We present ALMA Band 9 observations of the C II158 μm emission for a sample of 10 main-sequence galaxies at redshift z ˜ 2, with typical stellar masses (log M⋆/M⊙ ˜ 10.0-10.9) and star formation ...rates (˜35-115 M⊙ yr-1). Given the strong and well-understood evolution of the interstellar medium from the present to z = 2, we investigate the behaviour of the C II emission and empirically identify its primary driver. We detect C II from six galaxies (four secure and two tentative) and estimate ensemble averages including non-detections. The C II-to-infrared luminosity ratio (C II/LIR) of our sample is similar to that of local main-sequence galaxies (˜2 × 10-3), and ˜10 times higher than that of starbursts. The C II emission has an average spatial extent of 4-7 kpc, consistent with the optical size. Complementing our sample with literature data, we find that the C II luminosity correlates with galaxies' molecular gas mass, with a mean absolute deviation of 0.2 dex and without evident systematics: the C II-to-H2 conversion factor (α _C II ˜ 30 M⊙/L⊙) is largely independent of galaxies' depletion time, metallicity, and redshift. C II seems therefore a convenient tracer to estimate galaxies' molecular gas content regardless of their starburst or main-sequence nature, and extending to metal-poor galaxies at low and high redshifts. The dearth of C II emission reported for z > 6-7 galaxies might suggest either a high star formation efficiency or a small fraction of ultraviolet light from star formation reprocessed by dust.
The influence of high thermal gradient processing on the creep and low cycle fatigue properties of the AM1 Ni-based single crystal superalloy has been studied. Isothermal creep (from 750°C up to ...1200°C) and low cycle fatigue (750°C and 950°C) experiments were performed for AM1 alloy solidified with a conventional radiation cooled (Bridgman) and higher thermal gradient liquid-metal cooled (LMC) casting process to produce coarse and finer-scaled dendritic structures, respectively. There was no significant effect of the casting technique on creep properties, due to the very similar microstructures (γ′-size and γ-channel width) established after full heat treatment of both Bridgman and LMC samples. For low cycle fatigue properties, the benefit of the higher gradient LMC process was dependent on the testing temperature. At 750°C, cracks primarily initiated at pores created by solidification shrinkage in both Bridgman and LMC samples. Samples produced by the LMC technique demonstrated fatigue lives up to 4 times longer, compared to the Bridgman samples, due to refined porosity. At 950°C the low cycle fatigue properties of the LMC and conventionally solidified material were not distinguishable due to a shift of crack initiation sites from internal pores to oxidized surface layers or near-surface pores. The benefit of the LMC approach was, however, apparent in fatigue at 950°C when testing in a vacuum environment. Based on these results, a crack initiation model based on the local slip activity close to casting defect is proposed.
Isothermal and non-isothermal creep experiments are performed using AM3 Ni-based single crystal samples which were cooled from the solutioning temperature during heat treatment with different cooling ...rates. Cooling rates from the solution temperature influenced the precipitate size and distribution and influenced creep properties, with creep lifetimes increasing and secondary creep rates decreasing with faster cooling rates. Up to a cooling rate of about 100°C/min, the microstructure is very inhomogeneous and the γ׳-particles exhibit an irregular shape and are partially large in size. For the fastest cooling rate (300°C/min), the microstructure consists of ordered cubic γ׳-precipitates surrounded by narrow γ-channels. According to Orowan stress calculations, the investigated creep properties under both isothermal and non-isothermal conditions seem to be mainly controlled by the resistance to dislocation bowing in the γ-channels.
Mangroves are one of the most carbon‐dense forests on the Earth and have been highlighted as key ecosystems for climate change mitigation and adaptation. Hundreds of studies have investigated how ...mangroves fix, transform, store, and export carbon. Here, we review and synthesize the previously known and emerging carbon pathways in mangroves, including gains (woody biomass accumulation, deadwood accumulation, soil carbon sequestration, root and litterfall production), transformations (food web transfer through herbivory, decomposition), and losses (respiration as CO2 and CH4, litterfall export, particulate and dissolved carbon export). We then review the technologies available to measure carbon fluxes in mangroves, their potential, and their limitations. We also synthesize and compare mangrove net ecosystem productivity (NEP) with terrestrial forests. Finally, we update global estimates of carbon fluxes with the most current values of fluxes and global mangrove area. We found that the contributions of recently investigated fluxes, such as soil respiration as CH4, are minor (<1 Tg C year−1), while the contributions of deadwood accumulation, herbivory, and lateral export are significant (>35 Tg C year−1). Dissolved inorganic carbon exports are an order of magnitude higher than the other processes investigated and were highly variable, highlighting the need for further studies. Gross primary productivity (GPP) and ecosystem respiration (ER) per area of mangroves were within the same order of magnitude as terrestrial forests. However, ER/GPP was lower in mangroves, explaining their higher carbon sequestration. We estimate the global mean mangrove NEP of 109.1 Tg C year−1 (7.4 Mg C ha−1 year−1) or through a budget balance, accounting for lateral losses, a global mean of 66.6 Tg C year−1 (4.5 Mg C ha−1 year−1). Overall, mangroves are highly productive, and despite losses due to respiration and tidal exchange, they are significant carbon sinks.
