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The nexus between financial development, income level, and environment in Central and Eastern European Countries: a perspective on Belt and Road Initiative Полный текст
2019
Saud, Shah | Chen, Songsheng | Haseeb, Abdul | Khan, Khalid | Imran, Muhammad
A plethora of empirical work explored finance-income-environment nexus, aims to investigate high CO₂ emissions determinants, over the last few couples of decades. The prior empirical work assist the idea that finance and income have diverse impacts on the environment. The lack of consensus on finance-income-environment nexus in the Central and Eastern European Countries in the perspective of Belt and Road Initiative need to be examined. Therefore, the present study explores the nexus between financial development, income level, and environmental quality for a panel of eighteen Central and Eastern European Countries, over the period of 1980–2016. The Dynamic Seemingly Unrelated Regression, the Fully Modified Ordinary Least Squares, and the Dumitrescu-Hurlin panel casualty approaches are employed. The environmental Kuznets curve hypothesis also investigated for both time series panel and country-wise. The Dynamic Seemingly Unrelated Regression long-run panel results reveal that (i) financial development index and income negatively impact on environmental quality; (ii) energy consumption is the key determinant of CO₂ emissions and reduces environmental quality; (iii) urbanization and trade both enhance environmental quality via reduction of carbon emissions; and (iv) the environmental Kuznets curve hypothesis supported for the selected panel countries. The country-wise results depict that increase in environmental quality occurs due to increase in financial development (in four countries), income level (in five countries), trade (in five countries), and urbanization (in eight countries). However, the environmental quality decreases due to the increase in financial development (in six countries), income level (in eight countries), energy consumption (in twelve countries), trade (in six countries), and urbanization (in five countries). The environmental Kuznets curve hypothesis supported for five Central and Eastern European Countries. Additionally, the causality results confirmed the presence of feedback relationships among income and environmental quality, and financial development and energy consumption. Thus, we conclude that income level and financial development are the main drivers behind high carbon dioxide emissions in CEECs. The finding of the study opens up new insight for appropriate policymaking.
Показать больше [+] Меньше [-]Impact of intermittent turbulent bursts on sediment resuspension and internal nutrient release in Lake Taihu, China Полный текст
2019
Tang, Chunyan | Li, Yiping | Acharya, Kumud | Du, Wei | Gao, Xiaomeng | Luo, Liancong | Yu, Zhongbo
Intermittent turbulent bursts have great impacts on sediment resuspension in coastal regions, tidal estuaries, and lakes. In this study, the role of turbulence structure on sediment resuspension was examined at Meiliang Bay of Lake Taihu, the third largest freshwater lake in China. The instantaneous three-dimensional velocity and suspended sediment concentrations were synchronously recorded by Acoustic Doppler Velocimetry (ADV) and Optical Backscatter Sensor (OBS) placed close to the lakebed. Statistical and quadrant analyses results revealed that the coherent structure contributed significantly to sediment particle entrainment. The intermittent burst events (dominant ejection and sweep) were the main energy source for sediment resuspension processes. 99.2% of turbulent sediment fluxes were triggered by ejection and sweep events, whereas the contributions coming from the outward interactions and inward interactions were relatively small. The large-amplitude burst events in the coherent structure dominated the influence on the sediment diffusion. Additionally, it was found that instantaneous sediment particle entrainment occurred earlier than the mean critical shear stress, which was induced by the stochastic nature of turbulence. The amount of sediment flux considering the turbulence characteristics was one or two larger magnitudes than the flux amount assessed by the time-averaged flow field, which indicated the critical shear stress approach might underestimate the sediment resuspension. Therefore, the influence of turbulence performance on sediment entrainment shall be seriously considered when evaluating sediment flux and internal nutrient loads in Lake Taihu.
