NOx and ultrafine particle emission characteristics in a new steel slag modification device

Two density-separated Chinese coals and steel slag were prepared and then combusted in a modification furnace with different excess air ratio. Non-staged and Fuel-staged combustion experiments were compared under different pulverized coal mixing ratios. Thus, in the fuel-staged combustion experiments, the concentration of NOx in the flue gas was found to greatly decrease under a bitumite: anthracite mixing ratio of 1:1 and an air excess coefficient of 1,2 under the fuel-staged ratio is 15:85. The flue gas temperature was as high as 1 615 °C, while the NOx concentration in the flue gas was as low as 320 mg/m3. Compared with the other types of burners, the experimental combustion device designed herein efficiently reduced the NOx emissions ca. 80%. Fuel-staged combustion has a significant effect on reducing particulate matter (PM) emissions, and a suitable coal ratio was also beneficial for reducing particulate matter emissions

NOx and ultrafine particle emission characteristics in a new steel slag modification device

Two density-separated Chinese coals and steel slag were prepared and then combusted in a modification furnace with different excess air ratio. Non-staged and Fuel-staged combustion experiments were compared under different pulverized coal mixing ratios. Thus, in the fuel-staged combustion experiments, the concentration of NOx in the flue gas was found to greatly decrease under a bitumite: anthracite mixing ratio of 1:1 and an air excess coefficient of 1,2 under the fuel-staged ratio is 15:85. The flue gas temperature was as high as 1 615 °C, while the NOx concentration in the flue gas was as low as 320 mg/m3. Compared with the other types of burners, the experimental combustion device designed herein efficiently reduced the NOx emissions ca. 80%. Fuel-staged combustion has a significant effect on reducing particulate matter (PM) emissions, and a suitable coal ratio was also beneficial for reducing particulate matter emissions

Precise determination of stellar parameters of the ZZ Ceti and DAZ white dwarf GD 133 through asteroseismology

An increasing number of white dwarf stars show atmospheric chemical composition polluted by heavy elements accreted from debris disk material. The existence of such debris disks strongly suggests the presence of one or more planet(s) whose gravitational interaction with rocky planetesimals is responsible for their disruption by tidal effect. The ZZ Ceti pulsator and polluted DAZ white dwarf GD 133 is a good candidate for searching for such a potential planet. We started in 2011 a photometric follow-up of its pulsations. As a result of this work in progress, we used the data gathered from 2011 to 2015 to make an asteroseismological analysis of GD 133, providing the star parameters from a best fit model with $M$/$M_{\odot}$ = 0.630 $\pm$ 0.002, $T_{\rm eff}$ = 12400 K $\pm$ 70 K, log($M_{\rm He}/M$) = -2.00 $\pm$ 0.02, log($M_{\rm H}/M$) = -4.50 $\pm$ 0.02 and determining a rotation period of $\approx$ 7 days.Comment: 10 pages, 13 figures, accepted by MNRA

Study on alkali liquor roasting and sulphuric acid leaching of bayan obo rare earth concentrate

Take the roasted ore after the alkali liquor roasting and decomposition of Bayan Obo rare earth concentrate as the raw material, and use the sulphuric acid leaching to extract the elements including rare earth, thorium, tetravalent cerium, etc. The influence on the leaching of rare earth, thorium, tetravalent cerium made by the leaching conditions including mineral acid ratio, initial acidity, leaching temperature, and leaching time is researched. The result shows: when the mineral acid mass ratio is 1:1,1, the initial acid concentration is 6 mol/L, the reaction temperature is 90 °C, and the reaction time is 120 min, the gross leaching rate of rare earth is greater than 95 %, and the leaching rate of tetravalent cerium and thorium is greater than 97 %

The SPIRou Legacy Survey Rotation period of quiet M dwarfs from circular polarization in near-infrared spectral lines: I. The SPIRou APERO analysis

