The [C ii] emission as a molecular gas mass tracer in galaxies at low and high redshifts

Zanella, A,Daddi, E,Magdis, G,Diaz Santos, T,Cormier, D,Liu, D,Cibinel, A,Gobat, R,Dickinson, M,Sargent, M,Popping, G,Madden, S C,Bethermin, M,Hughes, T M,Valentino, F,Rujopakarn, W,Pannella, M,Bourna Oxford University Press 2018 MONTHLY NOTICES- ROYAL ASTRONOMICAL SOCIETY Vol.481 No.2

An extremely young massive clump forming by gravitational collapse in a primordial galaxy

Zanella, A.,Daddi, E.,Le Floc’h, E.,Bournaud, F.,Gobat, R.,Valentino, F.,Strazzullo, V.,Cibinel, A.,Onodera, M.,Perret, V.,Renaud, F.,Vignali, C. Nature Publishing Group, a division of Macmillan P 2015 Nature Vol.521 No.7550

When cosmic star formation history reaches a peak (at about redshift z ≈ 2), galaxies vigorously fed by cosmic reservoirs are dominated by gas and contain massive star-forming clumps, which are thought to form by violent gravitational instabilities in highly turbulent gas-rich disks. However, a clump formation event has not yet been observed, and it is debated whether clumps can survive energetic feedback from young stars, and afterwards migrate inwards to form galaxy bulges. Here we report the spatially resolved spectroscopy of a bright off-nuclear emission line region in a galaxy at z = 1.987. Although this region dominates star formation in the galaxy disk, its stellar continuum remains undetected in deep imaging, revealing an extremely young (less than ten million years old) massive clump, forming through the gravitational collapse of more than one billion solar masses of gas. Gas consumption in this young clump is more than tenfold faster than in the host galaxy, displaying high star-formation efficiency during this phase, in agreement with our hydrodynamic simulations. The frequency of older clumps with similar masses, coupled with our initial estimate of their formation rate (about 2.5 per billion years), supports long lifetimes (about 500 million years), favouring models in which clumps survive feedback and grow the bulges of present-day galaxies.

Effects of Scalp Acupuncture on Functional Deficits Induced by Early Sensorimotor Restriction

Angela K. Zanella,Jessié M. Gutierres,Felipe Stigger 사단법인약침학회 2019 Journal of Acupuncture & Meridian Studies Vol.12 No.3

The aim of this study was to investigate the effects of scalp acupuncture and electrostimulation, combined or not, in a disuse model consisted of early sensorimotor restriction in rats. Male Wistar pups received sensorimotor restriction from the second postnatal day (P2) until P28. Animals were divided into five different groups (n Z 6): control (CT), sensorimotor restricted (SR), acupuncture (AC), electrostimulation (EL), and electroacupuncture (ACþEL). Experimental animals received sham, acupuncture, or electrical stimulation, combined or not, of two scalp regions for 7 days (P29-P35). Before treatment period (P29) and after treatment (P36), animals were evaluated with the narrow suspended bar, horizontal ladder, and stride length tests. SR animals had worse performance in the narrow suspended and horizontal ladder tasks compared with SR animals at P29 (p 0.005). Significant improvements were observed in both tasks in AC, EL, and ELþAC groups comparing P29 and P36 (p < 0.001). Also, at P35, all treated animals performed significantly better motor tasks compared with SR group (p < 0.05). There was no difference between treated groups. Finally, acupuncture and electrical stimulation, combined or not, have beneficial effect on motor performance following early developmental disuse.

Silver nanoparticles incorporated into Na₂Ti6O13 microfibers

V. Rodríguez-González,I. Juárez-Ramírez,R. Zanella,M.E. Zarazúa,L.M. Torres-Martínez 한양대학교 세라믹연구소 2008 Journal of Ceramic Processing Research Vol.9 No.6

This research is concerned with novel semiconductor composites of sodium hexatitanate oxide (Na2Ti6O13), and silver metallic nanoparticles. The Na2Ti6O13 was prepared by two methods, a sol-gel process and a solid state reaction. The silver nanoparticles were incorporated into the titanate by a deposition-precipitation technique, using NaOH as precipitation agent in the dark. Ag/Na2Ti6O13 microfibers were obtained by the sol-gel method, meanwhile octagonal microbar agglomerates were the product of the solid state reaction. The SEM-TEM observations showed silver particles with a nanometric size (5-7 nm); and fibrillar structures in the sol-gel sodium titanates. The UV-Vis-RD spectroscopy showed a blue shift Eg from 3.3 to 3.4 nm; and a plasmon surface resonance in the visible region. These materials are proposed as potential photocatalysts for contaminated water purification. This research is concerned with novel semiconductor composites of sodium hexatitanate oxide (Na2Ti6O13), and silver metallic nanoparticles. The Na2Ti6O13 was prepared by two methods, a sol-gel process and a solid state reaction. The silver nanoparticles were incorporated into the titanate by a deposition-precipitation technique, using NaOH as precipitation agent in the dark. Ag/Na2Ti6O13 microfibers were obtained by the sol-gel method, meanwhile octagonal microbar agglomerates were the product of the solid state reaction. The SEM-TEM observations showed silver particles with a nanometric size (5-7 nm); and fibrillar structures in the sol-gel sodium titanates. The UV-Vis-RD spectroscopy showed a blue shift Eg from 3.3 to 3.4 nm; and a plasmon surface resonance in the visible region. These materials are proposed as potential photocatalysts for contaminated water purification.

