Papers by Keyword: Disintegration

Abstract: In the search for environmentally friendly materials, mycelium composites have been labelled as high potential bio-based alternatives to fossil-based and synthetic materials in various fields. Mycelium-based materials are praised for their biodegradability, however no scientific research nor standard protocols exist to substantiate this claim. This research therefore aims to develop an appropriate experimental methodology as well as to deliver a novel proof of concept of the material’s biodegradability. The applied methodology was adapted from a soil burial test under predefined laboratory conditions and hands-on preliminary experiments. The mycelium composite samples were placed in a nylon netting and then buried in potting soil with a grain size of 2 mm for different time-intervals ranging between one and sixteen weeks. Results showed that mycelium, which acted as the binder, had the tendency to decompose first. A weight loss of 43% was witnessed for inert samples made of the fungal strain Ganoderma resinaceum and hemp fibres after sixteen weeks. The disintegration rate in this method however depended on various parameters which were related to the material’s composition, its production method and the degradation process which involved the used equipment, materials and environmental properties.

Abstract: The article addresses the features of rock disintegration based on the principles of selective and preferential destruction in high-frequency cone vibratory crushers with a free-turning inner cone. Based on the common method for determining the ultimate strength of rocks, a method for investigating the process of ore destruction under repeated and versatile influences has been proposed depending on the structure of the crushed material. The results of an experimental research of the destruction of rock samples on a press with limited force are given.

Abstract: Bacterial cellulose (BC) has applied as a versatile biomaterial in a wide variety of applications, such as biomedical devices, acoustics, electronics, and paper products. The controlling of the procedure could significantly improve the chemical and structure properties of the BC foams. This study aims to compare the features of BC foam that synthesized from BC disintegrated by a high-speed blender (HSB) and high-pressure homogenizer (HPH). The methods are the synthesis of BC using pineapple skin extract, disintegration process using both HSB and HPH following by freeze-drying process and characterization using X-Ray Diffraction (XRD), Scanning Electron Microscopy (SEM), and FTIR. The results show that freeze-drying to the pellicle did not produce a foam structure of BC. SEM morphology indicates that the disintegration process using HPH produces a better porous BC foam compared than HBS process. XRD analysis shows three peaks associated with the structure of BC, which are at 14.47°, 16.85°, and 22.69°. The crystalline structure of BC foam produced from HPH process has higher than BC foam produced from HBS process. FTIR analysis shows that there is a new peak find out in BC foam after the disintegration process.

Abstract: Thin film coatings on fingernails and toenails are used for aesthetic reasons or to strengthen fragile nails. Coating disintegration is one of the most important characteristics of short-term coatings. The aim of this research was to investigate adhesion test methods for UV-cured urethane acrylate coatings. Coatings was compared evaluating gel fraction and degree of conversion of C=C bonds. Adhesion was measured using pull-off adhesion test and coating removability was evaluated after coating soak-off in solvent media with cross-cut tester. Systems with four different monomers in two concentrations was evaluated. All systems show a strong correlation of adhesion with the time of disintegration.

Abstract: Fast development of nanotechnology leads to the top-down preparation of nanoparticles by various disintegration techniques taking a major part in the industrial sector. A very promising way seems to be the use of cavitation implosions. In our approach, the main mechanism of this type of disintegration is based on mutual collisions of solid microparticles in dense dispersions, powered by implosions of vapour cavitation bubbles generated between the particles.This paper presents experimental results of the disintegration of silicon microparticles to the sub-micron scale. In our experiments, the primary silicon particles of mean size of 5927 nm were reduced to 160 nm and 736 nm by the ultrasonic disintegration process after 240 minutes and at the ultrasonic frequency of 32 kHz. We also present a phenomenological model of particles erosive disintegration where particle fragments are approximated by spheres of equivalent volume. This model allows us to calculate the energy needed for successful disintegration of primary microparticles by measuring the particle size distribution. Thus, we can estimate the minimal energy conserved in the cavitation bubble alongside with its radius at a normal pressure of the surrounding liquid.

