Conceptual Strategy for Mitigating the Risk of Hydrogen as an Internal Hazard in Case of Severe Accidents at Nuclear Power Plant Considering Existing Risks and Uncertainties Associated with the Use of Traditional Strategies

Hydrogen challenge mitigation stands as one of the main objectives in the management of severe accidents at Nuclear Power Plants (NPPs). Key strategies for hydrogen control include atmospheric inertization and hydrogen removal with Passive Autocatalytic Recombiners (PARs) being a commonly accepted approach. However, an examination of PAR operation specificity reveals potential inefficiencies and reliability issues in certain severe accident scenarios. Moreover, during the in-vessel stage of severe accident development, in some severe accident scenarios PARs can unexpectedly become a source of hydrogen detonation. The effectiveness of hydrogen removal systems depends on various factors, including the chosen strategies, severe accident scenarios, reactor building design, and other influencing factors. Consequently, a comprehensive hydrogen mitigation strategy must effectively incorporate a combination of strategies rather than be based on one strategy, taking into consideration the probabilistic risks and uncertainties associated with the implementation of PARs or other traditional methods. In response to these considerations, within the framework of this research it has been suggested a conceptual strategy to mitigate the hydrogen challenge during the in-vessel stage of severe accident development.

Weathering the Storm: Mitigating Hurricanes with Ground-Based CCN and Lightning

This research introduces a groundbreaking methodology aimed at mitigating storm and hurricane intensity through the application of a ground-based, manually operated Cloud Condensation Nuclei (CCN) Generator. To meet the demand for more comprehensive context and rationale, this study explores the escalating challenges presented by the growing intensity of hurricanes, exemplified by Hurricane IAN (2022). The controlled release of environmentally friendly aerosols into the atmosphere, achieved by combusting selected wood pieces and organic edible materials, is a pivotal response to the escalating threat of extreme weather events. By generating CCN, the novel approach seeks to augment positive lightning in the eyewall, providing a potential solution to the intensification of hurricanes. Results illustrate the successful implementation of the methodology, with released aerosols effectively reaching the clouds for seeding, thus contributing to the modification of convection in the outer wall of Hurricane IAN and consequent intensity reduction. Rigorous experiments, incorporating considerations of various parameters such as wind patterns and the experimental location in Sarasota City, emphasize the scientific rigor applied to weakening Hurricane IAN. This comprehensive approach not only holds promise in mitigating hurricane intensity but also sheds light on the potential impact of cloud seeding in reducing the severity of future hurricanes, addressing a critical need for sustainable solutions to climate-related challenges.

The Realistic Dilemma, Problem Tracking and Mitigating Strategies of Primary School Science Teachers’ Professional Happiness

The Science teachers in primary schools are the key group in developing science education, and they play a vital role in realizing the dream of strengthening the country through education. Their professional happiness deserves special attention. Whether this group is happy not only affects their own working conditions and quality of life, but also affects the work vitality of other teachers. Improving the professional happiness of science teachers in primary schools has become an important topic in the construction of teachers’ team in the new period. At present, the intensity of primary school science teachers’ own work is high, their non-own work is increasing, their physical and mental health is difficult to guarantee, and their professional happiness is reduced. The main causes of the problems are poor individual psychological quality, poor school management style and improper social cognitive evaluation. In order to solve this problem, we have explored strategies to improve the professional happiness of science teachers in primary schools through reshaping teachers’ work, democratic management of schools and national policy guarantee.

Analysis of input harmonic current mitigating performance in dual output phase-shift distribution transformer

A novel dual output phase-shift distribution transformer （ DOPSDT ） is proposed based on the electromagnetic filtering theory. First, its structural characteristics, winding connection mode and turn number ratio for special phase shifting are investigated. Secondly, the balance formulation of harmonic magneto-motive forces is derived and the electromagnetic filtering principle of the DOPSDT is introduced. The harmonic mitigating performance under different nonlinear load conditions are also analyzed using the field-circuit coupled method, The analysis results show that the DOPSDT can mitigate the primary current distortion even under severe nonlinear load conditions. By applying the zero sequence flux cancellation and phase-shift techniques at their secondary windings, the DOPSDT can significantly reduce the 3rd, 5th, 7th, 9th, 15th, 17th and 19th harmonics within its secondary windings.

