Micromechanical testing of Mo‐B‐C layers prepared by magnetron sputtering

Based on attractive mechanical properties of transition metal diborides the group of X2BC ternary compounds (X = Ti, V, Zr, Nb, Mo, Hf, Ta and W) became subject of theoretical calculations [1-3] and lately proved their applicability experimentally [4]. X2BC with X = Mo, Ta and W are the most promising candidates for protection of cutting and forming tools due to their unusually stiffness and moderately ductility. These properties can be understood by considering the electronic structure and particularly the extreme anisotropy (orthorhombic crystal lattice with a=0.309nm, b=1.735nm, c=0.305nm). Please click Additional Files below to see the full abstract

A Scoping Review of Home Produced Heroin and Amphetamine Type Stimulant Substitutes: Implications for Prevention, Treatment and Policy

Several home-produced substances such as krokodil and boltushka are prevalent in many Eastern European countries. Anecdotal reports of its use have been circulating in Germany and Norway; however, this has not been confirmed. Its use has also been reported by the media in the USA, although only one confirmed report of its use exists. Home-produced drugs are associated with high levels of morbidity and a number of complex health issues such as the spread of blood borne viruses, gangrene, and internal organ damage. The high incidence of HIV rates amongst people who inject home-produced substances is a public health concern. The resulting physical health consequences of injecting these crude substances are very severe in comparison to heroin or amphetamine acquired in black markets. Due to this fact and the increased mortality associated with these substances, professionals in the area of prevention, treatment, and policy development need to be cognisant of the presentation, harms, and the dangers associated with home-produced substances globally. This scoping review aimed to examine existing literature on the subject of home-produced heroin and amphetamine-type stimulant substitutes. The review discussed the many implications such research may have in the areas of policy and practice. Data were gathered through the use of qualitative secondary resources such as journal articles, reports, reviews, case studies, and media reports. The home production of these substances relies on the utilisation of precursor drugs such as less potent stimulants, tranquillizers, analgesics, and sedatives or natural plant ingredients. The Internet underpins the facilitation of this practice as recipes, and diverted pharmaceutical sales are available widely online, and currently, ease of access to the Internet is evident worldwide. This review highlights the necessity of prevention, education, and also harm reduction related to home-produced drugs and also recommends consistent monitoring of online drug fora, online drug marketplaces, and unregulated pharmacies

Productive Machining of Complex Shape Parts

This paper deals with technological conditions that are achieved during multi-axis milling operations. The work is focused on the improvement of quality and productivity of machining of complex shape parts. The importance of feed-rate analysis during multi-axis machining operations is mentioned. A postprocessor algorithm for correction of relative feed-rate during multi-axis machining operations has been proposed. The postprocessor generates corrected feed-rate for each block of an NC program when a multi-axis interpolation is found. Thanks to this new postprocessor algorithm, better conditions are achieved during multi-axis machining operations and also a shorter time for NC program execution when it is used without the Tool Center Point transformation. Practical benefits and the functionality of the postprocessor algorithm have been tested by machining the blade containing multi-axis tool paths

Effect of bonding structure on hardness and fracture resistance of W-B-C coatings with varying B/W ratio

Low ductility and brittle deformation behaviors are major drawbacks of currently used commercial hard ceramic-based protective coatings. Recent ab-initio calculations revealed that the coexistence of metallic, boride and carbide bonds in a nanolaminate structure of crystalline W2BC system provides a combination of high hardness together with moderate ductility. The present paper deals with coatings containing W, B and C with different compositions and investigates the effect of the boron to tungsten ratio (B/W) on the structural and mechanical properties of W-B-C coatings prepared by pulsed-DC magnetron sputtering at a moderate temperature. Coatings with low B/W were deposited in a nanocomposite structure, whereas coatings with high B/W ratios were near-amorphous. The structure of the coatings was not a decisive factor in determining their mechanical properties. These were, however, directly correlated with the chemical bonds present. All the coatings exhibited high fracture resistance. These properties together with good adhesion to cemented tungsten carbides make W-B-C coatings promising candidates for the future protective coatings of tools which undergo large deformation in their working cycle