Context. The rotation period of stars is an important parameter along with mass, radius, effective temperature. It is an essential parameter for any radial velocity monitoring, as stellar activity can mimic the presence of a planet at the stellar rotation period. Several methods exist to measure it, including long sequences of photometric measurements or temporal series of stellar activity indicators. Aims. Here, we use the circular polarization in near-infrared spectral lines for a sample of 43 quiet M dwarfs and compare the measured rotation periods to those obtained with other methods. Methods. From Stokes V spectropolarimetric sequences observed with SPIRou at CFHT and the data processed with the APERO pipeline, we compute the least squares deconvolution profiles using different masks of atomic stellar lines with known Land\'e factor appropriate to the effective temperature of the star. We derive the longitudinal magnetic field to examine its possible variation along the 50 to 200 observations of each star. For determining the stellar rotation period, we apply a Gaussian process regression enabling us to determine the rotation period of stars with evolving longitudinal field. Results. Among the 43 stars of our sample, we were able to measure a rotation period for 27 stars. For 8 stars, the rotation period was previously unknown. We find a good agreement of our rotation periods with periods found in the literature based on photometry and activity indicators and confirm that near-infrared spectropolarimetry is an important tool to measure rotation periods, even for magnetically quiet stars. Furthermore, we compute ages for 20 stars of our sample using gyrochronology

Improved isolation of cadmium from paddy soil by novel technology based on pore water drainage with graphite-contained electro-kinetic geosynthetics

Novel soil remediation equipment based on electro-kinetic geosynthetics (EKG) was developed for in situ isolation of metals from paddy soil. Two mutually independent field plot experiments A and B (with and without electric current applied) were conducted. After saturation using ferric chloride (FeCl3) and calcium chloride (CaCl2), soil water drainage capacity, soil cadmium (Cd) removal performance, energy consumption as well as soil residual of iron (Fe) and chloride (Cl) were assessed. Cadmium dissolved in the soil matrix and resulted in a 100% increase of diethylenetriamine-pentaacetic acid (DTPA) extracted phyto-available Cd. The total soil Cd content reductions were 15.20% and 26.58% for groups A and B, respectively, and electric field applications resulted in a 74.87% increase of soil total Cd removal. The electric energy consumption was only 2.17 kWh/m3 for group B. Drainage by gravity contributed to > 90% of the overall soil dewatering capacity. Compared to conventional electro-kinetic technology, excellent and fast soil water drainage resulted in negligible hydrogen ion (H+) and hydroxide ion (OH−) accumulation at nearby electrode zones, which addressed the challenge of anode corrosion and cathode precipitation of soil metals. External addition of FeCl3 and CaCl2 caused soil Fe and Cl residuals and led to 4.33–7.59% and 139–172% acceptable augments in soil total Fe and Cl content, correspondingly, if compared to original untreated soils. Therefore, the novel soil remediation equipment developed based on EKG can be regarded as a promising new in situ technology for thoroughly isolating metals from large-scale paddy soil fields

Genetic Abolishment of Hepatocyte Proliferation Activates Hepatic Stem Cells

Quiescent hepatic stem cells (HSCs) can be activated when hepatocyte proliferation is compromised. Chemical injury rodent models have been widely used to study the localization, biomarkers, and signaling pathways in HSCs, but these models usually exhibit severe promiscuous toxicity and fail to distinguish damaged and non-damaged cells. Our goal is to establish new animal models to overcome these limitations, thereby providing new insights into HSC biology and application. We generated mutant mice with constitutive or inducible deletion of Damaged DNA Binding protein 1 (DDB1), an E3 ubiquitin ligase, in hepatocytes. We characterized the molecular mechanism underlying the compensatory activation and the properties of oval cells (OCs) by methods of mouse genetics, immuno-staining, cell transplantation and gene expression profiling. We show that deletion of DDB1 abolishes self-renewal capacity of mouse hepatocytes in vivo, leading to compensatory activation and proliferation of DDB1-expressing OCs. Partially restoring proliferation of DDB1-deficient hepatocytes by ablation of p21, a substrate of DDB1 E3 ligase, alleviates OC proliferation. Purified OCs express both hepatocyte and cholangiocyte markers, form colonies in vitro, and differentiate to hepatocytes after transplantation. Importantly, the DDB1 mutant mice exhibit very minor liver damage, compared to a chemical injury model. Microarray analysis reveals several previously unrecognized markers, including Reelin, enriched in oval cells. Here we report a genetic model in which irreversible inhibition of hepatocyte duplication results in HSC-driven liver regeneration. The DDB1 mutant mice can be broadly applied to studies of HSC differentiation, HSC niche and HSCs as origin of liver cancer

