A Study on the Mechanical Properties of an Automobile Part Additively Printed through Periodic Layer Rotation Strategies

In metal product manufacturing, additive manufacturing (AM) is a method that has the advantage of fabricating complex shapes and customized production, unlike existing machining methods. However, owing to the characteristics of the AM process, anisotropy of macrostructure occurs because of various causes such as the scan direction, melting, fusion, and cooling of the powdered material. The macrostructure anisotropy is realized from the scan direction, and when a single layer is stacked in one direction, it is expressed as orthogonal anisotropy. Here, the classical lamination theory is applied to simply calculate the individual orthotropic layers by superimposing them. Through this, the authors analyzed whether the mechanical properties of the product are isotropically expressed with a periodic layer rotation strategy. To determine if the mechanical properties can be reasonably considered to be isotropic, a shock absorber mount for a vehicle was manufactured by AM. The tensile and vibration test performed on the product was compared with the finite element analysis and experimental results. As a result of the comparison, it was confirmed that the macroscopically of the product was considered isotropic as the load-displacement diagram and the fracture location coincided, as well as the natural frequency and mode shape.

Reduced dust generation when loading hoppers with powdered material. Part 1. Research methods

Расчетным путем показана целесообразность веерной загрузки бункеров порошкообразным сыпучим материалом. Предложена конструкция кольцевого загрузочного устройства, использующего эффект Коанда, для снижения пылеобразования. Численно и экспериментально определены рациональные конструктивно-технологические параметры разработанного устройства.

Reduced dust generation when loading hoppers with powdered material. Part 2. Results of numerical-experimental studies

On the basis of the obtained analytical dependencies, the expediency of fan loading of bunkers with powdery bulk material has been proved. The design of an annular charging device, which reduces dust formation, using the Coanda effect is proposed. The rational design and technological parameters of the developed device are numerically and experimentally determined.

Bio-Zirconium Metal–Organic Framework Regenerable Bio-Beads for the Effective Removal of Organophosphates from Polluted Water

Organophosphate-based pesticides, such as diazinon, are among the most toxic organic contaminants to human and environment. Effective removal of diazinon from contaminated water sources is critical. Zirconium Metal−organic frameworks (Zr-MOFs) are promising candidates for the removal of organic contaminants from wastewater. Herein, we report the adequacy of a bio based Zr-MOF named MIP-202 for the removal of diazinon from water. On the other hand, the use of these materials in powder form is not workable, the development of scalable and economical processes and integrative of these materials onto beads is paramount for industrial processes. Hence, it was reported a scalable, bio aqueous solution-based preparation strategy for Bio Zr-MOF beads production. The composite material exposed identical reactivity under the same ambient parameters compared to powdered material in an aqueous solution. These results signify a critical procedure to an integrated strategy for organophosphates removal using bio-based MOFs, which demonstrates high potential for manufacturing applications such as continued removal of organophosphates from wastewater supplies.

Compaction behavior of powder bed fusion feedstock for metal and polymer additive manufacturing

Purpose Powder bed-based additive manufacturing (AM) is a promising family of technologies for industrial applications. The purpose of this study is to provide a new metrics based on the analysis of the compaction behavior for the evaluation of flowability of AM powders. Design/methodology/approach In this work, a novel qualification methodology based on a camera mounted onto a commercially available tap density meter allowed to assess the compaction behavior of a selection of AM materials, both polymers and metals. This methodology automatizes the reading of the powder height and obtains more information compared to ASTM B527. A novel property is introduced, the “tapping modulus,” which describes the packing speed of a powdered material and is related to a compression/vibration powder flow. Findings The compaction behavior was successfully correlated with the dynamic angle of repose for polymers, but interestingly not for metals, shedding more light to the different flow behavior of these materials. Research limitations/implications Because of the chosen materials, the results may lack generalizability. For example, the application of this methodology outside of AM would be interesting. Originality/value This paper suggests a new methodology for assessing the flowing behavior of AM materials when subjected to compression. The device is inexpensive and easy to implement in a quality assurance environment, being thus interesting for industrial applications.

PHYTOCHEMICAL SCREENING, IN VITRO ANTIOXIDANT AND ANTI PROTEASE ACTIVITIES OF METHANOLIC EXTRACT OF NILGIRIANTHUS HEYNEANUS NEES STEM