Successive Picket Drive for Mitigating the Ablative Richtmyer–Meshkov Instability

The ablative Richtmyer–Meshkov instability(ARMI) is crucial to the successful ignition implosion of the inertial confinement fusion(ICF) because of its action as the seed of the Rayleigh–Taylor instability. In usual ICF implosions, the first shock driven by various foots of the pulses plays a central role in the ARMI growth. We propose a new scheme for refraining from ARMI with a pulse of successive pickets. With the successive-picket pulse design, a rippled capsule surface is compressed by three successive shocks with sequentially strengthening intensities and ablated stabilization, and the ablative Richtmyer–Meshkov growth is mitigated quite effectively.Our numerical simulations and theoretical analyses identify the validity of this scheme.

Ultrasound mechanotransduction on osteoblastic mineralization and mitigating bone loss

Introduction Mechanotransduction has demonstrated potentials for tissue adaptation in vivo and in vitro. It is well documented that ultrasound,as a mechanical signal,can produce a wide variety of biological effects in vitro and in vivo [1]. As an example,

Mitigating Disaster Impacts in Africa

The financial cost of disasters in Africa is estimated by the AU to run between 3 and 15 percent of the continent＇s GDR High vulnerability to disaster risk is thus a major challenge undermining Africa＇s accelerated and sustainable structural transformation efforts. But there is a plan in place to build resilience to disasters and reduce the risk impact,

MITIGATING THE DAMAGE OF BROWN BEARS IN MARYO TOWNSHIP

The need for the mitigation of brown bears has become so severe that many nomads have given up repairing their houses in Maryo Township’s Mendang Village(also named the First Administrative Village),a remote place located in the southwestern section of the Changtang National Nature Reserve(CNNR).Only part of the village belongs to Serling Tso Nature Reserve.

Numerical analysis of external magnetic field for mitigating backward flow momentum in weld pool

The external magnetic field is applied to mitigating backward flow jet of molten metal in weld pool so that humping bead may be suppressed during high speed gas metal arc welding（GMAW）. Therefore, the external magnetic field distribution in workpiece is critical to understand the interaction mechanisms of the external magnetic field with molten metal flow. In this study, the steady state external magnetic field induced by excitation device is numerically analyzed by using the the finite element software ANSYS and the three dimensional static magnetic scalar method. The distribution of external transverse magnetic field By in workpiece and arc area is calculated, and the influence of excitation current and air-gap distance on the distribution of transverse magnetic field By has been discussed. The magnetic field distribution in workpiece is measured by using a Tesla-Meter and compared with the simulated result. It is found that both are in good agreement.

Mitigating ROP Attacks via ARM-Specific In-Place Instruction Randomization

Defending against return-oriented programing(ROP) attacks is extremely challenging for modern operating systems.As the most popular mobile OS running on ARM,Android is even more vulnerable to ROP attacks due to its weak implementation of ASLR and the absence of effective control-flow integrity enforcement.In this paper,leveraging specific ARM features,an instruction randomization strategy to mitigate ROP attacks in Android even with the threat of single pointer leakage vulnerabilities is proposed.By popping out more registers in functions' epilogue instructions and reallocating registers in function scopes,branch targets in all(direct and indirect) branch instructions potential to be ROP gadgets are changed randomly.Without the knowledge of binaries' runtime instructions layout,adversary's repeated control flow transfer in ROP exploits will be subverted.Furthermore,this instruction randomization idea has been implemented in both Android Dalvik runtime and ART.Corresponding evaluations proved it is capable to introduce enough randomness for more than 99% discovered functions and thwart about 95% ROP gadgets in application's shared libraries and oat file compiled from Dalvik bytecode.Besides,evaluations on real-world exploits also confirmed its effectiveness on mitigating ROP attacks within acceptable performance overhead.

