120 research outputs found

    Evaluation Of Feasibility And Performance Of Foamed Fire-Resistant Coating Materials

    Get PDF
    A preliminary study found high-performance cement mortar, geopolymer mortar, and magnesium phosphate cement mortar (MPCM) have the potential as new fire-resistant materials. In this study, foam was added to these three fire-resistant materials to further improve their rheological, mechanical, and fire-resistant performance and reduce costs. Systematic design and experimental programs were conducted. The results showed the addition of foam enhanced workability, adhesiveness, and fire resistance, allowing the materials to withstand higher temperatures and further delay heat transfer. A mixture of 70% MPCM and 30% foam was identified as the optimum design, which could withstand 1000 °C with low heat transfer rates

    An Experimental Study on Attribute Validity of Code Quality Evaluation Model

    Get PDF
    Regarding the practicality of the quality evaluation model, the lack of quantitative experimental evaluation affects the effective use of the quality model, and also a lack of effective guidance for choosing the model. Aiming at this problem, based on the sensitivity of the quality evaluation model to code defects, a machine learning-based quality evaluation attribute validity verification method is proposed. This method conducts comparative experiments by controlling variables. First, extract the basic metric elements; then, convert them into quality attributes of the software; finally, to verify the quality evaluation model and the effectiveness of medium quality attributes, this paper compares machine learning methods based on quality attributes with those based on text features, and conducts experimental evaluation in two data sets. The result shows that the effectiveness of quality attributes under control variables is better, and leads by 15% in AdaBoostClassifier; when the text feature extraction method is increased to 50 - 150 dimensions, the performance of the text feature in the four machine learning algorithms overtakes the quality attributes; but when the peak is reached, quality attributes are more stable. This also provides a direction for the optimization of the quality model and the use of quality assessment in different situations

    Time-resolved reflectance measurements on layered tissues with strongly varying optical properties

    Get PDF
    Most biological tissues consist of layers with different optical properties. A few examples are the skin, the esophagus, the stomach and the wall of arteries. An understanding of how the light propagates in such layered systems is a prerequisite for any light based therapy or diagnostic scheme. In this study we investigate the influence of different kinds of layers on time resolved reflectance measurements. Experiments were performed on layered gel phantoms and the results compared to Monte Carlo simulations and diffusion theory. It is shown that when a low absorbing medium is situated on top of a high absorbing medium, the absorption coefficient of the lower layer is accessible if the differences in the absorption coefficient are only small. In the case of large difference the optical properties of the upper layer dominate the signal and shield information on the lowest layer. The degree of this shielding effect depends on layer thickness as well as optical properties. In the case of an almost absorption and scattering free layer in between two normal tissues, an overall increase of the signal is visible. However, the overall shape of the curve is about preserved. The apparent scattering coefficient is slightly decreased, while the apparent absorption coefficient is unaltered

    Near-infrared spectroscopy of a heterogeneous turbid system containing distributed absorbers

    Get PDF
    In most biological tissues, absorbers such as blood in the blood vessels are localized within a low-absorbing background medium. To study the effect of distributed absorbers on the near infrared reflectance, we developed a Monte Carlo code and performed time-domain measurements on heterogeneous tissue-vessel models. The models were made of low absorbing polyester resin mixed with TiO_2 as scatters. A series of tubes with diameters of 3.2 or 6.4 mm were made in the resin sample. The volume ratio of the tubes to the total sample is about 20%. During the measurement, these tubes were filled with turbid fluids with different absorption coefficients to simulate blood in various oxygenation states. We found that the apparent absorption coefficient of the resin/tube system, determined by using the diffusion equation fit, can be approximated by a volume-weighted sum of the absorption coefficients of the different absorbing components. This approximation has to be replaced by a more complex expression if the difference in absorption between the absorbers and background is very large (approximately 20 times). The results of the tissue phantom study are supported by the Monte Carlo simulation. Possible explanations for the photon migration in this kind of heterogeneous system is also presented

    Determination of blood oxygenation in the brain by time-resolved reflectance spectroscopy: influence of the skin, skull, and meninges

