Risk Protection Research Articles

Risk analysis and protection in case of intrusion of nuclear facilities

Abstract Physical protection systems (PPSs) are designed to counter and neutralize any theft or sabotage attempts carried out against a given site. PPS designs are crucial, requiring rigorous analysis and evaluation to ensure their reliability, sustainability and optimal security. This paper assumes a Hypothetical Nuclear Research Center (HNRC) for PPS analysis and evaluation. This work will determine the PPS’s most vulnerable path elements, by demonstrating expected intrusion attack scenarios by taking advantage of the HNRC’s design weaknesses. Also, this work determines the threats resulting from adversary intrusion through the weakness path elements located at the nuclear site. Additionally, this paper develops an analytical methodology for this evaluation and risk assessment, by using the Systematic Analysis of Vulnerability to Intrusion (SAVI) computer program. Through constructing adversary sequence diagrams (ASDs), SAVI can easily identify the HNRC’s most vulnerable paths, pinpointing the areas which require the most attention. Alongside SAVI is the quantitative risk analysis method - the Dai et al. Model – which can calculate the effectiveness and risk of the PPS itself by measuring its degree of uncertainty using effectiveness entropy. To comply with effectiveness and risk standards, this work also introduces security system upgrade processes and determines the optimal security solution for the HNRC.

LANDASAN HUKUM DAN PRINSIP-PRINSIP ASURANSI SYARIAH DI INDONESIA

Sharia insurance is a type of financial institution that functions in accordance with Islamic sharia, which upholds the concept of mutual protection (takaful) and mutual assistance (ta'awun). This thinking is regulated in Indonesian laws and regulations, including DSN-MUI Fatwa No. 21/DSN-MUI/X/2001, and is based on the teachings of the Koran, hadith, ijma, and ulama fatwas. Its guiding principles include mutual protection, cooperation in virtue, and avoiding aspects of riba, gharar (uncertainty), maisir (gambling), and activities that violate sharia. Islamic insurance offers Muslims a way to fulfill their risk protection requirements in line with Islamic principles, according to this research, which combines descriptive techniques with literature review methods. Sharia insurance builds a transparent and socially responsible financial system through the application of fair principles and a strong legal basis.

Cumulative Risk and Cumulative Protection: Relative Contributions to Predicting Substance Use, Antisocial Behaviour and Mental Health Across Development.

Cumulative risk scores predict negative outcomes including antisocial behaviour and mental health. Less work has examined the role of cumulative protection, despite the availability of preventive interventions focused on bolstering protection across domains. Understanding links between cumulative risk and protection measured in childhood and later outcomes can help to guide the timing of prevention programmes. The study aimed to understand the relative contributions of early adolescent cumulative risk and cumulative protection in Grade 6 on distal outcomes six to seven years later, at ages 18-19. Data are from the Community Youth Development Study, a community-randomised trial of the Communities That Care prevention system. The analysis sample consisted of 2002 participants from 12 control communities. Logistic regression models were estimated to quantify the main and interactive effects of Grade 6 cumulative risk and protection on alcohol, tobacco and cannabis use; antisocial behaviour, and depression at ages 18-19. When considered in separate models, cumulative risk and protection were each associated with later alcohol, tobacco and cannabis misuse; antisocial behaviour and depression. When considered together, coefficients for cumulative protection were attenuated, whereas coefficients for cumulative risk remained similar in magnitude. Cumulative risk was associated with larger outcome prevalence differences (average of 9%) than cumulative protection (average of 2%). Evidence for risk-protection interactions was not observed. Although early adolescent cumulative protection was associated with later outcomes, these associations were largely reduced when considering cumulative risk. Findings emphasise the importance of addressing cumulative risk when designing preventive interventions.

Introducing an integrated approach for fire safety assessment in healthcare facilities by interval valued neutrosophic-AHP and Fuzzy Inference System.