Effects of Skin Pass Rolling Parameters on Mechanical Properties of Steels

Jacopo Grassino,Maurizio Vedani,Gianmarco Vimercati,Guido Zanella 한국정밀공학회 2012 International Journal of Precision Engineering and Vol. No.

The influence of skin pass rolling on tensile and microstructural properties of three industrial grade steels was investigated. Skin pass rolling was performed on a laboratory mill equipped with a device designed to reproduce the effects of sheet tension and with load cells aimed at measuring the main working parameters. Analysis on tensile properties of skin pass rolled samples showed for an ultralow C grade and a low C grade a decreasing trend of the yield strength down to a minimum, followed by progressive rising values with increasing rolling elongation. This trend was related to changes of the tensile curve shape, leading to a transition from discontinuous to continuous yielding. A zinc-coated mild steel grade featured a tensile curve with a knee at transition from elastic to plastic regime. Accordingly, the change in yield strength with increasing skin pass elongation followed a linear trend. Microstructural and crystallographic information supplied by EBSD analyses suggested that the plastic strain induced by skin pass rolling originated a fairly homogeneous deformation field even on grains directly exposed on the strip surface. Micro-hardness profiles taken across strip thickness highlighted both increasing peak hardness values at strip surfaces and rising values at mid-thickness.

Crevice Corrosion Study of Materials for Propulsion Applications in the Marine Environment

( F Deflorian ),( S Rossi ),( M Fedel ),( C Zanella ),( D Ambrosi ),( E Hlede ) 한국부식방식학회(구 한국부식학회) 2015 Corrosion Science and Technology Vol.14 No.6

The present work addresses crevice and galvanic corrosion processes occurring at the cylinder head gasket/cylinder head interface and cylinder head gasket/cylinder liner interface of four-stroke medium-speed diesel engines for marine applications. The contact between these systems and the marine environment can promote formation of demanding corrosion conditions, therefore influencing the lifetime of the engine components. The electrochemical behavior of various metals and alloys used as head gasket materials (both ferrous alloys and copper alloys) was investigated. The efficacy of corrosion inhibitors was determined by comparing electrochemical behavior with and without inhibitors. In particular, crevice corrosion has been investigated by electrochemical tests using an experimental set-up developed starting from the requirements of the ASTM G-192-08, with adaptation of the test to the conditions peculiar to this application. In addition to the crevice corrosion resistance, the possible problems of galvanic coupling, as well as corrosive reactivity,were evaluated using electrochemical tests, such as potentiodynamic measurements. It was possible to quantify,in several cases, the corrosion resistance of the various coupled materials, and in particular the resistance to crevice corrosion, providing a basis for the selection of materials for this specific application.

Cr-doped BiYO3 photocatalyst for degradation of oxytetracycline under visible light irradiation

Hernández-Arellano Diana L.,Durán-Álvarez Juan C.,Cortés-Lagunes Silvana,Zanella Rodolfo,Soto Tania E.,López-Juárez Rigoberto 한국세라믹학회 2023 한국세라믹학회지 Vol.60 No.1

Chromium-doped BiYO3 powders were synthesized by the Pechini method at low temperature between 400 and 800 °C for 1 h. From the XRD results it was observed the coexistence between tetragonal and cubic phases for samples calcined at 400 °C for 1 h. Meanwhile, for samples calcined at 600 and 800 °C, a single cubic phase was observed. The powders consisted of agglomerates of nanocrystals as shown in the SEM and TEM images. The specific surface area was in the order of 3.01–7.74 m2 g−1, obtained from BET analysis. The band gap of BiYO3 and Cr-doped BiYO3 was < 2.21 eV which corroborates that these materials absorb light in the visible region of the electromagnetic spectrum. The photocatalytic decomposition of oxytetracycline was successfully achieved using Cr-doped BiYO3, where the best performance was obtained with BiY0.98Cr0.02O3 ceramic powders calcined at 800 °C for 1 h. For this composition the removal of oxytetracycline after 240 min of visible light irradiation was 100% of degradation and 75% of mineralization. The photocatalytic process was driven by the photo-holes, as a negligible production of ·OH radicals was observed in tests using scavengers. The photocatalytic activity of the BiY0.995Cr0.005O3 and BiY0.98Cr0.02O3 materials was corroborated under more realistic conditions, using tap water and trace concentration of the antibiotic. The high stability of the photocatalyst was observed through four consecutive reaction cycles. The results demonstrate that the Cr-doping has clearly improved the catalytic performance of BiYO3 for degradation of oxytetracycline under visible light irradiation.

