Approximate Optimal Control of Volterra-Fredholm Integral Equations Based on Parametrization and Variational Iteration Method

This article presents appropriate hybrid methods to solve optimal control problems ruled by Volterra-Fredholm integral equations. The techniques are grounded on variational iteration together with a shooting method like procedure and parametrization methods to resolve optimal control problems ruled by Volterra - Fredholm integral equations. The resulting value shows that the proposed method is trustworthy and is able to provide analytic treatment that clarifies such equations and is usable for a large class of nonlinear optimal control problems governed by integral equations

Adsorption of diazinon from aqueous solutions onto an activated carbon sample produced in Iran

Background: Considering the severe health and environmental hazards caused by the entry of diazinon toxin into water resources, its removal is very important. Given the high costs of imported adsorbents, this research attempted to evaluate, for the first time, the efficiency of Iranian activated carbon in removing diazinon from aqueous solutions. Methods: In this batch experimental study, the effects of contact time (5-90 minutes), adsorbent concentration (0.5-30 g/L), initial concentration of diazinon (5-50 mg/L), and pH (3-10) on the adsorption of diazinon onto the activated carbon were evaluated. Concentrations of diazinon were measured using a high pressure liquid chromatography (HPLC) instrument. The specific surface area of the adsorbent was determined by BET and BJH methods. The experimental adsorption data was analyzed using Langmuir and Freundlich isotherm models. Pseudo first-order and pseudo second-order kinetics models were employed to determine kinetics. Moreover, data was analyzed using SPSS version 19, and Pearson correlation and analysis of variance (ANOVA) tests were performed at a significance level of 0.05. Results: The optimum contact time, sorbent dose, and pH were 30 minutes, 10 g/L, and 5, respectively. The adsorbent could adsorb diazinon with a removal efficiency of 92.5% under optimum conditions (initial concentration: 20 mg/L). The experimental data was better described by the pseudo-second order kinetic and Langmuir isotherm. A maximum adsorption capacity of 71.4 mg/g was calculated by the Langmuir isotherm model

Modeling of environmental aspects related to reverse osmosis desalination supply chain

open access journalBackground: This study aimed to model optimization of strategic environmental management decisions in the operation of reverse osmosis desalination, emphasizing the costs required for the environmental protection during the production of freshwater using reverse osmosis technology. Methods: This analytical research was conducted in five cities of Hormozgan province in Iran for 18 months from February 2018 to September 2019. The research includes eight phases of defining the research problem, data collection, preliminary data analysis and decision criteria, mathematical modeling, model validation, information preparation, analysis and finally discussion, conclusions and suggestions. The main environmental issues were the carbon dioxide (CO2) release rate due to power demand and rejected brine water (RBW) were entered the mathematical model. Results: The desalination plants of Abu Musa, Bandar Abbas, Qeshm, Sirik, and Hormoz with water production flow rate of 2100, 89 000, 5300, 3300 and 1500 m3/d can generate 2360.82, 100053.80, 5958.260, 3709.86 and 1686.30 tons/year of CO2 emissions respectively. This output requires 1.35, 57.47,3.42, 2.13 and 0.97 million USD for controlling the process, respectively. For reduction of the negative effect of RBW 0.75, 22.79, 1.78, 1.15 and 0.55 million USD respectively, is needed. Conclusion: Recommendations for environmental impacts protection of RBW, for desalination capacity up to 50 000 m3/d, are; (a) for desalination capacity up to 50 000 m3/d; dilution the RBW using raw water before entering into the sea, (b) for capacity of 50 000-100 000 m3/d; dispersing RBW in sea using diffuser, and (c) for capacity more than 100 000 m3/d; hybrid water desalination plants and power plant. Application of power plant cooling water to dilute RBW may reduce cost

Seawater reverse osmosis membrane fouling causes in a full scale desalination plant; through the analysis of environmental issues: raw water quality

Background: Membrane clogging is one of the most important problem for desalination plant operators in Iran, therefore, this study was conducted to investigate the main causes of this problem using field analysis. Methods: In this study, six continuous membranes in a reverse osmosis (RO) pressure vessel under the 33-month service period (April 2017 to November 2019) were selected. The membranes were analyzed through visual evaluation of the outer and inner membrane surface, analyzing the damages and physical harms, oxidative stress tests, iron spot test, fouling chemical analysis using loss on ignition (LOI) tests, X-ray fluorescence (XRF), and Fourier-transform infrared (FTIR) spectroscopy. Results: Particle size distribution in raw seawater (EC = 55 000 μs/cm, turbidity = 11 NTU) was 66.4% smaller than 1 μ and 28.3% between 1 to 1.9 μm. Physical damages were not seen on the membranes but telescopic damages were observed which was due to membrane fouling. Removal efficiencies of turbidity and silt density index (SDI) were 84% and 18%, respectively. Membrane oxidation was also seen. Most of the sediments compositions on the membranes were SiO2, Al2O3, MgO, and Fe2O3. Biological fouling was detected on the membranes surface. Conclusion: Inaccurate use of chlorine neutralizer caused the residual chlorine to be present in the membrane entering water, which damaged the membrane. Accumulation of clogging agents on membrane surface showed malfunction of pretreatment function, therefore, revision of design and operation of units is necessary. Biological fouling is due to non-effective pre-chlorination of drinking water. Metallic compounds sedimentation on the membrane is due to improper use of anti-fouling chemicals. High SDI in the influent shows the need to change the cartridge filters. Keywords: Seawater, Drinking, Chlorides, Particle size, Chloride, Spectroscopy, Fourier transform infrared, Ira

