications for our understanding of CRSV, the legacy of violent conflict, and the gendered nature of politics.

Assessing dietary specialization to inform the conservation of the fairy pitta (Pitta nympha), an endangered vermivore.

Quantifying the diet of endangered species is crucial for conservation, especially for diet specialists, which can be more susceptible to environmental changes. The vulnerable fairy pitta (Pitta nympha) is considered a specialist that primarily feeds its nestlings with earthworms. However, there have been few studies of the nestling diet provisioned by parents, and no assessments of earthworm proportion in the diet of adults. Our study aimed to fill these gaps, shedding light on crucial factors for conservation. Combining new observations with existing literature, we confirmed a consistent dominance of earthworms in the nestling diet, regardless of rainfall, nestling age, and time of day. We extrapolated the total earthworm consumption during a breeding event, accounting for potential variation in the availability of earthworms and their prevalence in the adult diet. We used literature-based earthworm densities in pitta habitats and our estimates of family earthworm consumption to calculate the habitat area that could provide a pitta family with the number of earthworms consumed during a breeding event. The predictions matched observed pitta home range sizes when assumed that the adult diet is comprised of approximately 70% earthworms. The results highlight the importance of earthworm-rich habitats for conservation planning of the fairy pitta. To mitigate the effects of habitat destruction, we discuss conservation practices that may involve enhancing earthworm abundance in natural habitats and providing vegetation cover for foraging pittas in adjacent anthropogenic habitats rich in earthworms. To guide conservation efforts effectively, future studies should investigate whether previously reported breeding in developed plantation habitats is due to high earthworm abundance there. Future studies should also quantify correlations between local earthworm densities, home range size, and the breeding success of the fairy pitta.

Flash spinning polyethylene/Fe3O4 magnetic drive fibers for oil absorption underwater

Oil pollution in water has destructive effect on the ecological environment of water bodies. However, the treatments for oil pollution underwater in irregularly shaped and non-open environments face a challenge owing to the difficulty in driving oil absorption materials underwater. Herein, this work reports a facile strategy to prepare flash spinning magnetic polyethylene fibers (FSMPFs) for oil absorption application in irregularly shaped and non-open underwater environments. The as-prepared FSMPFs exhibit good oil absorption performance, of which the oil absorption in air and underwater is 76.70 g/g and 65.32 g/g, respectively, and the FSMPFs can maintain their oil absorption performance in environments with different salinities (1–5 %) and pH values (2–12). Also, the FSMPFs show good magnetic responsiveness and controllability when applied to oil–water separation underwater in irregularly shaped pipes, and the oil–water separation efficiency of FSMPFs for oil–water emulsion reaches 99.6 %. Besides, the FSMPFs have good mechanical properties and reusability, of which the tensile strength and elongation at break is 185.9 cN and 41.2 %, respectively, and oil absorption is 76.28 g/g (99.5 % of the initial value) after 10 cycles of absorption–desorption. The FSMPFs have great potential in practical applications for oil absorption under irregularly shaped and non-open environments.

Geometrically nonlinear vibration of toroidal sandwich shells with auxetic honeycomb core under periodic/impulsive pressure

The main objective of this paper is to evaluate the dynamic behaviour of sandwich toroidal shells composed of a core with negative Poisson ratio (auxetic honeycomb material) and nanocomposite enriched coating layers under impulsive/periodic pressures considering the geometrical nonlinearity. The set of nonlinear equilibrium equations based on the first-order shear deformation theory are and the resultant nonlinear differential motion equations are approximately solved by the Galerkin method and 4th-order Runge–Kutta solution, respectively. The achieved responses show that the amplitude of outward deformations is intensively increased when the proposed sandwich shells are subjected to rectangular periodic and impulsive loadings which shows the destructive effects of this type dynamic loading. The performed parametric studies shows that these destructive effects can be controlled by changing the geometrical properties of the honeycomb cells and the volume fractions of the nanocomposites in the coating layers. It is notable that in the previous studies the nonlinear dynamic response of toroidal shells subjected to various periodic and impulsive pressures was not investigated. However, in the present work, the mentioned dynamic responses were achieved and investigated without spending time-consuming computational. In fact, the novelty of this work is to develop such a robust and efficient tool.

Analysis of the Role of Hong Kong's Key Industries During the Pandemic of COVID-19

This study investigates the variables that affect and encourage inbound travel to Hong Kong using data from 2019 to 2020. Five important regional source markets for tourism in Hong Kong have been chosen, namely Singapore, Malaysia, Philippines, Japan, and South Korea. Based on the research results, the COVID-19 pandemic had a major destructive effect on Hong Kong's tourism sectors while significantly impact the quantity of inbound tourists due to government response to COVID-19 infection case. The quantity of inbound tourists to Hong Kong is significantly impacted by the government's actions based on the COVID-19 infection cases. Additionally, existence of COVID-19 in the tourism source countries is often considered when defining Hong Kong's travel restrictions. According to the empirical findings, the demand for visitor arrivals was also lowered by the distance to Hong Kong and the expensive cost of travel there, while the expansion of tourism was facilitated by improved aviation services and potential for the tourism sector. These results demonstrate that for the city to be recognized as an attracting and cherished tourist destination, the tourism sector and the government must collaborate to restore after the pandemic. The complementary nature of pandemic control and tourist recovery is highlighted by this study. To establish a positive ripple effect, these operative and budgetary standards must demand the government to provide early recovery support to tourism sectors.