Feasibility of Direct Utilization of Biomass Gasification Product Gas Fuels in Tubular Solid Oxide Fuel Cells for On-Site Electricity Generation

Biomass is one of the most abundant and cheap renewable energy sources, and gasification product gases from the pyrolysis process of biomass, such as mallee wood and wheat straw, contain typically 20-27% H2 and a small amount of CO and CH4 (8-13%). Here, preliminary results on the performance of Ni/Y2O3-ZrO2 cermet anode-supported tubular solid oxide fuel cells (SOFCs) for the electricity generation from gasification product gases are presented. Two product gases derived from mallee wood and wheat straw are used as the fuels. The tubular SOFCs deliver a maximum power density over 576 mW cm-2 at 800 °C, close to the power density based on the equivalent amount of pure H2 or CH4 fuel. The power density is affected by the flow rate of product gas, but there are no significant differences of power output among the product gas sources used. However, the cell performance decreases gradually, and the degradation in the electricity generation performance of the tubular SOFC is most likely due to the presence of impurities, such as sulfur- and chlorine-containing compounds in the biomass feedstock. The results demonstrate the feasibility of the gasification product gas-fueled SOFCs for the on-site electricity generation, and the deterioration effect of impurities could be mitigated by cleaning the product gases or developing the contaminant-tolerant electrodes

A Cloud Model-Based Risk Assessment Methodology for Tunneling-Induced Damage to Existing Tunnel

This study presents a cloud model-based approach for risk assessment of existing tunnels in tunneling construction environments where the cloud model provides a basis for uncertainty transformation between its qualitative concepts and quantitative expressions. An evaluation index system is established for risk assessment of existing tunnels based on the tunnel-induced failure mechanism analysis. The assessment result is obtained through the correlation with the cloud model of each risk level. Risk assessment for existing Guangzhou-Shenzhen-Hong Kong Railway Tunnel in the tunneling environment of Shenzhen Metro Line 6 is shown in a case study. Comparisons between Fuzzy Analytic Hierarchy Process (FAHP) methods are further discussed according to results. The proposed evaluation method is verified to be more competitive as the fuzziness and randomness of uncertainties in the risk assessment system can be considered comprehensively. This method can serve as a decision-making tool for other similar project risk assessment methods to increase the likelihood of a successful project in an uncertain environment

Y.: Parallelized annealed particle filter for realtime marker-less motion tracking via heterogeneous computing

Abstract We propose a parallelized Annealed Particle Filter method via heterogeneous computing (P-APF), to implement real-time marker-less motion tracking based on OpenCL framework. The overall computing procedure in P-APF is decomposed into several computational tasks with corresponding granularity. According to the degree of parallelism, the tasks are assigned to standard and attached processors respectively, to fully leverage heterogeneous computing ability. A task latency hidden strategy is used to further reduce time cost. Experiments on different human motion datasets demonstrate that P-APF can achieve real-time tracking performance without losing accuracy. With an average acceleration ratio of 106 compared to serial implementation, the time cost basically remains constant with the growth of particle number and view number in a limited range

Stability Analysis of TBM Tunnel Undercrossing Existing High-Speed Railway Tunnel: A Case Study from Yangtaishan Tunnel of Shenzhen Metro Line 6

During the construction of the underpass of a new tunnel, the excavation unloading effect disturbs surrounding rock masses and promotes surrounding rock deformation, inevitably changing stress and displacement in the existing tunnel. Taking Yangtaishan tunnel excavation of Shenzhen Metro Line 6 as an engineering example, effects of excavation programs of left and right lines on the deformation characteristics of newly excavated and existing tunnels were evaluated based on Midas numerical model and priority excavation advantages of the left line were determined. The settlement and horizontal deformation characteristics of the existing tunnel were analyzed using the construction monitoring method. Results showed that maximum settlement and horizontal deformation of the existing tunnel were 1.35 and 0.23 mm, respectively. Settlement of invert and inverted top along axis direction was from growth to decline, and then a V-shaped settlement trough was formed with maximum settlement values of 1.36 and 0.97 mm, respectively. Maximum settlement and uplift of the newly built tunnel appeared on the upper and bottom parts of invert, respectively. In the newly built tunnel segments, the top settlement was dominated and deformation was mainly distributed in both side areas. At the top of the existing tunnel segment, convergence settlement was 3.09 mm and settlement rate was slow first which was accelerated, then stabilized, and finally slowed down again which was opposite to the uplift development trend of the bottom of tunnel segment. The top of the existing tunnel segment showed four settlement stages, slow, rapid, stable, and slow settlement stages. Compared with the right line, preferential excavation of the left line had obvious advantages in terms of tunnel stability. The unloading effect of TBM excavation created vault settlement in the existing tunnels where actual settlement values were 1.12 and 1.13 times, which theoretically calculated settlement. The horizontal deformation of the existing tunnel was varied first linearly and then nonlinearly with maximum deformation in the convergence stage of 1.47 mm

Hydrothermal Synthesis and Structural Characterization of NiO/SnO2 Composites and Hydrogen Sensing Properties

