Mitigation Methods Research Articles

Exploring liquefaction resistance in saturated and gassy sands at different state parameters

Earthquake-induced liquefaction is a relevant natural hazard due to the damages caused in numerous buildings, facilities and infrastructures worldwide. The damages caused to the infrastructure by this phenomenon are caused by the loss of stiffness and strength in granular soils, which leads to settlements and lateral spreading. Earthquake-induced liquefaction typically occurs in saturated deposits composed of non-plastic soils. Hence, the degree of saturation reduction is considered one of the most favourable and optimistic methods for liquefaction resistance mitigation. This paper explores the earthquake-induced liquefaction in saturated and gassy sands, varying their degree of saturation and state parameters. The state parameter was used to analyse the mechanical behaviour by combining the effects of relative density (or initial void ratio) with confinement pressure. Results show that liquefaction resistance improvement caused by the reduction in the degree of saturation is higher as the state parameter increases. This improvement can be described and quantified by multivariate models integrating the effects of degree of saturation and state parameter on liquefaction resistance. This provides a potential solution for improving the resilience of infrastructures susceptible to earthquake-induced liquefaction.

Techniques to mitigate membrane displacement for vacuum-membrane solar-dish facets

The prospects of a multifaceted vacuum-membrane solar dish concentrator are considered in this work. The membrane depths of these facets can shift slightly due to varying ambient conditions throughout an operational day, leading to major focal point shifts and a reduced overall efficiency. The purpose of this work was to experimentally investigate different methods of membrane displacement mitigation. A controlled-environment (indoor) enclosure was employed to examine the effects of static ambient conditions, allowing for the independent manipulation of the surrounding pressure and temperature. Various manufacturing techniques were also investigated within the controlled-environment enclosure, which included alterations in pretension, changes in membrane thickness and adjustments to overall facet sizes. Furthermore, outdoor tests were conducted to determine how solar radiation and convection affected membrane displacement as well as to investigate the performance of various membrane depth control strategies using an Arduino Uno microcontroller. The indoor results showed that opting for a small facet would minimize membrane displacement. The results were supported by material tests and a finite element analysis. The outdoor test results indicated that solar radiation and wind affected the internal temperature and consequently also affected the membrane depth. Furthermore, a focus control system maintaining a constant differential pressure across the membrane achieved the required accuracy of ±2 mm membrane displacement limitation. However, another focus control system consisting of a Hall effect module actively monitoring membrane depth emerged as the most effective, with an increase of about 0.09 mm and a decrease of approximately 0.02 mm from an initial depth of 10 mm. This level of stability with a focus control system will ensure that the facet maintains a consistent optical performance, ultimately advancing the reliability and efficiency of low-cost vacuum-membrane technology.

Corrigendum to “A system-level harmonic mitigation method for HVDC systems – A practical case study” [Int. J. Electr. Power Energy Syst. 161 (2024) 110147

Corrigendum to “A system-level harmonic mitigation method for HVDC systems – A practical case study” [Int. J. Electr. Power Energy Syst. 161 (2024) 110147

Energy management of residential buildings using innovative passive techniques

Abstract Recently, efforts on sustainability and energy savings in buildings have increased due to the growing global awareness of the energy use of buildings and the negative impacts of carbon dioxide emissions on climate change. As a result, it is critical to propose effective strategies to reduce such energy consumption. The goal of this project is to advance the idea of net-zero energy buildings as a worldwide mitigation method for climate change. Thus, a numerical model was developed and validated to investigate the passive cooling capabilities of an innovative phase change material (PCM)-based phase cube in residential buildings. The proposed phase cube includes six various PCM-compact storage module (PCM-CSM) configurations including Rubitherm’s SP-24E plates (Horizontal), Half Circular Inline, Half Circular Staggered, Vertical plates, Inline Cylindrical and Staggered Cylindrical compact storage modules. All the proposed designs were numerically simulated, and the obtained results were compared and analysed at an inlet air temperature and velocity of 35°C, and 4m/s, respectively and each phase cube contained the same mass of Rubitherm’s SP-24E PCM, which was 30.326 kg. The results showed that the Horizontal, Half Circular Inline and Vertical phase cubes can absorb heat at a higher rate from fresh air at nearly 496.19w, 465.9w and 458.16w, respectively translating the lowest outlet air temperature of about 25°C from the cube. Integrating such phase cubes into residential buildings for indoor passive air cooling substantially decreased the building cooling loads, resulting in reduced electric energy consumption by the air conditioning system.