Mitigating the catastrophic impacts of torrential rivers in semi-arid environments: a case of the Gash River in eastern Sudan

The climatic, geomorphic, hydrologic and aquifer characteristics of the torrential Gash River across mountainous areas, in far eastern Sudan, were analyzed in order to mitigate its recurring catastrophic impacts. Hydrologic and climatic data and interpretation of Gash River satellite images were from relevant research works carried out in Gash Basin from 1985 to 2008. The results indicated that the total catchment area of Gash River is about 21,000 km2, and the basin area is 31,000 km2. The total length of Gash River is 450 km and the average slope is 200 cm/km. The width of the catchment varies from 30 m to 90 m and that of the basin is from 100 m to 800 m, and the course of the river is varied. During the period of 1980？2008, the mean annual rainfall was 250 mm and the mean annual discharge was 6.8 ×10~8 m^3, and the flooding is approximately one time per 5 years. Torrential floods measured at Kassala town since 1907 showed that an absolute maximum discharge was 876 m3/s and a mean maximum discharge was 365 m3/s. These characteristics differ widely between catchment and basin areas. The author proposes that, by analyzing the climatic, geomorphic, hydrologic and aquifer characteristics of the Gash River and considering the role of community, a concise database could be provided to formulate the aquifer, geomorphic, hydrologic and climatic （AQUIGEOHYCLIM） regional approach to mitigate Gash River recurring catastrophic impacts.

An Alternative Strategy for Mitigating the Effect of Rainfall Variability in Burkinabe Sahel

This study was carried out in the Burkinabe Sahel aimed at studying contribution of the practice of supplemental irrigation (SI) via excavated rainwater harvesting basin (RWHB) for mitigating effect of rainfall variability on agricultural production and impact of these RWHB on the dynamics of the water table. This study was conducted during two growing seasons (2013 and 2014) and used a test plot cultivated in corn and fitted out with measuring instruments to analyze water transfer in the soil-plant-atmosphere system on the one hand and the atmosphere-RWHB-water table system on the other hand. Four treatments—one under rainfall regime (T0) and three under SI (T1, T2, and T3)—were used in the experimental design to assess the contribution of the RWHB in improving corn yield. These SI were applied during the mid-season of corn (flowering, pollination, and grain filling). Water flow beneath a partially waterproofed RWHB was assessed using HYDRUS- 2D/3D program. Results showed that water stored in the RWHB allowed applying up to three SI, and increased corn yield up to 24% and 26% respectively in 2013 and 2014. However, SI targeting flowering and grain filling were the best scenarios to mitigate effect of dry spell in rainfed agriculture. Water flow under RWHB during the simulation period showed that dynamic of the saturated front depended on the magnitude of the water depth in the RWHB and the hydrodynamic characteristics of the underlying layers. Deep drainage was observed around 25th day after sowing (DAS) in 2013 and 45th DAS in 2014 according to water profile. This caused the decrease of the infiltration rate in the RWHB that was associated with a significant rise of 4% of the water table level ten days later in 2014. Recharge rate was estimated at 0.5 mm·d-1 during the mid-season and the late season of corn.

Measures for Mitigating the Effects of Climate Change on Crop Production in Nigeria

This paper examined the causes, effects and measures for mitigating climate change to ensure adequate supply of food through crop production to address the food insecurity which has occupied a central focus of the Nigerian economy. Unfortunately, crop production is fraught with many ecological challenges including climate change. This climate change which occurs as a result of the buildup of Green House Gases (GHGs) occasioned by industrialization, technological modeling and agriculture, exert significant effects on crop yield, water availability, ecosystem disequilibrium resulting in cases of drought, flood earthquake among others. For crop production to be scaled-up to meet the food requirement of the ever growing Nigerian population amidst these challenges, there is need to mitigate these adverse effects of climate change through the adoption of sustainable land management practices that can reduce the atmospheric stock of GHGs such as zero-tillage, appropriate use of fertilizers, avoidance of bush burning, graze land management, improved water management among others. Achieving great success in these areas requires that Nigerian government should be more proactive in their policies that hold promise for sustainable cultures in agricultural production as well as evolving global partnerships on ecological issues.

A Mitigating Technique for the Treatment of Small Volumes Drinking Water from Radon Gas

We made an evaluation of a suitable mitigation technique for the treatment of drinking water that was artificially enriched with Rn-222 in laboratory by placing a radium rich granite stone (pitchblende) in a closed container filled with tap water for several days in order to allow Rn-222 concentration to approach its highest possible level. Experiments were designed to investigate the effectiveness of removal of Rn-222 by diffused bubble aeration method at room temperature. The results showed that this method becomes more efficient at higher airto-water ratios. Better aeration depends on the length of travel of bubbles through the water depth. This method is practical and has low capital cost. The removal of Rn-222 from artificially enriched water can be practically achieved by diffused bubble aeration method to greater than 98%.

