A study on the liquid length and flame lift-off length for Hydrogenated Catalytic Biodiesel/Diesel blended fuel in a constant volume combustion chamber

( Zhixia He ),( Weiwei Shang ),( Qian Wang ),( Xianyin Leng ),( Wenjun Zhong ),( Jiawei Cao ),( Bei Li ) 한국액체미립화학회 2017 한국액체미립화학회 학술강연회 논문집 Vol.2017 No.-

The spray and combustion process is the fundamental factors affecting performance and emission of diesel engine, while the physicochemical properties of the fuel directly determine the spray combustion characteristics. The renewable and clean alternative fuel, which showed great potential of energy saving and emission reduction, makes studying on the influence of fuel physicochemical properties on the spray combustion characteristics very essential. In this paper, the effects of fuel physical and chemical properties on the spray combustion characteristics of diesel engine were studied by using mixed fuel with the catalytic hydrogenation biodiesel and diesel in constant volume combustion chamber. The effects of fuel physicochemical properties on the liquid length (LL) under combustion and evaporation conditions were studied based on the laser Mie scattering technic. The results showed that the LL under combustion conditions is shorter than the LL under evaporation conditions, and the difference became little when the ambient density is higher. In addition, the LL under combustion conditions decreases with the increase of fuel density and ambient temperature, while the ambient oxygen concentration and injection pressure have little effect on the LL. By using laser Mie scattering technology and chemical fluorescence visualization method innovatively, the LL under combustion and lift-off flame (LOL) was studied simultaneously, studying the interaction between them showed that the combustion LL and LOL can be in a stable state simultaneously with the injection duration long enough. With the increase of ambient density and ambient temperature, the LOL and LL decreases, the influence of ambient temperature on the LOL is greater than the effect on the LL. For the conditions where the combustion LL is shorter than the LOL, there will be more interspace for the mixing of air and fuel, and the fuel vaporization has completed before the fuel reaches the combustion region. For the conditions where the LL is longer than the LOL, there will be an overlap between liquid phase and combustion flame. The flame and liquid phase will interact with each other at these conditions. The vaporization of the liquid fuel is enhanced by the heat of the combustion and the combustion rate is reduced by the vaporization cooling. In addition, with the increase of cetane number of fuel density, the difference between LOL and liquid length became smaller and the decrease of LOL is greater than the decrease of LL. The physical and chemical properties of fuel have little effect on the difference between LOL and LL, when the injection pressure is low and the ambient oxygen concentration is high.

Multi-modal Medical Image Fusion Based on Non-subsampled Shearlet Transform

Xing Xiaoxue,Cao Fucheng,Shang Weiwei,Liu Fu 보안공학연구지원센터 2015 International Journal of Signal Processing, Image Vol.8 No.2

In order to provide more comprehensive and effective information for cancer diagnosis and tumor treatment planning, it is necessary to fuse multi-modal medical images, such as CT/MRI image, CT/PET image, MRI/SPECT image and so on. In this paper, a multi-modal medical image fusion method based on Non-subsampled Shearlet Transform is proposed. Firstly, in this method, source images are decomposed into low-pass and high-pass subbands by NSST. Then, due to the characteristic features--large sparsity and strong contrast, the high-frequency and low-frequency coefficients of the images are fused by the different fusion rules. Finally, the image is reconstructed by the inverse non-sampled shearlet transform. In the method, the fusion rules are designed based on the regional energy and the average gradient; the image entropy, relative quality, average gradient, standard deviation and spatial frequency were used to evaluate the fusion results objectively. In the experiments, CT and MRI images are chosen to verify the method. Both the visual and the objective analysis show that the proposed method is better than the conventional Wavelet-based and non-subsampled Contourlet-based methods.

