273 research outputs found
Design Product-Service Systems by Using a Hybrid Approach: The Fashion Renting Business Model
As is known, sustainability issues represent one of the main challenges companies have to face. Among all, the fashion industry is considered one of the most impactful, both in terms of resource utilization and pollution. Fashion renting is a recent business model for companies to reduce their environmental footprint, following a circular economy approach. The study aims to develop and discuss the proposed hybrid approach to effectively support fashion companies in designing new business models, taking into account both the customer and the company perspective. On the one hand, agent-based modeling (ABM) allow us to represent customers’ behaviour and interaction. On the other hand, discrete event simulation (DES) paradigm is used to model fashion renting processes. Because customers’ attitude to that service reflects its successful implementation, motivators and barriers have been investigated to be included in the model. The practical implication is defining a model to support fashion companies in designing rental business models before implementing them. From a theoretical point of view, it overcomes the literature gap about the definition of a unique model for fashion renting, including processes, customers and interactions between agents. Follow-up research will include the presentation of simulation results
Genetic model for the color anomalies at the termination of pegmatitic gem tourmaline crystals from the island of Elba, Italy
Tourmaline crystals from the island of Elba commonly display a
sharp transition to dark colors at the analogous termination due to the
incorporation of Fe and/or Mn during the latest stages of crystallization
in pegmatites. The formation of such color anomalies is related to a
dramatic physicochemical change in the crystallization environment as a
consequence of an opening of the geochemical system. However, mechanisms
that may lead to the availability of Fe and/or Mn in the residual cavity fluids
have been unclear. On the basis of chemical and spectroscopic
investigations, combined with structural and paragenetic observations of the
cavities, we propose a general genetic model in which, as a consequence of a
pocket rupture event, chemical alteration of Fe- and Mn-rich
minerals that formed early in the pegmatitic rock surrounding the cavities occurred through
leaching processes, produced by the action of the highly reactive late-stage
cavity fluids. Such processes were responsible for the release of Fe and Mn
in the geochemical system, allowing the formation of the late-stage dark-colored terminations in the tourmaline crystals. In some cavities, a high
availability of Mn and/or Fe determined the evolution of the crystals from
an initial elbaite/fluor-elbaite composition to celleriite, foitite or
schorl. This compositional evolution trend can be described by the following general
chemical substitution: XNa+ + Y(Li1.5 + Al0.5)3+ + WF− ↔ X□ + 2Y(Fe,Mn)2+ + WOH−.</p
Gem-Quality Tourmaline from LCT Pegmatite in Adamello Massif, Central Southern Alps, Italy: An Investigation of Its Mineralogy, Crystallography and 3D Inclusions
In the early 2000s, an exceptional discovery of gem-quality multi-coloured tourmalines, hosted in Litium-Cesium-Tantalum (LCT) pegmatites, was made in the Adamello Massif, Italy. Gem-quality tourmalines had never been found before in the Alps, and this new pegmatitic deposit is of particular interest and worthy of a detailed characterization. We studied a suite of faceted samples by classical gemmological methods, and fragments were studied with Synchrotron X-ray computed micro-tomography, which evidenced the occurrence of inclusions, cracks and voids. Electron Microprobe combined with Laser Ablation analyses were performed to determine major, minor and trace element contents. Selected samples were analysed by single crystal X-ray diffraction method. The specimens range in colour from colourless to yellow, pink, orange, light blue, green, amber, brownish-pink, purple and black. Chemically, the tourmalines range from fluor-elbaite to fluor-liddicoatite and rossmanite: these chemical changes occur in the same sample and affect the colour. Rare Earth Elements (REE) vary from 30 to 130 ppm with steep Light Rare Earth Elemts (LREE)-enriched patterns and a negative Eu-anomaly. Structural data confirmed the elbaitic composition and showed that high manganese content may induce the local static disorder at the O(1) anion site, coordinating the Y cation sites occupied, on average, by Li, Al and Mn2+ in equal proportions, confirming previous findings. In addition to the gemmological value, the crystal-chemical studies of tourmalines are unanimously considered to be a sensitive recorder of the geological processes leading to their formation, and therefore, this study may contribute to understanding the evolution of the pegmatites related to the intrusion of the Adamello pluton
Hybrid fibroin/polyurethane small-diameter vascular grafts: from fabrication to in vivo preliminary assessment