Mitigating the Environmental Effects of Oil and Gas Exploitation: Issues of Compliance, Cost of Production, and Community Awareness

This study assessed the effectiveness of mitigation measures adopted to address the environmental effects of oil and gas industries from the perspective of compliance, cost of production, and community awareness. The research applied a case study through multi-method-qualitative and quantitative approaches. The target population of 547,368 people involved people in Takoradi, Shama and Newtown communities. A sample size of 150 was selected and categorised under 36% for Shama, 30% for Newtown and 34% for Takoradi. A combination of probability (simple random) and non-probability (cluster and convenience) sampling frames were used to access the respondents for the study. Data collection tools were limited to questionnaires and interview sessions. The descriptive statistics, Relative Importance Index (RII) and significance testing using a one-sample t-test module guided the analysis. Interview sessions were compiled into transcripts and later categorized into themes that directly reflected the patterns of the questions on the questionnaire. The conclusion rated major decisions in mitigating oil and gas impacts on the environment as first for conscious effort to package fuel and other chemicals in safe storages, followed by the use of best road systems to reduce the risk of accidents, then application of strict rules and regulations to curb impacts and lastly capacity building for participants in the oil and gas production industry. While significant measures have been adopted to mitigate the effects of oil and gas exploration, there remain challenges with effectiveness as a result of weakness in community involvement efforts, lack of motivation, weak laws and regulations and loss of respect. For effectiveness in reducing the challenges to mitigate the environmental impacts of the oil and gas production activity, policymakers, as well as the practitioners in the oil production industry, are advised to motivate people into buying into their policy to reduce such impacts.

Building Failure Causes in Nigeria and Mitigating Roles by Engineering Regulation and Monitoring

This paper assessed some of the reported cases of building failures and their possible causes in Nigeria between 1977 and 2011. The reported major failure causes are structural failure (SF), Carelessness (CLSS), poor workmanship (PW), poor supervision (PS), poor materials (PM), and quackery (Q).These causes of failure were subjected to Chi-Square statistical test at 5% significant level and 4 degree of freedom to know the most common cause of failure in Nigeria. The analysis showed quackery as the principal culprit in the reported building failures in Nigeria with prevalence of 8 over poor supervision being the minimum in occurrence. Structural failure occurred 5 times, while poor materials, carelessness and poor workmanship occurred 4, 2 and 2 respectively. The Council for the Regulation of Engineering in Nigeria (COREN) with Engineering Regulation and Monitoring (ERM) as her arm as a technical professional group discouraging quackery and failures generally in Engineering Practice. The holistic approach needs effective training of Engineers starting with strong mathematical and scientific background at the secondary and tertiary education levels in conjunction with rigorous field and Industrial training exercises. There after effective scrutiny, professional registration process of competent engineers is followed.

Community Perspectives on the Use of Recycled Plastic Posts in Mitigating Livestock Predation in Amboseli Ecosystem, Kenya

In the last few decades, the impacts of human activities on ecosystem have rapidly increased resulting to detrimental ecosystem changes. Human-wildlife conflict (HWC) is one of the greatest consequences of human impacts on the environment. Although HWC has been there for decades, its intensity seems to be growing with the spread of human settlements, changes in land use patterns and diminishing suitable natural habitats for wildlife. To mitigate HWC, various strategies have been devised and implemented. This study focused on predator-proof bomas (PPBs) approach that is ongoing in Amboseli ecosystem. The aim was to establish reasons behind the slow adoptions of the recycled plastics poles by owners of PPBs that were constructed using wooden posts between the years 2010 to 2013. Randomly selected 36 PPB homestead owners were interviewed and the physical structures of their PPBs assessed. Results revealed a positive relationship between PPB size and number of poles damaged;and a significant association between the damaged posts and the number of indigenous posts replaced in the three group ranches (X2 = 34.9331, df = 2, p < 0.05). Most of the respondents (89%) cited posts and doors (72%) as the main parts that needed repairs. About 80% of the respondents would recommend the plastic posts for use in constructing new PPBs by other people. Most of the PPB beneficiaries whose PPBs were constructed in 2010-2013 have opted for an “easy” alternative source of posts from the sparsely distrusted trees around their homesteads. It is recommend that an open window period should be tried to entice the wooden post PPBs owners to adopt the recycled plastic posts. This may necessitate upgrading the existing old wooden bomas to a “smart PPBs”. It is suggested that the “smart PPBs” should not only have recycled plastic posts but also “free” energy saving stoves in each household to reduce the level of deforestation.