Modeling of environmental aspects related to reverse osmosis desalination supply chain

Background: This study aimed to model optimization of strategic environmental management decisions in the operation of reverse osmosis desalination, emphasizing the costs required for the environmental protection during the production of freshwater using reverse osmosis technology. Methods: This analytical research was conducted in five cities of Hormozgan province in Iran for 18 months from February 2018 to September 2019. The research includes eight phases of defining the research problem, data collection, preliminary data analysis and decision criteria, mathematical modeling, model validation, information preparation, analysis and finally discussion, conclusions and suggestions. The main environmental issues were the carbon dioxide (CO2) release rate due to power demand and rejected brine water (RBW) were entered the mathematical model. Results: The desalination plants of Abu Musa, Bandar Abbas, Qeshm, Sirik, and Hormoz with water production flow rate of 2100, 89 000, 5300, 3300 and 1500 m3/d can generate 2360.82, 100053.80, 5958.260, 3709.86 and 1686.30 tons/year of CO2 emissions respectively. This output requires 1.35, 57.47, 3.42, 2.13 and 0.97 million USD for controlling the process, respectively. For reduction of the negative effect of RBW 0.75, 22.79, 1.78, 1.15 and 0.55 million USD respectively, is needed. Conclusion: Recommendations for environmental impacts protection of RBW, for desalination capacity up to 50 000 m3/d, are; (a) for desalination capacity up to 50 000 m3/d; dilution the RBW using raw water before entering into the sea, (b) for capacity of 50 000-100 000 m3/d; dispersing RBW in sea using diffuser, and (c) for capacity more than 100 000 m3/d; hybrid water desalination plants and power plant. Application of power plant cooling water to dilute RBW may reduce cost. Keywords: Mathematical modeling, Freshwater, Osmosis, Brine, Seawater

