Bamboo as future bio-industrial material: Physical behaviour and bending strength of Malaysia’s Beting bamboo (Gigantochloa levis)

In this paper, bending strength and physical properties (specific gravity, dimensional stability and equilibrium moisture content) of a Malaysian bamboo locally known as Beting bamboo (Gigantochloa levis) are addressed. Characterizations of physical and bending strength of G. levis in terms of the variability of location along culm height (top, middle, bottom), culm section (nodes and internodes), fiber orientation (longitudinal, tangential and radial) and culm layer (outer and inner) were conducted. Comparison of these properties is also made to some bamboo and commercial timber species. It was found that G. levis has favorable physical and mechanical properties although the specific gravity of G. levis has tendency to be on the higher side. The characteristics studied were found to have some variability at different locations, sections, and directions. There was variability in terms of bending strength along with the culm height of bamboo. It is indicated from this study that the bending strength and physical properties of G. levis were found to be satisfactory.

ESTIMATION OF INDUSTRIAL MATERIAL FLOW PRODUCED BY „DEVNYA CEMENT“AD FOR REMEDIATION OF ACID SPILS

The issues of acidity and liming of soils were raised in Bulgaria more than 60-70 years ago. „Devnya Cement“ produces the Restart product, as an integral part of the process in the installation of cement clinker in a dry way and contains a high amount of calcium oxide (lime material). The aim of the study is to establish the effect of the studied product RESTART and possibilities for its use as an ameliorant on acid soils. A vegetation experiment was performed with a test crops of corn with different percentages of ameliorant. The chemical and physico-mechanical parameters of the treated soil were studied and the changes in the degree of soil acidity were established. Preliminary consumption rates of the ameliorant have been determined, when it is used for amelioration of acid soils. The chemical characteristics of the plant samples show, that the values of the chemical elements are in optimal concentrations and cannot have a harmful effect, when used as animal feed. To correct the acidity of soils with similar acidic properties as in the Devnya region, it may be recommended to apply about 1-2t/daa of the studied ameliorant.

Genotoxic Potential of Nanoparticles: Structural and Functional Modifications in DNA

The rapid advancement of nanotechnology enhances the production of different nanoparticles that meet the demand of various fields like biomedical sciences, industrial, material sciences and biotechnology, etc. This technological development increases the chances of nanoparticles exposure to human beings, which can threaten their health. It is well known that various cellular processes (transcription, translation, and replication during cell proliferation, cell cycle, cell differentiation) in which genetic materials (DNA and RNA) are involved play a vital role to maintain any structural and functional modification into it. When nanoparticles come into the vicinity of the cellular system, chances of uptake become high due to their small size. This cellular uptake of nanoparticles enhances its interaction with DNA, leading to structural and functional modification (DNA damage/repair, DNA methylation) into the DNA. These modifications exhibit adverse effects on the cellular system, consequently showing its inadvertent effect on human health. Therefore, in the present study, an attempt has been made to elucidate the genotoxic mechanism of nanoparticles in the context of structural and functional modifications of DNA.

Strength Enhancement of Superduplex Stainless Steel Using Thermomechanical Processing

The impact of microstructure evolution on mechanical properties in superduplex stainless steel UNS S32750 (EN 1.4410) was investigated. To this end, different thermomechanical treatments were carried out in order to obtain clearly distinct duplex microstructures. Optical microscopy and scanning electron microscopy, together with texture measurements, were used to characterize the morphology and the preferred orientations of ferrite and austenite in all microstructures. Additionally, the mechanical properties were assessed by tensile tests with digital image correlation. Phase morphology was not found to significantly affect the mechanical properties and neither were phase volume fractions within 13% of the 50/50 ratio. Austenite texture was the same combined Goss/Brass texture regardless of thermomechanical processing, while ferrite texture was mainly described by α-fiber orientations. Ferrite texture and average phase spacing were found to have a notable effect on mechanical properties. One of the original microstructures of superduplex stainless steel obtained here shows a strength improvement by the order of 120 MPa over the industrial material.