To address the need of alternatives to autologous vessels for small-calibre vascular applications (e.g. cardiac surgery), a bio-hybrid semi-degradable material composed of silk fibroin (SF) and polyurethane (Silkothane (R)) was herein used to fabricate very small-calibre grafts (o(in) = 1.5 mm) via electrospinning. Bio-hybrid grafts were in vitro characterized in terms of morphology and mechanical behaviour, and compared to similar grafts of pure SF. Similarly, two native vessels from a rodent model (abdominal aorta and vena cava) were harvested and characterized. Preliminary implants were performed on Lewis rats to confirm the suitability of Silkothane (R) grafts for small-calibre applications, specifically as aortic insertion and femoral shunt. The manufacturing process generated pliable grafts consisting of a randomized fibrous mesh and exhibiting similar geometrical features to rat aortas. Both Silkothane (R) and pure SF grafts showed radial compliances in the range from 1.37 +/- 0.86 to 1.88 +/- 1.01% 10(-2) mmHg(-1), lower than that of native vessels. The Silkothane (R) small-calibre devices were also implanted in rats demonstrating to be adequate for vascular applications; all the treated rats survived the surgery for three months after implantation, and 16 rats out of 17 (94%) still showed blood flow inside the graft at sacrifice. The obtained results lay the basis for a deeper investigation of the interaction between the Silkothane (R) graft and the implant site, which may deal with further analysis on the potentialities in terms of degradability and tissue formation, on longer time-points
Product-service systems evolution in the era of Industry 4.0
Funder: Università degli studi di BergamoAbstract: Recent economic transformations have forced companies to redefine their value propositions, increasing traditional product offerings with supplementary services—the so-called Product-Service System (PSS). Among them, the adoption of Industry 4.0 technologies is very common. However, the directions that companies are undertaking to offer new value to their customers in the Industry 4.0 have not yet been investigated in detail. Based on a focus group, this paper contributes to this understanding by identifying the main trajectories that would shape a future scenario in which PSS and Industry 4.0 would merge. In addition, future research directions addressing (a) the transformation of the PSS value chain into a PSS ecosystem, (b) the transformation inside a single company towards becoming a PSS provider, and (c) the digital transformation of the traditional PSS business model are identified
NIPBL: a new player in myeloid cells differentiation
NUCLEOPHOSMIN1 (NPM1) is the most frequently mutated gene in acute myeloid leukemia. Notably, NPM1 mutations are always accompanied by additional mutations such as those in cohesin genes RAD21, SMC1A, SMC3, STAG2 but not in the cohesin regulator NIPBL. In this work, we analyze a cohort of adult patients with acute myeloid leukemia and NPM1 mutation and we observe specific reduction in the expression of NIPBL but not in other cohesin genes. In our zebrafish model, the overexpression of the mutated form of NPM1 also induced the down-regulation of nipblb, the zebrafish orthologue of the human NIPBL. To investigate the hematopoietic phenotype and the interaction between mutated NPM1 and nipblb, we generate a zebrafish model with nipblb down-regulation that shows an increased number of myeloid progenitors. This phenotype is due to a hyper activation of the canonical Wnt pathway: the rescue of myeloid cells blocked in an undifferentiated state is possible when the Wnt pathway is inhibited by ddk1b mRNA injection or indomethacin administration. Our results reveal for the first time a role for NIPBL during zebrafish hematopoiesis and suggest that NIPBL/NPM1 interplay may regulate myeloid differentiation in zebrafish and humans through the canonical Wnt pathway and that dysregulation of these interactions may drive to leukemic transformations
Status of QUBIC, the Q&U Bolometer for Cosmology
The Q&U Bolometric Interferometer for Cosmology (QUBIC) is a novel kind of
polarimeter optimized for the measurement of the B-mode polarization of the
Cosmic Microwave Back-ground (CMB), which is one of the major challenges of
observational cosmology. The signal is expected to be of the order of a few
tens of nK, prone to instrumental systematic effects and polluted by various
astrophysical foregrounds which can only be controlled through multichroic
observations. QUBIC is designed to address these observational issues with a
novel approach that combines the advantages of interferometry in terms of
control of instrumental systematics with those of bolometric detectors in terms
of wide-band, background-limited sensitivity.Comment: Contribution to the 2022 Cosmology session of the 33rd Rencontres de
Blois. arXiv admin note: substantial text overlap with arXiv:2203.0894
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