Refine search
Results 4801-4810 of 6,535
Assessment of renewable energy supply for green ports with a case study Full text
2020
Sadek, Ibrahim | Elgohary, Mohamed
Seaports are considered one of the sources involved in the deterioration of the maritime environment due to the excessive amount of exhaust gases emitted from their activities. The majority of seaports depend on the national electric grid as a source of power for the domestic and ships’ electric demands. This paper discusses the possibility of shifting ports from relying on the national grid electricity to green power-based ports. Offshore wind turbines and fuel cell units appear as two typical promising clean energy sources for ports. As a case study, the paper investigates the prospect of converting Alexandria Port in Egypt to be an eco-friendly port with the study of technical, logistic, and financial requirements. The results show that the fuel cell, followed by a combined system of wind turbines and fuel cells, is the best choice regarding electricity production unit cost by 0.101 and 0.107 $/kWh, respectively. Furthermore, using fuel cells and offshore wind turbine as a green power concept will achieve a reduction in emissions’ quantity of CO₂, NOx, and CO emissions by 80,441, 20,814, and 133,025 ton per year, respectively. Finally, the paper highlights the role that renewable energy can play when supplying Alexandria Port with green energy to lift the burden on the government in supporting the electricity, with a possibility of achieving a profit from 3.85 to 22.31% of the annual electricity cost compared with the international prices.
Show more [+] Less [-]Particulate matter emissions of less harmful-looking super-slim size cigarettes appealing to women: a laser spectrometric analysis of second-hand smoke Full text
2020
Braun, Markus | Langenstein, Amelie | Klingelhöfer, Doris | Zulauf, Nicole | Müller, Ruth | Groneberg, David A.
Slim tobacco products shall appear by their look less harmful. In 2013, the European Union ministers discussed to ban them. However, only a ban on small package sizes was realized. To add more data for exposure risk assessment of slim tobacco products, the particulate matter (PM) amount in second-hand smoke (SHS) of super-slim size cigarettes compared with a king size brand was investigated. PM amount of four super-slim size cigarette types of the brand Couture was analysed in comparison with the king-size reference cigarette. Therefore, SHS was produced in an enclosed space with a volume of 2.88 m³ by an automatic environmental tobacco smoke emitter. PM size fractions PM₁₀, PM₂.₅ and PM₁ were measured in real time using a laser aerosol spectrometer. SHS of Couture Gold contained about 36% and Couture Purple about 28% more PM than the reference cigarette. In contrast, Couture Green emitted about 37% and Couture Silver about 53% less PM than the reference cigarette. Depending on the brand, the PM₂.₅ mean concentrations increased up to 1538 μg/m³. This exceeds the 24-h mean concentration of at most 25 μg/m³ according to the WHO Air quality guidelines about 62-fold. Smoking in enclosed rooms leads to a massive increase of PM. The PM pollution by slim-size tobacco products are substantial and sometimes higher than by king size tobacco products. Therefore, SHS exposure from slim-size tobacco products is not less harmful to health. Decision makers should take this aspect in consideration.
Show more [+] Less [-]FerrateVI oxidation of polycyclic aromatic compounds (PAHs and polar PACs) on DNAPL-spiked sand: degradation efficiency and oxygenated by-product formation compared to conventional oxidants Full text
2020
Johansson, Clotilde | Bataillard, Philippe | Biache, Coralie | Lorgeoux, Catherine | Colombano, Stéfan | Joubert, Antoine | Pigot, Thierry | Faure, Pierre
In situ chemical oxidations are known to remediate PAH contaminations in groundwater and soils. In this study, batch-scale oxidations aim to compare the PAC (polycyclic aromatic compound) degradation of three oxidation processes traditionally applied for soil treatment: permanganate, heat-activated persulfate (60 °C) and Fenton-like activated by magnetite, to results obtained with ferrates (Feⱽᴵ). Widely studied for water treatments, ferrates are efficient on a wide range of pollutants with the advantage of producing nontoxic ferric sludge after reaction. However, fewer works focus on their action on soil, especially on semi-industrial grade ferrates (compatible with field application). Oxidations were carried out on sand spiked with dense non-aqueous phase liquid (DNAPL) sampled in the groundwater of a former coking plant. Conventional 16 US-EPA PAHs and polar PACs were monitored, especially potential oxygenated by-products that can be more harmful than parent-PAHs. After seven reaction days, only the Fenton-like showed limited degradation. Highest efficiencies were obtained for heat-activated persulfate with no O-PAC ketones formed. Permanganate gave important degradation, but ketones were generated in large amount. The tested ferrates not only gave slightly lower yields due to their auto-decomposition but also induced O-PAC ketone production, suggesting a reactional pathway dominated by oxidoreductive electron transfer, rather than a radical one.
