140 research outputs found

    Acclimatization of Rhizophagus irregularis Enhances Zn Tolerance of the Fungus and the Mycorrhizal Plant Partner

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    Arbuscular mycorrhizal (AM) fungi confer heavy metal tolerance to plants, but this characteristic differs between different AM fungal strains. We tested the hypotheses if acclimatization of an AM fungus to Zn stress is possible and if this leads also to higher Zn tolerance of mycorrhizal plants. The AM fungus Rhizophagus irregularis was acclimatized in root organ cultures (Daucus carota L.) to Zn resulting in an acclimatized (Acc+) strain. The non-acclimatized (Acc-) strain remained untreated. Fungal development and RNA accumulation of a set of stress-related genes were analyzed in root organ cultures and the capacity of conferring Zn tolerance to maize plants was investigated in pot cultures. Development of Acc+ strain was significantly higher than Acc- strain, when strains were grown in Zn-enriched root organ cultures, whereas the growth of the Acc+ strain was reduced on normal medium probably due to a higher Zn demand compared to the Acc- strain. RNA accumulation analyses revealed different expression patterns of genes encoding glutathione S-transferase (RiGST), superoxide dismutase (RiSOD) and glutaredoxin (RiGRX) between the two strains. Plants inoculated with the Acc+ strain showed higher biomass and lower Zn content than those inoculated with the Acc- strain. The results showed that R. irregularis can be acclimatized to increased amounts of Zn. This acclimatization leads not only to improved fungal development in Zn-stress conditions, but also to an increase of mycorrhiza-induced Zn tolerance of colonized plants.Peer Reviewe

    Research of methods for determining dynamic stress of the bars in the main structure of gantry crane installed on the cap of bridge pier to serve installation of Super-T girder

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    The article presents briefly findings in researching methods for determining dynamic stress of the bars in the main structure of gantry crane installed on the cap of bridge pier to install and launch SUPER-T girder. In order to study the dynamic stresses in the bars of the main truss structure of the gantry, the author first had to build a dynamic model, using Matlap software to solve the problem of dynamics with two cases cargo lowering combination combines braking and moving of gantry with cargo to find out the rules and values of dynamic cable tension, dynamic inertial force ( time-varying force), then consider these forces is the external force acting on the main truss structure model of the gantry, from which the author calculates the value of internal force and stress of each bar corresponding to the value of dynamic cable tension and corresponding dynamic inertia force. with two adverse working cases of the gantry. Using Matlap software to calculate the author has obtained a graph of internal force, stress changes over time of each bar in the main truss steel structure of the gantry. The findings of the research provided methods for determining the dynamic stress of the bars in the main structure of gantry crane, pointed out values and rules of change of the dynamic stress of the bars in the main structure of gantry crane. The findings of the research may be used to calculate fatigue, life-span of the main steel structures as well as other parts of the gantry cran

    Study on the influence of bus suspension parameters on ride comfort

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    This study proposes a three-dimensional vibration model of bus with 10 DOF (degree of freedom) based on Dragan Sekulić model to analyze the suspension parameters directly influenced ride comfort. The suspension parameters which include the stiffness and damping parameters are analyzed based on the weighted r.m.s. (root-mean-square) acceleration responses of the space of a driver, passenger in the middle part of the bus and passenger in the rear overhang according to ISO 2631-1:1997. The results show that both stiffness and damping parameters of vehicle suspension have important influences on ride comfort. Especially, the stiffness and damping values of vehicle suspension are within the value ranges (0.5k0 ≤ k ≤ 0.75 k0) and (0.5c0 ≤ c ≤ 0.75c0) to improve the ride comfort of driver and passengers

    Surface Roughness Modeling of Hard Turning 080A67 Steel

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    Surface roughness is an important parameter to evaluate the quality of a machining process in mechanical manufacturing. The construction of a surface roughness model of a machining process is the basis for predicting surface roughness corresponding to each certain case. This paper presents the construction of a surface roughness model in 080A67 steel turning. An experimental process was carried out with a total of 15 experiments, designed according to the Box-Behnken matrix. The cutting speed, feed rate, and cutting depth were changed in each experiment, and surface roughness values were measured to build a model that showed the mathematical relationship between surface roughness and the three cutting parameters. A second surface roughness model was also constructed using the Box-Cox transformation. The accuracy of these two models was compared through five coefficients: R2, R2(pred), R2(adj), Percentage Absolute Error (PAE), and Percentage Square Error (PSE). The results showed that all these coefficients of the model using the Box-Cox transformation were better than those of the first one. In detail, the values of R2, R2(pred), R2(Adj), PAE, and PSE of the first model were 94.55%, 12.79%, 84.74%, 8.79%, and 1.42%, while for the second model were 99.09%, 85.42%, 97.44%, 2.26%, and 0.18%, respectively, showing that the accuracy of the surface roughness model was improved by using the Box-Cox transformation

    INGREX: An Interactive Explanation Framework for Graph Neural Networks

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    Graph Neural Networks (GNNs) are widely used in many modern applications, necessitating explanations for their decisions. However, the complexity of GNNs makes it difficult to explain predictions. Even though several methods have been proposed lately, they can only provide simple and static explanations, which are difficult for users to understand in many scenarios. Therefore, we introduce INGREX, an interactive explanation framework for GNNs designed to aid users in comprehending model predictions. Our framework is implemented based on multiple explanation algorithms and advanced libraries. We demonstrate our framework in three scenarios covering common demands for GNN explanations to present its effectiveness and helpfulness.Comment: 4 pages, 5 figures, This paper is under review for IEEE ICDE 202

    An effective method for clustering-based web service recommendation

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    Normally web services are classified by the quality of services; however, the term quality is not absolute and defined relatively. The quality of web services is measured or derived using various parameters like reliability, scalability, flexibility, and availability. The limitation of the methods employing these parameters is that sometimes they are producing similar web services in recommendation lists. To address this research problem, the novel improved clustering-based web service recommendation method is proposed in this paper. This approach is mainly dealing with producing diversity in the results of web service recommendations. In this method, functional interest, quality of service (QoS) preference, and diversity features are combined to produce a unique recommendation list of web services to end-users. To produce the unique recommendation results, we propose a varied web service classification order that is clustering-based on web services’ functional relevance such as non-useful pertinence, recorded client intrigue importance, and potential client intrigue significance. Additionally, to further improve the performance of this approach, we designed web service graph construction, an algorithm of various widths clustering. This approach serves to enhance the exceptional quality, that is, the accuracy of web service recommendation outcomes. The performance of this method was implemented and evaluated against existing systems for precision, and f-score performance metrics, using the research datasets

    Influence of damping coefficient into engine rubber mounting system on vehicle ride comfort

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    This study presents a method to improve vehicle ride comfort using additional damping coefficient values for an internal combustion engine (ICE) rubber mounting system. To analyze the effect of the adding damping coefficient values into the rubber mounting system on vehicle ride comfort, a full-vehicle vibration model with 10 degrees of freedom is established under the combination of road surface roughness and ICE excitations. The damping coefficient values are added into ICE rubber mounting system which are respectively analyzed and evaluated according to the international standard ISO 2631-1 (1997). The study results do not only evaluate the influence of the adding damping coefficients on vehicle ride comfort but also suggest the optimal design solution for ICE mounting system to improve vehicle ride comfort
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