US Energy Policy During 2011–2022 and its Impact on China–Saudi Arabia Relations

IntroductionThe China–Saudi Arabia relations have witnessed significant growth and development from 2011 to 2022. Primarily driven by oil relations, the relations between the two countries have flourished in areas such as trade, investment, technology, and military cooperation. In December 2022, the two countries established the highest level of bilateral ties by signing 34 investment agreements valued at around 30 billion dollars, spanning various sectors such as clean energy, hydrogen production, solar energy, information technology, transportation, medical and housing industries, and building materials factories. Furthermore, China’s oil imports from Saudi Arabia increased from 5 million and 66 thousand barrels per day in 2011 to 10 million and 852 thousand barrels per day in 2020. The figure remained above 10 million barrels during 2022, despite the challenges posed by the COVID–19 pandemic and unfavorable economic conditions. This trend Indicates growing relations between China and Saudi Arabia.China and Saudi Arabia have exchanged a large share of capital in the energy sector. The Saudi active presence in the Chinese oil market has positioned it as China’s largest trade partner in the West Asia and African region. The bilateral investment volume between the two countries stands at approximately 73 billion dollars. Saudi Arabia’s extensive investments aimed at controlling China’s oil import network, refineries, and petrochemical industry, along with its involvement in the plan to double China’s strategic oil reserve, underscore the importance of maintaining China’s energy market for Saudi Arabia. Consequently, given China’s status as the largest energy consumer and Saudi Arabia’s position as the largest oil exporter, both countries possess the requisite capacity to foster cooperation in this field.In addition, Vision 2030 and the One Belt One Road Initiative are strategic factors facilitating the expansion of China–Saudi Arabia relations. In this regard, the two countries have signed comprehensive strategic cooperation agreements, leading to the establishment of the High-Level Joint Committee. During the committee’s second meeting in Riyadh in August 2017, contracts valued at 70 billion dollars were signed. Moreover, an important milestone was reached by signing a memorandum of understanding between the two countries for the establishment of a joint investment fund worth 20 billion dollars. Furthermore, Industrial Development Fund, China’s Silk Road Fund, and Everbright Bank were established. These agreements, memoranda, and funds intend to expedite the development of China’s One Belt One Road Initiative and Saudi Arabia’s Vision 2030. Although China is trying to maximize its energy security by distributing its oil imports among different countries (e.g., the US), Saudi Arabia’s consistent share of approximately 20% in recent years remains of utmost significance.Literature ReviewSeveral studies have examined the topics of US energy policy and the development of China–Saudi Arabia relations. However, few works have linked these two phenomena in an analytical manner. The novelty of this article lies in its attempt to bridge this gap and provide an analysis by exploring the interplay between these two issues.Materials and MethodsThis research adopted a mixed methods design, utilizing both quantitative and qualitative data. Documents and library resources were used to collect the data. Relying on an examination of research, analytical and statistical texts, the study focused on indexing and defining variables and their influential factors in a bid to conduct an analytical and inferential exploration to elucidate the trends and interrelationships between the independent and dependent variables.ConclusionThe US–Saudi oil relations have witnessed unparalleled growth and encompassed various economic, political, and security sectors in recent decades. Furthermore, to ensure its own growth and development, it is imperative for China to maintain stability and security in the energy sector. This objective can be achieved through effective management of competition and, in certain instances, cooperation with the United States. The ongoing trend of expanding relations between China and Saudi Arabia in the energy sector is unprecedented, solidifying China’s position as a significant competitor to the United States.     The growing China–Saudi Arabia relations are driven by the mutual needs in the energy sector and strategic development plans. Yet the present research aimed to analyze China–Saudi Arabia relations with an eye to the US energy policy, relying a neo-mercantilist approach. Consequently, the primary question addressed in this article is: how has the US energy policy during 2011–2022 influenced the dynamics of China–Saudi Arabia relationship. The study was based on the hypothesis that the US energy policy during 2011–2022, characterized by increased oil and shale gas production and a reinforced neo-mercantilist approach in the energy sector, played a crucial role in fostering closer ties between China and Saudi Arabia, primarily in the oil sector, and supported their efforts to broaden mutual cooperation across other fields. The hypothesis was tested through empirical and explanatory methods. The research findings suggest that China–Saudi Arabia cooperation is expected to expand further in the future, while taking into account the sensitivities associated with these relations from the perspective of the United States

Drinking water resources criteria in emergencies and disasters:A systematic literature review

Background: Disasters occur unexpectedly each year, killing thousands around the world. Millions are directly under the influence of the outcomes of these events and their survival depends on the immediate state and international aid. This supports should be obtained in early hours after disasters. The main important need after disasters is safe water supply, which along with providing shelter, medicine, and nutrition, is vital to prevent diseases. So, immediate actions are needed to replace suitable drinking water resources for affected people. Methods: This study was conducted in 2019 using Web of Science, PupMed, Springer, Scopus, Embase databases (from 2000 to 31 September 2019). The PRISMA guideline was used to compile the study. All articles included in this study were original articles, short communications, letters to editor, editorials, systematic reviews, and articles presented at conferences and international congresses on the main topic of the study. Only English full-text articles were included in this study. Results: According to the results, water resources supply in disasters and emergencies criteria were classified into 4 main and 30 sub-criteria. The main criteria include environmental, economic, technology performance, quantitative and qualitative characteristics of water resources, which have 4, 2, 12, and 12 sub-criteria, respectively. Conclusion: This study intends to assist disaster service officials and decision makers and supervisors to plan for drinking water supply from area water resources, before the disaster and based on the history and geographical characteristics of the area, to take actions and meet the drinking water needs of the region. Keywords: Disaster, Emergency, Drinking water, Criteri

Estimates, trends, and drivers of the global burden of type 2 diabetes attributable to PM2.5 air pollution, 1990-2019 : an analysis of data from the Global Burden of Disease Study 2019