    Get PDF
    Near infrared light has been used for the determination of blood oxygenation in the brain but little attention has been paid to the fact that the states of blood oxygenation in arteries, veins, and capillaries differ substantially. In this study, Monte Carlo simulations for a heterogeneous system were conducted, and near infrared time-resolved reflectance measurements were performed on a heterogeneous tissue phantom model. The model was made of a solid polyester resin, which simulates the tissue background. A network of tubes was distributed uniformly through the resin to simulate the blood vessels. The time-resolved reflectance spectra were taken with different absorbing solutions filled in the network. Based on the simulation and experimental results, we investigated the dependence of the absorption coefficient obtained from the heterogeneous system on the absorption of the actual absorbing solution filled in the tubes. We show that light absorption by the brain should result from the combination of blood and blood-free tissue background

    MediaEval 2016 Predicting Media Interestingness Task

    Get PDF
    Volume: 1739 Host publication title: MediaEval 2016 Multimedia Benchmark Workshop Host publication sub-title: Working Notes Proceedings of the MediaEval 2016 WorkshopNon peer reviewe

    Bio-inspired water-driven electricity generators: From fundamental mechanisms to practical applications

    Get PDF
    Harvesting water energy in various forms of water motion, such as evaporation, raindrops, river flows, ocean waves, and other, is promising to relieve the global energy crisis and reach the aim of carbon neutrality. However, this highly decentralized and distributed water energy poses a challenge on conventional electromagnetic hydropower technologies that feature centralization and scalization. Recently, this problem has been gradually addressed by the emergence of a myriad of electricity generators that take inspiration from natural living organisms, which have the capability to efficiently process and manage water and energy for survival in the natural competition. Imitating the liquid–solid behaviors manifested in ubiquitous biological processes, these generators allow for the efficient energy conversion from water–solid interaction into the charge transfer or electrical output under natural driving, such as gravity and solar power. However, in spite of the rapid development of the field, a fundamental understanding of these generators and their ability to bridge the gap between the fundamentals and the practical applications remains elusive. In this review, we first introduce the latest progress in the fundamental understanding in bio-inspired electricity generators that allow for efficient harvesting water energy in various forms, ranging from water evaporation, droplet to wave or flow, and then summarize the development of the engineering design of the various bio-inspired electricity generator in the practical applications, including self-powered sensor and wearable electronics. Finally, the prospects and urgent problems, such as how to achieve large-scale electricity generation, are presented

    Time-resolved reflectance measurements on layered tissues with strongly varying optical properties

    Get PDF
    Most biological tissues consist of layers with different optical properties. A few examples are the skin, the esophagus, the stomach and the wall of arteries. An understanding of how the light propagates in such layered systems is a prerequisite for any light based therapy or diagnostic scheme. In this study we investigate the influence of different kinds of layers on time resolved reflectance measurements. Experiments were performed on layered gel phantoms and the results compared to Monte Carlo simulations and diffusion theory. It is shown that when a low absorbing medium is situated on top of a high absorbing medium, the absorption coefficient of the lower layer is accessible if the differences in the absorption coefficient are only small. In the case of large difference the optical properties of the upper layer dominate the signal and shield information on the lowest layer. The degree of this shielding effect depends on layer thickness as well as optical properties. In the case of an almost absorption and scattering free layer in between two normal tissues, an overall increase of the signal is visible. However, the overall shape of the curve is about preserved. The apparent scattering coefficient is slightly decreased, while the apparent absorption coefficient is unaltered

    Determination of blood oxygenation in the brain by time-resolved reflectance spectroscopy: influence of the skin, skull, and meninges

    Get PDF
    Near infrared light has been used for the determination of blood oxygenation in the brain but little attention has been paid to the fact that the states of blood oxygenation in arteries, veins, and capillaries differ substantially. In this study, Monte Carlo simulations for a heterogeneous system were conducted, and near infrared time-resolved reflectance measurements were performed on a heterogeneous tissue phantom model. The model was made of a solid polyester resin, which simulates the tissue background. A network of tubes was distributed uniformly through the resin to simulate the blood vessels. The time-resolved reflectance spectra were taken with different absorbing solutions filled in the network. Based on the simulation and experimental results, we investigated the dependence of the absorption coefficient obtained from the heterogeneous system on the absorption of the actual absorbing solution filled in the tubes. We show that light absorption by the brain should result from the combination of blood and blood-free tissue background
    corecore