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Proportion of renewable energy consumption and economic growth: theoretical and empirical analysis Texto completo
2022
Zhang, Wenbin | Hu, Jian | Hao, Jiaxin
The energy consumption revolution led by renewable energy replacing fossil energy has become an important means of energy conservation, emission reduction, quality improvement, and efficiency enhancement to achieve sustainable development. Based on the perspective of energy consumption value, this paper introduces renewable energy and fossil energy into Solow growth model and theoretically analyzes the economic growth effect of renewable energy replacing fossil energy. It shows that with the increase of the proportion of renewable energy in the short term, there is an inverted “U-shaped” curve, in which economic growth increases first and then decreases. Subsequently, this paper selects 34 countries from the year of 2007 to 2017 as sample data to verify the theoretical hypothesis. The results provide evidence to the theoretical hypothesis, and the economic growth will decrease once the proportion of renewable energy consumption reaches to 58% approximately. At present, most countries have not yet reached this inflection point and then can promote renewable energy development by building technological innovation-driven systems and distributed energy systems.
Mostrar más [+] Menos [-]Pilot study on the treatment of low carbon and nitrogen ratio municipal sewage by A1/O2/A3/A4/O5 sludge-membrane coupling process with multi-point inflow Texto completo
2022
Zhang, De-Wei | Zheng, Jun-Tian | Zheng, Jun | Zhao, Meng-Ke | Wang, Meng-Lin | Zhang, Shihua
A new multi-point inflow pre-anoxic/oxic/anaerobic/anoxic/oxic (A1/O2/A3/A4/O5) sludge-membrane coupling process and pilot plant were developed and designed to solve the problem of nitrogen and phosphorus removal of low carbon and nitrogen (C/N) ratio domestic sewage in southern China. The removal effect and transformation rule of organic matter, nitrogen, and phosphorus in the system were studied by changing the distribution ratio of multi-point influent. The average C/N ratio of the influent was 2.09 and the influent distribution ratio was 1:1. When the temperature was 16–25 °C, the average concentrations of chemical oxygen demand (COD), ammonia nitrogen (NH₄⁺- N), total nitrogen (TN), and total phosphorus (TP) in the effluent were 21.31 (±2.65), 0.60 (±0.24), 12.76 (±1.09), and 0.34 (±0.05) mg/L, respectively, and their average removals are 87.3 (±1.2)%, 98.7 (±0.4)%, 74.1 (±1.3)%, and 88.1 (±0.4)% respectively. When the low temperature was 12–15 °C, the average removals were 78.6 (±1.1)%, 90.5 (±1.3)%, 73.7 (±1.13)%, and 86.6 (±1.7)%, respectively. Compared with the traditional anaerobic/anoxic/aerobic (A2O) process under the same conditions, the TN removal was increased by 15.4%, and the TP removal was increased by 22.2%. This system has obvious advantages in treating wastewater with low C/N ratio, thereby solving the problem wherein the effluent of biological phosphorus removal from low C/N ratio domestic sewage was difficult when it was lower than 0.5 mg/L.
Mostrar más [+] Menos [-]Influence of the effect of nanoparticle additives blended with mahua methyl ester on performance, combustion, and emission characteristics of CRDI diesel engine Texto completo
2022
Nutakki, Prabhu Kishore | Gugulothu, Santhosh Kumar
This research work aims to investigate the effect of fuel-borne additives when added to mahua methyl ester (MME) blend operated on common rail direct injection diesel engine. Nanoparticles (Al₂O₃ and Fe₂O₃) were chosen with the help of a homogenizer and ultrasonicator as fuel additives at dosing levels of 40, 80, and 120 ppm, respectively, and the biodiesel is prepared by blending 80% diesel and 20% MME. The performance, emission, and combustion characteristics were considered for analysis. The experimental study revealed that while using the Al₂O₃ nanoparticle additives’ blended biodiesel (MME20+AONP120), the number of harmful pollutants like smoke (5.38%), HC (6.39%), carbon monoxide (10.24%), NOx, etc. has reduced to a considerable extent and there was a commendable improvement in the BTE by 8.8% in comparison with MME20. Moreover, MME20+AONP120 blend resulted in high in-cylinder pressure, HRR of about 58.4 bar, and 118 J/⁰CA, respectively, which are higher than diesel and MME20. So, it can be summarized that when biodiesel and nano additives are blended together, the combustion and performance of the engine were improved considerably and pollutant emissions were decreased.