Background Experimental and epidemiological studies indicate an association between exposure to particulate matter (PM) air pollution and increased risk of type 2 diabetes. In view of the high and increasing prevalence of diabetes, we aimed to quantify the burden of type 2 diabetes attributable to PM2.5 originating from ambient and household air pollution.Methods We systematically compiled all relevant cohort and case-control studies assessing the effect of exposure to household and ambient fine particulate matter (PM2.5) air pollution on type 2 diabetes incidence and mortality. We derived an exposure-response curve from the extracted relative risk estimates using the MR-BRT (meta-regression-Bayesian, regularised, trimmed) tool. The estimated curve was linked to ambient and household PM2.5 exposures from the Global Burden of Diseases, Injuries, and Risk Factors Study 2019, and estimates of the attributable burden (population attributable fractions and rates per 100 000 population of deaths and disability-adjusted life-years) for 204 countries from 1990 to 2019 were calculated. We also assessed the role of changes in exposure, population size, age, and type 2 diabetes incidence in the observed trend in PM2.5-attributable type 2 diabetes burden. All estimates are presented with 95% uncertainty intervals.Findings In 2019, approximately a fifth of the global burden of type 2 diabetes was attributable to PM2.5 exposure, with an estimated 3.78 (95% uncertainty interval 2.68-4.83) deaths per 100 000 population and 167 (117-223) disability-adjusted life-years (DALYs) per 100 000 population. Approximately 13.4% (9.49-17.5) of deaths and 13.6% (9.73-17.9) of DALYs due to type 2 diabetes were contributed by ambient PM2.5, and 6.50% (4.22-9.53) of deaths and 5.92% (3.81-8.64) of DALYs by household air pollution. High burdens, in terms of numbers as well as rates, were estimated in Asia, sub-Saharan Africa, and South America. Since 1990, the attributable burden has increased by 50%, driven largely by population growth and ageing. Globally, the impact of reductions in household air pollution was largely offset by increased ambient PM2.5.Interpretation Air pollution is a major risk factor for diabetes. We estimated that about a fifth of the global burden of type 2 diabetes is attributable PM2.5 pollution. Air pollution mitigation therefore might have an essential role in reducing the global disease burden resulting from type 2 diabetes. Copyright (C) 2022 The Author(s). Published by Elsevier Ltd.Peer reviewe

Estimates, trends, and drivers of the global burden of type 2 diabetes attributable to PM2.5 air pollution, 1990-2019 : An analysis of data from the Global Burden of Disease Study 2019

Background Experimental and epidemiological studies indicate an association between exposure to particulate matter (PM) air pollution and increased risk of type 2 diabetes. In view of the high and increasing prevalence of diabetes, we aimed to quantify the burden of type 2 diabetes attributable to PM2·5 originating from ambient and household air pollution. Methods We systematically compiled all relevant cohort and case-control studies assessing the effect of exposure to household and ambient fine particulate matter (PM2·5) air pollution on type 2 diabetes incidence and mortality. We derived an exposure–response curve from the extracted relative risk estimates using the MR-BRT (meta-regression—Bayesian, regularised, trimmed) tool. The estimated curve was linked to ambient and household PM2·5 exposures from the Global Burden of Diseases, Injuries, and Risk Factors Study 2019, and estimates of the attributable burden (population attributable fractions and rates per 100 000 population of deaths and disability-adjusted life-years) for 204 countries from 1990 to 2019 were calculated. We also assessed the role of changes in exposure, population size, age, and type 2 diabetes incidence in the observed trend in PM2·5-attributable type 2 diabetes burden. All estimates are presented with 95% uncertainty intervals. Findings In 2019, approximately a fifth of the global burden of type 2 diabetes was attributable to PM2·5 exposure, with an estimated 3·78 (95% uncertainty interval 2·68–4·83) deaths per 100 000 population and 167 (117–223) disability-adjusted life-years (DALYs) per 100 000 population. Approximately 13·4% (9·49–17·5) of deaths and 13·6% (9·73–17·9) of DALYs due to type 2 diabetes were contributed by ambient PM2·5, and 6·50% (4·22–9·53) of deaths and 5·92% (3·81–8·64) of DALYs by household air pollution. High burdens, in terms of numbers as well as rates, were estimated in Asia, sub-Saharan Africa, and South America. Since 1990, the attributable burden has increased by 50%, driven largely by population growth and ageing. Globally, the impact of reductions in household air pollution was largely offset by increased ambient PM2·5. Interpretation Air pollution is a major risk factor for diabetes. We estimated that about a fifth of the global burden of type 2 diabetes is attributable PM2·5 pollution. Air pollution mitigation therefore might have an essential role in reducing the global disease burden resulting from type 2 diabetes

Mapping 123 million neonatal, infant and child deaths between 2000 and 2017

Since 2000, many countries have achieved considerable success in improving child survival, but localized progress remains unclear. To inform efforts towards United Nations Sustainable Development Goal 3.2—to end preventable child deaths by 2030—we need consistently estimated data at the subnational level regarding child mortality rates and trends. Here we quantified, for the period 2000–2017, the subnational variation in mortality rates and number of deaths of neonates, infants and children under 5 years of age within 99 low- and middle-income countries using a geostatistical survival model. We estimated that 32% of children under 5 in these countries lived in districts that had attained rates of 25 or fewer child deaths per 1,000 live births by 2017, and that 58% of child deaths between 2000 and 2017 in these countries could have been averted in the absence of geographical inequality. This study enables the identification of high-mortality clusters, patterns of progress and geographical inequalities to inform appropriate investments and implementations that will help to improve the health of all populations