58 research outputs found

    DPSA: Dense pixelwise spatial attention network for hatching egg fertility detection

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    © 2020 SPIE and IS & T. Deep convolutional neural networks show a good prospect in the fertility detection and classification of specific pathogen-free hatching egg embryos in the production of avian influenza vaccine, and our previous work has mainly investigated three factors of networks to push performance: depth, width, and cardinality. However, an important problem that feeble embryos with weak blood vessels interfering with the classification of resilient fertile ones remains. Inspired by fine-grained classification, we introduce the attention mechanism into our model by proposing a dense pixelwise spatial attention module combined with the existing channel attention through depthwise separable convolutions to further enhance the network class-discriminative ability. In our fused attention module, depthwise convolutions are used for channel-specific features learning, and dilated convolutions with different sampling rates are adopted to capture spatial multiscale context and preserve rich detail, which can maintain high resolution and increase receptive fields simultaneously. The attention mask with strong semantic information generated by aggregating outputs of the spatial pyramid dilated convolution is broadcasted to low-level features via elementwise multiplications, serving as a feature selector to emphasize informative features and suppress less useful ones. A series of experiments conducted on our hatching egg dataset show that our attention network achieves a lower misjudgment rate on weak embryos and a more stable accuracy, which is up to 98.3% and 99.1% on 5-day and 9-day old eggs, respectively

    Influence of Drying on Accelerated Carbonation Testing of Concrete

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    The aim of this work is to better understand the influence of drying conditions and moisture content of concrete on the carbonation kinetics during accelerated tests. Cylindrical specimens of a typical concrete formulation for buildings were dried, after 28 days wet curing, under three different conditions: 80°C, 45°C and 20°C and 50% RH. The carbonation depth and the height of water absorption were measured during 70 days testing under 3% CO2, 20°C and 65% RH. The results show that there is a significant difference in the drying behavior of cylindrical specimens between the lateral cast surface and their circular free surface. But, the drying cycle before accelerated carbonation tests has more influence on the carbonation rate than the type of exposed surfac

    Global distribution and evolutionary transitions of angiosperm sexual systems

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    Angiosperm sexual systems are fundamental to the evolution and distribution of plant diversity, yet spatiotemporal patterns in angiosperm sexual systems and their drivers remain poorly known. Using data on sexual systems and distributions of 68453 angiosperm species, we present the first global maps of sexual system frequencies and evaluate sexual system evolution during the Cenozoic. Frequencies of dioecy and monoecy increase with latitude, while hermaphrodites are more frequent in warm and arid regions. Transitions to dioecy from other states were higher than to hermaphroditism, but transitions away from dioecy increased since the Cenozoic, suggesting that dioecy is not an evolutionary end point. Transitions between hermaphroditism and dioecy increased, while transitions to monoecy decreased with paleo-temperature when paleo-temperature >0℃. Our study demonstrates the biogeography of angiosperm sexual systems from a macroecological perspective, and enhances our understanding of plant diversity patterns and their response to climate change.acceptedVersio

    An enhanced anonymous authentication protocol for wireless sensor networks

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    Exposure levels and health damage assessment of dust in a coal mine of Shanxi Province, China

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    The concentrations, health risks and quantitative probabilistic health effects for dust at four workplaces from a coal mine in Shanxi were discussed. A total of 582 dust samples from 21 types of works in various workplaces were collected and analyzed, and their mean concentration ranged from 1.29 to 19.38 mg/m. The probabilistic health damages assessment for coal miners caused by dust were conducted by Monte Carlo simulations and the United States Environmental Protection Agency (USEPA) inhalation risk model. The roadheader drivers and drillers in driving place suffered the greatest health risks with the average value of 5.60×10 and 5.55×10, respectively. The health risks in other workplaces are relatively lower and in the sequence of coal place, transshipment point, and shotcreting point. The health damages for coal miner at various workplaces followed a lognormal distribution, the disability-adjusted life year (DALY) ranked in the following sequence: driving face (1.76±0.14a) > coal face (1.63±0.06a) > transshipment point (1.24±0.11a) > shotcreting point (0.97±0.07a). Sensitivity analyses indicate that exposure duration (ED) have the greatest impact on the dust health damages, followed by exposure time (ET), inhalation rate (IR) and dust concentration (C). These results provide basic information for dust pollution control and health management in coal mines

    Bamboo Sawdust as a Partial Replacement of Cement for the Production of Sustainable Cementitious Materials

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    This paper reports on the utilization of recycled moso bamboo sawdust (BS) as a substitute in a new bio-based cementitious material. In order to improve the incompatibility between biomass and cement matrix, the study firstly investigated the effect of pretreatment methods on the BS. Cold water, hot water, and alkaline solution were used. The SEM images and mechanical results showed that alkali-treated BS presented a more favorable bonding interface in the cementitious matrix, while both compressive and flexural strength were higher than for the other two treatments. Hence, the alkaline treatment method was adopted for additional studies on the effect of BS content on the microstructural, physical, rheological, and mechanical properties of composite mortar. Cement was replaced by alkali-treated BS at 1%, 3%, 5%, and 7% by mass in the mortar mixture. An increased proportion of BS led to a delayed cement setting and a reduction in workability, but a lighter and more porous structure compared to the conventional mortar. Meanwhile, the mechanical performance of composite decreased with BS content, while the compressive and flexural strength ranged between 14.1 and 37.8 MPa and 2.4 and 4.5 MPa, respectively, but still met the minimum strength requirements of masonry construction. The cement matrix incorporated 3% and 5% BS can be classified as load-bearing lightweight concrete. This result confirms that recycled BS can be a sustainable component to produce a lightweight and structural bio-based cementitious material

