Influence of mesostasis in volcanic rocks on the alkali-aggregate reaction

Mesostasis material present in the interstices of volcanic rocks is the main cause of the alkali-aggregate reaction (AAR) in concretes made with these rock aggregates. Mesostasis often is referred to as volcanic glass, because it has amorphous features when analyzed by optical microscopy. However, this study demonstrates that mesostasis in the interstitials of volcanic rocks most often consists of micro to cryptocrystalline mineral phases of quartz, feldspars, and clays. Mesostasis has been identified as having different characteristics, and, thus, this new characterization calls for a re-evaluation of their influence on the reactivity of the volcanic rocks. The main purpose of this study is to correlate the characteristics of mesostasis with the AAR in mortar bars containing basalts and rhyolites.     

Stereoscopy and Scanning Electron Microscopy of Brazil Nut (Bertholletia excelsa H.B.K.) Shell,Brown Skin,and Edible Part: Part One—Healthy Nut

In this article, tissue layers and cells characteristics of the Brazil nut (Bertholletia excelsa H.B.K.) shell (tegument), brown skin (testae), and edible part (cotyledons) were identified by stereoscopy (SM) and scanning electron microscopies (SEM). (a) The shell (a lignin rich, protective wall) varies in thickness throughout the nut structure and comprises different tissue types (total 3)/texture (hard/mid‐hard/soft), layers (2 to 5), colors (light to dark brown and white to cream), cell shape (amorphous/flattened on both surfaces; polygonal and cylindrical with thick, porous primary and secondary wall in cross‐section), and vascular distribution (helically and polyedrical thickened vessels at soft tissue and locule/channel structures). These variations are observed either in the shell faces, face corners, nut tips, or locule in testae. (b) The brown skin (shell nut part linked to both the shell and edible part) is made of flattened irregular‐shaped parenchymal cells distributed in several layers with more flexible fibrous, thinner wall tissue than shell. It has both rough and smooth shiny texture on the upper and lower surfaces, respectively. However, the nut (c) edible part, that is the nut storage tissue, shows several different tissue/cell layers starting from epidermis (double/triple cells sequence of round and palisade shapes) layer–the endosperm tissue. The parenchymal tissues show cells of irregular shape with small and larger sizes distributed in regular and randomly layers, respectively, separated by a short meristem tissue layer. The cortex cells increase in size as they approach the cotyledons junction. The Brazil nut part's tissue layers and cells were identified by the SM and SEM microscopy methods applied, which provides knowledge for further understanding of nut alterations that may occur either in the forest or during the factory processing.     

DEM modelling analysis of tree root growth in street pavements

The coexistence of urban green spaces and infrastructure is often difficult. Trees find inhospitable environments in urban areas, whereas tree root systems can damage sidewalk, street and parking lot. The main form of failure concerns the growing of tree roots beneath the pavements, which produce upheavals and displacements on wearing course. The main objective of this study was a distinct element method modelling analysis of the potential interactions between tree root systems and street pavements. This calculation code allowed us to simulate the dynamic behaviour of the ground-pavement system as result of the roots growth. The performed modelling, representative of various planting strategies commonly used in urban contexts, have highlighted the progressive reduction of deformations with the increase of the roots penetration depth. Such displacements were strongly influenced by other factors such as the porosity and the grain-size distribution of the soil and the type of pavement considered.     

Generating value across academic and professional design practice in the Internet of Things

ABSTRACT

This article accounts for how value in design research can be derived from knowledge exchange that occurs through the collaborative discourse of doing design. To demonstrate this point, the article details the arc and impact of a design research collaboration that extended over several years with design practitioners in the field of internet-connected devices. As a result of this ongoing collaborative work, a programmatic set of design ideals and intentions concerning how to construct a more transparent and ethical relationship with technology was shaped. We examine this sustained and transformative collaboration as a series of knowledge exchanges. Within each particular collaborative project, worldviews and knowledge are exchanged among design researchers and practitioners, enabling them to traverse ‘through practices’ of academic and professional design. To unpack these exchanges and how they built and fed into each other, the article examines how collaboration unfolded and produced value on two levels: first on the scale of the academics and practitioners directly involved in a project; and secondly on the scale of the larger international community of design practitioners concerned with Internet-connected devices, with whom we had shared our work.     