Development of Detection and Mitigation of Advanced Persistent Threats Using Artificial Intelligence and Multi-Layer Security on Cloud Computing Infrastructure

This research proposes a novel approach for detecting and mitigating Advanced Persistent Threats (APTs) in cloud computing infrastruc ture, offering more comprehensive protection compared to previous methods. By integrating detection and mitigation, this study addresses the shortcomings of prior research that focused solely on detection. Based on the conducted research, Artificial Intelligence (AI) detected Cross-Site Scripting (XSS) attacks with an accuracy of 0.9951, SQL Injection (SQLI) at 0.9964, and Remote Code Execution (RCE) at 0.9876. In trials against new attacks, the detection success rates reached 70% for XSS, 98% for SQLI, and 100% for RCE. During the deployment phase, the system successfully identified 23.040 out of 108.394 requests as XSS attacks, 2.684 out of 128.750 as SQLI attacks, and 1.135 out of 46.450 as RCE attacks. The detection and mitigation methods were directly tested on cloud server experiencing APT attacks. The daily attacks on the server reached 1.980, with 663.000 requests. Additionally, the number of attacks directed at authentication or sensitive pages reached 17.913.701. Attack mitigation was tested through seven layers of security, including DNS Protection, Config Server Firewall (CSF), OWASP ModSecurity, HTTP middleware, data filter or sanitizer, template engine, and manual mitigation successfully blocking million of persistent attacks. The DNS protection layer successfully mitigated 59,000 out of a total of 19 million requests. The CSF layer mitigated 173 sources IP of DDoS attacks. The ModSecurity layer mitigated 17,916,204 attacks. All attacks were successfully mitigated before reaching the HTTP Middleware stage or next layer. The use of NIST 2.0 standards helps manage security risks through identification, protection, detection, response, and recovery. Test results indicate that this multi-layered system is more efficient and effective in detecting and mitigating attacks compared to traditional methods. However, the complexity of implementation and maintenance poses challenges that must be addressed. This research significantly contributes to a more adaptive and sustainable cybersecurity strategy.

Enhanced methods for multicollinearity mitigation in stochastic frontier analysis estimation

Enhanced methods for multicollinearity mitigation in stochastic frontier analysis estimation

Computational vibration mitigation using phase interpolation in digital holographic microscopy for overlay metrology

Digital holographic microscopy retrieves amplitude and phase information of an image which allows us to computationally correct for imperfections in the imaging optics. However, digital holographic microscopy is an interferometric technique that is inherently sensitive to undesired phase variations between object and reference beam. These phase variations lower the fringe contrast if they are integrated over a finite exposure time which leads to a reduced amplitude of the retrieved image. This results in significant errors in applications that rely on a stable and accurate amplitude measurement, such as optical overlay metrology in the semiconductor industry. We present experimental results on a computational vibration mitigation method for the application of overlay metrology using phase interpolation between a sequence of measured holograms and demonstrate its capability to improve metrology precision in an overlay metrology application that uses digital holographic microscopy.