Fire safety in healthcare facilities is extremely important due to limited evacuation capacity of occupants. Therefore, poor fire safety precautions lead to more fatalities and financial losses. This study introduces an effective fire risk management approach for healthcare buildings utilizing an interval valued neutrosophic-fuzzy framework. This framework identifies fire risks and determine appropriate safety measures. In addition, essential fire risk criteria in healthcare centers were systematically identified through a multi-factor decision-making process, employing the Fuzzy-Delphi technique and a comprehensive literature review. The proposed framework initially determines the importance weights of these factors using the Interval Valued Neutrosophic-Analytical Hierarchy Process (IVN-AHP). Subsequently, three main parameters - Potential Risk Level (PRL), Acceptance Risk Level (ARL) and Protection Level (PL) - were calculated as alternatives in IVN-AHP technique using novel mathematical equations. A fuzzy inference system (FIS) was then employed to estimate the risk magnitude and subsequently classify departments within the healthcare building based on their risk level. The fire risk control strategy is then determined based on this risk classification. The proposed approach was applied to departments within a hospital in Iran. Its validity was evaluated by comparing the results with the comprehensive Fire Risk Assessment Method for Engineering (FRAME) technique. Additionally, the sensitivity of the IVN-AHP in determining the weights of factors and alternatives was validated using real data. The results revealed that the utilities and kitchen departments exhibited a critical risk class exceeding 50%. Furthermore, the operating room, laundry, post-NICU 1 and 2, and waste disposal were classified as critical, with more than 50% falling within the major risk class. A strong correlation coefficient of 99.1% was observed between the Fire Risk Magnitude (FRM) obtained using the proposed farmwork and the FRM for occupants obtained using the FRAME technique. These findings demonstrate the applicability and reliability of the proposed approach as a valuable tool for risk management and decision-making in healthcare facilities.

Multidimensional vulnerability and financial risk protection in health in contexts of protracted conflict: Evidence from the Occupied Palestinian Territory.

This paper proposes a multidimensional vulnerability index for a setting of protracted conflict, which is applied to study the relationship between financial vulnerability and catastrophic healthcare expenditure (CHE) incidence in the Occupied Palestinian Territory in 2018. We find that our index better captures the extent of financial risk protection in health compared to conventional measures of financial welfare. Results indicate that the most vulnerable groups experience a significantly higher likelihood of incurring CHE, and this likelihood is increased for those living in the West Bank compared to the Gaza Strip. We also find a lack of protection from existing health insurance types against the risk of CHE. Our analysis provides valuable insights about key aspects, such as health financing and insurance bottlenecks, that will deserve careful policy attention in efforts to rebuild the Palestinian health system, following the Israel-Hamas war.

Risk of Aedes-borne diseases in and around the Tanzanian seaport of Tanga despite community members being more concerned about malaria

