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The paper deals with the low-speed impact of rigid bodies.The elasticity and damping forces,acting on a body during the impact,depend on the physical properties of the material;in this work these forces are considered according to...
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The paper deals with the low-speed impact of rigid bodies.The elasticity and damping forces,acting on a body during the impact,depend on the physical properties of the material;in this work these forces are considered according to the Kelvin-Voigt,Bingham and Maxwell models of the medium.New models of the forces,acting during the impact,are elaborated.Numerical solutions of the equations for various impact forces are obtained.
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Identifying the deleterious ecological effects of developments, such as roads, mining, and urban expansion, is essential for informing development decisions and identifying appropriate mitigation actions. However, there are many t...
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Identifying the deleterious ecological effects of developments, such as roads, mining, and urban expansion, is essential for informing development decisions and identifying appropriate mitigation actions. However, there are many types of ecological impacts that slip 'under the radar' of conventional impact evaluations and undermine the potential for successful impact mitigation (including offsets). These 'enigmatic' impacts include those that are small but act cumulatively; those outside of the area directly considered in the evaluation; those not detectable with the methods, paradigms, or spatiotemporal scales used to detect them; those facili-tated, but not directly caused, by development; and synergistic impact interactions. Here, we propose a framework for conceptualising enigmatic impacts and discuss ways to address them.
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The objective of this study was to analyse and evaluate the protection function and feasibility of two types of human neck safety equipment under unusual landings. Human head and neck dynamic responses were simulated by constructi...
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The objective of this study was to analyse and evaluate the protection function and feasibility of two types of human neck safety equipment under unusual landings. Human head and neck dynamic responses were simulated by constructing a mechanical model of the human-seat system, which was equipped with two kinds of head support systems. The force and moment in the human neck were calculated. The protection function of the head support systems was evaluated according to the injury criteria HIC (head injury criterion) and Ny (neck injury criterion). Two kinds of safety equipment were used under unusual landing. The results of the experiment showed that Ny is smaller than the injury criterion limits under normal landings, and that the safety equipment provided effective protection. The safety equipment was confirmed to reduce the degree of neck injuries resulting from unusual landing impacts.
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In this short paper we recall the (Garfield) Impact Factor of a journal, we improve and extend it, and eventually present the Total Impact Factor that reflects the most accurate impact factor.
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This paper focuses on the impact of soil moisture anomalies on subsequent precipitation and surface air temperature over Asia based on numerical experiments using a regional climate model. Soil moisture anomalies are applied on 1 ...
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This paper focuses on the impact of soil moisture anomalies on subsequent precipitation and surface air temperature over Asia based on numerical experiments using a regional climate model. Soil moisture anomalies are applied on 1 March, 1 June, and 1 September for the spring, summer, and autumn experiments, respectively, and their impacts on both the climate mean and extremes are examined. Major findings are the following. (1) The land surface memory for soil moisture anomalies is longer in the midlatitudes and shorter in the Tropics, and such memory is enhanced by soil moisture-precipitation feedback. (2) The wet (dry) initial soil moisture anomalies increase (reduce) the subsequent precipitation amount and reduce (increase) surface temperature. For precipitation, the strongest impacts are found in midlatitude to high-latitude regions including northwest China, central Asia, southern Siberia; for temperature, the strongest response is found in India and Indochina regions and most of the midlatitude areas in spring, in high-latitude and midlatitude regions in summer, and in India and eastern China (lower Yellow river basin) in autumn. (3) The impact on mean climate variables can last for 2-3months over most regions of strong response, and the impact of wet initial soil moisture anomalies tends to be stronger but dissipates faster than the dry initial anomalies. (4) Both the dry and wet initial soil moisture anomalies tend to reinforce severe flood extremes, while other climate extremes respond to initial anomalies in a way similar to the mean climate: wet (dry) initial soil moisture anomalies reduce (amplify) the drought extremes, diminish (reinforce) the hot extremes, and enhance (reduce) the cold extremes over areas of strong soil moisture-atmosphere coupling.
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? 2022 Elsevier LtdThis paper is devoted to Reinforced Concrete (RC) beams that can be subjected to accidental falls of substantial masses (hard impacts at low velocities), such as the beams of bridges, industrial buildings, or fa...
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? 2022 Elsevier LtdThis paper is devoted to Reinforced Concrete (RC) beams that can be subjected to accidental falls of substantial masses (hard impacts at low velocities), such as the beams of bridges, industrial buildings, or factories. Here the reference is to existing RC beams, which have no purposely designed reinforcement to resist impacts. The paper focuses on a mass that falls around the midspan, where the capacity of a RC beam to resist an impact is minimum, due to a potential primary cracking pattern that consists of vertical cracks. The impact here is defined by the combination of the mass that falls down and its velocity at the impact. The paper provides an analytical formulation to predict the combinations that trigger the collapse of a RC beam (i.e., ultimate combinations). After having framed the research question, the paper presents the two possible failure modes, the derivation of the equations, the sensitivity of the bearing capacity to the main parameters, comparisons with existing results from literature, and two applications, whose results are discussed.
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Various methods have been suggested in the literature to normalise the impact factor of journals. However, these methods have their own limitations. Present communication suggests a simple alternative method to normalise the impac...
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Various methods have been suggested in the literature to normalise the impact factor of journals. However, these methods have their own limitations. Present communication suggests a simple alternative method to normalise the impact factor of journals based on average impact of journals. http://dx.doi.org/10.14429/djlit.31.5.1194.
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This work presents a new model that predicts the wear that results from impacts occurring between two solid bodies under both normal and compound impact, a capability lacking from existing approaches. This frequently occurs in man...
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This work presents a new model that predicts the wear that results from impacts occurring between two solid bodies under both normal and compound impact, a capability lacking from existing approaches. This frequently occurs in many engineering and industrial situations and depending on the relative sizes of the bodies, bulk material properties, and the number and frequency of impacts, damage can result. Although this eventually causes severe wear problems that limit service life, it is one of the least investigated types of primary wear mechanism. Due to this, robust data, and validated models derived from that data, are rare.
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