Acoustic resonant metasurfaces with roughened necks for effective low-frequency sound absorption

The rise in environmental low-frequency noise from human-induced activities due to global urbanization has had a noticeable effect on the health and life quality of urban residents. Despite the implementation of conventional noise mitigation methods, they are only effective within a narrowband frequency range and their efficiency deteriorates when dealing with low-frequency noise. To address the existing problem in noise attenuation, an acoustic resonant metasurface that incorporates sliced Helmholtz-resonator-like substructures with embedded roughened necks is designed to achieve low-frequency sound absorption within a subwavelength scale. The theoretical model of this metasurface is first established, and then parametric studies are conducted to analyze the impact of various geometrical parameters on the sound absorption effect of the proposed metasurface. Subsequently, the sound absorption performance of the proposed design is investigated through numerical and experimental studies using two samples at both single and broadband frequencies. Excellent absorption performances by the samples at a low-frequency spectrum have been achieved. To understand the underlying absorptive mechanism of the proposed metasurface models, theoretical investigations are conducted for acoustic impedance and complex frequency, while numerical studies are also carried out to examine the distribution of acoustic pressure, acoustic velocity and thermoviscous power dissipation density. The research findings presented in this study may facilitate the development of an effective acoustic barrier for low-frequency noise (≤ 200 Hz).

A Review of Agrivoltaic Systems: Addressing Challenges and Enhancing Sustainability

Agrivoltaics is a relatively new term used originally for integrating photovoltaic (PV) systems into the agricultural landscape and expanded to applications such as animal farms, greenhouses, and recreational parks. The dual use of land offers multiple solutions for the renewable energy sector worldwide, provided it can be implemented without negatively impacting agricultural production. However, agrivoltaics represent a relatively new technology, facing challenges including economic viability, vulnerability to wind loads, and interference with growing crops. This paper reviews the recent research on integrating agrivoltaics with farming applications, focusing on challenges, wind impact on agrivoltaics, and economic solutions. The effect of agrivoltaics on temperature control of the lands is a critical factor in managing (1) water and the soil of the land, (2) animal comfort, and (3) greenhouse productivity, positively or negatively. In this review, a contradiction between the different versions of the American Society of Civil Engineers (ASCE) standards and the wind tunnel results is shown. Important factors affecting the wind load, such as damping and mass increase, optimum stow position, and aerodynamic edge modification, are highlighted with emphasis on the significant knowledge gap in the wind load mitigation methods.

Research on the effect of training program based on service-oriented leadership theory on nurses' job burnout

Objective: To explore the effect of training program based on service-oriented leadership theory on alleviating the degree of job burnout of clinical nurses, and provide reference for improving the situation of job burnout of nurses. Methods: From January to December 2023, 10 head nurses of a Grade A general hospital were selected by random number table method for training, and 5 nurses were selected from the department of each head nurse by random number table method, a total of 50 nurses were selected as research objects. Through the training program based on the service-oriented leadership theory, the selected head nurses were trained on the service-oriented leadership theory, job burnout and burnout mitigation methods and passed the examination. The training period was 2 months. The general data of 50 nurses were collected, and the job burnout of nurses was investigated by using the Maslach Burnout Inventory before and 6 months after the training of head nurses, and the changes of scores of each dimension were compared by paired t-test. Results: The nurses were (30.4±5.5) years old and their working life was (8.1±6.1) years. The total detection rate of job burnout before training was 100% (50/50), the detection rate of moderate to severe emotional exhaustion was 60% (30/50), and the detection rate after training was 36% (18/50). The detection rate of moderate to severe depersonalization was 72% (36/50) and 40% (20/50) after training. The detection rate of moderate to severe lack of job accomplishment was 86% (43/50) and 54% (27/50) after training. After 6 months of head nurses training, the scores of emotional exhaustion and depersonalization of nurses were significantly lower than those before training, while the scores of personal achievement were significantly higher than those before training, with statistical significances (P<0.05) . Conclusion: The training program based on service-oriented leadership theory can scientifically prevent and alleviate nurses' job burnout after receiving training of administrators, which is helpful to improve the current situation of nurses' job burnout and reduce the degree of nurses' job burnout, and can play a positive role in promoting nurses' physical and mental health.