Realization of Unified Power Quality Conditioner for Mitigating All Voltage Collapse Issues

This paper proposes about a powerful control mechanism of UPQC (Unified Power Quality Conditioner) work on voltage source inverter which can effectively compensate source current harmonics and also mitigate all voltage collapse such as dip, swell, voltage unbalances and harmonics. The consolidation of series and parallel active power filters sharing mutual DC bus capacitor forms UPQC. PI (Proportional Integral) controller is mainly used in order to maintain continual DC voltage along with the hysteresis current controller. The parallel and series power filters were designed using 3-phase voltage source inverter. The reference signals for shunt and series active power filters were obtained by Synchronous Reference Frame (SRF) theory and Power Reactive (PQ) theory respectively. By using these theories, reference signals were obtained which was fed to the controllers for generating switching pulses for parallel and series active filters. The UPQC dynamic performance is obtained through testing terms like the compensation of voltage, current harmonics and all voltage distortion associated with 3-phase 3-wire power system which is simulated using MATLAB-Simulink software.

A Two-layer Framework for Mitigating the Con-gestion of Urban Power Grids Based on Flexible Topology with Dynamic Thermal Rating

The urban power grid(UPG)combines transmission and distribution networks.Past studies on UPG congestion mitigation have primarily focused on relieving local congestion while ignoring large-scale energy transfer with safety margins and load balancing.This situation is expected to worsen with the proliferation of renewable energy and electric vehicles.In this paper,a two-layer congestion mitigation framework is proposed,one which considers the congestion of the UPG with flexible topologies.In the upper-layer,the particle swarm optimization algorithm is employed to optimize the power supply distribution(PSD)of substation transformers.This is known as the upper-layer PSD.The lower-layer model recalculates the new PSD,known as the lower-layer PSD,based on the topology candidates.A candidate topology is at an optimum when the Euclidean distance mismatch between the upper-and lower-layer PSDs is the smallest.This optimum topology is tested by standard power flow to ascertain its feasibility.The optimum transitioning sequence between the initial and optimum topologies is also determined by the two-layer framework to minimize voltage deviation and line overloading of the UPG considering dynamic thermal rating.The proposed framework is tested on a 56-node test system.Results show that the proposed framework can significantly reduce congestion,maintain safety margins,and determine the optimum transitioning sequence.

Numerical evaluation of enhanced green infrastructures for mitigating urban heat in a desert urban setting

The cities of desert climates are anticipated to recognize a synergy of urban heat island(UHI)and severe heat waves during summertime.To improve the urban thermal environment,the present study aims quantitatively explore a strategically designed network of vegetation patches called green infrastructure(GI)in subtropical desert cities such as Dubai.To achieve a more comfortable temperature environment,we built and simulated four GI situations with higher GI fractions,GI25,GI50,GI75,and GI100.Using a mesoscale urban model,the mosaic approach is utilized to test potential thermal improvement and urban climate impact,and a portion of each urban grid cell in the model domain is altered with various species of urban vegetation patches by 25%,50%,75%,and 100%.The daily peak reduction in ambient temperature at 17:00LT is similar to 0.0168℃ per unit of GI increase when compared to the untreated scenario;however,the maximum anticipated daytime summer temperature decline for GI25,GI50,GI75,and GI100 is 0.6℃,1.1℃,1.4℃,and 1.7℃,respectively.The associated reduction in nighttime ambient temperature per unit increase in the GI is 0.0432℃,with a maximum temperature drop of around 2.4℃ for the GI100 scenario.Increased GI reduces the height of the planetary boundary layer(PBL)by up to 468 m,which might lead to greater pollution concentrations.While GI-based cooling has a significant influence on delayed sea breeze and humidity,it may raise the risk of heat discomfort in the indoor building environment.This study adds to our understanding of the potential for GI mitigation as well as the seasonal impact of developing GIs on the desert urban boundary layer.