EXPERIENCE OF INSPECTION OF DAMAGES OF METAL BEARING STRUCTURES

The article deals with the damaged metal structural elements of the out-center compressed I-pillar, corner of a single corner and others. The work of the metal element in the elastic region was experimentally studied and compared with the results of FEM calculation using ANSYS software. Good convergence of results (less than 5%) is received at calculation of stresses in a place of death of the damaged basic brace of a truss of an industrial building. The reliability of the truss element with a defect (0.892) and without it (1.0) and the category of technical condition before and after damage are determined. Despite the fact that the voltage at the site of the defect does not exceed the maximum permissible, the category of technical condition changes from serviceable to serviceable category, and the design itself must be repaired with the elimination of damage on the support strip.

Hetero-Element-Doped Molybdenum Oxide Materials for Energy Storage Systems

In order to meet the growing demand for the electronics market, many new materials have been studied to replace traditional electrode materials for energy storage systems. Molybdenum oxide materials are electrode materials with higher theoretical capacity than graphene, which was originally used as anode electrodes for lithium-ion batteries. In subsequent studies, they have a wider application in the field of energy storage, such as being used as cathodes or anodes for other ion batteries (sodium-ion batteries, potassium-ion batteries, etc.), and electrode materials for supercapacitors. However, molybdenum oxide materials have serious volume expansion concerns and irreversible capacity dropping during the cycles. To solve these problems, doping with different elements has become a suitable option, being an effective method that can change the crystal structure of the materials and improve the performances. Therefore, there are many research studies on metal element doping or non-metal doping molybdenum oxides. This paper summarizes the recent research on the application of hetero-element-doped molybdenum oxides in the field of energy storage, and it also provides some brief analysis and insights.

Influence of Reaction Time, Temperature And Heavy Metal On Characteristics of Cellulose- And Wood-Derived Hydrochars From Hydrothermal Carbonization

Hydrothermal carbonization (HTC) is a promising technique to convert biomass into valuable solid fuels. In this work, cellulose and wood-derived hydrochars were synthesized under hydrothermal carbonization conditions with different temperatures (200-250 ℃), reaction times (6 h or 12 h) and to determine their influence on hydrochars. Heavy metal element zinc is chosen to introduce into samples to simulate the heavy metal accumulate in biomass. The physical, chemical, and combustion properties of the hydrochars revealed that the majority of cellulose and wood conversion occurs at first 6 h, and faster conversion occurs at higher temperatures. The content of fixed carbon in the cellulose-derived hydrochar is higher than in wood-derived hydrochar. Moreover, cellulose is easier to be carbonized during HTC reaction than wood. O/C and H/C ratios of all hydrochars were similar to those of lignite and decreased with increasing reaction temperature. The composition of solids recovered after 12 h is similar at all temperatures, consisting primarily of sp2 carbons (furanic and aromatic groups) and alkyl groups. When a large amount of metal is introduced, part of the metal is combined with the energetic group, while the rest condense on the surface of the sample as zinc ions.