Risk-Cost Optimized Maintenance Strategy for Steel Bridge Subjected to Deterioration

This paper aims to develop a deteriorated bridge maintenance strategy that ensures the safe operation of steel structures and minimizes the total risk. Five common failure modes are considered for the deteriorated bridge: flexure, shear, deflection, fatigue failure for girder, and chloride attack for the concrete deck. Time-dependent and system reliability analyses are carried out to find the probability of failure under these failure modes. Risk-cost optimization is then used to determine the maintenance strategy. This method was applied to a working example. It was found that the developed maintenance strategy can predict when, where, and what to maintain for a bridge to ensure its safe and serviceable operation during its lifespan. The proposed methodology can help structural engineers and asset managers repair and maintain bridges under deterioration.

Seasonal Variation of Phthalate Esters in Urban River Sediments: A Case Study of Fengshan River System in Taiwan

The Fengshan River system is one of the major rivers in Kaohsiung City, Taiwan. This study investigated the concentration of eight phthalate esters (PAEs) in sediments of the river and the impact of potential ecological risks during the dry and wet seasons. The potential risk assessment of sediment PAEs was evaluated by adopting the total risk quotient (TRQ) method. The total PAEs concentrations (∑PAEs) in the sediments of the Fengshan River system are between 490–40,190 ng/g dw, with an average of 8418 ± 11,812 ng/g dw. Diisononyl phthalate (38.1%), bis(2-ethylhexyl) phthalate (36.9%) and di-isodecyl phthalate (24.3%) accounted for more than 99.3% of ∑PAEs. The concentration of ∑PAEs in sediments at the river channel stations is higher during the wet season (616–15,281 ng/g dw) than that during the dry season (490–1535 ng/g dw). However, in the downstream and estuary stations, the wet season (3975–6768 ng/g dw) is lower than the dry season (20,216–40,190 ng/g dw). The PAEs in sediments of the Fengshan River may have low to moderate potential risks to aquatic organisms. The TQR of PAEs in sediments at the downstream and estuary (TQR = 0.13) is higher than that in the upstream (TQR = 0.04). In addition, during the wet season, rainfall transported a large amount of land-sourced PAEs to rivers, leading to increased PAEs concentration and potential ecological risks in the upper reaches of the river.

Diagnosis and Treatment of Elderly and Senile Chronic Constipation: an Expert Consensus

Aim. An appraisal of practitioners with chronic constipation management details in older and senile adults.Key points. Chronic constipation is a common issue in geriatrics. Aside to age-related physiological bowel disfunction, a higher constipation incidence is conditioned by declined physical activity and frailty, polypharmacy and a series of secondary constipation-developing chronic states and diseases. Chronic constipation is associated with a higher risk of cardiovascular disease and complications, impaired general perception of health and pain, growing alarm and depression, and reduced quality of life. The treatment tactics in chronic constipation is cause-conditioned and should account for the patient’s history and therapy line, overall clinical condition, cognitive status and functional activity level. An essential baseline aspect of constipation management is apprising the patient and his family of the underlying factors and methods for non-drug and drug correction. An higher-fibre diet is recommended as first measure, with osmotic laxatives added and titrated to clinical response if none observed towards the non-drug and high-fibre regimens. Stimulant laxatives and prokinetics should be recommended in patients reluctant to fibre supplements and osmotic laxatives. Subsidiary correction includes biofeedback, transanal irrigation, acupuncture, foot reflexology and percutaneous tibial nerve stimulation.Conclusion. Elderly and senile chronic constipation is a prevalent multifactorial state requiring an efficient management via assessment and correction of total risk factors and consistent use of non-medication and drug therapies.

QUANTITATIVE RISK ASSESSMENT FOR COLLISIONS INVOLVING DOUBLE HULL OIL TANKERS

In recent decades, the safety of ships at sea has become a major concern of the global maritime industries. Ships are rarely subject to severe accidents during their life cycle. Collision is one of the most hazardous accidents, with potentially serious consequences such as the loss of human life, structural damage and environmental damage, especially if large tankers, LNG and/or nuclear-powered vessels are involved. This study presents a Quantitative Risk Assessment (QRA) for double hull oil tankers that have collided with different types of ships. The methodology used to perform the QRA is based on the International Maritime Organization’s (IMO) definition of a Formal Safety Assessment (FSA). Using probabilistic approaches, ship-ship collision scenarios are randomly selected to create a representative sample of all possible scenarios. The collision frequency is then calculated for each scenario. As this is a virtual experiment, the LS-DYNA nonlinear finite element method (NLFEM) is used to predict the structural consequences of each scenario selected. In addition, the environmental consequences are estimated by calculating the size of each scenario’s oil spill. To assess the economic consequences, the property and environmental damages are calculated in terms of monetary units. The total risk is then calculated as the sum of the resultant structural and environmental damages. Exceedance curves are established that can be used to define the collision design loads in association with various design criteria.

Capital Structure of Companies Listed at the Warsaw Stock Exchange and the COVID-19 Pandemic Effect on Their Risk

Subject: The financial management of companies is examined in the context of the COVID-19 pandemic. Specifically, the relationship between their capital structure and risk changes during the pandemic is scrutinised. The purpose of the article: To determine how companies’ total, systematic and idiosyncratic risks changed during the COVID-19 pandemic depending on their capital structure based on a sample of organisations listed at the Warsaw Stock Exchange. Methodology: The study involves the use of a panel data regression model. Results of the research: The COVID-19 pandemic had an impact on the risk of overleveraged companies and underleveraged ones alike. Its influence on their total risk was weaker among the underleveraged organisations. Regarding systematic risk, its levels did not generally change significantly in the wake of the pandemic, but idiosyncratic risk, only in the case of the overleveraged companies increased statistically significantly.

