Experimental investigations on the wear behaviour of micro-EDM-fabricated textured tools during dry turning of Ti6Al4V

Purpose This paper aims to focus on analysing the wear characteristics of tungsten carbide tools on which various micro patterns are fabricated to study its effect on the machinability of Ti-6Al-4V at dry turning conditions. Design/methodology/approach Micro-patterns such as dimples, linear grooves and a novel combination of dimples and linear grooves were fabricated on rake faces of uncoated tools by micro-EDM process. Impact of these patterns on tool wear and chip morphology characteristics under dry machining conditions were analysed, and their performances were compared with the non-textured tool (NTT). Findings Encouraging results in terms of minimal tool wear and favourable chip morphology characteristics were observed in case of all the textured tools, which demonstrated better tribological characteristics in contrast to NTT. The average flank wear was reduced by 43.5, 32 and 24.7% in dimple textured tool (DTT), linear textured tool (LTT) and hybrid textured tool (HTT), respectively, as compared to NTT. The average chip curl diameters measured for NTT, DTT, LTT, and HTT were observed to be 6.60, 3.51, 4.0 and 4.31 mm, respectively. Originality/value The contribution of this work lies in fabricating innovative patterns using cost-effective micro-EDM process and analysing how the patterns, depending upon their dimensional area and wear debris accumulation characteristics, influence the machinability of Ti-6Al-4V in the absence of any lubrication mediums.

Linguistic ambivalence amidst suburban diversity: LGBTQ2S municipal ‘social inclusions’ on Vancouver’s periphery

Social inclusion frameworks to enhance ‘diversity’ inform late neoliberal municipal governance in North American metropolitan areas, especially in central cities, but suburban LGBTQ2S constituencies are neglected by researchers. This paper, therefore, uses linguistic discourse and content analysis of an LGBTQ2S-inclusion archive of municipal public-facing communication in the Canadian peripheral municipalities of Burnaby, New Westminster, and Surrey, in the Vancouver city-region to trace the micro-patterns of linguistic ambivalence shaping suburban sexual citizenship. It demonstrates municipal variance in vernacular vocabularies of LGBTQ2S social inclusion that signals equivocation within divergent local linguistic political opportunity structures for suburban sexual and gender minorities. It concludes with a typological narration that details varied gradations of linguistic obfuscation, revealing patterns of civic ambivalence towards LGBTQ2S social inclusion amidst suburban diversity. Across a shared regional geography, the paper shows that LGBTQ2S populations are infrequently referenced relative to other marginalized social groups and that their presence in social inclusion frameworks is dictated by the extent to which they align with civic priorities, particularly festivalization and marketization, but also safety, welcoming newcomers, integrating seniors, and anti-discrimination initiatives.

СЕМАНТИЧНАТА ДЕРИВАЦИЯ КАТО ЕДИН ОТ НАЙ-ВАЖНИТЕ ВИДОВЕ ЕЗИКОВИ ИНОВАЦИИ (ВЪРХУ МАТЕРИАЛ ОТ СЪВРЕМЕННИ МЕДИЙНИ ТЕКСТОВЕ) / SEMANTIC DERIVATION AS A MAJOR TYPE OF LANGUAGE INNOVATION (BASED ON CONTEMPORARY MEDIA TEXTS)

The study focuses on the most productive patterns of semantic derivation, namely metaphorical and metonymic transfer, exemplified by contemporary Russian media texts. The metaphorical and metonymic patterns outlined in the study are based on the principle of anthropocentrism, which is realized in two interrelated directions highlighting the cognitive nature of semantic relations: 1) person → surrounding world (external personalization); 2) surrounding world → person (description in view of the extralinguistic reality). Specific micro patterns are based on the concrete → abstract macro pattern. It can be argued that semantic derivation functions as a means of linguistic ex-pression of ideas about intangible entities, thus creating the respective images in the mind of the addressee. The results of the study are of relevance to lexical semantics, cognitive linguistics, media linguistics, etc. Keywords: semantic derivation, metaphor, metonymy, Russian, media texts, anthropocentrism

Rapid construct superhydrophobic microcracks on the open-surface platform for droplet manipulations