BackgroundIncreased global trade, while beneficial economically, can also increase the spread of vector-borne diseases, particularly those transmitted by Aedes mosquitoes spreading via trade routes. Given the heightened trade-induced activity at ports of entry, it is particularly crucial to assess the risk of mosquito-borne diseases in these settings. This study compared the risks of Aedes-borne disease in and around the eastern Tanzanian seaport of Tanga.MethodsA 200 m × 200 m grid-based system was used to sample mosquitoes within the port area, and in surrounding areas at 2 km, 2.5 km, and 5 km away, between June and December 2023. We characterized mosquito breeding habitats, collected mosquito larvae using standard dippers and tested susceptibility of raised adult Aedes aegypti populations to different insecticides. Adult mosquitoes were collected using BG sentinel traps (daytime) and Centers for Disease Control (CDC) light traps (night-time). Additionally, more than 200 port users and neighboring residents were surveyed to assess their experiences with and perceptions of mosquito biting and disease risks.ResultsThere were 2931 breeding sites, with (60.8%, n = 1782) positive for Aedes larvae. The percentage of water-holding containers infested with Aedes immatures, i.e., the container index (CI), was highest in the port area (66.2%), and lowest 5 km away (44.6%). The port area also had a greater proportion of temporary breeding sites (64.9%) than did the surrounding areas. The adult mosquito surveys revealed 20,449 mosquito species including: Culex quinquefasciatus (56.2%), Mansonia uniformis (38.6%), Ae. aegypti (5.1%), Anopheles gambiae (0.1%), and Anopheles funestus. Ae. aegypti were more abundant in the port area than in the surrounding areas (P < 0.001), whereas Culex sp., and Mansonia sp., were significantly outside (P < 0.001). Adult Anopheles sp., were found only in the port area, but Anopheles larvae were found both within and outside the port areas. Tests on Ae. aegypti sp., revealed susceptibility to bendiocarb and DDT, and resistance to permethrin. Awareness of mosquito-borne diseases among respondents was high for malaria (64.8%), but low for dengue (26.3%) and Chikungunya (1.7%). Most respondents reported being bothered by mosquitoes mostly at night (53.4%) or in the evening (40.7%). In addition to insecticidal bednets, which are used primarily against malaria, preventive measures for Aedes-borne diseases are limited.ConclusionsThis study identified significant potential risk of Aedes species, specifically Ae. aegypti sp., and associated diseases, but low perception of risk and inadequate personal protection measures in the study area. This low perception of risk highlights the need to improve public knowledge of the transmission and control of Aedes-borne diseases.Graphical

Financial impact and healthcare expenditures among surgical patients in Burundi.

The largest proportion of people at risk of catastrophic expenditures for surgical care live in low- and middle-income countries. This study aims to evaluate the financial impact among surgical patients at Kibuye Hope Hospital (KHH) in Burundi. Data were collected from patients undergoing a surgical procedure at KHH from January to October 2019. A predesigned questionnaire was used to collect information regarding socio-demographics, pre-hospital and hospitalization characteristics, finances, and surgical outcomes. Out-of-pocket (OOP) health expenditure, catastrophic health expenditure (CHE), impoverishing health expenditure (IHE), and financial distress (FD) were summarized. Of a total of 301 patients, 60% lived below the extreme poverty line ($2.15) at baseline. After surgery, 66% of patients faced CHE, 66% faced FD, and 73% faced IHE. Almost all patients (94%) reported having an insurance plan, although the rate of OOP expenditure was high (98%). The median cost of medications ($215.5) or surgery ($305.6) surpassed the median monthly household expenditure allocated to food ($183.4). The proportion of patients facing extreme poverty at baseline increased from 60% to 96% after direct medical expenses. Many patients reported borrowing money (30%) or selling their land/possessions (46%) to cover OOP expenses. Most surgical patients at KHH face extremely high risks of CHEs and impoverishment due to OOP expenses for care, despite insurance coverage. The risk of families being forced into poverty and experiencing FD from surgical care are indicators of the lack of effective financial risk protection programs in Burundi.

Analysis of financial risk protection indicators in Sri Lanka for pediatric surgery.

To investigate the incidence of the Sri Lankan pediatric population who seek emergency surgical services and who are subsequently at risk of impoverishment and catastrophic expenditure. Prospective data collection at a tertiary pediatric Sri Lankan hospital of direct out-of-pocket (OOP) medical and nonmedical expenses related to pediatric surgical interventions. Catastrophic expenditure and risk of impoverishment were respectively described as expenses superior to 10% of household income and falling below the impoverishment line due to income drop. PPP = purchasing power parity: I$ 3.65, I$ 2.15, and national poverty line (NPL). Distribution of income were estimated using a gamma distribution. Two hundred and twenty pediatric patient surveys completed by carers were collected. Two hundred had complete data for analysis. Ninety-six patients required emergency procedures; the others underwent elective surgeries. The overall direct medical and nonmedical expenses (total direct=TD) mean per patient was I$116.6 and the overall indirect expenses mean per patient was I$94.9. 53.2% were affected by catastrophic expense. 85% (n=170) of the study population was below the NPL. Receiving surgical care would impact up to 74.1% at the NPL threshold and up to 87.1% at the I$3.65 PPP/day limit. If pediatric surgery care is required, 25.9% of the Sri Lankan population is at risk of impoverishment or catastrophic expenditure. There is need for financial aid.