Effect of Crude Protein Levels in Concentrate and Concentrate Levels in Diet on In vitro Fermentation

Dung, Dinh Van,Shang, Weiwei,Yao, Wen Asian Australasian Association of Animal Productio 2014 Animal Bioscience Vol.27 No.6

The effect of concentrate mixtures with crude protein (CP) levels 10%, 13%, 16%, and 19% and diets with roughage to concentrate ratios 80:20, 60:40, 40:60, and 20:80 (w/w) were determined on dry matter (DM) and organic matter (OM) digestibility, and fermentation metabolites using an in vitro fermentation technique. In vitro fermented attributes were measured after 4, 24, and 48 h of incubation respectively. The digestibility of DM and OM, and total volatile fatty acid (VFA) increased whereas pH decreased with the increased amount of concentrate in the diet (p<0.001), however CP levels of concentrate did not have any influence on these attributes. Gas production reduced with increased CP levels, while it increased with increasing concentrate levels. Ammonia nitrogen ($NH_3$-N) concentration and microbial CP production increased significantly (p<0.05) by increasing CP levels and with increasing concentrate levels in diet as well, however, no significant difference was found between 16% and 19% CP levels. Therefore, 16% CP in concentrate and increasing proportion of concentrate up to 80% in diet all had improved digestibility of DM and organic matter, and higher microbial protein production, with improved fermentation characteristics.

pH/Temperature Responsive Curcumin-Loaded Micelle Nanoparticles Promote Functional Repair after Spinal Cord Injury in Rats via Modulation of Inflammation

Qian Taibao,Li Zhixiang,Shang Lijun,Huang Sutao,Li Guanglin,Zheng Weiwei,Mao Yingji 한국조직공학과 재생의학회 2023 조직공학과 재생의학 Vol.20 No.6

BACKGROUND: The formation of an inhibitory inflammatory microenvironment after spinal cord injury (SCI) remains a great challenge for nerve regeneration. The poor local microenvironment exacerbates nerve cell death; therefore, the reconstruction of a favorable microenvironment through small-molecule drugs is a promising strategy for promoting nerve regeneration. METHODS: In the present study, we synthesized curcumin-loaded micelle nanoparticles (Cur-NPs) to increase curcumin bioavailability and analyzed the physical and chemical properties of Cur-NPs by characterization experiments. We established an in vivo SCI model in rats and examined the ability of hind limb motor recovery using Basso–Beattie– Bresnahan scoring and hind limb trajectory assays. We also analyzed neural regeneration after SCI using immunofluorescence staining. RESULTS: The nanoparticles achieved the intelligent responsive release of curcumin while improving curcumin bioavailability. Most importantly, the released curcumin attenuated local inflammation by modulating the polarization of macrophages from an M1 pro-inflammatory phenotype to an M2 anti-inflammatory phenotype. M2-type macrophages can promote cell differentiation, proliferation, matrix secretion, and reorganization by secreting or expressing pro-repair cytokines to reduce the inflammatory response. The enhanced inflammatory microenvironment supported neuronal regeneration, nerve remyelination, and reduced scar formation. These effects facilitated functional repair in rats, mainly in the form of improved hindlimb movements. CONCLUSION: Here, we synthesized pH/temperature dual-sensitive Cur-NPs. While improving the bioavailability of the drug, they were also able to achieve a smart responsive release in the inflammatory microenvironment that develops after SCI. The Cur-NPs promoted the regeneration and functional recovery of nerves after SCI through anti-inflammatory effects, providing a promising strategy for the repair of SCIs.

An Image Fusion Algorithm Based on Non-subsampled Shearlet Transform and Compressed Sensing

XING Xiaoxue,LI Jie,FAN Qinyin,SHANG Weiwei 보안공학연구지원센터 2016 International Journal of Signal Processing, Image Vol.9 No.3

In order to obtain rapid fusion speed, an image fusion algorithm based on Non-subsampled Shearlet Transform (NSST) and Compressed Sensing (CS) is presented. The source images are decomposed with NSST. Based on local area energy, the low-frequency coefficients are fused. The high-frequency coefficients are compressed, fused and reconstructed with CS. Based on global gradient, the measurements of high-frequency coefficients are fused. The inverse NSST is used to get the final fused image. During the fusion course, only the compressed data of the high-frequency coefficients are fused, so the fusion effects can’t be affected. At the same time, the running time can be reduced. In this paper, the multi-focus images are used to verify the algorithm effectiveness. The simulation results indicate that the fusion image can be achieved without prior knowledge of the original images. Although the fusion quality is sacrificed when the sampling rate becomes higher, the algorithm can significantly reduce the time cost and hardware requirements. The algorithm provides an idea on how to satisfy the real time requirements in the fusion system.