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Результаты 5401-5410 из 6,546
Identifying modeling forms of instrument panel system in intelligent shared cars: a study for perceptual preference and in-vehicle behaviors Полный текст
2020
Yang, Hao | Zhao, Ying | Wang, Yueran
A sustainable human-machine interface design has been highlighted for shared cars which is environmentally friendly. To improve people’s perceptual, psychological, and behavioral experience in shared cars, this study revealed the relationship between modeling forms of the instrument panel and interaction performance. Modeling forms include the panel layout and the central screen installation type. After classifying existing panel layout designs into four kinds, this study relied on System Usability Scale (n = 182) to score them and clarify the usability of each kind. The one with the best usability (the symmetrical driver-oriented layout) was identified and ANOVA was used to judge the significance of the difference. Then, three central screen installation types were analyzed and sorted by means of analytic hierarchy process. Based on the above analysis for perceptual preference, behavioral experiments were carried out (n = 60) in intelligent vehicles equipped with the two advantageous screens (all-in-one type and semi-detached type) to analyze electrocardiograph data and workload of typical interaction behaviors. The logit model showed that when interacting with the SD-AIO panel (the panel of symmetrical driver-oriented layout with an all-in-one type screen), tension level was often lower in both driving and secondary tasks. Besides, we explored how the heart rate of specific tasks influenced the total completion time. The conclusion confirmed the advantages of SD-AIO panel, which could contribute to a sustainable interaction with high traffic efficiency.
Показать больше [+] Меньше [-]Short-term impacts of biochar, tillage practices, and irrigation systems on nitrate and phosphorus concentrations in subsurface drainage water Полный текст
2020
Farahani, Saeid Shahvarooghi | Asoodar, Mohammad Amin | Moghadam, Bijan Khalili
Leaching of nitrogen (N) and phosphorus (P) from agricultural lands can cause serious environmental problems such as eutrophication. The objective of this study was to investigate the impacts of biochar application, tillage practices, and irrigation systems on nitrate and dissolved phosphorus (DP) concentrations in subsurface drainage water and grain yield of winter wheat using a strip-split plot design with 3 replications. Irrigation at three different levels (flood (Ifₗ), furrow (Ifᵤ), and sprinkler (Iₛ) systems) considered as main factor, tillage at two levels (reduced tillage (Tᵣ) and conventional systems (Tc)) as subplot factor, and bagasse biochar at two levels (without biochar (B₀) and 20 ton ha⁻¹ biochar (B₁)) as sub-subplot factor. Polyvinyl chloride (PVC) standpipes were used in each sub-subplot to collect leachate water at 100-cm depth. The results indicated that irrigation had significant effects on yield, collected water volume (CWV), nitrate, and DP concentrations (P < 0.01). Interaction of tillage and irrigation was significant for grain yield (P < 0.05). Biochar application only caused a significant decrease in nitrate concentration under sprinkler irrigation (P < 0.05), while no significant impact was observed under flood and furrow irrigation systems. Under sprinkler irrigation, the total nitrate collected in the PVC standpipes decreased by 37.51 and 34.29% compared with flood and furrow irrigations, respectively. Biochar application reduced the total nitrate collected by 16.84%, while difference among tillage treatments was negligible (4.51%). The total DP collected under sprinkler irrigation was lower in comparison with flood and furrow irrigations by 42.24 and 38.76%, respectively. Biochar application reduced the total DP collected by 10.84%, while reduced tillage increased the total DP collected by 8.90% compared with the conventional tillage.
