131 research outputs found
Ionic Liquids as Electrodeposition Additives and Corrosion Inhibitors
Ionic liquids (ILs) are molten salts with a melting point of 100Ā°C or below and solely consist of cations and anions. As a kind of novel green solvent, ILs have been obtained broad and deep investigations, and enormous progresses in various fields have been made during the recent 20 years. Despite the fact that the application studies of ILs have been proposed in various fields, no processes have yet been developed to an industrial scale. However, the main interests are still focused on their industrial applications. In this chapter, two perspective applications of ILs in electrochemical fields including additives for metal electrodeposition and inhibitors for metal anti-corrosion were introduced
Toxinogenicity of Helicobacter pylori in the pathogenesis of chronic gastritis and peptic ulcer and the nature of the host's immune responses
Despite the widespread recognition of the role of H. pylori infection in chronic gastritis and peptic ulceration, the mechanisms by which the bacterium induces mucosal damage and the apparent different outcome in infected patients are still not well understood. It has been suggested that the toxinogenicity of H. pylori and the host response may be important in these respects. Neutrophil function is an important host defence mechanism against microbial infection. It provides a major soiirce of reactive oxygen metabolites which are known to cause tissue damage. H. pylori has been shown to activate neutrophils and there are variations among H. pylori strains in the neutrophil activating activity. It is not known if cytotoxin-producing strains of H. pylori are associated with the generation of an oxidative burst in neutrophils. This has been investigated in this thesis. Cytotoxin positive strains of H. pylori displayed an enhanced induction of the oxidative burst in non-opsonised neutrophils compared to toxin negative strains from patients with chronic gastritis only. However, some non-cytotoxin-producing strains also induced a significant neutrophil oxidative burst, suggesting that some component(s) other than cytotoxin itself may be responsible for the induction of the neutrophil oxidative burst. Nevertheless the finding that cytotoxin-producing strains of H. pylori induced an enlianced neutrophil respiratory burst may suggest that the neutrophil activating property may be more strongly expressed in most toxinogenic strains of H. pylori. The ability of some strains of H. pylori to produce cytotoxin and to induce the oxidative burst in neutrophils may be important in the pathogenesis of peptic ulcer disease. Subsequent study investigated the possible component(s) of H. pylori which induces the neutrophil oxidative burst. It was found that soluble products of H. pylori could activate neutrophils to release ROM and more than one bacterial product may be involved in the activation of neutrophils. The results also showed that the neutrophil activating activity was destroyed by proteinase K, suggesting that the active components are mainly proteins. Cytotoxin and urease containing fractions from chromatography did not induce a significant CL response, suggesting that the cytotoxin and/or urease are not the active components for the neutrophil activation. In vitro studies have suggested that toxinogenic strains of H. pylori, which possess CagA(cytotoxin-associated protein) and/or VacA(vacuolating cytotoxin), may induce a more potent inflammatory response, evidenced by an enhanced induction of interleukin 8(IL-8) and neutrophil oxidative burst. It is unclear whether there is any relationship between in vivo mucosal production of IL-8 and neutrophil-derived reactive oxygen metabolites(ROM) release and whether mucosal levels of IL-8 and ROM are increased in those patients infected with toxinogenic strains. It has been shown in this thesis that there is a good correlation between IL-8 concentration and ROM release in antral gastric mucosa. This suggests that local mucosal production of IL-8 in response to H. pylori infection does occur in vivo and may play an important role in attracting and activating phagocytes to release ROM. (Abstract shortened by ProQuest.)
A novel method to enhance the sensitivity for two-degrees-of-freedom straightness measurement
A low cost and high precision system which can measure two-degrees-of-freedom straightness simultaneously is proposed based on a laser collimator. In the system, a miniature fiber coupled diode laser generates a collimating beam. The sensitivity of the straightness error measurement is magnified by a factor of 4 compared with the lateral movement of the retro-reflector itself after the multi-reflections. A Renishaw ML10 laser interference measurement system was used to verify the developed system in a series of experiments in the laboratory environment. Experimental results agree with the expected results. The two-dimensional straightness error measurement had linear correlativity close to 1 and the standard one-to-one deviation error was better than 0.32 Āµm obtained over a travel range of 600 Āµm.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/58131/2/mst7_12_014.pd
Carbon-based polymer nanocomposite for high-performance energy storage applications
In recent years, numerous discoveries and investigations have been remarked for the development of carbon-based polymer nanocomposites. Carbon-based materials and their composites hold encouraging employment in a broad array of fields, for example, energy storage devices, fuel cells, membranes sensors, actuators, and electromagnetic shielding. Carbon and its derivatives exhibit some remarkable features such as high conductivity, high surface area, excellent chemical endurance, and good mechanical durability. On the other hand, characteristics such as docility, lower price, and high environmental resistance are some of the unique properties of conducting polymers (CPs). To enhance the properties and performance, polymeric electrode materials can be modified suitably by metal oxides and carbon materials resulting in a composite that helps in the collection and accumulation of charges due to large surface area. The carbon-polymer nanocomposites assist in overcoming the difficulties arising in achieving the high performance of polymeric compounds and deliver high-performance composites that can be used in electrochemical energy storage devices. Carbon-based polymer nanocomposites have both advantages and disadvantages, so in this review, attempts are made to understand their synergistic behavior and resulting performance. The three electrochemical energy storage systems and the type of electrode materials used for them have been studied here in this article and some aspects for example morphology, exterior area, temperature, and approaches have been observed to influence the activity of electrochemical methods. This review article evaluates and compiles reported data to present a significant and extensive summary of the state of the art