Показать больше [+] Меньше [-]Efficient removal of copper ions using a hydrogel bead triggered by the cationic hectorite clay and anionic sodium alginate Полный текст
2019
Tong, Dongshen | Fang, Kai | Yang, Haiyan | Wang, Jie | Zhou, Chunhui | Yu, Weihua
Sodium alginate (SA) is a linear biopolymer, which is the nontoxic, biodegradable, and rich in carboxyl and hydroxyl groups. In the paper, the SA-based hydrogel bead was prepared by the cationic hectorite clay and anionic sodium alginate with a simple ionic gelation method under freeze-drying, and the adsorption properties were evaluated by the removal of copper ions from aqueous solutions. The composites were characterized by X-ray diffraction (XRD), nitrogen adsorption-desorption isotherm (BET), thermal analysis (TG), and Fourier transform infrared spectroscopy (FT-IR). The pseudo-first-order and pseudo-second-order kinetic models were used to describe the kinetic data and the Langmuir, Freundlich, Dubinin–Radushkevich (D-R), and Temkin models were applied to describe the adsorption isotherms. The results showed that the adsorption process was found to follow the Freundlich isotherm model and the maximum sorption capacity was observed to be 160.28 mg/g under the initial concentration from 10 to 700 mg/L at 45 °C. Adsorption kinetics data fitted well with pseudo-second-order rate model. The porous structure of the composite was responsible for the adsorption of Cu²⁺ ions. But the adsorption ability could be improved by pH. Finally, the adsorption mechanism was suggested. Graphical abstract
Показать больше [+] Меньше [-]Relevance of dissolved organic matter generated from green manuring of Chinese milk vetch in relation to water-soluble cadmium Полный текст
2019
Xie, Jie | Dong, Aiqin | Liu, Jia | Su, Jinping | Hu, Bo | Xu, Changxu | Chen, Jingrui | Wu, Qitang
Dissolved organic matter (DOM) can become a carrier of soil contaminants. Therefore, an understanding of the evolution and characteristics of DOM produced by Chinese milk vetch during green manuring is crucial. In this study, DOM solutions from 28 days’ manuring with three different organic materials were characterized using three-dimensional fluorescence excitation–emission matrix (3D-EEM) with parallel factor (PARAFAC) analysis, and ultraviolet–visible spectroscopy. With the green manuring milk vetch at flowering period (MVFP), the DOC and water-soluble cadmium (WS-Cd) in soil solution reached 1875 mg/l and 2.64 μg/l, respectively, on day 6 after manuring. The PARAFAC analysis modeled three components: protein-like (tryptophan) and two humic-like components (humic acid and fulvic acid); DOM produced by MVFP was primarily protein-like during the early stage of decomposition. The aromaticity and molecular weight of DOM in the MVFP treatment was lower than in the other treatments, which could promote the release of soil particle-adsorbed Cd to soil solution. Principal components analysis showed that aromaticity was the main factor affecting Cd solubility, and the negative linear correlation of aromaticity with WS-Cd reached 0.4827. The results of this study supported the idea that manuring with MVFP might accelerate Cd infiltration to deep soil with water under gravity.
Показать больше [+] Меньше [-]Investigating the combined effect of thermal barrier coating and antioxidants on pine oil in DI diesel engine Полный текст
2019
Viswanathan, Karthickeyan | Balasubramanian, Dhinesh | Subramanian, Thiyagarajan | Varuvel, Edwin Geo
The present study presented an inclusive analysis of engine exhaust emission characteristics of direct injection diesel engine fuelled with diesel and biofuel. Biofuel used in this investigation was obtained by steam distillation from pine oil. A single-cylinder, four-stroke diesel engine was used for this purpose. In this work, performance characteristics like brake thermal efficiency (BTE) and brake-specific fuel consumption (BSFC) were analysed. The engine pollutants, namely nitrogen oxide (NO), carbon monoxide (CO), hydrocarbon (HC), and smoke, were examined. In addition, combustion characteristics like in-cylinder pressure and heat release rate were presented. Two engine modification techniques, namely thermal barrier coating and the addition of antioxidant to biofuel, were attempted. The advantage of thermal barrier coating is to reduce heat loss from the engine and convert the accumulated heat into useful piston work. In this work, partially stabilised zirconia was used as the coating material. The usage of antioxidant-treated biofuel in a diesel engine was said to be the prominent approach for NOx emission reduction. Three different antioxidants, namely butylated hydroxyanisole (BHA), butylated hydroxytoluene (BHT), tertiary-butyl hydroquinone (TBHQ), were exclusively dissolved at a concentration of 1% by volume with PO fuel. The obtained performance and emission characteristics of the uncoated engine were compared with the thermally coated engine. From the results, it was observed that the PO biofuel may be a promising alternative in the near prospect with the thermal barrier coating technique to enhance the performance, combustion and emission characteristics of diesel engine. The PO+TBHQ blend was considered as more beneficial than PO+BHT and PO+BHA on account of its performance, combustion and emission characteristics. The effectiveness of the antioxidant was shown in the order of TBHQ>BHA>BHT.