An INS/UWB fusion localization scheme for wireless sensor network

Abstract As the demand for indoor services relying on location information grows, achieving precise indoor positioning is becoming an urgent issue to address. The ultra-wide band (UWB) accuracy can reach centimeter level, but is susceptible to non-line-of-sight (NLOS) effects. The inertial navigation system (INS) is not affected by the environment, but the error will diverge over time. Therefore, this paper focuses on the UWB/INS combined positioning system, which can combine the advantages of both. We propose a loosely-coupled INS/UWB indoor localization scheme based on factor graph optimization (FGO). Firstly, an agglomerative hierarchical clustering based NLOS mitigation method is applied to preprocess the UWB raw measurement data. The position estimates under UWB are then obtained using an improved extended Kalman filter to mitigate NLOS errors and provide more accurate location data for combined navigation. Then, we build the IMU preintegration factor and the zero-bias factor. Finally, FGO is used to fuse the information to get the final location. Designed experiments demonstrate the superiority of the algorithm. The simulation and experimental results show that the proposed scheme outperforms the comparison algorithms.

SD-MDN-TM: A traceback and mitigation integrated mechanism against DDoS attacks with IP spoofing

Traceback has been very attractive against DDoS attacks with IP spoofing instead of traditional mitigation methods because attacks require removal near attackers, resulting in affecting legitimate traffic as little as possible. There have been some approaches dedicated to achieving effective traceback. However, existing approaches often modify protocols to apply to multi-domain scenarios, and the implemented mitigation usually lags behind traceback. Therefore, this paper proposes the Software-Defined Multi-Domain Network Tracer and Mitigator (SD-MDN-TM) to traceback and mitigate DDoS attacks with IP spoofing in multi-domain SDN scenarios. We apply systematic sampling and flow feature extraction based on the Count-Min Sketch data structure for the lightweight statistics collection of massive DDoS attack traffic. We also design the TracebackTree data structure to construct the traceback paths of attackers of distributed attack sources. The Border Switch Trigger Mechanism is proposed to overcome the drawbacks of the commonly-used packet marking in cross-domain traceback information transfer, achieving no modification of existing network protocols and independent traceback among multiple domains. Mitigation is integrated with traceback for faster removal of attacks from the network. The proposed scheme can traceback DDoS attack sources both inside and outside domains accurately and effectively by constructing traceback path. It can be implemented without modifying the existing protocols, therefore achieving direct application to the existing network architecture. Furthermore, the traceback of attack sources outside domains can maintain independence in multi-domain scenarios. Mitigation integrated with traceback can achieve less impact on legitimate traffic and faster removal of attacks from the network.

Per- and polyfluoroalkyl substances contamination of drinking water sources in Africa: Pollution sources and possible treatment methods

Despite the detection of poly- and perfluorinated alkyl substances (PFAS) in the water system in Africa, the effort towards mitigating PFAS in water in Africa needs to be better understood. Therefore, this review evaluated the contamination status and mitigation methods for handling PFAS-contaminated water systems in Africa. The findings revealed the presence of PFAS in wastewater treatment plant (WWTP) effluents, surface water and commercially available bottled and tap water in African countries. The concentration of PFAS in drinking water sources reviewed ranged from < limits of quantification to 778 ng L−1. The sources of PFAS in water systems in Africa are linked to uncontrolled importation of PFAS-containing products, WWTP effluents and inappropriate disposal of PFAS-containing materials. The information on treatment methods for PFAS-contaminated water systems is scanty. Unfortunately, the treatment method is challenged by poor water research infrastructure and facilities, lack of awareness, poor research funding and weak legislation; however, adsorption and membrane technology seem favourable for removing PFAS from water systems in Africa. It is essential to focus on monitoring and assessing drinking water quality in Africa to reduce the disease burden that this may cause. Most African countries' currently implemented water treatment facilities cannot efficiently remove PFAS during treatment. Therefore, governments in Africa need to fund more research to develop an efficient water treatment technique that is sustainable in Africa.