Показать больше [+] Меньше [-]Lignocellulosic biomass supported metal nanoparticles for the catalytic reduction of organic pollutants Полный текст
2020
Akhtar, Kalsoom | Ali, Fayaz | Sohni, Saima | Kamal, Tahseen | Asiri, Abdullah M. | Bakhsh, Esraa M. | Khan, Sher Bahadar
Lignocellulosic biomass waste is a cheap, eco-friendly, and sustainable raw material for a wide array of applications. In the present study, an easy, fast, and economically feasible route has been proposed for the preparation of different zero-valent metal nanoparticles (ZV-MNPs) based on Cu, Co, Ag, and Ni NPs using empty fruit bunch (EFB) biomass residue as support material. The catalytic efficiency of ZV-MNPs/EFB catalyst was investigated against five model pollutants, such as methyl orange (MO), congo red (CR), methylene blue (MB), acridine orange (AO), and 4-nitrophenol (4-NP) using NaBH₄ as a source of hydrogen and electron. Comparative study revealed that among as-prepared ZV-MNPs/EFB catalysts, Cu-NPs immobilized onto EFB (Cu/EFB) exhibited maximum catalytic efficiency towards pollutant abasement. Degradation reactions were highly efficient, and were completed within a short time (4 min) in case of MO, CR, and MB, whilst AO and 4-NP were reduced in less than 15 min. Kinetic investigation revealed that the degradation rate of model pollutants accorded with pseudo-first order model. Furthermore, supported catalysts were easily recovered after the completion of experiment by simply pulling the catalyst from reaction system. Recyclability tests performed on Cu/EFB revealed that more than 97% of the reduction was achieved in case of MO dye for four successive cycles of reuse. The as-prepared heterostructure showed multifunctional properties, such as enhanced uptake of contaminants, high catalytic efficiency, and easy recovery, hence, offers great prospects in wastewater purification.
Показать больше [+] Меньше [-]Spatiotemporal changes in vegetation coverage and its causes in China since the Chinese economic reform Полный текст
2020
Du, Jiaqiang | Quan, Zhanjun | Fang, Shifeng | Liu, Chengcheng | Wu, Jinhua | Fu, Qing
With the rapid development of the economy over 40 years since the initiation of Chinese economic reform, terrestrial ecosystems in China have undergone large-scale changes. In this study, we investigated vegetation dynamics in China and their relationships with climatic factors and anthropogenic drivers over 15 progressive periods of 18–32 years starting in 1982. This was accomplished by using the third-generation global satellite Advanced Very High Resolution Radiometer (AVHRR), Normalized Difference Vegetation Index (NDVI) dataset, night-time satellite data, and climate data. Across China, NDVI increased significantly during 1982–2013; especially significant increases were observed in all periods during the growing season and spring. At the pixel scale, 21–38% of the vegetated area in the 15 periods experienced a significant positive trend in vegetation growth. This increase was mostly located in central and southern China. A significant negative trend was observed in 1–8% of the vegetated area pixels, and this pattern was mainly seen in northwestern China, the Yangtze River Delta region, and the Pearl River Delta region. The contribution of spring NDVI to vegetation improvement increased, while the contribution of summer NDVI decreased. Vegetation activity in China was mainly regulated by thermal factors, especially pronounced in mountainous regions of northern China. However, the restrictive effect of moisture factors was very marked to vegetation growth in areas with less than 400 mm of precipitation. Urbanization in China has led to vegetation degradation in most urban centers and surrounding areas in central and eastern China. The increase of agricultural plantations, the Grain for Green Project, and a series ecological restoration projects in some areas have promoted vegetation coverage.
Показать больше [+] Меньше [-]Toxicity of multi-wall carbon nanotubes inhalation on the brain of rats Полный текст
2020
Samiei, Fatemeh | Shirazi, Farshad Hosseini | Naserzadeh, Parvaneh | Dousti, Faezeh | Seydi, Enayatollah | Pourahmad, Jalal
This study was designed to investigate the brain toxicity following the respiratory contact with multi-wall carbon nanotubes (MWCNTs) in male Wistar rats. Rats were exposed to 5 mg/m³ MWCNT aerosol in different sizes and purities for 5 h/day, 5 days/week for 2 weeks in a whole-body exposure chamber. After 2-week exposure, mitochondrial isolation was performed from different parts of rat brain (hippocampus, frontal cortex, and cerebellum) and parameters of mitochondrial toxicity including mitochondrial succinate dehydrogenase (SDH) activity, generation of reactive oxygen species (ROS), mitochondrial membrane potential (MMP) collapse, mitochondrial swelling, and cytochrome c release, ATP level, mitochondrial GSH, and lipid peroxidation were evaluated. Our results demonstrated that MWCNTs with different characteristics, in size and purity, significantly (P < 0.05) decreased SDH activity, GSH, and ATP level, and increased mitochondrial ROS production, lipid peroxidation, mitochondrial swelling, MMP collapse, and cytochrome c release in the brain mitochondria. In conclusion, we suggested that MWCNTs with different characteristics, in size and purity, induce damage in varying degrees on the mitochondrial respiratory chain and increase mitochondrial ROS formation in different parts of rat brain (hippocampus, frontal cortex, and cerebellum).