Performance comparison between Islamic and conventional stocks: evidence from Pakistan's equity market

PurposeThis paper aims to examine the performance of Islamic and conventional stocks listed at the Pakistan Stock Exchange by using both parametric and non-parametric approaches. The motivation is to do risk-return analysis of Islamic stock prices and conventional stock prices.Design/methodology/approachIt uses various measures of performance, e.g. Sharpe ratio, Treynor ratio, Jensen's alpha, beta, generalized auto-regressive conditional heteroskedasticity and stochastic dominance. Using the Karachi Meezan Index-30 (KMI-30) and the Karachi Stock Exchange Index-30 (KSE-30) as proxies for Islamic and conventional stock prices, respectively, it examines the performance of Islamic and conventional stocks. The daily data of KMI-30 and KSE-30, covering period from June 9, 2009 to June 20, 2020 are used.FindingsThe results show that the overall KMI-30 outperforms the KSE-30. The returns of the KMI-30 are greater than the KSE-30. However, the risk and volatility of the KMI-30 and KSE-30 are similar. Further, the KMI-30 has higher excess returns per unit of total risk than the KSE-30. But both indexes have similar excess returns per unit of systematic risk. Moreover, the KMI-30 returns have stochastically dominance over the KSE-30 returns. These results reveal that the Islamic index performs better than the conventional index.Practical implicationsThe findings provide several practical implications in financial and investment decisions making by investors, managers and policymakers such as strategies for asset allocation and investment. Further, in risk management, it provides guidance for allocating portfolios and managing risk. The investment in Islamic stocks may mitigate potential risk within asset portfolios.Originality/valueThis research is unique in its approach to the analysis of the performance comparison of conventional and Islamic stock by using comprehensive parametric and non-parametric estimation techniques. Such research has not been undertaken in the Pakistan's equity market since.

Studying safety and risk management in the gas transmission system using GIS technology

In this current research, the combination of gas transportation system in line with analytical process was applied to conduct an assessment on the risk management of gas transferring pipe lines. By this process, classification and qualification of the numerous types of transportation risks would be accessible. Index and transportation index indicate risk probability and risk severity, respectively. In this regard, total risk is calculated based on the multiplication of all risk probability using geographical information systems (GIS) classified risks that have been throughout the pipeline route using attributive information. This information also gave database alternative monitoring of gas transportation.

Factors impacting the financial efficiency of pig farming models in Can Tho City

The study’s objective is to evaluate the financial efficiency and determine the factors affecting pig farming models’ financial efficiency in Can Tho City. The study collected data from 118 households raising pigs for meat. The methods used in the study include financial ratios analysis and multivariable linear regression. The research results show that models of raising pigs for meat have high financial efficiency. The financial performance of the models is positively correlated with the educational level of the farmer and the participation in technical training programs. In contrast, financial efficiency is negatively correlated with seed cost, feed cost, farm drug cost, and total risk.

The Effects of ERM Adoption on European Insurance Firms Performance and Risks

We investigate the effects of adopting enterprise risk management (ERM) on the performance and risks of European publicly listed insurance firms. Using a dataset for 24 years, we report new results which show that ERM adopters realize significant ERM premiums after controlling for other covariates and endogeneity. Several firm characteristics such as size, opacity, and the choice of external monitoring agents such as auditors are significant determinants of adopting ERM. We fill a gap in the literature by assessing the impact of adopting ERM on firm risks and report new findings for our sample, which show that ERM adopters effectively reduce firm total and systematic risks and, to a greater extent, idiosyncratic risk. Firm-level variables such as size, leverage, dividend payments events, and diversification impact firm total risk. Insurers use corporate events such as dividend payments to signal information about reducing risk. Industry and international diversification reduce firm total risk and idiosyncratic risk, respectively.

Investigation of pollution level of groundwater in the ALjazaier Area, Babil

A total with 15 samples was collected from 3 wells in the aljazaier distreet in Babil governorate for the period from January to April 2020, to study the microbial contamination represented by fecal bacteria, while chemical contamination includes a physochemical and the heavy element’s properties. The goal of this study: Study the water of some wells from some microbes and chemical aspects and evaluate this according to Iraqi standards and specifications. Results showed microbial pollution by fecal Coliform bacteria in well water when using Using the agar media. Results showed the difference in the mean of (MPN) of well water. It was found that the EC value (1061) μs/cm was exceeded the permissible limit in W1, Cl values (325, 430)mg/l, pb values (0.43, 0.14) μg/l and Ni values (0.11, 0.11) μg/l and the permissible limit were exceeded in W1, W2 and SO4 values (681, 653, 584) mg / l also the permissible limit was exceeded in W1, W2 and W3 as well as Ag value (0.12) μg/l is in W1 only. The total risk index (HIT) in the groundwater for W1, W2, W3 was acceptable for adult values ΣHI( 0.23, 0.97, 3.8E-4 ) and children values ΣHI ( 2.6E-2, 1.6E-2, 1.3E-3 ) respectively.