Показать больше [+] Меньше [-]Antimony Causes Mortality and Induces Mutagenesis in the Soil Functional Bacterium Azospirillum brasilense Sp7 Полный текст
2019
Obiakor, Maximilian Obinna | Wilson, Susan C. | Tighe, Matthew | Pereg, Lily
Antimony (Sb) is increasing in the environment but effects of exposure in ecosystems are not well understood. The aim of this work was to examine effects of antimony exposure on the multifunctional, plant growth promoting, ubiquitous soil bacterium Azospirillum brasilense Sp7. Contaminated mine water with high Sb concentrations (0.13 ± 0.09 mg L⁻¹) was lethal to A. brasilense Sp7 in laboratory experiments. Exposure-dose- and time-dependent incubation toxicity assays on A. brasilense Sp7 with Sb(III) and Sb(V) at different concentrations (0.05–5 mg L⁻¹) also resulted in cell mortality which was dose and time dependent. Median effect concentrations of 0.004–0.049 and 0.019–0.467 mg L⁻¹ were estimated for Sb(III) and Sb(V), respectively. Exposure to Sb(III) resulted in greater cell mortality than Sb(V) at all concentrations tested. Exposure also resulted in the emergence of phenotypic variants that were more frequent with exposure to Sb(III). The toxicity assays demonstrated that Sb alone could have been responsible for the mortality observed with exposure to the contaminated mine water even without any other contaminants present. A. brasilense Sp7 was highly sensitive to Sb exposure and the observed effects suggest possible consequences for microbial function, plant-bacterial symbioses and ecosystem health with Sb contamination.
Показать больше [+] Меньше [-]Concentrations of cadmium and lead, but not zinc, are higher in red fox tissues than in rodents—pollution gradient study in the Małopolska province (Poland) Полный текст
2019
Ziętara, Joanna | Wierzbowska, Izabela A. | Gdula-Argasińska, Joanna | Gajda, Agnieszka | Laskowski, Ryszard
The main purpose of our research was to assess the chronic exposure of red foxes to Cd, Pb and Zn. We have determined concentrations of these metals in the kidney, liver and muscle of 36 red foxes hunted between December 2002 and March 2003 in differently polluted areas in southern Poland. Tissue concentrations of Pb and Cd in the red foxes significantly co-varied with concentrations of these elements in the soil, and differed between the tissues. We compared concentrations of Pb, Cd, and Zn in red foxes with two rodent species, Apodemus flavicollis and Myodes glareolus, trapped simultaneously in the same area. Concentrations of Pb and Cd appeared significantly higher in the red foxes than in the rodents, but the slopes of the relationship between metal concentrations in tissues and in soil were similar in all species. This indicates that extrapolation from results of monitoring studies conducted on rodents to mammalian carnivores is possible but requires applying an extrapolation factor.