Out-of-Pocket Expenditure (OOPE) on Selected Surgeries in the Obstetrics and Gynaecology Department incurred by Ayushman Bharat Pradhan Mantri Jan Arogya Yojana (AB-PMJAY), Private Health Insurance and Uninsured Patients in a Tertiary Care Teaching Hospital in Karnataka state of India.

Introduction OOPE for healthcare services is a major concern within the Indian healthcare system. 30% of the population remains uninsured despite increasing health insurance coverage. For obstetrics and gynaecology (OBG) patients financial obstacles like OOPE can delay access to health care, evaluating spending patterns can inform policies to enhance accessibility, affordability and equitable health. Methodology A retrospective study was conducted at a tertiary care teaching hospital in Karnataka state of India to analyze OOPE for 905 OBG patients who underwent Cesarean Section(C-Section), Laparoscopic Hysterectomy, Laparoscopic Cystectomy, Laparoscopic Myomectomy and Laparoscopic Assisted Vaginal Hysterectomy (LAVH). These were the top five most performed obstetrics and gynecology surgeries in the tertiary care teaching hospital between January 2023 and July 2023. Data was collected across AB-PMJAY, private health insurance, uninsured patients and analyzed using descriptive statistics (mean, median) and the Shapiro-Wilk test for data normality. Results The study analyzed OOPE across 905 OBG patients. Findings show AB-PMJAY provided full coverage with zero OOPE for all surgeries. Though private health insurance reduced OOPE compared to uninsured patients under private health insurance still faced significant financial burden. Variations existed in minimum and maximum OOPE and percentage of OOPE across different private insurances. All the uninsured patients incurred 100% OOPE, with a median OOPE of Rs. 33,257 (405.67 USD) to Rs. 57,053 (695.76 USD) and a mean OOPE of Rs. 39,848 (485.95 USD) to Rs. 60,687 (740 USD) across the surgeries. Discussion Findings of the study show that AB-PMJAY is highly effective in reducing OOPE and enhancing financial risk protection for OBG patients. Patients covered by private health insurance incurred less OOPE, yet the burden remained considerable. High OOPE rates for uninsured patients (100%) and private health insurance (38.15%) compared to 0% OOPE in AB-PMJAY emphasizes the need for the continued expansion of AB-PMJAY.

Evaluating the Sustainability of Longtime Operating Infrastructure for Romanian Flood Risk Protection

Flood protection infrastructures are crucial for enhancing the resilience of societies exposed to natural hazards. Newly designed infrastructures are evaluated for sustainability using a coherent and internationally recognized method defined by the International Hydropower Association (IHA). However, in operation, old structures require a different assessment approach. Different work proposes a modified IHA protocol, mHSAP, which identifies opportunities for improvement and develops a sustainability evaluation framework for existing infrastructures. This paper applies the modified protocol to evaluate the sustainability of two types of flood protection structures: a unique canal system for flood–drought protection of an urban area and a flood protection dike. The time of operation of these structures is over 250 years and over 50 years, respectively. The application of the modified framework demonstrates its advantages in identifying areas for improving flood protection structure operation while maintaining the structure’s sustainability. It also illustrates how Romanian water boards can use such tools to facilitate collaboration between structure owners and stakeholders, allowing them to assess the risks and effects of flooding on society. Through these two examples from Romania, we also show that the mHSAP framework has the potential to actively support the fulfillment of the United Nations Agenda 2030 Sustainable Development Goals (SDGs). The results presented here show that this method can be further utilized by water board authorities to account for climate change effects, address related challenges in a coordinated and efficient manner, develop resilient flood management strategies, inform infrastructure investment decisions, and enhance collaboration among water management authorities.

