Using full-scale duckweed ponds as the finish stage for swine waste treatment with a focus on organic matter degradation

Artigo Publicado em: IWA - Water Science & TechnologyThe rapid increase in the number of swine has caused pronounced environmental impacts worldwide, especially on water resources. As an aggregate, smallholdings have an important role in South American pork production, contributing to the net diffusion of pollution. Thus, duckweed ponds have been successfully used for swine waste polishing, mainly for nutrient removal. Few studies have been carried out to assess organic matter degradation in duckweed ponds. Hence, the present study evaluated the efficiency of two full-scale duckweed ponds for organic matter reduction of swine waste on small pig farms. Duckweed ponds, in series, received the effluent after an anaerobic biodigester and storage pond, with a flow rate of 1 m3 day 1. After 1 year of monitoring, an improvement in effluent quality was observed, with a reduction in biochemical oxygen demand (BOD) and total chemical oxygen demand (tCOD), respectively, of 94.8 and 96.7%, operating at a loading rate of approximately 27 kgBOD ha 1 day 1 and 131 kgCOD ha 1 day 1. Algae inhibition due to duckweed coverage was strongly observed in the pond effluent, where chlorophyll a and turbidity remained below 25 μg L 1 and 10 NTU. Using the study conditions described herein, duckweed ponds were shown to be a suitable technology for swine waste treatment, contributing to the environmental sustainability of rural areas

Multigap RPC time resolution to 511 keV annihilation photons

The time resolution of Multigap Resistive Plate Counters (MRPCs) to $511$ keV gamma rays has been investigated using a $^{22}$Na source and four detectors. The MRPCs time resolution has been derived from the Time-of-Flight information, measured from pairs of space correlated triggered events. A GEANT4 simulation has been performed to analyze possible setup contributions and to support experimental results. A time resolution (FWHM) of $376$ ps and $312$ ps has been measured for a single MRPC with four $250$ $\mu$m gas gaps by considering respectively one and two independent pairs of detectors.Comment: 25 pages, 14 figure

Recovering Metallicity in A4C60: The Case of Monomeric Li4C60

The restoration of metallicity in the high-temperature, cubic phase of Li4C60 represents a remarkable feature for a member of the A4C60 family (A = alkali metal), invariably found to be insulators. Structural and resonance technique investigations on Li4C60 at T > 600 K, show that its fcc structure is associated with a complete (4e) charge transfer to C60 and a sparsely populated Fermi level. These findings not only emphasize the crucial role played by lattice symmetry in fulleride transport properties, but also re-dimension the role of Jahn-Teller effects in band structure determination. Moreover, they suggest the present system as a potential precursor to a new class of superconducting fullerides.Comment: 4 pages, 3 figure

Metabolic reprogramming promotes myogenesis during aging

Sarcopenia is the age-related progressive loss of skeletal muscle mass and strength finally leading to poor physical performance. Impaired myogenesis contributes to the pathogenesis of sarcopenia, while mitochondrial dysfunctions are thought to play a primary role in skeletal muscle loss during aging. Here we studied the link between myogenesis and metabolism. In particular, we analyzed the effect of the metabolic modulator trimetazidine (TMZ) on myogenesis in aging. We show that reprogramming the metabolism by TMZ treatment for 12 consecutive days stimulates myogenic gene expression in skeletal muscle of 22-month-old mice. Our data also reveal that TMZ increases the levels of mitochondrial proteins and stimulates the oxidative metabolism in aged muscles, this finding being in line with our previous observations in cachectic mice. Moreover, we show that, besides TMZ also other types of metabolic modulators (i.e., 5-Aminoimidazole-4-Carboxamide Ribofuranoside-AICAR) can stimulate differentiation of skeletal muscle progenitors in vitro. Overall, our results reveal that reprogramming the metabolism stimulates myogenesis while triggering mitochondrial proteins synthesis in vivo during aging. Together with the previously reported ability of TMZ to increase muscle strength in aged mice, these new data suggest an interesting non-invasive therapeutic strategy which could contribute to improving muscle quality and neuromuscular communication in the elderly, and counteracting sarcopenia

Entangling macroscopic diamonds at room temperature: Bounds on the continuous-spontaneous-localization parameters

A recent experiment [K. C. Lee et al., Science 334, 1253 (2011)] succeeded in detecting entanglement between two macroscopic specks of diamonds, separated by a macroscopic distance, at room temperature. This impressive results is a further confirmation of the validity of quantum theory in (at least parts of) the mesoscopic and macroscopic domain, and poses a challenge to collapse models, which predict a violation of the quantum superposition principle, which is the bigger the larger the system. We analyze the experiment in the light of such models. We will show that the bounds placed by experimental data are weaker than those coming from matter-wave interferometry and non-interferometric tests of collapse models.Comment: 7 pages, 3 figures, v2: close to the published version, LaTe

Electron cloud buildup and impedance effects on beam dynamics in the future circular e+e− collider and experimental characterization of thin TiZrV vacuum chamber coatings