Two
in-situ
test techniques were used to obtain insight into the isothermal precipitation kinetics of
γ
″ and
γ
′ in superalloy 718. The first method consisted of measurements of Young’s modulus ...using a dynamic-resonance method (DRM), and the other comprised determination of the evolution of the lattice parameter of the
γ
-matrix phase
via
neutron diffraction. For both techniques, solution-treated-and-water-quenched samples were heated to a nominal test temperature of 923 K, 953 K, 1013 K, or 1053 K and held for a time of ~ 5 to 50 hours, at the end of which a near-steady condition in terms of an apparently-constant modulus/lattice parameter had been achieved. The observations from each test technique suggested sequential periods of rapid initial increase in volume fraction followed by a gradually-decreasing rate of change. The data were converted to transformed fraction as a function of time and interpreted in terms of phenomenological (JMAK) and mechanistic (nucleation-and-growth) models. From the former approach, Avrami exponents which decreased from approximately unity at the lower two temperatures to ~ 0.5 at the highest temperature, were deduced. The transformed fraction-versus-time behaviors were well replicated using fast-acting numerical simulations based on the mechanistic model. These simulations highlighted the competition between nucleation and growth in determining overall transformation kinetics.
Currently, anatase/rutile core/shell structures are accepted as highly efficient building blocks for TiO2-based catalysts or photoelectrodes used in dye-sensitized solar cells (DSSCs). It is ...understood that a thin layer of rutile covering the core anatase pillar would improve the performance of DSSCs by retarding the charge recombination at the semiconductor/sensitizer/electrolyte interfaces. In this work, we report on the synthesis of core/shell nanostructured TiO2 thin films using reactive magnetron sputtering at a glancing angle with different power applying modes: well-separated pillars of pure anatase were synthesized using the DC mode, and then high-pulse peak power was applied to the Ti target (high-power impulse magnetron sputtering (HiPIMS)), resulting in the covering of the anatase columns with a thin layer of rutile. The latter technique is well-known to increase the energy load during the growth of the film, which is a key parameter to successfully obtain the TiO2 phase normally only achieved at high temperature, i.e., rutile. The peak current, the frequency, and the pulse width were optimized to obtain the desired crystalline structure and thickness of the rutile top layer. Scanning electron microscopy (SEM) cross-section views of the synthesized films clearly show that the pillar-like structures are not affected by the energetic species striking the surface during the HiPIMS process. Grazing incidence X-ray diffraction (GIXRD) suggests the presence of both anatase and rutile phases in the films. Further characterization of the anatase/rutile core/shell interface by electron transmission techniques such as transmission electron microscopy (TEM) and electron energy loss spectroscopy (EELS) mapping confirms the hypothesis and reveals that the anatase pillars are partly covered by a rutile crust.
The reported data on surgery plus radiotherapy for retroperitoneal soft tissue sarcomas (RPS) have been mostly from retrospective studies. We evaluated the long-term outcome of patients with operable ...RPS who were treated with protocol-based preoperative radiotherapy followed by complete surgical resection.
Data from two prospective trials that included preoperative radiotherapy and surgery for patients with radiographically resectable RPS were combined to define long-term relapse rates and survival.
Seventy-two patients with intermediate- or high-grade RPS were treated with preoperative radiotherapy (median dose, 45 Gy; range, 18.0-50.4 Gy). Fifty-four patients (75%) had primary RPS, whereas 18 (25%) had recurrent disease. The median tumor size was 15.5 cm. Sixty-four patients completed the planned preoperative radiotherapy; 57 (89%) underwent laparotomy with curative intent, and 54 (95%) had a macroscopically complete (R0 or R1) resection. With a median follow-up of 40.3 months, 28 patients (52%) who received preoperative radiotherapy and underwent a macroscopically complete resection had recurrences. For the 54 patients who underwent R0 or R1 resection after preoperative radiotherapy, the 5-year local recurrence-free, disease-free, and overall survival rates were 60%, 46%, and 61%, respectively. The median overall survival has not been reached (>60 months).