Mostrar más [+] Menos [-]Catalytic oxidative desulfurisation over Co/Fe-γAl2O3 catalyst: performance, characterisation and computational study Texto completo
2022
Nazmi, Nor Atiq Syakila Mohd | Razak, Fazira Ilyana Abdul | Mokhtar, Wan Nur Aini Wan | Ibrahim, Mohamad Nasir Mohamad | Adam, Farook | Yahaya, NoorFatimah | Rosid, Salmiah Jamal Mat | Shukri, Nurasmat Mohd | Abdullah, Wan Nazwanie Wan
The world faces the challenge to produce ultra-low sulfur diesel with low-cost technology. Therefore, this research emphasised on production of low sulfur fuel utilising nanoparticle catalyst under mild condition. A small amount of cobalt oxide (10–30 wt%) was introduced into the Fe/Al₂O₃ catalyst through the wet impregnation method. Cobalt modification induces a positive effect on the performance of the iron catalyst. Hence, the insertion of cobalt species into Fe/Al₂O₃ led to the formation of lattice fringes in all directions which resulted in the formation of Co₃O₄ and Fe₃O₄ species. The optimised catalyst, Co/Fe–Al₂O₃, calcined at 400 °C with a dopant ratio of 10:90 indicating the highest desulfurisation activity by removing 96% of thiophene, 100% of dibenzothiophene (DBT) and 92% of 4,6-dimethyl dibenzothiophene (4,6-DMDBT). Based on the density functional theory (DFT) on Co/Fe–Al₂O₃, two pathways with the overall energy of −40.78 eV were suggested for the complete oxidation of DBT.
Mostrar más [+] Menos [-]Does air pollution increase child mortality? Evidence from 58 developing countries Texto completo
2022
Hassan, N. (Nazmul) | Murad, S. M Woahid
This study aims to investigate the effects of air quality on child mortality in developing countries. We consider annual data covering the period from 2010 to 2016 of 58 countries and estimate the empirical models using recently developed panel quantile regression with the method of moments (MM-QR). It is found that outdoor air quality (measured by the concentration of PM₂.₅ in the air) has a positive and significant effect on total child mortality, post-neonatal mortality, and under-five child mortality. However, its effect on neonatal mortality is not statistically significant at lower quantiles. Furthermore, Household air pollution (HAP) also has a positive and significant effect on total child mortality, neonatal mortality, and under-five child mortality. The effect of HAP on post-neonatal mortality is not significant in most cases. Overall, the adverse effect of HAP is larger than the PM₂.₅. For instance, a 1% increase of PM₂.₅ concentration in the outdoor causes 0.231% total child mortality due to respiratory diseases at [Formula: see text], while a 1% increase of HAP causes 0.532% total child mortality at the same quantile. In many cases, the coefficients of PM₂.₅ and HAP increase at the higher quantiles, supporting asymmetric effects of pollutants on child mortality. However, per capita income, access to basic drinking water and sanitation facilities, and domestic and external health expenditures significantly reduce child mortality. On the contrary, open defecation increases mortality. Consequently, policymakers should take adequate measures to improve indoor and outdoor air quality to combat child mortality due to respiratory diseases in developing countries. They should also take initiatives to enhance per capita income, basic drinking water, and sanitation facilities, domestic and external health expenditures, and public awareness against open defecation.
Mostrar más [+] Menos [-]Evaluation of symmetric dimethylarginine and Doppler ultrasonography in the diagnosis of gentamicin-induced acute kidney injury in dogs Texto completo
2022
Elgazzar, Youssef M. Y. | Ghanem, Mohamed M. | Abdel-Raof, Yassein M. | Kandiel, Mohamed M.M. | Helal, Mahmoud A. Y.
Acute kidney injury is a common problem in dogs and is associated with significant morbidity and mortality. So, the present study aimed to evaluate symmetric dimethylarginine (SDMA) and Doppler ultrasonography including resistive index (RI) in the diagnosis of acute kidney injury in dogs. Ten healthy mongrel dogs were injected with gentamicin sulfate 10% at the dose of 30 mg/kg body weight daily for 10 days for induction of acute kidney injury. Clinical, biochemical, ultrasonographic, and Doppler ultrasonographic examinations and urinalysis were performed for all dogs on 0 day before induction, on the 5th day, and on the 10th day of induction. The results of the current study showed significant increase in plasma level of SDMA, serum urea, creatinine, phosphorus, and potassium and a significant decrease in serum sodium, calcium, and chloride on the 5th day and 10th day of induction, and there was an increase in renal cortical echogenicity of the right and left kidney compared to adjacent liver and spleen, respectively. RI value showed a significant increase on the 5th day and 10th day of induction. The present study showed that SDMA is a sensitive and promising biomarker for diagnosis of acute kidney injury in dogs compared to routine biomarkers; also, the RI of Doppler ultrasonography is useful for early identifying acute kidney injury when the only observable change is an increase in cortical echogenicity.