Microbiological and physicochemical characterisation of green table olives of Halkidiki and Conservolea varieties processed by the Spanish method on industrial scale

The microbiological and physicochemical changes of industrially fermented Halkidiki and Conservolea green table olives were determined. Samples were analysed to monitor the population of lactic acid bacteria (LAB), yeasts and Enterobacteriaceae, together with changes in pH, acidity, salinity, colour, lactic acid, acetic acid and ethanol. LAB and yeast species diversity was evaluated at the beginning (1 day), middle (75 days) and final (135 days) stages of fermentation by RAPD-PCR genomic fingerprinting. Results revealed vigorous lactic acid processes as indicated by the dominance of LAB over yeasts. No Enterobacteriaceae could be detected after 30 days. Lactiplantibacillus plantarum (formerly Lactobacillus plantarum) dominated in the beginning of fermentation in both varieties. In the end, Lactiplantibacillus pentosus (formerly Lactobacillus pentosus) and Pediococcus ethanolidurans prevailed in Halkidiki and Conservolea varieties, respectively. As for yeasts, Kluyveromyces lactis/marxianus and Pichia manshurica prevailed at the onset of fermentation in Halkidiki and Conservolea varieties, whereas in the end Pichia membranifaciens dominated in both varieties.     

Field‐based robotic phenotyping of sorghum plant architecture using stereo vision

Sorghum (Sorghum bicolor) is known as a major feedstock for biofuel production. To improve its biomass yield through genetic research, manually measuring yield component traits (e.g. plant height, stem diameter, leaf angle, leaf area, leaf number, and panicle size) in the field is the current best practice. However, such laborious and time‐consuming tasks have become a bottleneck limiting experiment scale and data acquisition frequency. This paper presents a high‐throughput field‐based robotic phenotyping system which performed side‐view stereo imaging for dense sorghum plants with a wide range of plant heights throughout the growing season. Our study demonstrated the suitability of stereo vision for field‐based three‐dimensional plant phenotyping when recent advances in stereo matching algorithms were incorporated. A robust data processing pipeline was developed to quantify the variations or morphological traits in plant architecture, which included plot‐based plant height, plot‐based plant width, convex hull volume, plant surface area, and stem diameter (semiautomated). These image‐derived measurements were highly repeatable and showed high correlations with the in‐field manual measurements. Meanwhile, manually collecting the same traits required a large amount of manpower and time compared to the robotic system. The results demonstrated that the proposed system could be a promising tool for large‐scale field‐based high‐throughput plant phenotyping of bioenergy crops.     

Synthesis and characterization of a titanium phosphate-tellurite glass for Faraday rotators

This work is focused on investigation of thermal, structural, optical, magnetic, and magneto-optical properties of novel titanium phosphate-tellurite glass applied as Faraday rotators. The glass belonging to the system 35Li₂O–10Al₂O₃–5TiO₂–45P₂O₅–5TeO₂ was prepared by a nonconventional wet route of raw materials processing, followed by melting-quenching-annealing steps. Some important physical properties of the investigated glass have been measured and calculated, providing knowledge related to glass compactness, electronic structure, glass forming capability, etc. XRD analysis evidenced an amorphous network structure of the investigated glass. The optical absorption in the Vis domain is mainly due to Ti³⁺ ions and Te₂ clusters formed during the glass melting process. A relatively low optical absorption is noticed over 600 nm that activates a significant Faraday magneto-optical effect. Photoluminescence bands in the blue, red, and infrared domains are observed, caused by Te₂ clusters formed during the glass melting process. The magnetization in dependency on applied magnetic field reveals a complex behavior of the glass, depending on temperature. Thus, it is found a ferromagnetic behavior up to 2000 Oe, a paramagnetic component up to 40 000 Oe, followed by a diamagnetic one over 40 000 Oe. Faraday rotation angle and Verdet constant values in the visible domain are correlated with the reduced TeO₂ content of the glass.     

Femtosecond-laser selective printing of graphene oxide and PPV on polymeric microstructures

Direct laser writing techniques are suitable for the high precision-patterning of 2D and 3D micro/nanostructures, featuring a variety of geometries and materials. Here, we demonstrated the use of laser-induced forward transfer with fs-pulses (fs-LIFT) to selectively transfer graphene oxide and poly(p-phenylene vinylene) patterns onto polymeric microstructures, fabricated by two-photon polymerization. The influence of different fs-LIFT experimental parameters on the width and height of the printed patterns was investigated. Upon optimum fs-LIFT parameters, we achieved homogeneous printed areas of both materials onto specific regions of the microstructures. Raman spectroscopy confirmed that fs-LIFT does not change the donor material upon transfer. Overall, this work demonstrates a promising strategy with precise printing capabilities, thus opening new opportunities for the development of photonic and optoelectronic devices.