Показать больше [+] Меньше [-]Sol-gel hydrothermal synthesis of nano crystalline silicotitanate and its strontium and cesium adsorption Полный текст
2020
Wang, Rong | Luo, Zhenggang | Tan, Qiuxia | Wang, Rui | Chen, Shuyuan | Shu, Jiancheng | Chen, Mengjun | Xiao, Zhengxue
Crystalline silicotitanate (CST) was synthesized via a sol-gel hydrothermal method using Na₂Si₂O₃·9H₂O and TiCl₄ as silicon and titanium sources. The effects of pH, silicon concentration, hydrothermal temperature, and time on the CST synthesis were studied at a fixed molar ratio of silicon:titanium (0.98:1). Pure nano-CST crystals were synthesized at pH = 12.5, silicon concentration of 5 g L⁻¹, 170 °C for 7 days. The average CST particle size was < 100 nm, with a Sr²⁺/Cs⁺ distribution coefficient up to 1.9 × 10⁶ mL g⁻¹/9.4 × 10³ mL g⁻¹ under the optimum conditions. In addition, nano-CST absorbed Sr²⁺/Cs⁺ over a wide pH range. The nano-CST also displayed a much faster equilibrium time, 4 h, as compared with previous studies. Furthermore, nano-CST adsorption of Sr²⁺/Cs⁺ followed a Langmuir adsorption model and was consistent with pseudo-second-order kinetics.
Показать больше [+] Меньше [-]Effect of acid-treated and hexadecyltrimethylammonium bromide–modified montmorillonites on adsorption performance of mycotoxins Полный текст
2020
Mao, Jiaqi | Lv, Guanglie | Zhou, Renxian
A series of modified montmorillonites treated by acid and hexadecyltrimethylammonium bromide (HTAB) were prepared and characterized, and their adsorption performances for three mycotoxins (aflatoxin B1, zearalenone, and deoxynivalenol) were evaluated at pH 2.8 and 8.0, respectively. The results indicate that the layers of raw montmorillonite are exfoliated after acid treatment and more active sites for adsorption of weak polar mycotoxins are exposed. While the intercalation of HTAB leads to an obvious increase of the interlamellar spacing and hydrophobic character of montmorillonite. The HTAB-AMMT-3 modified by acid and HTAB exhibits excellent adsorption capacity towards aflatoxin B1 (AFB1) and zearalenone (ZEA) whether in acidic or alkaline conditions compared with raw montmorillonite (MMT). However, all modified montmorillonites have low adsorption capacity for DON due to its poor planarity preventing it from entering into interfacial layer of montmorillonite.