Process monitoring for material extrusion additive manufacturing: a state-of-the-art review

Qualitative uncertainties are a key challenge for the further industrialization of additive manufacturing. To solve this challenge, methods for measuring the process states and properties of parts during additive manufacturing are essential. The subject of this review is in-situ process monitoring for material extrusion additive manufacturing. The objectives are, first, to quantify the research activity on this topic, second, to analyze the utilized technologies, and finally, to identify research gaps. Various databases were systematically searched for relevant publications and a total of 221 publications were analyzed in detail. The study demonstrated that the research activity in this field has been gaining importance. Numerous sensor technologies and analysis algorithms have been identified. Nonetheless, research gaps exist in topics such as optimized monitoring systems for industrial material extrusion facilities, inspection capabilities for additional quality characteristics, and standardization aspects. This literature review is the first to address process monitoring for material extrusion using a systematic and comprehensive approach.

Research into the chemical composition of refinery slag from silicon production for its efficient recycling

The aim was to investigate the chemical composition of refinery slag obtained during silicon production in order to identify approaches to its further recycling. Research samples were collected from the slag remained after oxidation refining at the JSC Silicon (AO Kremny), RUSAL (Shelekhov, Irkutsk Oblast). The methods of X-ray phase, X-ray fluorescence, metallographic and scanning electron microscopy were employed to investigate the chemical composition of the samples. It was found that the refinery slag under study includes such basic components as elemental silicon, its carbide and oxide, as well as elemental carbon. It was shown that silicon carbide is the product of incomplete reduction, resulting from melting silica-containing ores in a smelting furnace. According to the conducted X-ray fluorescent analysis, the samples also contain (wt %): Ca - 7.40; Al - 3.80; Fe - 0.30; Ba - 0.19; K - 0.14; Na - 0.09; Sr - 0.09; Mg - 0.08; Ti - 0.05; S - 0.02. Calcium and aluminium are present in the slag mostly in the form of oxides. Complex oxides of an anor-thite type were also found: CaO Al2O3 2SiO2. The refinery slag under study also features insignificant amounts of other metal oxides, which are released from the furnace slag forming during the smelting process. The slag produced by oxidation refining during crystalline silicon production is a technogenic raw material containing valuable components. Due to the significant content of silicon in the refinery slag (from 42% to 65%), the existing methods applied to recycle such an industrial material were analysed in terms of additional silicon extraction or production of commercial silicon-containing products, which are in demand in various industries.

Isolation, modification and characterisation of cellulose from wild Dioscorea bulbifera

This study attempted to valorise wild Dioscorea bulbifera yam presently known to be poisonous and inedible obtained from three sources. The functional properties as well as its chemical composition were determined and isolated. Isolated cellulose was modified by the actions of sodium hydroxide and maleic anhydride. The biomass, isolated products and modified cellulose were characterized. Results showed that the highest cellulose obtained was 82.6%. FT-IR results showed successful modification of cellulose with the presence of a carbonyl (C = O) adsorption band at around 1725 cm-1. SEM images and XRD data showed a clear decrease in crystallinity but a slight increase in crystallite size after modification of the mercerized cellulose. TGA results showed the polymers degraded between 284 and 414 °C. The study reveals that the modified cellulose has potential application as an adsorbent and industrial material.

Low melting oxide glasses prepared at a melt temperature of 500 °C

Transparent low-melting inorganic glass is an attractive industrial material based on its high thermal and light resistance compared with conventional engineering plastics. If the melting temperature of inorganic glass could be decreased, the doping of guest materials or compression moulding on the glass surface would be easier. Although phosphate glass is considered as a potential candidate because of its transparency in the visible region and low-melting behaviour, water durability often becomes a problem for implementation. Here, we prepared inorganic low-melting phosphate glass at a temperature of 500 °C via a melting and quenching methodology. It was found that tin-doped phosphate glasses exhibited higher thermal and light resistance properties than polycarbonates. Colourless transparent oxide glasses without organic components are capable of bringing about new possibilities for the application of inorganic glasses.