Swelling behaviour of compacted Maryland clay under different boundary conditions

This paper presents an experimental study on the swelling response of compacted Maryland clay specimens subjected to hydration under a range of boundary conditions. The research is multi-scale with swelling tests complemented by comprehensive mercury intrusion porosimetry analyses. The objective of the experimental programme is to establish the locus of final swollen states (in terms of void ratio and swelling pressure) and assess its robustness by testing a range of boundary conditions or combinations thereof. Five initial soil conditions were tested and swelling was generated by flooding or incremental suction reduction by way of the osmotic technique. The paper shows that, for a given soil condition, there is no influence of the stress–volume path on the final swollen state. This observation was corroborated at the microscopic level by the mercury intrusion porosimetry. It was concluded that the effect of different stiffness can actually be analysed in terms of the maximum stress applied to the specimen. In particular, a clear correlation was identified between the macroscopic strains and the confinement applied during the test, regardless of the boundary conditions. Also, the conceptual model relating the water ratio and micro void ratio proposed by E. Romero and co-workers in 2011 was found to prevail, regardless of the boundary conditions.Peer ReviewedPostprint (author's final draft

Simulation analysis of the conveyor chain system based on MATLAB

Abstract. In the aluminium ingot casting machine conveyor chain system, the vibration of the production process caused by the transport chain crawl and polygon effect produces water ripple, which directly affect the quality of the products. So this article combined with the MATLAB simulation technology to analyze the signal which affect the conveyor chain stability. And using its powerful graphics functions and mathematical functions to further improve the stability of conveyor chain provides reference

Image enhancement suggestions based on machine learning

Images in image libraries are sometimes oriented incorrectly. For example, a photograph taken with a camera held vertically may be displayed horizontally, or vice-versa. Further, users often capture images of documents; however, the resultant image can include distortions due to camera angle, poor lighting, etc. The captured image of a document often also includes objects outside the document boundary, e.g., a surface on which the document is placed. For some photos, automatic enhancements can enhance the quality of the image. This disclosure applies machine learning techniques to detect if an image is that of a document, if the image is mis-rotated, if the image can benefit from automatic enhancement, etc. When such images are detected, enhancements such correction of rotation, cropping, distortion-removal, etc., are automatically suggested to the user, e.g., when the image is displayed. With user permission, an acceptance or dismissal of the suggestion is used as a training signal for the machine learning model. Enhancement suggestions are surfaced, e.g., as tappable or clickable buttons, when an image is being viewed and are applied upon user selection of the suggestion

A Bacterial Acetyltransferase Destroys Plant Microtubule Networks and Blocks Secretion

The eukaryotic cytoskeleton is essential for structural support and intracellular transport, and is therefore a common target of animal pathogens. However, no phytopathogenic effector has yet been demonstrated to specifically target the plant cytoskeleton. Here we show that the Pseudomonas syringae type III secreted effector HopZ1a interacts with tubulin and polymerized microtubules. We demonstrate that HopZ1a is an acetyltransferase activated by the eukaryotic co-factor phytic acid. Activated HopZ1a acetylates itself and tubulin. The conserved autoacetylation site of the YopJ / HopZ superfamily, K289, plays a critical role in both the avirulence and virulence function of HopZ1a. Furthermore, HopZ1a requires its acetyltransferase activity to cause a dramatic decrease in Arabidopsis thaliana microtubule networks, disrupt the plant secretory pathway and suppress cell wall-mediated defense. Together, this study supports the hypothesis that HopZ1a promotes virulence through cytoskeletal and secretory disruption

Emergent Search of UAV Swarm Guided by the Target Probability Map

In the cooperative searching scenario, most traditional methods are based on the top–down mechanisms. These mechanisms are usually offline and centralized. The characteristics limit the adaptability of unmanned aerial vehicle (UAV) swarm to the complex mission environments, such as those with inaccurate information of the targets and grids. In order to improve the searching ability of UAV swarm, a novel searching method named emergent search of UAV swarm guided by the target probability map (ESUSTPM) is proposed. ESUSTPM is based on local rules to organize and guide UAV agents to achieve the flocking state, search the mission area and detect the hidden targets concurrently. In ESUSTPM, local rules contain the flocking rules and the guiding rules. The flocking rules are the interactions between the agents, which are designed by a novel constructed function based on two exponential functions in this paper. The new constructed function can better maintain the relatively stable distances between the agents and realize the smooth transition of the positions at the given centers. The local guiding rules based on the target probability information of the nearby grids are firstly designed to realize the multi-function of the swarm, including full area coverage, target detection and reduction in environmental uncertainty (EU). Finally, the simulations verify that ESUSTPM can achieve the full coverage of the mission area while taking into account the target search. The statistical results also indicate that the searching efficiency of the proposed ESUSTPM is higher than the traditional searching algorithms based on the division and allocation of the area or the heuristic algorithms

Laser Promoting Oxygen Vacancies Generation in Alloy via Mo for HMF Electrochemical Oxidation

Abstract It is well known that nickel‐based catalysts have high electrocatalytic activity for the 5‐hydroxymethylfurfural oxidation reaction (HMFOR), and NiOOH is the main active component. However, the price of nickel and the catalyst's lifetime still need to be solved. In this work, NiOOH containing oxygen vacancies is formed on the surface of Ni alloy by UV laser (1J85‐laser). X‐ray absorption fine structure (XAFS) analyses indicate an interaction between Mo and Ni, which affects the coordination environment of Ni with oxygen. The chemical valence of Ni is between 0 and 2, indicating the generation of oxygen vacancies. Density functional theory (DFT) suggests that Mo can increase the defect energy and form more oxygen vacancies. In situ Raman electrochemical spectroscopy shows that Mo can promote the formation of NiOOH, thus enhancing the HMFOR activity. The 1J85‐laser electrode shows a longer electrocatalytic lifetime than Ni‐laser. After 15 cycles, the conversion of HMF is 95.92%

Response of different osmotic membranes and calibration of a coupled model capturing the temperature effect for the osmotic method

Reliable suction control is of paramount importance for experimental unsaturated soil mechanics. The osmotic method, based on polyethylene glycol (PEG) and semi-permeable membranes, is one of the possible methods to control suction. Although this method is quite simple to implement, reliable results can only be obtained with adequate calibration curves linking suction and PEG concentration, and a good understanding of the factors influencing the method. Several studies have investigated different aspects of this method, including the osmotic potential generated by given PEG concentrations, but the effect of temperature is not yet fully captured. This paper presents the results of a comprehensive study of the osmotic method looking at the long-term response of three different types of membranes, the effect of temperature, PEG molecular weight (MW) and the combination of different MW cut off (MWCO) on the calibration curves. Finally the data were used to calibrate a model capturing the temperature effect, in a coupled manner, in order to provide a robust calibration