Show more [+] Less [-]Achieving environmental sustainability through information technology: “Digital Pakistan” initiative for green development Full text
2020
Ahmad Nizam Hassan, | Zaman, Khalid | Khan, Khan Burhan | Batool, Rubeena | Khurshid, Muhammad Adnan | Shoukry, Alaa Mohamd | Sharkawy, Mohamed A. | Aldeek, Fares | Khader, Jameel | Gani, Showkat
The importance of information and communication technologies (ICTs) in environmental resource management opens a new debate for the policy makers in order to promote green technologies to mitigate high mass carbon emissions across the globe. “Digital Pakistan” initiative is taken by the government that aimed to use technology for country’s social welfare, which further be enhance for achieving environmental sustainability over a time horizon. This study examined the long-run relationship between ICTs, energy demand, and carbon emissions in a context of Pakistan by using a time series data from 1975 to 2017. The results show that energy demand increases economic growth in the short-run while it decreases economic growth in the long-run. The country’s economic growth substantially increases along with an increase in trade openness and mobile-telephone subscription (ICTs) in the short-run; however, the result is changed in the long-run due to increase in carbon emissions in a given time period. The results provoke that continued economic growth and ICT penetration substantially decreases energy demand, whereas urbanization increases energy demand in a country. The results show that variations in emissions associated with proportionate changes in ICTs penetration, economic growth, energy demand, and population growth. Human capital, trade openness, and energy demand are the significant drivers of ICT penetration in a country. The study concludes that the use of green technology is imperative for achieving long-term sustainable growth in a country.
Show more [+] Less [-]Combining habitat area and fragmentation change for ecological disturbance assessment in Jiangsu Province, China Full text
2020
Jin, Zhifeng | Wang, Jing | Kong, Xuesong
Understanding where and how human land use causes ecological consequences is essential for habitat conservation. However, the assessment of the ecological disturbance caused by human land use is usually shaped by the area change in ecological land. The comprehensive evaluation of ecological disturbance based on the losses and gains of ecological patches is neglected. This paper analyzed the land use change between agricultural land, construction land, and ecological land from 1995 to 2015 in Jiangsu Province of eastern China. The ecological disturbance was quantificationally evaluated by a proposed index that considered both the changes of habitat area and fragmentation caused by the losses and gains of ecological landscape patches. The findings showed that there was a slight increase in area of ecological land in Jiangsu Province; however, ecological fragmentation was becoming severe with the growth of human land use, which, in turn, resulted in increased ecological disturbance. The losses and gains in the area and fragmentation of ecological land were comprehensively reflected using the proposed ecological disturbance index. Negative ecological disturbance was more likely to be observed at the edge of the city centers, ecologically sensitive areas, and counties with low area ratios of ecological land. Ecological governance policies should be formulated and implemented based on quantity, quality, and spatial relationships between human land use and ecological disturbance.
Show more [+] Less [-]Potential anti-inflammatory and anti-apoptotic effect of Coccinia grandis plant extract in LPS stimulated-THP-1 cells Full text
2020
Albrahim, Tarfa | Alnasser, Moonerah M. | Al-Anazi, Mashael R. | ALKahtani, Muneera D. | Alkahtani, Saad | Al-Qahtani, Ahmed A.