The discrepancy between objective and subjective assessments of catastrophic health expenditure: evidence from China.

The pro-rich nature of catastrophic health expenditure (CHE) indicators has garnered criticism, inspiring the exploration of the subjective approach as a complementary method. However, no studies have examined the discrepancy between subjective and objective approaches. Employing data from the Chinese Social Survey (CSS) 2013-2021 waves, we analysed the discrepancy between objective and subjective CHE and its associated socioeconomic factors using logit regression modelling. Overall, self-rating generated higher CHE incidence (28.35% to 33.72%) compared to objective indicators (9.92% to 21.97%). Objective indicators did not support 17.57% to 23.90% of self-rated cases of household CHE, while 2.73% to 8.42% of households classified with CHE by objective indicators did not self-rate with CHE. The normative subsistence spending indicator showed the least consistency with self-rating (70.66% to 74.28%), while the budget share method produced the most consistent estimation (72.73% to 76.10%). Living with elderly and young children (AOR: 1.069 to 1.169, p<0.1), lower educational attainment (AOR: 1.106 to 1.225, P<0.1), lower income (AOR: 1.394 to 2.062, P<0.01), and lower perceived social class (AOR: 1.537 to 2.801, P<0.05) were associated with higher odds of self-rated CHE without support from objective indicators. Conversely, low socioeconomic status (AOR: 0.324 to 0.819, P<0.1) was associated with lower odds of missing CHE cases classified by objective indicators in self-rating. The commonly used objective indicators for assessing CHE may attract doubts about their fairness from socioeconomically disadvantaged people. The CHE subjective approach can be adopted as a complementary measure to monitor financial risk protection.

Effect of a state-funded social health insurance programme, on equitable access to health care, financial risk protection and economic well-being in Khyber Pakhtunkhwa Province, Pakistan

Objective: To determine the effect of the SCP on access to health care, financial risk protection and perceived economicwell-being among beneficiaries.Methods: Using a comparative, cross-sectional design, household survey was conducted across 10 districts of the KPprovince during Nov22-Feb23. A total of 3619 households were recruited in which at least one member had received SCPinpatient services (users=1874) and neighbourhood households where a hospitalized member did not use SCP inpatientservices (nonuser=1745). Generalised regression models were used for analyses after adjusting for the propensity scores.Results: Socio-economic and demographic differences were not found between SCP user and non-user groups. Comparedto SCP nonusers, SCP users were more likely to seek inpatient care from private hospitals and covered more distance to getto empanelled health facilities, stay longer in hospitals, especially for patients with chronic diseases and injuries. There wasa significant reduction in medical care component of mean out-of-pocket expenditure for inpatient services among SCPusers (PKR 1,006 ±9,248) as compared with SCP nonusers (PKR 30,042 ±69,014). The nonmedical component (transport etc.)was not substantively different in both groups. The level of catastrophic health expenditure was significantly lower amongSCP users 253 (14%) compared to SCP nonusers 621 (35%), leading to higher perceived economic wellbeing among SCPusers.Conclusion: KP Government’s SCP has been effective in improving financial risk protection among its beneficiaries, resultingin an increased sense of economic well-being, as compared to SCP nonusers. SCP needs to devise strategy to increase accessto inpatient services, particularly among poorer families to maximize its impact.Keywords: Sehat Card Plus (SCP), Financial Risk Protection, Inpatient Care, Out-of-Pocket Expenditure, CatastrophicHealth Expenditure.