Controlled reduction of photobleaching in DNA origami gold nanoparticle hybrids

The amount of information obtainable from a fluorescence-based measurement is limited by photobleaching: Irreversible photochemical reactions either render the molecules nonfluorescent or shift their absorption and/or emission spectra outside the working range. Photobleaching is evidenced as a decrease of fluorescence intensity with time, or in the case of single molecule measurements, as an abrupt, single-step interruption of the fluorescence emission that determines the end of the experiment. Reducing photobleaching is central for improving fluorescence (functional) imaging, single molecule tracking, and fluorescence-based biosensors and assays. In this single molecule study, we use DNA self-assembly to produce hybrid nanostructures containing individual fluorophores and gold nanoparticles at a controlled separation distance of 8.5 nm. By changing the nanoparticles? size we are able to systematically increase the mean number of photons emitted by the fluorophores before photobleaching.Fil: Pellegrotti, Jesica Vanesa. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Centro de Investigaciones en Bionanociencias "Elizabeth Jares Erijman"; Argentina. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Departamento de Física; ArgentinaFil: Acuña, Guillermo. Technische Universität Braunschweig. Institute for Physical and Theoretical Chemistry. NanoBioSciences Group; AlemaniaFil: Puchkova, Anastasiya. Technische Universität Braunschweig. Institute for Physical and Theoretical Chemistry. NanoBioSciences Group; AlemaniaFil: Holzmeister, Phil. Technische Universität Braunschweig. Institute for Physical and Theoretical Chemistry. NanoBioSciences Group; AlemaniaFil: Gietl, Andreas. Technische Universität Braunschweig. Institute for Physical and Theoretical Chemistry. NanoBioSciences Group; AlemaniaFil: Lalkens, Birka. Technische Universität Braunschweig. Institute for Physical and Theoretical Chemistry. NanoBioSciences Group; AlemaniaFil: Stefani, Fernando Daniel. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Centro de Investigaciones en Bionanociencias "Elizabeth Jares Erijman"; Argentina. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Departamento de Física; ArgentinaFil: Tinnefeld, Philip. Technische Universität Braunschweig. Institute for Physical and Theoretical Chemistry. NanoBioSciences Group; Alemani

Non-Centered Spike-Triggered Covariance Analysis Reveals Neurotrophin-3 as a Developmental Regulator of Receptive Field Properties of ON-OFF Retinal Ganglion Cells

The functional separation of ON and OFF pathways, one of the fundamental features of the visual system, starts in the retina. During postnatal development, some retinal ganglion cells (RGCs) whose dendrites arborize in both ON and OFF sublaminae of the inner plexiform layer transform into RGCs with dendrites that monostratify in either the ON or OFF sublamina, acquiring final dendritic morphology in a subtype-dependent manner. Little is known about how the receptive field (RF) properties of ON, OFF, and ON-OFF RGCs mature during this time because of the lack of a reliable and efficient method to classify RGCs into these subtypes. To address this deficiency, we developed an innovative variant of Spike Triggered Covariance (STC) analysis, which we term Spike Triggered Covariance – Non-Centered (STC-NC) analysis. Using a multi-electrode array (MEA), we recorded the responses of a large population of mouse RGCs to a Gaussian white noise stimulus. As expected, the Spike-Triggered Average (STA) fails to identify responses driven by symmetric static nonlinearities such as those that underlie ON-OFF center RGC behavior. The STC-NC technique, in contrast, provides an efficient means to identify ON-OFF responses and quantify their RF center sizes accurately. Using this new tool, we find that RGCs gradually develop sensitivity to focal stimulation after eye opening, that the percentage of ON-OFF center cells decreases with age, and that RF centers of ON and ON-OFF cells become smaller. Importantly, we demonstrate for the first time that neurotrophin-3 (NT-3) regulates the development of physiological properties of ON-OFF center RGCs. Overexpression of NT-3 leads to the precocious maturation of RGC responsiveness and accelerates the developmental decrease of RF center size in ON-OFF cells. In summary, our study introduces STC-NC analysis which successfully identifies subtype RGCs and demonstrates how RF development relates to a neurotrophic driver in the retina