Coccinia grandis (C. grandis) L is an Indian medicinal plant from the Cucurbitaceae family whose extracts possess anti-oxidant, anti-infective, and anti-inflammatory properties. The objective of the present study was to probe the potential immunomodulatory of C. grandis crude extract on different pathways in THP-1 cells as probed by changes in expression of several proteins. THP-1 cells were differentiated into macrophages after treatment with phorbol-12-myristate 13-acetate, followed by exposure to lipopolysaccharide (LPS) with or without 50 or 100 μg/ml of C. grandis extract. Treatment of the cells with the extract significantly downregulated the expression and release of pro-inflammatory cytokines (IL-6, IL-1β, CCL2, CCL22, CXCL10/IP-10, CX3CL1 and CXCL8/IL-8), proteins (ERK5, BAX, BCL2, Cyclin D, ERK1, NF-κB, P-IκBα,P- NF-κB and P-p38) and molecular signaling pathways (NF-κB, p38 MAPK, ERK1/2 and IL-6/JAK/STAT3 signaling cascades). This study is the first to highlight the ability of C. grandis extract to modulate several pathways, including proliferation, the expression of inflammatory cytokines, phagocytosis, migration properties and apoptosis, in human monocytic THP-1 cells.
Show more [+] Less [-]The impact of technology-environmental innovation on CO2 emissions in China’s transportation sector Full text
2020
Chen, Fang | Zhao, Tao | Liao, Zhiming
Along with the development of urbanization and informationization, an increasing attention has been attracted to CO₂ emissions of China’s transportation sector and its influencing factors. Such researches mainly utilize single indicator or two indicators to represent technology process. This research aims to verify the influence of technology-environmental innovation indicator system on CO₂ emissions of China’s transportation sector by decoupling elasticity and econometric model. We firstly recognize the decoupling status of CO₂ emissions of China’s transportation sector from social economic development and aggregate China’s 30 provinces into two groups according to the varied decoupling status, namely expansive coupling and weak decoupling groups. Then, we develop a relatively comprehensive technology-environmental innovation indicator system to measure technology process. Finally, the multi-region comparison of emission drivers is studied among overall China and the two groups. The result shows that the decoupling elasticity of China’s transportation has experienced an evolution process trending to desired development status and all the provinces have experienced expansive coupling and weak decoupling from 2001 to 2016, except Qinghai. Innovation performance indicators exert most important influence on the CO₂ emissions of transportation sector. Finally, the influences of technology-environmental innovation indicators are similar across groups with different magnitude, suggesting that common but differentiated strategies should be provided when mitigating CO₂ emissions with technology process. Graphical abstract
Show more [+] Less [-]Dithiothreitol-based oxidative potential for airborne particulate matter: an estimation of the associated uncertainty Full text
2020
Molina, Carolina | Andrade, Catalina | Manzano, Carlos A. | Richard Toro, A. | Verma, Vishal | Leiva-Guzmán, Manuel A.
Oxidative stress is considered as one of the main mechanisms by which airborne particles produce adverse health effects. Several methods to estimate the oxidative potential (OP) of particulate matter (PM) have been proposed. Among them, the dithiothreitol (DTT) assay has gained popularity due to its simplicity and overall low implementation cost. Usually, the estimations of OPᴰᵀᵀ are based on n-replicates of a set of samples and their associated standard deviation. However, interlaboratory comparisons of OPᴰᵀᵀ can be difficult and lead to misinterpretations. This work presents an estimation of the total uncertainty for the OPᴰᵀᵀ measurement of PM₁₀ and PM₂.₅ samples collected in Santiago (Chile), based on recommendations by the Joint Committee for Guides in Metrology and Eurachem. The expanded uncertainty expressed as a percentage of the mass-normalized OPᴰᵀᵀ measurements was 18.0% and 16.3% for PM₁₀ and PM₂.₅ samples respectively. The dominating contributor to the total uncertainty was identified (i.e., DTT consumption rate, related to the regression and repeatability of experimental data), while the volumetric operations (i.e., pipettes) were also important. The results showed that, although the OP measured following the DTT assay has been successfully used to estimate the potential health impacts of airborne PM, uncertainty estimations must be considered before interpreting the results.
