333 research outputs found

    Repair heavy-duty generator rotor shaft by electro spark deposition process

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    EffectĀ ofĀ CeramicĀ PropertiesĀ andĀ Depth-of-penetration TestĀ ParametersĀ onĀ theĀ Ballistic PerformanceĀ ofĀ Armour CeramicsĀ 

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    Through an analysis on the relationship among ceramic properties, the depth of penetration (DOP) test parameters and the ballistic performance of armour ceramics based on literatures, the effects of ceramic type, tile thickness and projectile velocity on the ballistic performance of different kinds of ceramics were investigated systematically. The results show that the ballistic performance of different armour ceramics mainly depends on its density, and by using thin ceramic tiles or under high velocity impact, the ceramic composite armour could not provide effective ballistic protection. Furthermore, the differences in the ballistic performance of armour ceramic are found due to the different ballistic performance criteria and DOP test conditions. Additionally, the slope of the depth of penetration (not include tile thickness) (Pa) versus tile thickness has negative correlation with flexural strength of ceramics, indicating the flexural strength can be one of the criteria to evaluate the performance of armour ceramics

    "LIVING HIGH-TRAINING LOW" ALTITUDE TRAINING ON IMPROVEMENT OF SEA LEVEL HEMOGLOBIN/HEMATOCRIC IN MALE AND FEMALE ELITE SWIMMERS

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    This study investigated the effect of "living high-training low" altitude on improvement of sea level hemoglobin and hematocric in male and female elite swimmers. A total of ten elite swimmers at the international and national level was recruited and randomly divided into two groups, altitude training group and control group. The athletes in altitude training group lived high condition while training at sea level for three weeks. The altitude was set at 2,800m. The all subjects in both groups accepted same training in the intensity, frequency and duration. Hemoglobin and hematocric were measured at sea level on seven occasions, the day before starting the experiment, during the period of experiment and the day completing the experiment. The results showed that the hemoglobin and hematocric in altitude training group increased 8.6% and had significant difference compared with those before the experiment. While the level of hemoglobin and hematocric in control group did not show any obvious change. "Living high-training low" altitude training can significantly improve the level of hemoglobin and hematocric

    Development of an UAS for Earthquake Emergency Response and Its Application in Two Disastrous Earthquakes

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    To support humanitarian action after a disaster, we require reliable data like high-resolution satellite images for analyses aimed to define the damages of facilities and/or infrastructures. However, we cannot obtain satellite images in few days after an event. Thus, in situ surveys are preferred. Advances in unmanned aircraft system (UAS) have promoted them to become precious tools for capturing and assessing the extents and volume of damages. Safety, flexibility, low cost, and ease of operation make UAS suitable for disaster assessment. In this chapter, we developed an example of UAS for swiftly acquiring disaster information. With the selected fixed-wing UAS, we successfully performed data acquisition at specified scales. For the image analysis, we applied a photogrammetric workflow to deal with the very high resolution of the images obtained without ground control points. The results obtained from two destructive earthquakes demonstrated that the presented system plays a key role on the processes of investigating and gathering information about a disaster in the earthquake epicentral areas, like road detection, structural damage survey, secondary disaster investigation, and quick disaster assessment. It can effectively provide disaster information in hardly entered areas to salvation headquarters for rapidly developing the relief measures

    Image Classifier Based Generative Method for Planar Antenna Design

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    To extend the antenna design on printed circuit boards (PCBs) for more engineers of interest, we propose a simple method that models PCB antennas with a few basic components. By taking two separate steps to decide their geometric dimensions and positions, antenna prototypes can be facilitated with no experience required. Random sampling statistics relate to the quality of dimensions are used in selecting among dimension candidates. A novel image-based classifier using a convolutional neural network (CNN) is introduced to further determine the positions of these fixed-dimension components. Two examples from wearable products have been chosen to examine the entire workflow. Their final designs are realistic and their performance metrics are not inferior to the ones designed by experienced engineers.Comment: 13 pages, 18 figure

    Pelvic infection caused by periodontitis: A case report

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    Oral bacteria in patients with periodontitis can disseminate into the bloodstream via broken oral epithelial cells, causing odontogenic maxillofacial infections, brain abscesses and endocarditis. However, pelvic infection caused by periodontitis is rare. The case of a 48-year-old woman with a long history of recurrent periodontal infections, who complained of abdominal distention and pain for 14 days after dental implantation, is reported here. Pelvic ultrasound and magnetic resonance imaging signaled multiple inflammatory encapsulated effusions in the posterior uterus, which were removed by laparoscopic surgery and tested with metagenomic next-generation sequencing (mNGS). Through mNGS, numerous oral pathogens, including Filifactor alocis, were identified in the pelvic effusions. The patient was subsequently diagnosed with a pelvic infection originating from periodontitis, and recovered after undergoing surgery and targeted antibacterial treatment. Thus, the possibility of extrabuccal complications in patients with a history of periodontitis or invasive oral procedures merits closer attention

    Multi-band remote sensing based retrieval model and 3D analysis of water depth in Hulun Lake, China

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    Hulun Lake, a large lake located on the cold and arid Hulunbeir grassland in the Inner Mongolia Autonomous Region, is the fifth largest in China and the largest in the north of the country. However, the information on the lakeā€™s characteristics (e.g., water depth versus surface area) is scarce in literature. Based on the lakeā€™s physiographic features, this study developed and used a model that merges the sunlight reflection band with the thermal infrared radiation band to simulate the lakeā€™s characteristics. The model verification and error analysis indicated an optimal model structure of logarithm. Thus, this logarithmic model was selected to analyze the spectral data. The results indicated that the model did a good job in reproducing observed water depths and accurately predicted the depths on 24 September 2007. This showed that this model can be reliably applied to the cold and arid region. Subsequently, the results were used to generate a triangular irregular network (TIN) model, which in turn was used to compute the functional relations between water level, surface area, and volume. The correlation between water level and volume is superior to that between water level and area. The regression equation developed in this study can be used to estimate the volume when water elevation is knowninfo:eu-repo/semantics/publishedVersio
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