278 research outputs found
Study of hydrogen internal combustion engine vehicles based on the whole life cycle evaluation method
In order to better achieve the goal of low carbon emissions from vehicles, a whole life cycle assessment of hydrogen-fueled internal combustion engine vehicles has been conducted in recent years. Based on the study of hydrogen use around the world, we studied the emission and economic performance of hydrogen-fueled internal combustion engine vehicles from the beginning of hydrogen production to the end of use (Well-to-Wheel, WTW) based on the whole life cycle evaluation method. The results show that the overall environmental impact of hydrogen production by steam reforming of natural gas is the smallest, and that the rational use of "abandoned electricity" for hydrogen production from electrolytic water in the western part of China significantly reduces the overall environmental impact and the cost of hydrogen production. In the use phase, the emissions are less, which not only can meet the National 6 emission standard, but also can reach higher emission standard after adding exhaust gas recirculation (EGR). From the whole life cycle point of view, hydrogen-fueled internal combustion engine has a very good development prospect.Citation:Â Guo, P., Xu, J., Zhao, C., and Zhang, B. (2022). Study of hydrogen internal combustion engine vehicles based on the whole life cycle evaluation method. Trends in Renewable Energy, 8, 27-37. DOI: 10.17737/tre.2022.8.1.0013
Paleoecology of Pennsylvanian phylloid algal buildups in south Guizhou, China
Pennsylvanian phylloid algal reefs are widespread and well exposed in south Guizhou, China. Here we report on reefs ranging from 2 to 8m thickness and 30-50m lateral extension. Algae, the main components, display a wide spectrum of growth forms, but are commonly cyathiform (cup-shaped) and leaf-like (undulate plates). The algal reef facies is dominated by boundstone. Algal thalli form a dense carpet whose framework pores are filled with marine cement and peloidal micrite. The peloidal matrix is dense, partly laminated or clotted with irregular surfaces and often gravity defying. Algal reefs in Guizhou differ from examples reported to date by the high biodiversity of organisms other than phylloids: e.g., the intergrowth of algae with corals (some of which are twice the size of algal thalli) and numerous large brachiopods. This contrasts to previous views that phylloid algal "meadowsâ dominated the actual seafloor, excluding other biota. Also, the pervasive marine cements (up to 50%) including botryoidal cement are noteworthy. Algal reefs developed at platform margins, a depositional environment similar to that of modern Halimeda mounds in Java, Australia and off Bahamas, and to that of time-equivalent examples reported from the Canadian Arctic Archipelago. Whereas nutrients appear decisive in the growth of Halimeda reefs, algal reefs reported herein seemingly grew under conditions of low nutrient levels. Overall, algal reefs in Guizhou challenge previous views on growth forms, diversity patterns, and depositional environments and add to the spectrum of these partly puzzling biogenic structure
Paleoecology of Pennsylvanian phylloid algal buildups in south Guizhou, China
Pennsylvanian phylloid algal reefs are widespread and well exposed in south Guizhou, China. Here we report on reefs ranging from 2 to 8 m thickness and 30â50 m lateral extension. Algae, the main components, display a wide spectrum of growth forms, but are commonly cyathiform (cup-shaped) and leaf-like (undulate plates). The algal reef facies is dominated by boundstone. Algal thalli form a dense carpet whose framework pores are filled with marine cement and peloidal micrite. The peloidal matrix is dense, partly laminated or clotted with irregular surfaces and often gravity defying. Algal reefs in Guizhou differ from examples reported to date by the high biodiversity of organisms other than phylloids: e.g., the intergrowth of algae with corals (some of which are twice the size of algal thalli) and numerous large brachiopods. This contrasts to previous views that phylloid algal âmeadowsâ dominated the actual seafloor, excluding other biota. Also, the pervasive marine cements (up to 50%) including botryoidal cement are noteworthy. Algal reefs developed at platform margins, a depositional environment similar to that of modern Halimeda mounds in Java, Australia and off Bahamas, and to that of time- equivalent examples reported from the Canadian Arctic Archipelago. Whereas nutrients appear decisive in the growth of Halimeda reefs, algal reefs reported herein seemingly grew under conditions of low nutrient levels. Overall, algal reefs in Guizhou challenge previous views on growth forms, diversity patterns, and depositional environments and add to the spectrum of these partly puzzling biogenic structures
pH and temperature dual-sensitive molecular imprint polymers for BSA based on Cu2+ coordination
A novel kind of pH and temperature dual-sensitive Molecular imprint polymers (MIPs) combined with Cu2+ coordination (SiO2@CS/NIPAM-Cu2+-MIP) has been synthesized using glycidyl methacrylate-iminodiacetic acid (GMA-IDA) as a metalchelating ligand, with bovine serum albumin (BSA) as template protein, combined with pNIPAM and chiston (CS) as temperature and pH sensitive monomers, respectively. The coordination effect of GMA-IDA-Cu2+ has been shown to be beneficial to improve the adsorption capacity and adsorption specificity of BSA. The influence of pH not only changed the charge force between the polymer and protein in the imprinting system, but also deformed the imprinting cavity through the protonation of NH3+ on CS. Further, the thermo-sensitivity of the imprinted polymer was also found to be satisfactory. Withthe joint efforts of coordination, electrostatic action and good matching of imprinted sites, higher adsorption capacity (173.48 mgâg-1) and imprinting factor (2.72) have been obtained at pH 4.6 and 35ÂșC. Although it took about 4 h to reach saturation adsorption, the cyclability of the SiO2@CS/NIPAM-Cu2+-MIP was found to be acceptable and the adsorptioncapacity was maintained at original 81.16% after six cycles. It is for the first time that GMA-IDA-Cu2+ has been used to prepare the pH and temperature dual-sensitive imprinted polymer for BSA