Abstract: The paper shows fundamental possibility of processing of gold-bearing technogenic raw materials using the method of electric explosion. A series of experiments using a laboratory and pilot-production high-voltage pulsed discharge (HVPD) installation for the processes of enrichment of gold-bearing mineral raw materials of Komsomolsk mine tailings in Kemerovo region is conducted with a relatively low energy electrical discharge in the pulse of up to 112.5 Joules and the cost of electric power of about 1.5 kW/ton of raw material, that allows complete destruction of clay components agglomerations to less than 0.045 mm (micron and submicron sizes). Solid minerals such as quartz are simultaneously destroyed by defects in the grains and withdrawn from the installation with water, thus increasing gold degree of the concentrate. The results of particle-size and X-ray structural analyses of gold-bearing mineral raw materials of Komsomolsk mine tailings in Kemerovo region obtained by the method of electric explosion are discussed.

Abstract: Mineral additives are materials which are used in wide range of industries including construction, cosmetics, agricultural and biotechnology. Such materials as plasters, paints, abrasives etc. are produced using mineral powders. Main qualities of mineral additives are purity of chemical composition, grading properties and shape factor. To obtain powder like material most common method is milling. One of most effective milling method for refining of brittle material is grinding by collision in disintegrator. One of advantage of this method is that high milling energy is transferred to the milling material in short period of time. In present research three types of mineral materials were treated in disintegrator with specific energy E_s applied 8.4 and 25.2 kWh/t: natural quartz sand 0.3/1mm, quartz-limestone 0.3/2.5mm sand and dolomite screenings 0/4mm. Results indicate that powder like material with d₉₀ form 66 to 141 µm could be obtained at E_s 8.4 kWh/t while increase of E_s reduces d₉₀ value to 48 to 72 µm and the milling efficiency was effected by the sand type.

Abstract: Determination of operational parameters of disintegrative machines and also other machines and devices is important in terms of effective management of the operation of machines, but also as an important indicator that can be used in the design process and dimensioning of machines and devices. Any operating parameters that we can measure and record during operation of the machine are significant help for understanding of processes which are taking place in the process and by this can be used for further improvement of structure and function of a machines or devices. The following article deals with the monitoring of operating parameters of disintegrative machine. It also describes the measurement methodology and evaluation of measured data.

Abstract: For comprehensive study the adverse engineering properties of Banxi Group slate along Changsha Metro Line 2, slate samples were tested and analyzed to research their mineral composition, physical and mechanical properties, weathered properties and disintegration. Test results show that sandy slate and argillite interbedded with each other, the main minerals of slate are quartz and clay minerals, the oxide are SiO2、Al2O3, the natural compressive strength of sandy slate is five to eight times that of argillite, its softening coefficient is less than 0.75, slate is easy to soften, argillite is easy to disintegration and the disintegration of sandy slate is medium grade. The adverse engineering characteristics lead to slate rock mass uneven with hard-soft. Differential weather of slate causes there are some bedrock weathered slots along Changsha Metro Line 2. So during construction, appropriate process and tool must be selected, control the tunnel oriented, strengthen the protection and shorten the bare time of rock mass.

Abstract: Carbon Mudstone will have a complicated change in the aspect of physics, chemistry and mechanics behavior when wet. Thus, it is difficult to describe the process in a quantitative standard. In order to find out the effect of testing conditions and water content, there are two different conditions in test drying and original state samples, one is outdoor test and the other is indoor soaking test. What’s more, Fractal Theory is used in the research of Carbon Mudstone. The result shows: A short-lived process of water absorption and weight increment appears in the initial disintegration; Different conditions will result in different destructional forms of samples; The key reason of disintegration is that wetting and drying cycle results in the change of water content; The difference of water content partly affects the process before disintegration, but less affects fractal dimension after disintegration.