70 research outputs found
Thermal Stability and Material Balance of Nanomaterials in Waste Incineration
Nanostructured materials are widely used to improve the properties of consumer products such as tires, cosmetics, light weight equipment etc. Due to their complex composition these products are hardly recycled and thermal treatment is preferred. In this study we investigated the thermal stability and material balance of nanostructured metal oxides in flames and in an industrial waste incinerator. We studied the size distribution of nanostructured metal oxides (CeO₂, TiO₂, SiO₂) in a flame reactor and in a heated reaction tube. In the premixed ethylene/air flame, nano-structured CeO₂ partly evaporates forming a new particle mode. This is probably due to chemical reactions in the flame. In addition sintering of agglomerates takes place in the flame. In the electrically heated reaction tube however only sintering of the agglomerated nanomaterials is observed. Ceria has a low background in waste incinerators and is therefore a suitable tracer for investigating the fate of nanostructured materials. Low concentrations of Ceria were introduced by a two-phase nozzle into the post-combustion zone of a waste incinerator. By the incineration of coal dust in a burning chamber the Ceria nanoparticles are mainly found in the size range of the fly ash (1 – 10 µm) because of agglomeration. With gas as a fuel less agglomeration was observed and the Ceria nanoparticles were in the particle size range below 1 µm
Thermische Stabilität von Nanopartikeln und Freisetzungsuntersuchungen an einer Sonderabfallverbrennungsanlage
Towards quantum 3d imaging devices
We review the advancement of the research toward the design and implementation of quantum plenoptic cameras, radically novel 3D imaging devices that exploit both momentum–position entanglement and photon–number correlations to provide the typical refocusing and ultra-fast, scanning-free, 3D imaging capability of plenoptic devices, along with dramatically enhanced performances, unattainable in standard plenoptic cameras: diffraction-limited resolution, large depth of focus, and ultra-low noise. To further increase the volumetric resolution beyond the Rayleigh diffraction limit, and achieve the quantum limit, we are also developing dedicated protocols based on quantum Fisher information. However, for the quantum advantages of the proposed devices to be effective and appealing to end-users, two main challenges need to be tackled. First, due to the large number of frames required for correlation measurements to provide an acceptable signal-to-noise ratio, quantum plenoptic imaging (QPI) would require, if implemented with commercially available high-resolution cameras, acquisition times ranging from tens of seconds to a few minutes. Second, the elaboration of this large amount of data, in order to retrieve 3D images or refocusing 2D images, requires high-performance and time-consuming computation. To address these challenges, we are developing high-resolution single-photon avalanche photodiode (SPAD) arrays and high-performance low-level programming of ultra-fast electronics, combined with compressive sensing and quantum tomography algorithms, with the aim to reduce both the acquisition and the elaboration time by two orders of magnitude. Routes toward exploitation of the QPI devices will also be discussed
Biological Effects in Lung Cells In Vitro of Exhaust Aerosols from a Gasoline Passenger Car With and Without Particle Filter
Iron Behaving Badly: Inappropriate Iron Chelation as a Major Contributor to the Aetiology of Vascular and Other Progressive Inflammatory and Degenerative Diseases
The production of peroxide and superoxide is an inevitable consequence of
aerobic metabolism, and while these particular "reactive oxygen species" (ROSs)
can exhibit a number of biological effects, they are not of themselves
excessively reactive and thus they are not especially damaging at physiological
concentrations. However, their reactions with poorly liganded iron species can
lead to the catalytic production of the very reactive and dangerous hydroxyl
radical, which is exceptionally damaging, and a major cause of chronic
inflammation. We review the considerable and wide-ranging evidence for the
involvement of this combination of (su)peroxide and poorly liganded iron in a
large number of physiological and indeed pathological processes and
inflammatory disorders, especially those involving the progressive degradation
of cellular and organismal performance. These diseases share a great many
similarities and thus might be considered to have a common cause (i.e.
iron-catalysed free radical and especially hydroxyl radical generation). The
studies reviewed include those focused on a series of cardiovascular, metabolic
and neurological diseases, where iron can be found at the sites of plaques and
lesions, as well as studies showing the significance of iron to aging and
longevity. The effective chelation of iron by natural or synthetic ligands is
thus of major physiological (and potentially therapeutic) importance. As
systems properties, we need to recognise that physiological observables have
multiple molecular causes, and studying them in isolation leads to inconsistent
patterns of apparent causality when it is the simultaneous combination of
multiple factors that is responsible. This explains, for instance, the
decidedly mixed effects of antioxidants that have been observed, etc...Comment: 159 pages, including 9 Figs and 2184 reference
c-kit Haploinsufficiency impairs adult cardiac stem cell growth, myogenicity and myocardial regeneration
An overdose of Isoproterenol (ISO) causes acute cardiomyocyte (CM) dropout and activates the resident cardiac c-kitpos stem/progenitor cells (CSCs) generating a burst of new CM formation that replaces those lost to ISO. Recently, unsuccessful attempts to reproduce these findings using c-kitCre knock-in (KI) mouse models were reported. We tested whether c-kit haploinsufficiency in c-kitCreKI mice was the cause of the discrepant results in response to ISO. Male C57BL/6J wild-type (wt) mice and c-kitCreKI mice were given a single dose of ISO (200 and/or 400 mg/Kg s.c.). CM formation was measured with different doses and duration of BrdU or EdU. We compared the myogenic and regenerative potential of the c-kitCreCSCs with wtCSCs. Acute ISO overdose causes LV dysfunction with dose-dependent CM death by necrosis and apoptosis, whose intensity follows a basal-apical and epicardium to sub-endocardium gradient, with the most severe damage confined to the apical sub-endocardium. The damage triggers significant new CM formation mainly in the apical sub-endocardial layer. c-kit haploinsufficiency caused by c-kitCreKIs severely affects CSCs myogenic potential. c-kitCreKI mice post-ISO fail to respond with CSC activation and show reduced CM formation and suffer chronic cardiac dysfunction. Transplantation of wtCSCs rescued the defective regenerative cardiac phenotype of c-kitCreKI mice. Furthermore, BAC-mediated transgenesis of a single c-kit gene copy normalized the functional diploid c-kit content of c-kitCreKI CSCs and fully restored their regenerative competence. Overall, these data show that c-kit haploinsufficiency impairs the endogenous cardioregenerative response after injury affecting CSC activation and CM replacement. Repopulation of c-kit haploinsufficient myocardial tissue with wtCSCs as well c-kit gene deficit correction of haploinsufficient CSCs restores CM replacement and functional cardiac repair. Thus, adult neo-cardiomyogenesis depends on and requires a diploid level of c-kit
Impact of transpulmonary thermodilution-based cardiac contractility and extravascular lung water measurements on clinical outcome of patients with Takotsubo cardiomyopathy after subarachnoid hemorrhage: a retrospective observational study
Removal of SO2 and the simultaneous removal of SO2 and NO from simulated flue gas streams using dielectric barrier discharge plasmas
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