Показать больше [+] Меньше [-]Silicon-mediated role of 24-epibrassinolide in wheat under high-temperature stress Полный текст
2019
Hussain, Muzaffer | Khan, Tanveer Alam | Yusuf, Mohammad | Fariduddin, Qazi
High temperature poses a severe extortion to productivity of many crops like wheat. Therefore, well documented roles of brassinosteroid (BR) and silicon (Si) in terms of abiotic stress tolerance, the current study was designed to evaluate the response of wheat (Triticum aestivum L. Var. PBW-343) to 24-epibrassinolide (EBL) mediated by silicon grown under high temperature stress. At 10- and 12-day stage after sowing, the seedlings were administered Si (0.8 mM) through the sand, and the plants at 20, 22, or 24 days after sowing (DAS) were given EBL (0.01μM) through foliage. Plants were treated to high-temperature stress (35/28 or 40/35 °C), for 24 h with 12-h photoperiod in plant growth chamber at 25- and 26-day stage of growth. High temperatures cause significant reduction in growth performance and photosynthesis-related attributes at 35 days after sowing. However, antioxidant enzymes and proline content also augmented substantially with increasing temperature. BR and Si enhanced antioxidant activity and proline content, which was earlier increased by the high temperature. It is established that interaction of EBL and Si considerably improved the growth features, photosynthetic efficacy, and several biochemical traits under high-temperature stress through elevated antioxidant system and osmoprotectant.
Показать больше [+] Меньше [-]In utero exposure to commercial artificial sweeteners affects mice development and mammary gland structure Полный текст
2019
Al-Qudsi, Fatma M. | Al-Hasan, Manar M.
Commercial artificial sweeteners present in the market are usually made of combination of nutritive and artificial sweeteners such as sorbitol and aspartame. The aim of this research was to study the effect of in utero exposure to commercial artificial sweeteners on the mouse development and on mammary gland in different stages (18-day embryos and 4-week-old mice). Pregnant mice of treated groups were given 50 mg/kg body weight of commercial artificial sweetener. The dose was given on day 1 of pregnancy until 3-week nursing, while the controls were given distilled water. Congenital malformations were seen in treated 18-day fetus and 4-week-old mice, such as a significant decrease in the diameter of the placenta and the weight of the fetuses, while in 4-week-old mice, a significant decrease in the length of the body, limbs, and tail was seen compared to the controls. The result of this study showed that in 18-day fetuses, clusters of mammary gland in the treated mice seemed to be more differentiated than the controls. In 4-week-old mice, the number of mammary gland ducts in the treated group was significantly more than the control group, and the lumen of the ducts in the treated sections seemed to be narrower than the controls, also many regressing terminal end buds (TEBs) were seen in the treated group. A significant increase in the mammary gland area of treated group was seen compared to the controls.
Показать больше [+] Меньше [-]The Influence of Stimulation Techniques on the Microbiological Changes and n-Alkane Transitions in the Soil Contaminated of Petroleum-Derived Substances Полный текст
2019
Konieczny, Marcin | Krzyśko–Łupicka, Teresa
Removal of petroleum products from contaminated soil is a long-term process requiring attention and constant monitoring. The aim of this study was to determine the effect of Fyre-Zyme enzyme preparation and/or calcium carbonate on microbiological changes and conversion of n-aliphatic hydrocarbons in soil contaminated of petroleum-derived substances. The material for testing was soil contaminated with petroleum substances. The total concentration of n-alkanes with a C8–C40 chain length was 420.1 mg·kg⁻¹ DM. The pot tests were carried out by introducing stimulators. As a decomposition promoter for n-alkanes in contaminated soil, a 6% water solution of Fyre-Zyme and/or 1% sterile CaCO₃ was used. The pots were incubated at 25 °C for 21 days. The dynamics of changes in the microbiota and concentration of n-alkanes were controlled for 21 days, every 7 days taking soil for testing. Microbiological tests included determining the total number of bacteria and fungi. Chemical analysis was performed by chromatographic method. Stimulating of soil bioremediation of contaminated hydrocarbons with calcium carbonate increased the number of bacteria, and stimulation with Fyre-Zyme and calcium carbonate—the number of filamentous fungi. There was no significant correlation between the concentration of n-alkanes in the soil and the total number of bacteria and fungi but stimulating of soil bioremediation with calcium carbonate increased the number of bacteria, and stimulation with Fyre-Zyme and calcium carbonate—the number of filamentous fungi. The observed correlations indicate that the concentration of n-alkanes in the contaminated soil increases with the addition of Fyre-Zyme.
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