Hydrogen production by sorption-enhanced steam reforming of glycerol

Catalytic steam reforming of glycerol for H(2) production has been evaluated experimentally in a continuous flow fixed-bed reactor. The experiments were carried out under atmospheric pressure within a temperature range of 400-700 degrees C. A commercial Ni-based catalyst and a dolomite sorbent were used for the steam reforming reactions and in situ CO(2) removal. The product gases were measured by on-line gas analysers. The results show that H(2) productivity is greatly increased with increasing temperature and the formation of methane by-product becomes negligible above 500 degrees C. The results suggest an optimal temperature of approximately 500 degrees C for the glycerol steam reforming with in situ CO(2) removal using calcined dolomite as the sorbent, at which the CO(2) breakthrough time is longest and the H(2) purity is highest. The shrinking core model and the 1D-diffusion model describe well the CO(2) removal under the conditions of this work

Lead halide perovskite nanowires stabilized by block copolymers for Langmuir-Blodgett assembly

The rapid development of solar cells based on lead halide perovskites (LHPs) has prompted very active research activities in other closely-related fields. Colloidal nanostructures of such materials display superior optoelectronic properties. Especially, one-dimensional (1D) LHPs nanowires show anisotropic optical properties when they are highly oriented. However, the ionic nature makes them very sensitive to external environment, limiting their large scale practical applications. Here, we introduce an amphiphilic block copolymer, polystyrene-block-poly(4-vinylpyridine) (PS-P4VP), to chemically modify the surface of colloidal CsPbBr3 nanowires. The resulting core-shell nanowires show enhanced photoluminescent emission and good colloidal stability against water. Taking advantage of the stability enhancement, we further applied a modified Langmuir-Blodgett technique to assemble monolayers of highly aligned nanowires, and studied their anisotropic optical properties. [Figure not available: see fulltext.]

Source-Relaxed Domain Adaptation for Image Segmentation

Domain adaptation (DA) has drawn high interests for its capacity to adapt a model trained on labeled source data to perform well on unlabeled or weakly labeled target data from a different domain. Most common DA techniques require the concurrent access to the input images of both the source and target domains. However, in practice, it is common that the source images are not available in the adaptation phase. This is a very frequent DA scenario in medical imaging, for instance, when the source and target images come from different clinical sites. We propose a novel formulation for adapting segmentation networks, which relaxes such a constraint. Our formulation is based on minimizing a label-free entropy loss defined over target-domain data, which we further guide with a domain invariant prior on the segmentation regions. Many priors can be used, derived from anatomical information. Here, a class-ratio prior is learned via an auxiliary network and integrated in the form of a Kullback-Leibler (KL) divergence in our overall loss function. We show the effectiveness of our prior-aware entropy minimization in adapting spine segmentation across different MRI modalities. Our method yields comparable results to several state-of-the-art adaptation techniques, even though is has access to less information, the source images being absent in the adaptation phase. Our straight-forward adaptation strategy only uses one network, contrary to popular adversarial techniques, which cannot perform without the presence of the source images. Our framework can be readily used with various priors and segmentation problems

A YOLOV8-based approach for steel plate surface defect detection

Hot-rolled steel strips are a commonly used product in both production and daily life. However, the manufacturing process inevitably leads to the occurrence of surface defects. To solve this problem, Our method uses YOLOV8 and squeeze-and-excitation (SE) attention mechanism to detect surface defects in hot-rolled steel strips. Our method balances accuracy and real-time performance, while detecting four common surface defects. The method has an average accuracy of 90,9 % and a maximum accuracy of 98,5 % for detecting a single category of surface defects. Experimental results confirm good performance of our proposed method in classifying and localizing surface defects in hot-rolled steel strips, and has the potential for broad application and promotion

A YOLOV8-based approach for steel plate surface defect detection

Hot-rolled steel strips are a commonly used product in both production and daily life. However, the manufacturing process inevitably leads to the occurrence of surface defects. To solve this problem, Our method uses YOLOV8 and squeeze-and-excitation (SE) attention mechanism to detect surface defects in hot-rolled steel strips. Our method balances accuracy and real-time performance, while detecting four common surface defects. The method has an average accuracy of 90,9 % and a maximum accuracy of 98,5 % for detecting a single category of surface defects. Experimental results confirm good performance of our proposed method in classifying and localizing surface defects in hot-rolled steel strips, and has the potential for broad application and promotion

Incipient Separation in Shock Wave Boundary Layer Interactions as Induced by Sharp Fin