Reviewing the Phenomenon of Antimicrobial Resistance in Hospital and Municipal Wastewaters: The Crisis, the Challenges and Mitigation Methods

Antibiotic resistance is a major crisis that the modern world is confronting. This review highlights the abundance of different types of antibiotic resistance genes (ARGs) in two major reservoirs in the environment, namely hospital and municipal wastewater, which is an unforeseen threat to human lives across the globe. The review helps understand the current state of affairs and the whereabouts on the dissemination of ARGs in both these environments. The various traditional wastewater treatment methods, such as chlorination and UV treatment, and modern methods, such as electrochemical oxidation, are discussed, and the gaps in these technologies are highlighted. The need for the development of newer techniques for wastewater treatment with enhanced efficiency is urgently underscored. Nanomaterial applications for ARG removal were observed to be less explored. This has been discussed, and prospective nanomaterials and nanocomposites for these applications are proposed.

PSLBII-29 Effects of heat stress mitigation methods on growth performance, environmental, and economic outcomes of feedlot cattle raised in a hot climate

Abstract The increase in average global temperatures presents a challenge for the beef industry, especially in the feedlot sector where heat stress is a major animal welfare and economic concern. To combat this, shade stands out as one of the most practical methods to mitigate heat stress in feedlot cattle. An experiment was conducted as a completely randomized design with Bos indicus bulls (n = 1,560) with initial body weights (BW) of 287 kg. Three shade structure types were used to investigate the effects of different heat stress mitigation methods on cattle growth performance, environmental, and economic outcomes using live animal data, and a partial lifecycle assessment (LCA) using the Integrated Farm System Model (IFSM). The live animal portion of the experiment was done once a year over a 2-yr period with three pen replications per treatment per year (n = 6 per treatment). Four shade structures used were: conventional shade (SC; steel shade 1.8 m2 of shade/animal), double conventional shade (DS; steel shade 3.6 m2 of shade/animal), dome structures without fans (DSA; 8.5 m2/animal with 98% solar radiation blocked), and domes with fans (DCA; three large sized low-speed fans). Each pen held 65 bulls in an area of 570 m2. Live animal data were analyzed as a completely randomized design using the GLM procedure of SAS (version 9.4) with shade type as fixed effect, pen as the experimental unit, and repetition (year) considered a random effect. Cattle housed under DCA had 22 kg and 20 kg heavier final body BW (P &amp;lt; 0.05) compared with those housed under SC and DS, respectively. Final BW of DCA and DSA cattle were similar (P &amp;gt; 0.10). Average daily gain, feed efficiency, and hot carcass weight (HCW) were greater (P &amp;lt; 0.05) for cattle housed under DCA compared with the rest of the shade types. Dry matter intake was not affected (P &amp;gt; 0.10). When treatment results were extrapolated to the annual feedlot turnover of 209,700 animals, cattle in DSA and DCA versus SC and DS had 3 to 8 % reductions in greenhouse gas and ammonia emissions intensities. Compared with SC, DCA increased profitability by $29.66/animal, followed by DSA and DS with profit increases of $5.79 and $8.90/animal, respectively. Overall, the implementation of advanced shade structures improved cattle performance and profitability while reducing the environmental impact of beef production.

Performance of integrated FB and WEC for offshore floating solar photovoltaic farm considering the effect of hydroelasticity

The offshore floating solar photovoltaic (PV) farm deployed in the open sea could be subjected to large environmental loading due to waves or wakes from travelling ships. To reduce the motion of the solar farm, mitigation methods such as protection of the solar farm via floating breakwater (FB) could be deployed. The FB serves as a buffer between the floating farm and the incoming wave force, and as it attenuates the wave forces, this creates a sheltered zone on the leeward side of the FB. The energy generation from the solar farm could be further enhanced via the integration of attenuator-type wave energy converters (WEC) with the FB. This paper investigates the performance of the hybrid FB – WECs as a coastal protection structure cum wave energy extraction devices. The effect of FB on mitigating the hydroelastic response of the floating solar farm is investigated. Four types of FB, i.e., I-, L-, U- and BOX-shape FBs are considered and their effectiveness in wave attenuation under regular waves arriving from different directions are studied. In addition, due to the long structure length-to-wavelength ratio of the floating solar farm and FB, the hydroelastic response of the structures is taken into consideration.