Patients with intermediate- or high-grade RPS treated with preoperative radiotherapy plus complete resection had a median survival >60 months. This compares favorably to historical data for similar patients treated with surgery alone.
A suite of experimental tools and fast-acting, numerical-simulation techniques was used to quantify the precipitation behavior of three nickel-base superalloys: IN-100, LSHR, and 718. Experimental ...methods comprised differential scanning calorimetry (DSC) to establish the specific heat as a function of temperature and selected direct-resistance heating trials (using a Gleeble
®
machine) to obtain samples for microstructural analysis. For the DSC experiments, each alloy was cooled at a prescribed constant rate (between 5 and 20 K/min) after an initial soak/equilibration in the high-temperature, single-phase (supersolvus) temperature regime. On-heating DSC trials beginning at ambient temperature were also performed on alloy 718 in three different starting conditions: super-
δ
-solvus solution treated and water quenched (denoted as ST), solution treated and aged (STA), and solution treated and overaged (STOA). DSC results, revealing the thermal signatures associated with the kinetics of precipitation of
γ
′ (IN-100, LSHR) or
γ
′ and
γ
″ (718), were interpreted using a previously-developed fast-acting routine that treats concurrent nucleation, growth, coarsening, and dissolution. For these simulations, special attention was paid to various thermo-kinetic input parameters including equilibrium solvus-approach curves, bulk free energies of transformation, matrix-precipitate interface energies, and effective diffusivities. For the
γ
-
γ
′ superalloys (IN-100 and LSHR), estimates of precipitate volume fraction as a function of temperature from the specific-heat data revealed semi-quantitative agreement with simulation predictions. For the
γ
-
γ
′-
γ
″ superalloy (718), simulation predictions of precipitate volume fractions were converted to specific heat as a function of temperature and showed semi-quantitative agreement with the direct measurements.
Estuarine ecosystems are intrinsically resilient to the dynamic fluctuations of environmental conditions. Yet, it is unknown how the changes in environmental variability associated with climate ...change will affect fish communities. We assessed how species turnover over space and time in estuaries is influenced by changes in environmental conditions over years. We used fish abundances and water quality sampled at 42 stations among 7 estuaries in New Brunswick (Canada) from 2005 to 2012 to estimate (1) spatial turnover between stations based on the local contribution to beta diversity (LCBD) index, and (2) temporal turnover from year to year based on the β-Sørensen index. We found that beta diversity was potentially structured (i) over space due to inherent within-year differences in each estuary and (ii) over time related to the environmental condition of the previous year which led to changes in salinity, dissolved oxygen, and water temperature at sampling stations. Species contribution to spatial beta diversity (SCBD) was attributed across all years to 4 key species which were sensitive to dissolved oxygen. The current environmental condition of dissolved oxygen, temperature, salinity, and eelgrass Zostera marina affected temporal year-to-year turnover. When each year is analyzed separately, the estuaries with the greatest annual summer temperature fluctuations within a station contribute the most to spatial beta diversity between estuaries. Understanding how fish community structure responds to changes in environmental conditions can help inform the management of estuarine resources in the face of a rapidly changing environment.
A fast-acting, mean-field method for simulating precipitation of the
γ
′′ and
γ
′ phases during aging of superalloy 718 following super-delta-solvus solution treatment was formulated and validated ...using observations in the literature. The approach assumed classical (homogeneous) nucleation and diffusion-controlled growth (N&G) of disk/ellipsoidal-shaped-
γ
′′ and spherical-
γ
′ particles. For the
γ
′′ precipitates in particular, the evolution equations for both nucleation and growth incorporated corrections for the non-spherical shape, assuming a fixed aspect ratio. In addition, special attention was paid to the choice of input material properties for simulations. These parameters included the bulk free energies of transformation, particle-matrix (misfit) elastic strain energy (for
γ
′′), effective diffusivities, and the
γ
′′–
γ
and
γ
′–
γ
interface energies. The applicability of the diffusivities and interface energies chosen for the N&G simulations was established by their consistency in replicating previously measured rate constants for the diffusion-controlled coarsening of both
γ
′′ and
γ
′. The N&G formulation was discretized to obtain numerical (spreadsheet) solutions
via
the Kampmann–Wagner approach. Simulation results for the temporal evolution of volume fraction and average size of the precipitates showed good agreement with experimental measurements. The sensitivity of model predictions to various input parameters was also quantified.
![The [C ii] emission as a mo...](http://api.summon.serialssolutions.com/2.0.0/image/issn/XR4PS5YY4K/0035-8711/small "The [C ii] emission as a molecular gas mass tracer in galaxies at low and high redshifts")
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