Pure SnO2 and NiO doped SnO2 nanostructures were successfully synthesized via a simple and environment-friendly hydrothermal method. X-ray powder diffraction (XRD), scanning electron microscopy (SEM), energy dispersive X-ray spectroscopy (EDS), and X-ray photoelectron spectra (XPS) were used to investigate the crystalline structures, surface morphologies and microstructures, and element components and their valences of the as-synthesized samples. Furthermore, planar chemical gas sensors based on the synthesized pure SnO2 and NiO/SnO2 composites were fabricated and their sensing performances to hydrogen, an important fault characteristic gas dissolved in power transformer oil, were investigated in detail. Gas sensing experiments indicate that the NiO/SnO2 composites showed much higher gas response and lower working temperature than those of pure SnO2, which could be ascribed to the formation of p-n heterojunctions between p-type NiO and n-type SnO2. These results demonstrate that the as-synthesized NiO/SnO2 composites a promising hydrogen sensing material

Efficiency analysis of sorption-enhanced method in steam methane reforming process

The sorption-enhanced method can change the thermodynamic equilibrium by absorbing CO2. However, it also brings about the problems of high regeneration temperature of adsorbent and large regeneration energy consumption. In order to study the impact of enhanced adsorption methods on the overall energy cost of the system in the hydrogen production process, this paper analyzes and compares steam methane reforming and reactive adsorption-enhanced steam methane reforming with the energy consumption of hydrogen production products as the evaluation index. The results showed that the energy consumption per unit hydrogen production decreased from 276.21 MJ/kmol to 131.51 MJ/kmol, and the decomposition rate of H2O increased by more than 20% after the addition of adsorption enhancement method. It is proved that the advantage of sorption enhanced method on pre-separation of CO2 in the product makes up for the disadvantage of energy consumption of adsorbent regeneration. In addition, the ability of the process to obtain H element is improved by the high decomposition rate of H2O, which realizes a more rational distribution of the element

TG-FTIR study catalytic effect of inherent metal salt on biomass pyrolysis

The raw rice straw and leached with deionized water and hydrochloric acid were studied using the method of thermogravimetric(TG) coupled with Fourier transform infrared spectrometry(FTIR) to investigate the catalytic effect of inherent metal salt during biomass pyrolysis. The results indicated alkali metals promoted decomposition reaction comparing to alkaline earth metals especially Ca hindered the reaction. The releasing gas was detected online by FTIR. The main products were CO2, CO, H2O, CH4 and some volatilizable organics contained C=O and C-O-C functional groups. Compared with raw sample, the yield of CO2, CO decreased, CH4 and some volatilizable organics increased after water leaching, all product gas of acid leaching sample were remarkable less than other two samples, which were related with the different catalytic effects of alkali and alkaline earth metals

Inhibition of LPS-Induced Skin Inflammatory Response and Barrier Damage via MAPK/NF-κB Signaling Pathway by <i>Houttuynia cordata</i> Thunb Fermentation Broth

Houttuynia cordata Thunb is rich in active substances and has excellent antioxidant and anti-inflammatory activity. Scanning electron microscopy and gel permeation chromatography were used to analyze the molecular characteristics of the fermentation broth of Houttuynia cordata Thunb obtained through fermentation with Clavispora lusitaniae (HCT-f). The molecular weight of HCT-f was 2.64265 × 105 Da, and the polydispersity coefficient was 183.10, which were higher than that of unfermented broth of Houttuynia cordata Thunb (HCT). By investigating the active substance content and in vitro antioxidant activity of HCT-f and HCT, the results indicated that HCT-f had a higher active substance content and exhibited a superior scavenging effect on 2,2-diphenyl-1-picrylhydrazyl radicals and hydroxyl radicals, with IC50 values of 11.85% and 9.01%, respectively. Our results showed that HCT-f could effectively alleviate the increase in the secretion of inflammatory factors and apoptotic factors caused by lipopolysaccharide (LPS) stimulation, and had a certain effect on repairing skin barrier damage. HCT-f could exert an anti-inflammatory effect by down-regulating signaling in the MAPK/NF-κB pathway. The results of erythrocyte hemolysis and chicken embryo experiments showed that HCT-f had a high safety profile. Therefore, this study provides a theoretical basis for the application of HCT-f as an effective ingredient in food and cosmetics

Lactobacillus plantarum fermented Laminaria japonica alleviates UVB-induced epidermal photoinflammation via the Keap-1/Nrf2 pathway

UVB-induced human immortal keratinocyte (HaCaT) cell damage model was established to investigate the mitigating effect of Laminaria japonica Lactobacillus plantarum subsp. plantarum fermentation broth (LJf) on epidermal photoinflammation and barrier function impairment. Compared to unfermented Laminaria japonica (LJ), LJf contains higher levels of potent substances, as well as stronger in vitro antioxidant activity. LJf is able to scavenge excessive reactive oxygen species (ROS) and increase intracellular antioxidant enzyme content and synthesis levels. We also find that LJf is superior to LJ in inhibiting the release of ILs, TNF-α and MMP-9. LJf also increased the synthesis level of barrier function proteins and decreased the secretion level of Kallikrein-7 (KLK-7), effectively alleviating the level of inflammation, abnormal cell shedding, and impaired barrier function in the epidermis. LJf can inhibit the transcription levels of downstream regulators and inflammatory factors by activating the Nrf2 signaling pathway. Safety experiments reveal that LJf is non-irritating