Enhanced Hydrogen Generation Performance of Al-Rich Alloys by a Melting-Mechanical Crushing-Ball Milling Method

The main problem for the application of hydrogen generated via hydrolysis of metal alloys is the low hydrogen generation rate (HGR). In this paper, active Al alloys were prepared using a new coupled method-melting-mechanical crushing-mechanical ball milling method to enhance the HGR at room temperature. This method contains three steps, including the melting of Al, Ga, In, and Sn ingots with low melting alloy blocks and casting into plates, then crushing alloy plate into powders and ball milling with chloride salts such as NiCl2 and CoCl2 were added during the ball milling process. The microstructure and phase compositions of Al alloys and reaction products were investigated via X-ray diffraction and scanning electron microscopy with energy dispersed X-ray spectroscopy. The low-melting-point Ga-In -Sn (GIS) phases contain a large amount of Al can act as a transmission medium for Al, which improves the diffusion of Al to Al/H2O reaction sites. Finer GIS phases after ball milling can further enhance the diffusion of Al and thus enhance the activity of Al alloy. The hydrogen generation performance through hydrolysis of water with Al at room temperature was investigated. The results show that the H2 generation performance of the Al-low-melting point alloy composite powder is significantly higher than the results reported to date. The highest H2 generation rate and H2 conversion efficiency can reach 5337 mL·min−1·g−1 for the hydrolysis of water with 1 g active alloy.

Biogenic action of Lactobacillus plantarum SBT2227 promotes sleep in Drosophila melanogaster

Lactic acid bacteria (LAB) influence multiple aspects of host brain function via the production of active metabolites in the gut, which is known as the pre/pro-biotic action. However, little is known about the biogenic effects of LAB on host brain function. Here, we reported that the Lactobacillus plantarum SBT2227 promoted sleep in Drosophila melanogaster. Administration of SBT2227 primarily increased the amount of sleep and decreased sleep latency at the beginning of night-time. The sleep-promoting effects of SBT2227 were independent of the existing gut flora. Furthermore, heat treatment or mechanical crushing of SBT2227 did not suppress the sleep-promoting effects, indicative of biogenic action. Transcriptome analysis, and RNAi mini-screening for gut-derived peptide hormones revealed the requirement of neuropeptide F, a homologue of the mammalian neuropeptide Y, for the action of SBT2227. These biogenic effects of SBT2227 on the host sleep provide new insights into the interaction between the brain and gut bacteria.

Possibility of Tuff Waste Application in the Production of Thermal Insulation Materials

Possible methods of dust, sand and gravel waste involvement during tuff mining for production of modern thermal-insulating construction materials using energy-efficient technologies are presented. The possibility of using the valuable properties of these wastes for the production of modern competitive materials and products, particularly clinkerless binders, artificial porous fillers, foam concrete, etc is described. The volcanic rocks, which have a glass-like structure, i.e. easily modified, give the system sufficient energy potential, which is accumulated in the rock, allowing work to be performed through chemical reaction. The possibility of increasing rock reactivity both by mechanical (crushing, grinding) and chemical methods (creation of basic, sulfate environments) is presented. It has been theoretically substantiated and practically confirmed that by using the waste materials it is possible to obtain artificial construction conglomerates of various structures using resource-saving technologies and the activities of rocks endowed with nature. The composition of concrete with a cellular structure has been developed and its physical and mechanical characteristics have been brought forth.

HANDY: a device for assessing resistance to mechanical crushing of maize kernel

Background How to control the physical damage during maize kernel harvesting is a major problem for both mechanical designers and plant breeders. A limitation of addressing this problem is lacking a reliable method for assessing the relation between kernel damage susceptibility and threshing quality. The design, construction, and testing of a portable tool called “HANDY”, which can assess the resistance to mechanical crushing in maize kernel. HANDY can impact the kernel with a special accelerator at a given rotating speed and then cause measurable damage to the kernel. These factors are varied to determine the ideal parameters for operating the HANDY. Results Breakage index (BI, target index of HANDY), decreased as the moisture content of kernel increased or the rotating speed decreased within the tested range. Furthermore, the HANDY exhibited a greater sensitivity in testing kernels at higher moisture level influence on the susceptibility of damage kernel than that in Breakage Susceptibility tests, particularly when the centrifugation speed is about 1800 r/min and the centrifugal disc type is curved. Considering that the mechanical properties of kernels vary greatly as the moisture content changes, a subsection linear (average goodness of fit is 0.9) to predict the threshing quality is built by piecewise function analysis, which is divided by kernel moisture. Specifically, threshing quality is regarded as a function of the measured result of the HANDY. Five maize cultivars are identified with higher damage resistance among 21 tested candidate varieties. Conclusions The HANDY provides a quantitative assessment of the mechanical crushing resistance of maize kernel. The BI is demonstrated to be a more robust index than breakage susceptibility (BS) when evaluating threshing quality in harvesting in terms of both reliability and accuracy. This study also offers a new perspective for evaluating the mechanical crushing resistance of grains and provides technical support for breeding and screening maize varieties that are suitable for mechanical harvesting.

Multiple functional materials from crushing waste thermosetting resins

A new family of multiple functional materials from waste thermosetting resins is developed by simple mechanical crushing.