The Future Circular Collider FCC-ee is a study toward a high luminosity electron-positron collider with a centre-of-mass energy from 91 GeV to 365 GeV. Due to the beam parameters and pipe dimensions, collective effects and electron cloud can be very critical aspects for the machine and can represent the main limitations to its performance. An estimation of the electron cloud build up in the main machine components and an impedance model are required to analyze the induced instabilities and to find solutions for their mitigation. Special attention has been given to the resistive wall impedance associated with a layer of nonevaporable getter (NEG) coating on the vacuum chamber required for electron cloud mitigation. The studies presented in this paper will show that minimizing the thickness of this coating layer is mandatory to increase the single bunch instability thresholds in the proposed lepton collider at 45.6 GeV. For this reason, NEG thin films with thicknesses below 250 nm have been investigated by means of numerical simulations to minimize the resistive wall impedance. In parallel, an extensive measurement campaign was performed at CERN to characterize these thin films, with the purpose of finding the minimum effective thickness satisfying vacuum and electron cloud requirements

Unusual polymerization in the Li4C60 fulleride

Li4C60, one of the best representatives of lithium intercalated fullerides, features a novel type of 2D polymerization. Extensive investigations, including laboratory x-ray and synchrotron radiation diffraction, 13C NMR, MAS and Raman spectroscopy, show a monoclinic I2/m structure, characterized by chains of [2+2]-cycloaddicted fullerenes, sideways connected by single C-C bonds. This leads to the formation of polymeric layers, whose insulating nature, deduced from the NMR and Raman spectra, denotes the complete localization of the electrons involved in the covalent bonds.Comment: 7 pages, 6 figures, RevTex4, submitted to Phys. Rev.

Defects and Dopants in Silicon Nanowires Produced by Metal-Assisted Chemical Etching

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Ultrastructural aspects of two different mast cell populations in human healthy gingival tissue

The results of our recent microscopy studies clearly have demonstrated the constant presence of numerous metachromatic cells in healthy human gingival connective tissue. Despite the great number of studies on mast cell population in many human organs (lung, skin, uterus, and bowel), at the present time few are the studies regarding the morphostructural aspects of mast cells in the human gingiva. The aim of this study was to assess by transmission electron microscopy the presence of mast cells in the healthy human gingiva and to characterize the ultrastructural aspects of mast cells populations. 30 specimens of human gingival tissue were collected from 30 patients with informed consent. The samples were prepared for T.E.M. examination. In all the ultrathin sections observed we detected numerous and ubiquitarious mast cells. These exhibited several morphological types of cytoplasmic granules with characteristic subgranular architectural variety in shape and density. This allowed us to divide mast cells into two groups: cells with granules consisted of compact coiled scrolls, fine granular material and lattice - grating configuration, and cells containing granules with discrete scrolls formed by more concentric lamellae and particulate structure. The two ultrastructural aspects observed correspond to McTC and McT of the international literature. Therefore in the human gingival connective tissue, like in other organs, two types of mast cells are clearly present. Surprisingly, the human gingival tissue shows, like the lung, McT as the prevailing subpopulation, in contrast to the skin, uterus and gastrointestinal submucosa where McTC prevail. Dans le cadre d’une étude sur la population cellulaire du tissu conjonctif gingival humain nous avons constaté, en microscopie optique, la présence constante de nombreuses cellules metachromatiques. Pour définir la nature de telles cellules et pour en déterminer les aspects ultra-structuraux, nous avons étudié au microscope électronique à transmission 30 biopsies du tissu gingival humain, cliniquement sain. Dans tous les échantillons examinés nous avons observé de nombreux mastocytes dont le contenu granulaire nous est apparu caractérisé par un aspect « à particules » et « en rouleaux » ou bien, dans d’autres éléments cellulaires, par un aspect «en grillage». Les deux aspects ultrastructuraux décrits nous permettent de distinguer les mastocytes gingivaux en deux sous-populations, différentes comme l’ont confirmé plusieurs auteurs, selon la localisation anatomique, selon la structure intérieure et le contenu enzymatique des granules, et, enfin, selon la réaction à des substances sécrétagogues

Fireballs Loading and the Blast Wave Model of Gamma Ray Bursts

A simple function for the spectral power $P(\epsilon,t) \equiv \nu L(\nu)$ is proposed to model, with 9 parameters, the spectral and temporal evolution of the observed nonthermal synchrotron power flux from GRBs in the blast wave model. Here $\epsilon = h\nu/$m$_e$c$^2$ is the observed dimensionless photon energy and $t$ is the observing time. Assumptions and an issue of lack of self-consistency are spelled out. The spectra are found to be most sensitive to the baryon loading, expressed in terms of the initial bulk Lorentz factor $\Gamma_0$, and an equipartition term $q$ which is assumed to be constant in time and independent of $\Gamma_0$. Expressions are given for the peak spectral power $P_p(t) = P(\epsilon_p,t)$ at the photon energy $\epsilon = \epsilon_p(t)$ of the spectral power peak. A general rule is that the total fireball particle kinetic energy $E_0 \sim \Pi_0 t_d$, where $t_d \propto \Gamma_0^{-8/3}$ is the deceleration time scale and $\Pi_0 \equiv P(\epsilon_p,t_d) \propto \Gamma_0^{8/3}$ is the maximum measured bolometric power output in radiation, during which it is carried primarily by photons with energy ${\cal E}_0 = \epsilon_p(t_d) \propto q\Gamma_0^4$.Comment: 26 pages, including 4 figures, uses epsf.sty, rotate.sty; submitted to ApJ; revised version with extended introduction, redrawn figures, and correction