Lightning Risk Assessment, Control and Protection Scheme Design for a Rooftop Photovoltaic System in the New Capital of Egypt

Lightning Risk Assessment, Control and Protection Scheme Design for a Rooftop Photovoltaic System in the New Capital of Egypt

Self-rated health of the older adults in the northeastern region of India: Extent and determinants

AimTo analyse older adults’ self-rated health (SRH) in the northeastern region (NER) of India. MethodsThis study uses data from the 75th round survey on Household Social Consumption: Health conducted by the National Statistical Office (NSO), India, during July 2017–June 2018. The sample for the present consists of 3988 persons aged 60 years and above. Binary logistic regression procedure has been used to identify the determinants of SRH of the older adults. ResultsMore than three-fourth of the older adults in the region perceive their health as ‘good’ or ‘very good’. Older adults' SRH varies with their demographic and socioeconomic profiles. ConclusionIn the context of the NER, creating employment opportunities for the older adults may be of policy importance in the light of the fact that the majority of them report good or very good health but remain dependent on others financially – partially or fully. Achieving ‘healthy ageing’, as defined by WHO, nevertheless requires measures that goes beyond financial independence of the older adults to support their mental health and social wellbeing as well. Future studies may focus on older adults' objective health, health risks protection and their labor market participation in the region.

Consensual Qualitative Research on High-Risk Students Dependent on Smartphones: Focusing on Risk Factors and Protection Factors for Prevention of Dependence on Smartphones

Consensual Qualitative Research on High-Risk Students Dependent on Smartphones: Focusing on Risk Factors and Protection Factors for Prevention of Dependence on Smartphones

Using Precious Metals to Reduce the Downside Risk of FinTech Stocks

FinTech stocks are an important new asset class that reflects the rapidly growing FinTech sector. This paper studies the practical implications of using gold, silver, and basket-of-precious-metals (gold, silver, platinum, palladium) ETFs to diversify risk in FinTech stocks. Downside risk reduction is estimated using relative risk ratios based on CVaR. The analysis shows that gold provides the most downside risk protection. For a 5% CVaR, a 30% portfolio weight for gold reduces the downside risk by about 25%. The minimum variance and minimum correlation three-asset (FinTech, gold, and silver) portfolios (with portfolio weights estimated using a TVP-VAR model) have the highest risk-adjusted returns (Sharpe ratio, Omega ratio) followed by the fixed-weight FinTech and gold portfolio. These results show the benefits of diversifying an investment in FinTech stocks with precious metals. These results are robust to weekly or monthly portfolio rebalancing and reasonable transaction costs.

Modelling the potential impact of a tax on fruit juice in South Africa: implications for the primary prevention of type 2 diabetes and health financing

BackgroundSouth Africa is experiencing a persistent growth in non-communicable diseases. Diabetes is among the top ten causes of mortality, especially among women, which is partly driven by high levels of added sugar consumption and obesity. To reduce obesity rates and the incidence of diabetes, South Africa introduced a tax on sugar sweetened beverages (also known as the Health Promotion Levy (HPL)) in 2018. The tax is applicable to sugar-sweetened beverages but excludes 100% fruit juice. The government is currently considering extending the tax to include fruit juices. This study models the potential health and economic impact of taxing fruit juices at 20% of the retail price of one liter.MethodsTo analyze the distributional impact of the tax, this study uses extended cost-effectiveness analysis methodology. Data on price elasticities, healthcare cost, income, fruit juice consumption were sourced from the literature and representative national surveys. The potential impact of the tax on diabetes incidence, prevalence, mortality, and financial benefits were estimated for each income group (lowest, quintile 1 to highest, quintile 5).FindingsWe estimate that a 20% tax on fruit juice would avert 156,640 incident cases of type 2 diabetes mellitus over 20 years, with most disease averted occurring among the first- and fifth-income groups. Averted deaths from diabetes would average 2,000 deaths per quintile (for quintiles 1 to 4) and about 2,800 in quintile 5. The improved health resulting from averted incidence and deaths will reduce overall healthcare expenditure by R7.5 billion over 20 years, of which R2.3 billion will occur in the fifth quintile. The South African government will also save about R300 million in subsidizing diabetes-related healthcare cost as a result of prevention; and would raise R8.6 billion in tax revenues per annum. Out-of-pocket expenditure savings will be R303 million and a financial risk protection (money-metric value of insurance) of R4.6 billion over the 20-year period.ConclusionWe conclude that an HPL that significantly raises the retail price of fruit juices would reduce consumption and diabetes-related morbidity and mortality. The tax will also provide significant financial benefits in the form of reduced healthcare costs for both government and households as well as providing financial risk protection to individuals. Health taxes are win-win policies that improve population health and generate revenue for governments to fund public health services delivery and thus improve overall health financing activities of the government. Therefore, population level disease prevention measures such as health taxes are important for achieving universal health coverage.

