Environmental Impact Assessment Studies in Additive Manufacturing

International audienceThis chapter focuses on the environmental studies in additive manufacturing. For a cleaner production, environmental impacts that occur during the manufacturing phase should be assessed with accuracy. First, the literature on all the studies led to the characterization of the environmental impact of additive manufacturing processes. The studies on electric energy consumption of these processes are analyzed here, and then some studies taking into account raw material and all the flows through the process are detailed. Secondly, a new methodology in order to evaluate, with accuracy, the environmental impact of a part from its CAD model is presented. In this methodology, the work is not focused only on electrical consumption but also on fluids and material consumption which also contribute to the environmental impact. In addition, the inputs of this methodology correspond to the set part process, which allows taking into account different manufacturing strategies and their influences on the global environmental impact. The methodology developed is based on both analytic models (validated by experiments) and experimental models. And finally, an industrial example shows that for some manufacturing strategies, the environmental impact due to electrical consumption is not the predominant one. In this case study, material consumption has an important impact and has to be taken into consideration for a complete environmental impact assessment

Device for providing a radiation treatment

The present relates to a device for providing a radiation treatment to a patient comprising :- an electron source for providing a beam of electrons, and- a linear accelerator for accelerating said beam until a predetermined energy, and - a beam delivery module for delivering the accelerated beam from said linear accelerator toward the patient to treat a target volume with a radiation dose, The device further comprises intensity modulation means configured to modulate the distribution of the radiation dose in the target volume according to a predetermined pattern.The pattern is determined to match the dimensions of a target volume of at least about 50 cm3, and/or a target volume located at least about 5 cm deep in the tissue of the patient with said radiation dose,The radiation dose distributed is up to about 20 Gy delivered during an overall treatment time less than about 50 ms

Environmental performance modeling for additive manufacturing processes

International audienceSustainability means considering economic, social and environmental aspects. In the mechanical product design field, sustainability means thinking about eco-design and life cycle analysis, when the whole life cycle of the product (from raw material extraction to end of life) is concerned with environmental impacts. Nowadays, most of the manufacturing methods are driven only by money, and the environmental and social aspects are not taken into account. The goal of this paper is to propose an environmental assessment methodology of the manufacturing processes. In this methodology, all flows consumed and produced (material, fluids, electricity) are considered. A predictive model of flow consumption is defined from the CAD model of the product and the manufacturing program. The aim is to be able to minimize the environmental impacts of the manufacturing during the design stage. In this paper, the focus is put on additive manufacturing

Heat-induced and spontaneous expression of Hsp70.1Luciferase transgene copies localized on Xp22 in female bovine cells

<p>Abstract</p> <p>Background</p> <p>Expression of several copies of the heat-inducible <it>Hsp70.1Luciferase </it>(<it>LUC</it>) transgene inserted at a single X chromosome locus of a bull (<it>Bos taurus</it>) was assessed in females after X-chromosome inactivation (XCI). Furthermore, impact of the chromosomal environment on the spontaneous expression of these transgene copies before XCI was studied during early development in embryos obtained after in vitro fertilization (IVF), when the locus was carried by the X chromosome inherited from the bull, and after somatic cell nuclear transfer (SCNT) cloning, when the locus could be carried by the inactive Xi or the active Xa chromosome in a female donor cell, or by the (active) X in a male donor cell.</p> <p>Findings</p> <p>Transgene copies were mapped to bovine Xp22. In XX^{<it>LUC </it>}female fibroblasts, i.e. after random XCI, the proportions of late-replicating inactive and early-replicating active X^{<it>LUC </it>}chromosomes were not biased and the proportion of cells displaying an increase in the level of immunostained luciferase protein after heat-shock induction was similar to that in male fibroblasts. Spontaneous transgene expression occurred at the 8-16-cell stage both in transgenic (female) embryos obtained after IVF and in male and female embryos obtained after SCNT.</p> <p>Conclusions</p> <p>The X^{<it>LUC </it>}chromosome is normally inactivated but at least part of the inactivated X-linked <it>Hsp70.1Luciferase </it>transgene copies remains heat-inducible after random XCI in somatic cells. Before XCI, the profile of the transgenes' spontaneous expression is independent of the epigenetic origin of the X^{<it>LUC </it>}chromosome since it is similar in IVF female, SCNT male and SCNT female embryos.</p

Analysis of Sugar Component of a Hot Water Extract from Arabidopsis thaliana Pollen Tubes Using GC-EI-MS

International audienceExtraction with hot water is the oldest and simplest method used to recover pectin from an alcohol insoluble residue extract, although this method has not been widely used for the cell wall analysis of pollen tube, a model used to study cell wall. This protocol described this method applied for pectin extraction from 6 h-old Arabidopsis pollen tubes followed by a sugar composition analysis by gas chromatography mass spectrometry

Characterization of particle distribution in a black carbon-filled elastomer via nanoindentation

A new method to characterize the distribution of hard particles dispersed into a soft elastomer matrix is developed using nanoindentation. It is based on the measurement of the contact stiffness from the continuous stiffness measurement module (CSM). Theoretically, for a homogeneous material, the contact stiffness is directly proportional to the contact depth. However, when indenting a carbon black-filled fluoroelastomer (FKM) this relation is no longer valid and abnormal contact stiffness evolutions are measured (jumps). The tip-particle model developed in this work is simply based on the hypothesis that all the deformation is supported by the elastomer matrix and that black carbon aggregates play the role of hard extensions of the diamond tip, when touching it (grey particles 1,2 & 3, Fig. 1a). As a result, each abnormal variation of contact stiffness is related to a new aggregate in contact with the tip. By knowing the stiffness amplitude of a jump and the relative stiffness where it appeared , the equivalent projected area of a particle can be calculated (Fig. 1d). From this calculation, one can extract the distribution of particles surface density from nanoindentation measurements only. Ten experimental indentation tests have been performed and the results are displayed in Fig. 1e. The distribution of particles surface density extracted from experiments is compared to measurements performed by image analysis of a 100 nm thick slide of the material observed by Transmission Electron Microscopy (TEM) (black squares). Furthermore, the tip-particle model is simulated numerically on the same image analysis (down pointing triangles). The results obtained from this model are in excellent agreement with the TEM observation which is really promising. Indeed, this model is an alternative to microscopy characterization which can be complicated to implement. Please click Additional Files below to see the full abstract

Therapeutic protein transduction of mammalian cells and mice by nucleic acid-free lentiviral nanoparticles

The straightforward production and dose-controlled administration of protein therapeutics remain major challenges for the biopharmaceutical manufacturing and gene therapy communities. Transgenes linked to HIV-1-derived vpr and pol-based protease cleavage (PC) sequences were co-produced as chimeric fusion proteins in a lentivirus production setting, encapsidated and processed to fusion peptide-free native protein in pseudotyped lentivirions for intracellular delivery and therapeutic action in target cells. Devoid of viral genome sequences, protein-transducing nanoparticles (PTNs) enabled transient and dose-dependent delivery of therapeutic proteins at functional quantities into a variety of mammalian cells in the absence of host chromosome modifications. PTNs delivering Manihot esculenta linamarase into rodent or human, tumor cell lines and spheroids mediated hydrolysis of the innocuous natural prodrug linamarin to cyanide and resulted in efficient cell killing. Following linamarin injection into nude mice, linamarase-transducing nanoparticles impacted solid tumor development through the bystander effect of cyanid