    Risk Assessment of Miners’ Unsafe Behaviors: A Case Study of Gas Explosion Accidents in Coal Mine, China

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    China’s coal mine production situation is grim and various types of accidents occur frequently, and gas explosion accidents are the highest incidence of coal mine accidents. The authors selected 200 gas explosion accidents of coal mine enterprises in recent years, and extracted a large number of workers’ unsafe behaviors. Meanwhile, four working types related to gas explosion accidents were obtained, namely ventilation, gas prevention and fire extinguishing, blasting, and electrician. This article listed some influencing factors of unsafe behaviors and corrected the probability of unsafe behaviors. In addition, a probabilistic risk assessment model was established, and the Monte Carlo method was used to analyze the risks caused by unsafe behaviors of various working types. The results show that the risk of unsafe behaviors caused by the ventilation working type is the highest, followed by gas prevention and fire extinguishing, and finally blasting and electrician. This paper studies the influencing factors of miners’ unsafe behaviors from the perspective of behavior, guarantees effectively the safety management of coal mine enterprises, and lays a foundation for studying unsafe behaviors related to coal mine gas explosions

    Synergistic Activation of Electric Furnace Ferronickel Slag by Mechanical Grinding and Chemical Activators to Prepare Cementitious Composites

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    The use of electric furnace ferronickel slag (FNS) as a supplementary cementitious material is the current focus of research. This study investigates the effect of mechanical grinding and chemical additives on the activity excition of FNS, as well as the associated synergistic mechanisms. This study shows that the addition of triethanolamine (TEA) increases the fine-grained content in FNS powder, which facilitates the depolymerization of FNS and the early hydration of aluminum tricalcium. Furthermore, the addition of Ca(OH)2 raises the alkalinity of the cementitious system, which promotes the availability of Ca2+ ions and accelerates the hydration process, resulting in the generation of additional hydration products. The enhancement of late hydration of C3S by TEA and its combination with the secondary hydration of Ca2+ at high alkalinity are the pivotal factors to improve the strength of cementitious composite. A mixture of FNS and 0.03% TEA is subjected to grinding for 90 min, using the obtained micropowder which replaces 20% of the cement, and subsequently, after being excited with 3% Ca(OH)2, the FNS micropowder reaches the quality standards of S95 slag powder. It is worth remarking that the micropowder prepared by mixing FNS with 3% Ca(OH)2 and 0.03% TEA and grinding it for 81 min also meets the S95 standard for slag powder. The larger dosage of FNS in cement is supported by the observed synergy between TEA and Ca(OH)2. This research will provide valuable insights for the expanded application of FNS in construction materials

    Retracted: Long noncoding RNA NORAD is upregulated in epithelial ovarian cancer and its downregulation suppressed cancer cell functions by competing with miR‐155‐5p

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    Abstract Purpose In the present study, we evaluated the expression and function of human long noncoding RNA (lncRNA) activated by DNA damage (NORAD) in human epithelial ovarian cancer (EOC). Methods NORAD expression was evaluated by qRT‐PCR in EOC cell lines and in situ EOC clinical samples. Lentivirus‐mediated NORAD downregulation was conducted in OVCAR‐3 and ES‐2 cells, and its effect on cancer cell proliferation, bufalin chemoresistance, cell‐cycle transition in vitro, and xenotransplantation in vivo were examined, respectively. The likelihood of an lncRNA‐microRNA (miRNA) signaling pathway was examined by probing the possible downstream competing target of NORAD, hsa‐miR‐155‐5p. Moreover, hsa‐miR‐155‐5p was knocked down in NORAD‐downregulated EOC cells to functionally evaluate the correlation between NORAD and hsa‐miR‐155‐5p in EOC. Results We found that NORAD was substantially upregulated in both EOC cell lines and human tumors. In OVCAR‐3 and ES‐2 cells, lentivirus‐mediated NORAD downregulation had significant anticancer effects, as it suppressed cell proliferation, decreased bufalin chemoresistance, arrested cell‐cycle transition, and inhibited xenograft growth. Also, hsa‐miR‐155‐5p was confirmed to be the competing target of NORAD in EOC, and its knockdown in OVCAR‐3 and ES‐2 cells reversed the NORAD downregulation‐induced anticancer functions. Conclusions NORAD is upregulated in EOC. Inhibition of NORAD, possibly through endogenously competing against hsa‐miR‐155‐5p, can be a new tumor‐suppressing strategy in EOC
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