Mostrar más [+] Menos [-]Impact of climate change on biodiversity loss: global evidence Texto completo
2022
Muzafar Shah Habibullah, | Din, Badariah Haji | Tan, Siow-Hooi | Ḥasan, Zāhid
The present study investigates the impact of climate change on biodiversity loss using global data consisting of 115 countries. In this study, we measure biodiversity loss using data on the total number of threatened species of amphibians, birds, fishes, mammals, mollusks, plants, and reptiles. The data were compiled from the Red List published by the International Union for Conservation of Nature (IUCN). For climate change variables, we have included temperature, precipitation, and the number of natural disaster occurrences. As for the control variable, we have considered governance indicator and the level of economic development. By employing ordinary least square with robust standard error and robust regression (M-estimation), our results suggest that all three climate change variables – temperature, precipitation, and the number of natural disasters occurrences – increase biodiversity loss. Higher economic development also impacted biodiversity loss positively. On the other hand, good governance such as the control of corruption, regulatory quality, and rule of law reduces biodiversity loss. Thus, practicing good governance, promoting conservation of the environment, and the control of greenhouse gasses would able to mitigate biodiversity loss.
Mostrar más [+] Menos [-]Long-term statistical assessment of meteorological indicators and COVID-19 outbreak in hot and arid climate, Bahrain [Erratum: January 2022, v.29(1), p.1117] Texto completo
2022
Qaid, Adeb | Bashir, Muhammad Farhan | Remaz Ossen, Dilshan | Shahzad, Khurram
The COVID-19 pandemic has significantly impacted the global lifestyle, and the spreading of the virus is unprecedented. This study is aimed at assessing the association between the meteorological indicators such as air temperature (°C), relative humidity (%), wind speed (w/s), solar radiation, and PM₂.₅ with the COVID-19 infected cases in the hot, arid climate of Bahrain. Kendall and Spearman rank correlation coefficients and quantile on quantile regression were used as main econometric analysis to determine the degree of the relationship between related variables. The dataset analysis was performed from 05 April 2020, to 10 January 2021. The empirical findings indicate that the air temperature, humidity, solar radiation, wind speed indicators, and PM2.5 have a significant association with the COVID-19 newly infected cases. The current study findings allow us to suggest that Bahrain’s relatively successful response to neighboring GULF economies can be attributed to the successful environmental reforms and significant upgrades to the health care facilities. We further report that a long-term empirical analysis between meteorological factors and respiratory illness threats will provide useful policy measures against future outbreaks.
Mostrar más [+] Menos [-]A review on sources of heavy metals, their toxicity and removal technique using physico-chemical processes from wastewater Texto completo
2022
Rafique, Muhammad | Hajra, Syeda | Tahir, Muhammad Bilal | Gillani, Syed Sajid Ali | Irshad, Muneeb
The world is facing environmental pollution and is in an alarming situation due to industrialization and urbanization. Especially, industrial wastewater discharge is causing serious pollution in the environment (water, soil, and air) and has become a challenge for researchers and scientists. Wastewater contains heavy metals like Cu, Ni, Cr, Pb, and Ar and causes toxicity in living beings and the environment. In this review, the sources of heavy metals and their toxicological effects on the environment have been reviewed. Various remediation techniques such as reverse osmosis, chemical precipitation, and ultrafiltration are being used for the treatment of wastewater, but still are limited in their efficiencies, residues, cost, and versatility. In this study, the most promising wastewater treatment technique, the physic-chemical technique, has been reviewed along with its working mechanism and efficiency. Further, the pros and cons of this technique and sub-techniques have also been reviewed to provide a basic understanding to beginners and a pathway to experts in the selection of better techniques.
Mostrar más [+] Menos [-]Examining the role of financial inclusion towards CO2 emissions: presenting the role of renewable energy and globalization in the context of EKC Texto completo
2022
Mehmood, Usman
To achieve sustainable development, the role of financial inclusion has been discussed in limited studies. Therefore, this work aims to investigate the impacts of financial inclusion, renewable energy, globalization, and economic growth on carbon dioxide emissions in the context of environmental Kuznets curve. The annual data of 1990–2017 is analyzed by employing second-generation methods. Westerlund test confirm the long-run association among the panel data. Cross-sectional auto-regressive distributive lag approach has been applied because this method considers the cross-sectional dependence among the panel data to provide robust results. The findings show that financial inclusion is increasing carbon dioxide emissions. This means that financial inclusion requires to integrate it with greener environmental policies. Renewable energy is helpful in mitigating the carbon dioxide emissions but globalization and economic growth are increasing carbon dioxide emissions. On the base of the findings, it is recommended that Pakistan, India, Bangladesh, and Sri Lanka need to revise their international trade policies to reduce carbon dioxide emissions.
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