Показать больше [+] Меньше [-]Influence of nutrient mitigation measures on the fractional export of watershed inputs in an urban watershed Полный текст
2020
Gao, Wei | Duan, Zhongzhao | Yan, Chang’an | Liu, Change
Enhanced nutrient inputs due to human activities have been noted as a significant driving force for riverine nutrient exports which are responsible for the eutrophication issues in freshwaters. Current studies are mostly focused on the relationship between anthropogenic inputs and riverine exports, and little has been done to assess the role of nutrient mitigation measures in the fractional export of watershed nutrient inputs in urban regions. A highly urbanized watershed in Yun-Gui plateau of China, Lake Dianchi basin was studied as a case to assess the impact of nutrient mitigation measures on riverine nutrient exports. Based on net anthropogenic nitrogen and phosphorus inputs (NANI and NAPI, respectively) models, nutrient inputs from human activities in the basin from 1980 to 2015 were calculated, and the impact of nutrient mitigation measures were identified using a statistical model incorporating land use, precipitation, and temperature. Nutrient inputs from human action in the basin has increased rapidly, mainly from fertilizer application and food and feed imports. Enhanced riverine nutrient exports were found at the same time, and significantly correlated to nutrient inputs. The construction of water transfer projects and wastewater treatment plants in the basin has changed the controlling factors and processes of the fractional export of watershed nutrient inputs, which is weak in explanatory ability and eliminated the role of the land use. A modified model was established by incorporating the effect of water transfer projects and wastewater treatment plants, which showed a significant increase in model performance. The results from the modified model reveal that urban land percentage has become a positively driving force for the fractional export of watershed N and P inputs, and temperature a positive driving force for the fractional export of watershed N inputs while precipitation a negative driving force for the fractional export of watershed P inputs.
Показать больше [+] Меньше [-]Effect of biodegradation on haloacetic acid formation potentials of anthropogenic compounds during chlorination Полный текст
2020
Cordero, José Andrés | He, Kai | Okuta, Erika | Echigo, Shinya | Itoh, Sadahiko
During drinking water treatment processes, anthropogenic compounds act as important precursors of disinfection by-products such as haloacetic acids (HAAs). Several transformations in these precursors occur prior to the disinfection stage, such as partial biodegradation. We hypothesized that this partial biodegradation of anthropogenic compounds potentially affects their HAA formation potentials (HAAFPs). In this study, the HAAFPs of 51 anthropogenic compounds after short-term contact (less than 1 h) and long-term contact (24 h) with activated sludge were compared. Considerable changes were observed particularly in trichloroacetic acid (TCAA) formation potentials (FPs) of phenols, demonstrating that biodegradation should be considered in investigations of potential precursors of HAAs. Phenols with low HAAFPs, such as hydroquinone, show higher HAAFPs after biodegradation, but HAAFPs of most phenols and anilines decreased after biodegradation. Thus, biodegradation will most likely have a positive impact on water quality from the standpoint of HAAFP reduction. For most aliphatic compounds, changes in HAAFP were negligible, but the dichloroacetic acid (DCAA) FP of acrylic acid largely increased. This study illustrates that biodegradation may have a large effect on the HAAFPs of anthropogenic compounds.
Показать больше [+] Меньше [-]Transformation of hazardous lead into aluminosilicate ceramics: structure evolution and lead leaching Полный текст
2020
Yang, Jiani | Lu, Xingwen | Liu, Yuxin | Wang, Fei | Chao, Yuanqing
This study investigated crystallization mechanisms for the formation of lead aluminosilicate by sintering lead stabilization with kaolin-based precursors. PbAl₂Si₂O₈ was found to be the only stable lead aluminosilicate in low-PbO system and demonstrates its highly intrinsic resistance to acid attack in leaching test. A three-stage PbAl₂Si₂O₈ formation mechanism was supported by the results of the changing temperature in the system. Amorphization of sintered products was observed in both PbO/kaolinite and PbO/mullite systems at 600–700°C. When the temperature was increased to 750–900°C, the crystallochemical formation of lead aluminosilicates (i.e., Pb₄Al₄Si₃O₁₆, Pb₆Al₆Si₂O₂₁, and PbAl₂Si₂O₈) was observed. Pb₄Al₄Si₃O₁₆ and Pb₆Al₆Si₂O₂₁ were found to be the intermediate phases at 700–900°C. Finally, PbAl₂Si₂O₈ was found to be the only crystallite phase to host Pb at above 950°C. A maximum of 80% and 96.7% Pb can be incorporated into PbAl₂Si₂O₈ in PbO/kaolinite and PbO/mullite systems, respectively, but the final products exhibited different microstructures. To reduce environmental hazard of lead, this strategy demonstrated a preferred mechanism of immobilizing lead into PbAl₂Si₂O₈ structure via kaolin-based precursors.
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