Objective: The aim of this study was focussed on phytochemical screening, in vitro antioxidant and antiprotease activities of methanolic extract of Nilgirianthus heyneanus stem. Methods: The stem of the plant was washed thoroughly, shade dried and coarsely powdered. The powdered material of Niligirianthus heyneanus stem was extracted with methanol using soxhlet apparatus. Preliminary phytochemical screening for carbohydrates, proteins, alkaloids, phytosteroids, flavonoids, glycosides, polyphenolics, saponins, tannins was done by following standard procedure. In vitro antioxidant activities of methanolic extract were assessed using DPPH, ABTS and total antioxidant capacity. In vitro anti-protease activity of the plant was analysed using trypsin as an enzyme and BAEE (N-benzoyl-L-arginine ethyl ester) as a substrate. Results: The results showed that phytochemicals such as carbohydrates, proteins and amino acids, flavonoids, glycosides, tannins and polyphenolics are present in the methanolic extract of Niligirianthus heyneanus stem. The in vitro antioxidant and antiprotease activities of Niligirianthus heyneanus stem clearly showed that the plant has antioxidant and antiprotease activity. Conclusion: From this work, it can be concluded that Niligirianthus heyneanus stem has the potential to be a strong antioxidant and protease inhibitor.

Leonotis leonurus L. R. Br. (Lamiaceae): Anatomical features and recreational use survey of a possible substitute for Cannabis sativa L. (Cannabaceae)

Leonotis leonurusL. R. Br. (Lamiaceae) is a medicinal plant native to the South Africancontinent also employed as a recreational drug and a substitute to Cannabis sativaL. (Cannabaceae). Given the interest of the last mentioned species as a source of treatments for epilepsy among many other pathologies and its possible substitution for L. leonurus, the aim of this article is obtain anatomical and micrographical characters for its identification in chopped or powdered material and to survey the user ́s perceptions about this plant based in posts extracted from a recreational drug user Internet forum. L. leonurusleaves have pluricellular tector trichomes and two classes of pluricellular trichomes with unicellular and pluricellular heads, styloid crystals in its mesophyll among many other characters, while the flowers have wooly trichomes and characteristic pollen granules. Regarding the Internet forum survey, it was reported that L. leonurusleaves and flowers were the employed parts and that the mode of use was smoked. The reported effect was sedative. The anatomical data reported in this article may help to identify L. leonurusin pharmaceutical or forensic contexts.

Thermal Plasma Spray to Protect Large-Size Parts of Friction Joints against Wear

The authors thereof have developed a technology for application of wear-resistant coatings to protect against wear. The research team tested how efficiently powdered material could be heated in a plasma jet. They studied the physical and mechanical properties of coatings by kinetic micro-indentation and tested the plasma sprays for wear resistance. Tribological laboratory tests used the roller-on-roller method. Thus, WC/Co/Cr coatings had the most stable tribological properties and were more wear-resistant, compared to other tested coatings. Cylinder liners of heavy-duty diesel engines were enhanced by this technology. The pilot batch showed promise, as it might triple effectively the service life of diesel engines.

Effect of mesoporous silica and its combination with hydroxyapatite on the regeneration of rabbit’s bone defects: A pilot study

BACKGROUND: Bone volume augmentation is a routine technique used in oral implantology and periodontology. Advances in the surgical techniques and the biomaterials field have allowed a greater accessibility to these treatments. Nevertheless, dehiscence and fenestrations incidence during dental implant procedures are still common in patients with bone loss. OBJECTIVE: The main objective is to evaluate in a pilot experimental study the biological response to mesoporous silica (MS) hybrid scaffolds and its regenerative capacity in different formulations. METHODS: Two defects per rabbit tibia were performed (one for control and other for test) and the biomaterials tested in this study have been used to fill the bone defects, prepared in two different formulations (3D hybrid scaffolds or powdered material, in 100% pure MS form, or 50% MS with 50% hydroxyapatite (HA). Euthanasia was performed 4 months after surgery for bone histopathological study and radiographic images were acquired by computerized microtomography. RESULTS: Results showed that radiographically and histopathologically pure MS formulations lead to a lower biological response, e.g when formulated with HA, the osteogenic response in terms of osteoconduction was greater. CONCLUSIONS: We observed tolerance and lack of toxicity of the MS and HA, without registering any type of local or systemic allergic reaction.

Estimation of total tannins, total phenolics and total flavonoids of different extracts of cedrela toona roxb. Fruits.

Air dried powdered material of the fruits of cedrela toona Roxb. was successively extracted with petroleum ether, hexane, acetone, methanol and water extract by soxhlet extraction and subjected to various qualitative chemical tests to determine presence of various phytoconstituents like alkaloids, glycosides, carbohydrates, phenolics and tannins, phtosterols, fixed oils and fats, proteins, amino acids, flavonoids, saponins etc. Total flavonoids content was measured with the ‘Aluminium Chloride Colorimetric Assay Method’. Total Phenolic content in the aqueous and methanol extracts of fruits of Cedrela toona Roxb. were determined using the Folin Denis Method and expressed as mg of tannic acid equivalents per gram dry weight of extract. This study helps researchers for developmentof isolation method of active ingredient having vast pharmacological effects. Keywords: Cedrela toona, total flavonoids, total tannins and phenolics, Tannic acid