Graphitic carbon nitride doped copperāmanganese alloy as highāperformance electrode material in supercapacitor for energy storage
Here, we report the synthesis of copperāmanganese alloy (CuMnO2) using graphitic carbon nitride (gCN) as a novel support material. The successful formation of CuMnO2-gCN was confirmed through spectroscopic, optical, and other characterization techniques. We have applied this catalyst as the energy storage material in the alkaline media and it has shown good catalytic behavior in supercapacitor applications. The CuMnO2-gCN demonstrates outstanding electrocapacitive performance, having high capacitance (817.85 AĀ·gā1) and well-cycling stability (1000 cycles) when used as a working electrode material for supercapacitor applications. For comparison, we have also used the gCN and Cu2O-gCN for supercapacitor applications. This study proposes a simple path for the extensive construction of self-attaining double metal alloy with control size and uniformity in high-performance energy-storing material
MCS: Multi-Target Masked Point Modeling with Learnable Codebook and Siamese Decoders
Masked point modeling has become a promising scheme of self-supervised
pre-training for point clouds. Existing methods reconstruct either the original
points or related features as the objective of pre-training. However,
considering the diversity of downstream tasks, it is necessary for the model to
have both low- and high-level representation modeling capabilities to capture
geometric details and semantic contexts during pre-training. To this end,
MCS is proposed to enable the model with the above abilities. Specifically,
with masked point cloud as input, MCS introduces two decoders to predict
masked representations and the original points simultaneously. While an extra
decoder doubles parameters for the decoding process and may lead to
overfitting, we propose siamese decoders to keep the amount of learnable
parameters unchanged. Further, we propose an online codebook projecting
continuous tokens into discrete ones before reconstructing masked points. In
such way, we can enforce the decoder to take effect through the combinations of
tokens rather than remembering each token. Comprehensive experiments show that
MCS achieves superior performance at both classification and segmentation
tasks, outperforming existing methods
Ionic liquid-based polymer nanocomposites for sensors, energy, biomedicine and environmental applications:Roadmap to the future
Current interest toward ionic liquids (ILs) stems from some of their novel characteristics, like low vapor pressure, thermal stability, and nonflammability, integrated through high ionic conductivity and broad range of electrochemical strength. Nowadays, ionic liquids represent a new category of chemicalābased compounds for developing superior and multifunctional substances with potential in several fields. ILs can be used in solvents such as salt electrolyte and additional materials. By adding functional physiochemical characteristics, a variety of ILābased electrolytes can also be used for energy storage purposes. It is hoped that the present review will supply guidance for future research focused on ILābased polymer nanocomposites electrolytes for sensors, high performance, biomedicine, and environmental applications. Additionally, a comprehensive overview about the polymerābased compositesā ILs components, including a classification of the types of polymer matrix available is provided in this review. More focus is placed upon ILsābased polymeric nanocomposites used in multiple applications such as electrochemical biosensors, energyārelated materials, biomedicine, actuators, environmental, and the aviation and aerospace industries. At last, existing challenges and prospects in this field are discussed and concluding remarks are provided
Direct Signal Detection Without DataāAided: A MIMO Functional Network Approach
Functional network (FN) has been successfully applied in many fields, but so far no methods of direct signal detection (DSD) using FN have been published. In this chapter, a novel DSD approach using FN, which can be applied to cases with a plural source signal sequence, with short sequence, and even with the absence of a training sequence, is presented. Firstly, a multipleāinput multipleāoutput FN (MIMOFN), in which the initial input vector is devised via QR decomposition of the receiving signal matrix, is constructed to solve the special issues of DSD. In the meantime, the design method for the neural function of this special MIMOFN is proposed. Then the learning rule for the parameters of neural functions is trained and updated by backāpropagation (BP) algorithm. The correctness and effectiveness of the new approach are verified by simulation results, together with some special simulation phenomena of the algorithm. The proposed method can detect the source sequence directly from the observed output data by utilizing MIMOFN without a training sequence and estimating the channel impulse response
Electrocatalysts for electrooxidation of direct alcohol fuel cell: Chemistry and applications
In the present scenario, civilization wholly depends on energy generation and storage for better technological progress and extension in several scientific applications. Owing to limited conventional energy sources and high energy requirement, absolute, cost-effective, and eco-friendly substitute roots of energy are of the principal interest. In this direction, direct alcohol fuel cell is becoming more familiar and promising because of its straightforward configuration system, weight, and elevated power generation efficiency. Indeed, recent years have seen extensive research on the preparation and properties of the fuel cell system. The literature review presented in this article provides comprehensive information on electrooxidation of alcohol developed on different type of electrocatalyst. The integration of a range of nanomaterials is depicted to comprehend the effect of different properties such as a well-ordered porous structure, exemplary high specific surface areas, electronic conductivity, tremendous convenience to active sites, and improved mass transport for electrooxidation of fuel cell. In this article, we have presented a detailed review of fuel cells and defined the main perspective, rationale and motivation, research tasks, and objectives of study as well as the delimitation of the study
- ā¦