Integrating DMAIC Philosophy and Bow-Tie Model for Quantitative Risk Assessment in Health Care.

Medical risks are considered to endanger patients and impact the health care system. Such iatrogenic risks necessitate hospitals taking a more proactive method to quantitatively analyze medical risk, and then to implement more targeted precautions. To address this problem, a novel quantitative risk assessment framework is proposed and further applied in radiotherapy risk assessment. A framework combining DMAIC (Define, Measure, Analyze, Improve, Control) and bow-tie model is used to assess health care risk. The uncertainty of medical risks is quantified with fuzzy set theory. The impact and the priority of medical risks were classified based on the risk matrix, and then the precautions were implemented to mitigate their impact. A case study of radiation treatment is provided. The probabilities and impacts of risk events for radiation treatment were quantified based on the proposed framework, and risk protection measures were proposed to mitigate the undesired consequence. The proposed framework showing an effective method of quantitative risk assessment of health care. The study also enriches the risk assessment methods in health care by providing a conductive and normalized framework.

Mismatch between flood risk and insurance protection: A county-level analysis in the contiguous United States

Flood insurance plays a pivotal role in disaster management, providing the financial safety net for individuals and communities at risk. However, flood insurance penetration may not align with the actual flood risk over space. Using the National Risk Index and the National Flood Insurance Program (NFIP) Datasets, this study examines the county-level mismatch between flood risk and insurance protection across the contiguous United States, with an emphasis on both coastal and riverine flooding. Our findings indicate that, while a very limited number of high-risk counties are underinsured for coastal flooding, several high-risk counties experienced inadequate insurance protection for riverine flooding. These findings underscore the need for targeted policy interventions to improve flood risk awareness and insurance access in vulnerable areas facing the increasing impacts of climate change.

Numerical and experimental study on corrosion mechanism of the water-oil two-phase flow in the atmospheric tower top system

The atmospheric tower is the main component of the crude oil refining units and is a critical area of concern due to the risk of corrosion failure. Research on the corrosion mechanism and risk protection of atmospheric tower top systems plays a vital role in the safe operation of refineries. In this paper, the water-oil two phase process flow of the atmospheric tower top system was simulated by Aspen software. A corresponding flow corrosion simulation experiment was designed according to the main characteristic parameters of the simulated stream. The experimental results under varying temperature and impact angle conditions were analyzed by using microanalysis technology and CFD simulation methods. The process and mechanism of corrosion failure of tower top system under ammonia salt and dew point corrosion environment are revealed in physicochemical aspects. The results show that the corrosion rate was highest at the dew point temperature, but as the temperature decreases, the corrosion products adsorbed and accumulated on the surface are more difficult to remove from the surface, which slows down the corrosion rate. When the impact angle increased from 0° to 60°, the increment of the surface fluid impact force and turbulence intensity makes the corrosion products easier to be stripped off, which enhances the mass transfer efficiency between the corrosive medium and the surface to accelerate the corrosion rate. Different phase states and flow modes affected the morphology of corrosion pits on the surface. The depth and size of the pits in only water phase corrosion were larger than those in the two-phase flow corrosion, Additionally, as the impact angle increased from 0°, the morphology of pits changes from a relatively flat pattern to a more undulating shape. The research results reveal the characteristics of the main corrosion types occurring in the atmospheric tower top system of the oil refining industry, and provide a reference for corrosion risk protection methods.