GENERATION OF CRACKS IN HIGHWAY EMBANKMENT ON BLACK COTTON SOIL
This research revealed the crack generation of the highway embankment from the water losing shrinkage of the wet black cotton soil (BCS), which is a type of soil with high swell-shrink potential. The road seepage meter was used to test the permeability of filling materials, which was used to replace BCS. The moisture content and embankment deflection of BCS foundation were measured after the rainy season. Based on the coupled consolidation theory for unsaturated soil, the change in additional tension stress of the embankment induced by water loss shrinkage of BCS was simulated by Abaqus. The results indicated that the rainfall seeped into the foundation through highly permeable refill materials to result in BCS expansion and decrease the embankment strength. After the rainy season, the additional tensile stress caused by water loss shrinkage of BCS induces cracking of highway embankment, and the maximum cracking depth often appears at the shoulder of highway. The deep and wide cracks are easy to appear in the low embankment constructed on a thick BCS foundation under strong evaporation
Solid lipid nanoparticle suspension enhanced the therapeutic efficacy of praziquantel against tapeworm
Hydatid disease caused by tapeworm is an increasing public health and socioeconomic concern. In order to enhance the therapeutic efficacy of praziquantel (PZQ) against tapeworm, PZQ-loaded hydrogenated castor oil solid lipid nanoparticle (PZQ-HCO-SLN) suspension was prepared by a hot homogenization and ultrasonication method. The stability of the suspension at 4°C and room temperature was evaluated by the physicochemical characteristics of the nanoparticles and in-vitro release pattern of the suspension. Pharmacokinetics was studied after subcutaneous administration of the suspension in dogs. The therapeutic effect of the novel formulation was evaluated in dogs naturally infected with Echinococcus granulosus. The results showed that the drug recovery of the suspension was 97.59% ± 7.56%. Nanoparticle diameter, polydispersivity index, and zeta potential were 263.00 ± 11.15 nm, 0.34 ± 0.06, and â11.57 ± 1.12 mV, respectively and showed no significant changes after 4 months of storage at both 4°C and room temperature. The stored suspensions displayed similar in-vitro release patterns as that of the newly prepared one. SLNs increased the bioavailability of PZQ 5.67-fold and extended the mean residence time of the drug from 56.71 to 280.38 hours. Single subcutaneous administration of PZQ-HCO-SLN suspension obtained enhanced therapeutic efficacy against tapeworm in infected dogs. At the dose of 5 mg/kg, the stool-ova reduction and negative conversion rates and tapeworm removal rate of the suspension were 100%, while the native PZQ were 91.55%, 87.5%, and 66.7%. When the dose reduced to 0.5 mg/kg, the native drug showed no effect, but the suspension still got the same therapeutic efficacy as that of the 5 mg/kg native PZQ. These results demonstrate that the PZQ-HCO-SLN suspension is a promising formulation to enhance the therapeutic efficacy of PZQ
Study on tightly coupled LiDAR-Inertial SLAM for open pit coal mine environment
With the rapid development of artificial intelligence and unmanned and other related disciplines, the intelligence and unmanned of coal mining equipment has become a new trend. The application of intelligent equipment will greatly improve the productivity of coal mine operations as well as personnel safety. In this environment, the existing LIDAR-based Simultaneous localization and mapping (SLAM) solution is prone to positioning drift and large mapping errors. To address these problems, a tightly coupled SLAM algorithm based on LiDAR (Light Detection and Ranging) and IMU (Inertial Measurement Unit) is proposed, which uses both LiDAR and IMU sensors as data inputs.The front-end uses an iterative extended Kalman filter to fuse the pre-processed LiDAR feature points with the IMU data and uses backward propagation to correct the radar motion distortion, the back-end uses the LiDAR relative positional factor to use the LiDAR inter-frame alignment results as a constraint factor together with the loopback factor to complete the global factor map optimization. The robustness and accuracy of the algorithm are verified using open source dataset and open pit coal mine field dataset. The experimental results show that the accuracy of the proposed algorithm is consistent with the current LiDAR SLAM algorithm in the urban structured environment, while the proposed algorithm improves the localization accuracy by 46.00% and 23.15% with higher robustness than the FAST-LIO2 and LIO-SAM tightly coupled algorithms for the open pit coal mine field environment of more than 2000 meters long, respectively
The Maximum Height and Attenuation of Impulse Waves Generated by Subaerial Landslides
High-speed landslides that flow into reservoirs can cause impulsive water waves. To study the characteristics of the maximum impulse waveâs height and its attenuation, 25 sets of flume experiments were conducted using orthogonal theory and 6 main influencing factors were considered. Taking the impulse wave heights as the evaluation criteria and analyzing the 6 influencing factors at 5 different levels, the characteristics of the maximum impulse waveâs height and its attenuations were obtained. Then, statistical relationships between the maximum wave height and the controlling factors were proposed. Then, by combining the continuity equation and the hydrodynamic open channel transient flow movement equation, the process of landslide wave height attenuation was studied, and it was found that the attenuation of the wave is consistent with exponential attenuation. Then, combined with the data obtained from the orthogonal experiments, an attenuation equation for the surge was derived. Finally, the proposed equation was validated by applying it to the landslides that took place along the shore of the Zipingpu reservoir, which were triggered by the Wenchuan earthquake, and the results indicate that the calculated results are very close to the observed results
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