Droplet-based transport driven by surface tension has been explored as an automated pumping source for several biomedical applications. This paper presented a simple and fast superhydrophobic modify and patterning approach to fabricate various open-surface platforms to manipulate droplets to achieve transport, mixing, concentration, and rebounding control. Several commercial reagents were tested in our approach, and the Glaco reagent was selected to create a superhydrophobic layer; laser cutters are utilized to scan on these superhydrophobic surface to create gradient hydrophilic micro-patterns. Implementing back-and-forth vibrations on the predetermined parallel patterns, droplets can be transported and mixed successfully. Colorimetry of horseradish peroxidase (HRP) mixing with substrates also reduced the reaction time by more than 5-times with the help of superhydrophobic patterned chips. Besides, patterned superhydrophobic chips can significantly improve the sensitivity of colorimetric glucose-sensing by more than 10 times. Moreover, all bioassays were distributed homogeneously within the region of hydrophilic micropatterns without the coffee-ring effect. In addition, to discuss further applications of the surface wettability, the way of controlling the droplet impacting and rebounding phenomenon was also demonstrated. This work reports a rapid approach to modify and patterning superhydrophobic films to perform droplet-based manipulations with a lower technical barrier, higher efficiency, and easier operation. It holds the potential to broaden the applications of open microfluidics in the future.

Rapid construct superhydrophobic microcracks on the open-surface platform for droplet manipulations

Droplet-based transport driven by surface tension has been explored as an automated pumping source for several biomedical applications. This paper presented a simple and fast superhydrophobic modify and patterning approach to fabricate various open-surface platforms to manipulate droplets to achieve transport, mixing, concentration, and rebounding control. Several commercial reagents were tested in our approach, and the Glaco reagent was selected to create a superhydrophobic layer; laser cutters are utilized to scan on these superhydrophobic surface to create gradient hydrophilic micro-patterns. Implementing back-and-forth vibrations on the predetermined parallel patterns, droplets can be transported and mixed successfully. Colorimetry of horseradish peroxidase (HRP) mixing with substrates also reduced the reaction time by more than 5-times with the help of superhydrophobic patterned chips. Besides, patterned superhydrophobic chips can significantly improve the sensitivity of colorimetric glucose-sensing by more than 10 times. Moreover, all bioassays were distributed homogeneously within the region of hydrophilic micropatterns without the coffee-ring effect. In addition, to discuss further applications of the surface wettability, the way of controlling the droplet impacting and rebounding phenomenon was also demonstrated. This work reports a rapid approach to modify and pattering superhydrophobic films to perform droplet-based manipulations with a lower technical barrier, higher efficiency, and easier operation. It holds the potential to broaden the applications of open microfluidics in the future.

Controlling T cells spreading, mechanics and activation by micropatterning

We designed a strategy, based on a careful examination of the activation capabilities of proteins and antibodies used as substrates for adhering T cells, coupled to protein microstamping to control at the same time the position, shape, spreading, mechanics and activation state of T cells. Once adhered on patterns, we examined the capacities of T cells to be activated with soluble anti CD3, in comparison to T cells adhered to a continuously decorated substrate with the same density of ligands. We show that, in our hand, adhering onto an anti CD45 antibody decorated surface was not affecting T cell calcium fluxes, even adhered on variable size micro-patterns. Aside, we analyzed the T cell mechanics, when spread on pattern or not, using Atomic Force Microscopy indentation. By expressing MEGF10 as a non immune adhesion receptor in T cells we measured the very same spreading area on PLL substrates and Young modulus than non modified cells, immobilized on anti CD45 antibodies, while retaining similar activation capabilities using soluble anti CD3 antibodies or through model APC contacts. We propose that our system is a way to test activation or anergy of T cells with defined adhesion and mechanical characteristics, and may allow to dissect fine details of these mechanisms since it allows to observe homogenized populations in standardized T cell activation assays.

A Simple Route of Printing Explosive Crystalized Micro-Patterns by Using Direct Ink Writing

The production of energetic crystalized micro-patterns by using one-step printing has become a recent trend in energetic materials engineering. We report a direct ink writing (DIW) approach in which micro-scale energetic composites composed of 1,3,5-trinitro-1,3,5-triazinane (RDX) crystals in selected ink formulations of a cellulose acetate butyrate (CAB) matrix are produced based on a direct phase transformation from organic, solvent-based, all-liquid ink. Using the formulated RDX ink and the DIW method, we printed crystalized RDX micro-patterns of various sizes and shapes on silicon wafers. The crystalized RDX micro-patterns contained single crystals on pristine Si wafers while the micro-patterns containing dendrite crystals were produced on UV-ozone (UVO)-treated Si wafers. The printing method and the formulated all-liquid ink make up a simple route for designing and printing energetic micro-patterns for micro-electromechanical systems.