Earthquake damage mitigation methods for buried pipelines under compressive loads: A case study of the Thames water pipeline

Promoting tensile failure by providing a proper orientation angle between the pipe axis and the fault line is the main seismic design philosophy for buried steel pipelines. However, most of the severe damage and failures experienced by pipelines are mainly due to negative crossing angle and thus compressive loads acting along the pipeline. This paper investigates different earthquake damage mitigation methods such as Carbon Fiber Reinforced Polymer (CFRP) wrapped pipes, Steel Pipes for Fault Crossing (SPF), and corrugated pipes for buried steel pipelines which are mainly subjected to compressive loads. Therefore, the Thames water transmission pipeline, which is a well-known case study, that suffered major and minor damage due to compressive forces in the 1999 Kocaeli earthquake, is considered to simulate and compare the earthquake damage mitigation capabilities of these countermeasures. The numerical studies are performed by using a three-dimensional nonlinear finite element model. The results show that the use of CFRP composites in buried pipelines, regardless of their thickness, wrapping length, or layer orientation, does not have the expected damage reduction effect, but does increase the effective length between major wrinkles or change the type of pipe failure. On the other hand, SPFs and corrugated pipes are more effective in earthquake damage reduction due to their high axial and rotational capabilities.

Stone column strategies for mitigating liquefaction-induced uplift of tunnels

Tunnels embedded in liquefiable soil are frequently subjected to uplift and sustain serious damage during major earthquakes. Mitigation methods to prevent the flotation of these tunnels must be developed and implemented in the natural environment. For this purpose, this study proposes a new method that uses stone columns to enhance soil drainage and mitigate soil liquefaction around tunnels. A circular tunnel in liquefied soil is simulated using a 2D finite element model, PLAXIS 2D, and subjected to a sinusoidal input motion. The tunnel's pre-construction and post-construction scenarios are examined. Parametric studies are carried out to investigate the effect of changing several parameters, such as the distance between stone columns and tunnel springing, the diameter of stone columns, the spacing between stone columns, the number of stone column rows, and the stone column arrangement patterns on the effectiveness of liquefaction mitigation. The study reveals that liquefaction mitigation is enhanced by using stone columns closer to tunnel springing, with larger diameters, less spacing, and more rows of stone columns that are arranged in a square pattern. It also emphasizes the importance of timely implementation of stone columns for maximum benefit.

Small LEA proteins mitigate air-water interface damage to fragile cryo-EM samples during plunge freezing

Air-water interface (AWI) interactions during cryo-electron microscopy (cryo-EM) sample preparation cause significant sample loss, hindering structural biology research. Organisms like nematodes and tardigrades produce Late Embryogenesis Abundant (LEA) proteins to withstand desiccation stress. Here we show that these LEA proteins, when used as additives during plunge freezing, effectively mitigate AWI damage to fragile multi-subunit molecular samples. The resulting high-resolution cryo-EM maps are comparable to or better than those obtained using existing AWI damage mitigation methods. Cryogenic electron tomography reveals that particles are localized at specific interfaces, suggesting LEA proteins form a barrier at the AWI. This interaction may explain the observed sample-dependent preferred orientation of particles. LEA proteins offer a simple, cost-effective, and adaptable approach for cryo-EM structural biologists to overcome AWI-related sample damage, potentially revitalizing challenging projects and advancing the field of structural biology.

The Impact of Climate Change on Public Health

Climate change is becoming increasingly recognized as a major hazard to public health, with rising temperatures, irregular weather patterns, and environmental degradation all contributing to poor health outcomes worldwide. This study investigates the complex relationship between climate change and public health, focusing on major health concerns such as heat-related sickness, respiratory and cardiovascular disorders, and the expansion of vector-borne diseases. Vulnerable groups, such as those in lower socioeconomic levels and marginalized areas, incur greater risks. The paper also examines mitigation and adaptation methods that are critical for reducing the public health consequences of climate change. Addressing these difficulties would necessitate interdisciplinary collaboration and policy reform in order to protect health and resilience against future climate-related dangers. Keywords: Climate change, public health, environmental health, air pollution, heat-related illness.