Show more [+] Less [-]Cadmium tolerance and detoxification in Myriophyllum aquaticum: physiological responses, chemical forms, and subcellular distribution Full text
2020
Li, Guoxin | Li, Qingsong | Wang, Lei | Zhang, Dandan
Submerged macrophytes have been found to be promising in removing cadmium (Cd) from aquatic ecosystems; however, the mechanism of Cd detoxification in these plants is still poorly understood. In the present study, Cd chemical forms and subcellular distributing behaviors in Myriophyllum aquaticum and the physiological mechanism underlying M. aquaticum in response to Cd stress were explored. During the study, M. aquaticum was grown in a hydroponic system and was treated under different concentrations of Cd (0, 0.01, 0.05, 0.25, and 1.25 mg/L) for 14 days. The differential centrifugation suggested that most Cd was split in the soluble fraction (57.40–66.25%) and bound to the cell wall (24.92–38.57%). Furthermore, Cd in M. aquaticum was primarily present in NaCl-extractable Cd (51.76–91.15% in leaves and 58.71–84.76% in stems), followed by acetic acid–extractable Cd (5.17–22.42% in leaves and 9.54–16.56% in stems) and HCl-extractable Cd (0.80–12.23% in leaves and 3.56–18.87% in stems). The malondialdehyde (MDA) and hydrogen peroxide (H₂O₂) concentrations in M. aquaticum were noticeably increased under each Cd concentration. The activities of catalase (CAT), guaiacol peroxidase (POD), and superoxide dismutase (SOD) in leaves were initially increased under relatively low concentrations of Cd but were decreased further with the increasing concentrations of Cd. The ascorbate (AsA), glutathione (GSH), and nitric oxide (NO) concentrations in stems increased with increasing Cd concentrations. Taken together, our results indicate that M. aquaticum can be used successfully for phytoremediation of Cd-contaminated water, and the detoxification mechanisms in M. aquaticum include enzymatic and non-enzymatic antioxidants, subcellular partitioning, and the formation of different chemical forms of Cd.
Show more [+] Less [-]Bioaccumulation and toxic effects of penconazole in earthworms (Eisenia fetida) following soil exposure Full text
2020
Li, Ruisheng | Meng, Zhiyuan | Sun, Wei | Wu, Ruoyue | Jia, Ming | Yan, Sen | Tian, Sinuo | Zhu, Wentao | Zhou, Zhiqiang
As an agricultural fungicide, penconazole (PEN) is widely used and has adverse effects on various organisms. In order to evaluate the ecological safety risks of PEN, the bioaccumulation and toxic effects of PEN in earthworms were studied. Specifically, the results show that the biota-sediment accumulation factor (BSAF) of PEN in earthworms reaches its maximum within 1 day, and then decreases slowly. It reached its lowest value after 14 days of PEN exposure and then rose again. In addition, oxidative stress and metabolic disorder of the earthworm with PEN exposure were assessed. After PEN exposure, the related indicators of oxidative stress involved in the activities of SOD and CAT and the contents of GSH and MDA all changed significantly in earthworms. Moreover, metabolomics analysis of earthworms showed disturbed metabolic profiles following PEN exposure. Respectively, PEN exposure significantly altered the relative abundances of 14 metabolites in earthworms. In general, exposure to PEN caused oxidative stress and metabolic profile disorders of earthworms. The results of this study will be helpful for further evaluation of soil ecological security of PEN.
Show more [+] Less [-]