METAL DEFICIENCY IN CLUSTER STAR-FORMING GALAXIES AT<i>Z</i>= 2

Valentino, F.,Daddi, E.,Strazzullo, V.,Gobat, R.,Onodera, M.,Bournaud, F.,Juneau, S.,Renzini, A.,Arimoto, N.,Carollo, M.,Zanella, A. IOP Publishing 2015 The Astrophysical journal Vol.801 No.2

<P>We investigate the environmental effect on the metal enrichment of star-forming galaxies (SFGs) in the farthest spectroscopically confirmed and X-ray-detected cluster, CL J1449+0856 at z = 1.99. We combined Hubble Space Telescope/WFC3 G141 slitless spectroscopic data, our thirteen-band photometry, and a recent Subaru/Multi-object InfraRed Camera and Spectrograph (MOIRCS) near-infrared spectroscopic follow-up to constrain the physical properties of SFGs in CL J1449+0856 and in a mass-matched field sample. After a conservative removal of active galactic nuclei, stacking individual MOIRCS spectra of 6 (31) sources in the cluster (field) in the mass range 10 <= log(M/M-circle dot) <= 11, we find a similar to 4 sigma. lower [N II]/H alpha ratio in the cluster than in the field. Stacking a subsample of 16 field galaxies with H beta and [O III] in the observed range, we measure an [O III]/H beta ratio fully compatible with the cluster value. Converting these ratios into metallicities, we find that the cluster SFGs are up to 0.25 dex poorer in metals than their field counterparts, depending on the adopted calibration. The low metallicity in cluster sources is confirmed using alternative indicators. Furthermore, we observe a significantly higher H alpha luminosity and equivalent width in the average cluster spectrum than in the field. This is likely due to the enhanced specific star formation rate; even if lower dust reddening and/or an uncertain environmental dependence on. the continuum-to-nebular emission differential reddening may play a role. Our findings might be explained by the accretion of pristine gas around galaxies at z = 2 and from cluster-scale reservoirs, possibly connected with a phase of rapid halo mass assembly at z > 2 and of a high galaxy merging rate.</P>

Methodologies for the Determination of Endogenous Phosphorus Losses in Growing Pigs

Alves, Debora Aline,da Rocha, Leonardo Tombesi,dos Santos Camargo, Claudiele Aparecida,Figueiredo, Andriele Medianeira,Ceron, Marcos Speroni,Lucca, Walter,Zanella, Irineo,de Oliveira, Vladimir Asian Australasian Association of Animal Productio 2016 Animal Bioscience Vol.29 No.11

A study was conducted to compare the endogenous basal losses of phosphorus (EBLP) in pigs fed diets containing gelatin (GEL) or spray-dried porcine plasma (SDPP) as protein sources and to determine the standardized total tract digestibility (STTD) of phosphorus (P) in SDPP. The trial was carried out at the Federal University of Santa Maria, Brazil. Twelve castrated pigs with an initial body weight of 55 kg were individually allotted in metabolic crates during two 12-day periods, each with 7 days of adaptation and 5 days of total fecal collection. The beginning and the end of the collecting periods were determined according to the marker-to-marker approach, using ferric oxide as an indigestible marker. Pigs were submitted to four semi-purified diets, one being a P-free diet with 30% of GEL as the protein source and three were diets with 10%, 20%, and 30% inclusion of SDPP respectively. Data were subjected to analysis of variance and the model included the effects of period, animal and treatments; the results of the three diets with increased levels of SDPP were subjected to linear regression analysis. The intercept of the relation of between ingested P and absorbed P represented the EBLP, while the slope indicated the STTD of P in SDPP. The EBLP means obtained by P-free diet and regression method were compared with the Student t test. The EBLP were 128.95 mg/kg dry matter intake (DMI) and 153.63 mg/kg DMI (standard error = 77.0; p<0.06) using the P-free diet with GEL as the protein source and the regression method, obtained with diets containing increased levels of SDPP, respectively. The apparent digestibility of P was 87.9%, 94.2%, and 92.9% for the treatments containing 10%, 20%, and 30% inclusion of SDPP, respectively. The estimated STTD of P obtained with the linear regression was 97.4%. When the EBLP estimated by the P-free diet was used to corrected the apparent digestibility of P in diets containing SDPP, the STTD of P in SDPP was 96.9%, 98.8%, and 95.9% for 10%, 20%, and 30% SDPP, respectively. Therefore, it can be concluded that SDPP can replace GEL to estimate the endogenous losses of P. In addition, the STTD of P in SDPP estimated with the P-free diet was 97.2% and it was 97.4% by the regression method, utilizing SDPP.