The incipient separation induced by the shock wave turbulent boundary layer interaction at the sharp fin is the subject of present study. Existing theories for the prediction of incipient separation, such as those put forward by McCabe (1966) and Dou and Deng (1992), can have thus far only predicting the direction of surface streamline and tend to over-predict the incipient separation condition based on the Stanbrook's criterion. In this paper, the incipient separation is firstly predicted with Dou and Deng (1992)'s theory and then compared with Lu and Settles (1990)' experimental data. The physical mechanism of the incipient separation as induced by the shock wave/turbulent boundary layer interactions at sharp fin is explained via the surface flow pattern analysis. Furthermore, the reason for the observed discrepancy between the predicted and experimental incipient separation conditions is clarified. It is found that when the wall limiting streamlines behind the shock wave becomes\ aligning with one ray from the virtual origin as the strength of shock wave increases, the incipient separation line is formed at which the wall limiting streamline becomes perpendicular to the local pressure gradient. The formation of this incipient separation line is the beginning of the separation process. The effects of Reynolds number and the Mach number on incipient separation are also discussed. Finally, a correlation for the correction of the incipient separation angle as predicted by the theory is also given.Comment: 34 pages; 9 figure

Improving successful rate of transcranial electrical motor-evoked potentials monitoring during spinal surgery in young children

Introduction This prospective study was to investigate the successful rate of intraoperative motor evoked potentials (MEP) monitoring for children (0.05). As well, no difference in MEP successful rates was observed in two groups with different anesthetic techniques. No wake-up test and no post-operative neurological deficits occurred in this series of patients. Conclusion Low dose anesthesia by either TIVA with propofol or sevoflurane-based mixture anesthesia protocol can help the intraoperative spinal cord monitoring to successfully elicit MEP and perform reliable monitoring for patients below 12 years of age. © 2011 Springer-Verlag.published_or_final_versio

Effects of various forms of lipopolysaccharide on the expression of inflammatory mediators and cardiac biomarkers in human cardiac fibroblasts and human coronary smooth muscle cells

Inflammation is an important event in the development of vascular diseases such as hypertension, atherosclerosis, and restenosis. The stimulation of lipopolysaccharide (LPS) from bacteria induces the release of critical proinflammatory cytokines that activate potent immune responses which may cause injury of cells in vivo and in vitro. Upon cardiac cell death caused by inflammation, the apoptotic cardiac cells express higher amount of cardiac markers. In this study, the effect of various LPS on human cardiac fibroblasts (HCFs) and human coronary smooth muscle cells (HCSMCs) were evaluated. Various forms of LPS were applied to HCFs and HCSMCs for 24, 48, 72 and 96 h. Proliferation rate of these cells was evaluated after stimulation. The levels of lactate dehydrogenase (LDH), N-terminal pro B-type natriuretic peptide (pro-BNP) and the MB isoenzyme of creatine kinase (CK-MB) were measured by an automation system. Cytokine levels in culture supernatants and extracted protein of cells were mixed and measured with IL-1β, IL-6 and IL-10 ELISA kits. Significant increase in the proliferation of two cardiac cells (P<0.05) after incubation for 48 and 72 h was noted but not for 24 and 96 h (P>0.05). Cardiac markers and inflammatory cytokines were significantly higher than control at 48 and 72 h (P<0.05), which demonstrated that HCFs and HCMSCs were under inflammation leading to cell injury between 48 and 72 h. LPS is one of the factors giving rise to periodontal diseases, it is also involved in in vitro cardiac cell injury. Therefore, LPS may be used as a bio-marker to monitor local or systemic inflammation.Key words: Lipopolysaccharide, human cardiac fibroblasts, human coronary smooth muscle cell, inflammatory cytokines, cardiac bio-marker

Superconductivity, critical current density, and flux pinning in MgB_{2-x}(SiC)_{x/2} superconductor after SiC nanoparticle doping

We investigated the effect of SiC nano-particle doping on the crystal lattice structure, critical temperature T_c, critical current density J_c, and flux pinning in MgB_2 superconductor. A series of MgB_{2-x}(SiC)_{x/2} samples with x = 0 to 1.0 were fabricated using in-situ reaction process. The contraction of the lattice and depression of T_c with increasing SiC doping level remained rather small due to the counter-balanced effect of Si and C co-doping. The high level Si and C co-doping allowed the creation of intra-grain defects and highly dispersed nano-inclusions within the grains which can act as effective pinning centers for vortices, improving J_c behavior as a function of the applied magnetic field. The enhanced pinning is mainly attributable to the substitution-induced defects and a local structure fluctuations within grains. A pinning mechanism is proposed to account for different contributions of different defects in MgB_{2-x}(SiC)_{x/2} superconductors.Comment: 7 pages, 8 figure