Oversize Yield in Underground Mine Development

Stoping, which is the initial link in the chain of the production processes of coal-face operation, significantly determines the performance of handling and mining-andconveyor equipment, as well as losses and ore contamination. The size of the broken ore determines the cost of its mechanical crushing before lifting. Besides, the quality of breaking has a direct effect on the efficiency of ore enrichment. This influence manifests itself mainly in a significant increase in the cost of mechanical crushing and grinding of the ore, which are the most energy-consuming processes in ore dressing. The share of breaking in the direct financial costs of hard ore development, depending on the rock strength, reaches 20 – 35 %. Assuming that the main purpose of blasting operations in the mine is the destruction of the rock massif with creating the conditions for high-performance execution of the subsequent production processes of ore extraction, one should be careful about cost savings on breaking. The fact is that the proposed activities that reduce the cost of drilling and blasting may result in general deterioration of the quality of breaking. Therefore, the criterion of efficiency of any variant of blast hole drilling is to be an integrated indicator of the overall economic result of the entire production process chain, from coal-face operation to enrichment. Naturally, under certain conditions, when the effect of the results of stoping has local nature, the calculations can be made not for the entire production complex. This work analyzes the existing methods of calculating the parameters of blast hole drilling (BHD) in longhole stoping and considers the mining factors that affect the efficiency of stoping in similar geological conditions, namely, the oversize yield and the cost of coal-face operation. In practice, there are no methods for calculating the parameters of BHD that would be recognized as uniform and quite satisfying the needs of enterprises in all regions and types of mining. Depending on the local conditions, the homedeveloped methods proven by the practice are used, which are improved with experience. This work shows the experience in ore stoping at the Zapolyarny mine, and provides the results of industrial observations of the actual oversize yield.

HANDY: a device for assessing resistance to mechanical crushing of maize kernel

Background: How to control the physical damage during maize kernel harvesting is a major problem for both mechanical designers and plant breeders. A limitation of addressing this problem is lacking a reliable method and model for assessing the relation between kernel damage susceptibility and threshing quality. The design, construction, and testing of a portable tool called “HANDY”, which can assess the resistance to mechanical crushing in maize kernel. HANDY can impact the kernel with a special accelerator at a given rotating speed and then cause measurable damage to the kernel. These factors are varied to determine the ideal parameters for operating the HANDY. Results: Baseline testing of the HANDY is performed to determine the initial range of testing parameters. The result shows that the optimum number of test times is one. Breakage index (BI, target index of HANDY), decreased as the moisture content of kernel increased or the rotating speed decreased within the tested range. Furthermore, the HANDY exhibited a greater sensitivity in testing kernels at higher moisture level influence on the susceptibility of damage kernel than that in Breakage Susceptibility tests, particularly when the centrifugation speed is about 1800 r/min and the centrifugal disc type is curved. Considering that the mechanical properties of kernels vary greatly as the moisture content changes, a subsection linear (average goodness of fit is 0.9) to predict the threshing quality is built by piecewise function analysis, which is divided by kernel moisture. Specifically, threshing quality is regarded as a function of the measured result of the HANDY. Five maize cultivars are identified with higher damage resistance among 21 tested candidate varieties. Conclusions: The HANDY provides a quantitative assessment of the mechanical crushing resistance of maize kernel. The BI is demonstrated to be a more robust index than breakage susceptibility (BS) when evaluating threshing quality in harvesting in terms of both reliability and accuracy. This study also offers a new perspective for evaluating the mechanical crushing resistance of grains and provides technical support for breeding and screening maize varieties that are suitable for mechanical harvesting.

Influence of Amounts and Particle Diameter on the Mechanical Properties of Several Polymeric Composites Reinforced with GTR Particles

Nowadays, the massive use of tires generates large stocks of waste material which is a serious environmental problem. The usual method used for processing wasted tires is mechanical crushing, in which fiber, steel, and rubber are separated. The aim of this research is the recycling of the obtained rubber, called also GTR (Ground Waste Tires). With this purpose, the paper analyses the mechanical properties of the composites produced by mixing GTR with several industrial polymers. These composites are characterized by the percentage of GTR in the composite and its particle size. These two variables along with seven industrial polymers define a set of composites from which the mechanical properties are analyzed and presented. From the results, it can be drawn that this proposal could be a way to enhance some polymer properties and to contribute in some way to reduce the environmental wasted tires problem.

Investigating the Influences of Indentation Hardness and Brittleness of Rock-Like Material on Its Mechanical Crushing Behaviors

Indentation hardness and brittleness are the important factors to be considered in the study of rock-like materials’ mechanical crushing behaviors. The brittleness of rock-like materials is defined as the ratio of uniaxial compressive strength to tensile strength in this paper. In order to investigate the influences of hardness and brittleness on rock-like materials’ crushing behaviors, quartz sand and high strength α-hemi-hydrated gypsum were used to prepare rock-like materials with different hardness and brittleness through different mass ratios. The artificial rock-like materials can eliminate the effects of natural rock’s weak structure plane on experimental results. The indentation test, Uniaxial compressive test, and Brazilian tensile test were conducted for characterizing the indentation hardness and brittleness of this artificial rock-like materials. The experimental results showed that brittleness increased with the increase of indentation hardness with high correlation coefficient. The confining stress presented a positive impact on the indentation hardness of the rock-like materials. Based on those mechanical properties, the numerical rock models were calculated to study rock crushing behaviors using discrete element method (DEM). A series of rock crushing tests were conducted to investigate the influences of hardness and brittleness of rock-like materials on rock crushing behaviors using a conical pick cutter. The numerical results showed that the normalized specific energy was negatively correlated with indentation hardness index (IHI). The normalized specific energy decreased with the increase of brittleness index (BI) with a high correlation coefficient. This study is beneficial in utilizing IHI and BI to evaluate the mechanical properties, failure patterns, and mechanical crushing efficiency of rock-like materials.