Dependence Of Other Properties Research Articles

Effects of pyrolysis temperature and pressure on agronomic properties of biochar

This study focused on identifying the effect of pyrolysis temperature and pressure for lignocellulosic biomass on agronomic properties of biochar. For this purpose, two biomasses (vine shoots -VS and corn stover -CS) were pyrolyzed at different temperatures (350 and 500 °C) under different pressures (0.1 and 0.5 MPa) for a residence time of 60 min. Agronomic properties of biochars (including stability, pH, CEC, EC, bulk density, surface properties, and water holding capacity) were determined. Pyrolysis temperature impacted greatly on the biochar stability and the textural properties. The dependence of other properties of biochars on pressure and temperature varied as a function of the type of feedstock. In addition, the effects of pyrolysis temperature and pressure on 16 US EPA PAH concentration in biochar were also investigated. The PAH concentrations ranged between 0.822 and 5.112 mg kg−1. On average, VS-derived biochar had higher PAH concentrations than CS-derived one. The structural differences in biomass played a key role in determining the effect of pyrolysis conditions on total PAH concentration.

Environmental dependence of other properties of main galaxies at fixed luminosity

Using three volume-limited samples of the Sloan Digital Sky Survey Data Release 6 (SDSS DR6), we have investigated how other properties of galaxies depend on the environment at fixed luminosity. At fixed luminosity, we still observe strong environmental dependence of g - r color, concentration index, and morphology of galaxies: red, highly concentrated, and early type galaxies exist preferentially in the densest regions of the universe, while blue, poorly concentrated, and late type galaxies are located preferentially in low density regions. This shows that luminosity is not fundamental in correlations between galaxy properties and the environment.

ENVIRONMENTAL DEPENDENCE OF OTHER GALAXY PROPERTIES FOR THE SAME STAR FORMATION ACTIVITIES

Using two volume-limited Main galaxy samples of the Sloan Digital Sky Survey Data Release 6 above and below the value of M*, we have investigated the environmental dependence of other galaxy properties for the same star formation activities. Only in the luminous passive class, a strong environmental dependence of the g ? r color is observed, but the environmental dependence of other properties in this class is very weak. In other classes, we can conclude that the local density dependence of luminosity, g ? r color, concentration index ci, and morphologies for star-forming galaxies and passive ones is much weaker than that obtained in the volume-limited Main galaxy samples. This suggests that star formation activity is a galaxy property very predictive of the local environment. In addition, we also note that passive galaxies are more luminous, redder, highly concentrated, and preferentially early type.

Structure of CLAP glasses

Abstract In AlF3-based glasses (CLAP), variations of oxygen as small as 0.2 wt% are observed to have order of magnitude effects upon glass stability, to the extent that monophase glasses can be formed only at normal quenching rates when the oxygen concentration is 1.1 ± 0.3 wt%. Glass compositions within this concentration band were prepared and studied by extended X-ray absorption fine structure and Raman spectroscopy. These data and oxygen dependence of other properties, some of which have already been reported, are used to propose a structural model based upon the coexistence of chemically perturbed regions, of the order of 1 nm in size.

Vibrational spectra of single and mixed alkali pentasilicate glasses

Abstract The far infrared and laser Raman spectra of single and mixed alkali pentasilicate glasses, M 2 O·5SiO 2 (M = Li, Na, Kb, Cs), and x Cs 2 O(1 − x )Na 2 O·5SiO 2 are reported in both the annealed and unannealed forms. Study of the cation-motion bands in the far infrared shows that the vibrationally significant cation-network interactions are unaffected by either introduction of a second cation or by annealing, and these results are discussed in terms of the glass formation and annealing. The spectra of the network show the existence of intrinsic network strain, changes in distributions of bond angles related to alkali mixing and annealing, and evidence for the nature of the distribution of cations in the glass. The results are discussed in relation to the composition dependence of other properties of these and related mixed alkali glasses.

Effect of Fiber and Dyebath Variables on the Rate of Acid Dyeing of Nylon 6, 6

The results of an experimental study of the effects of several variables on the acid dyeing of nylon are presented. The dyeing rate was directly proportional to the number of amino-end groups (dye sites) in the fiber for the two dyes tested; the dyeing rate approached zero as the number of dye sites approached zero. The dyeing rate was the same for samples with viscosity average molecular weights of ∼25,000 and 30,000, but was somewhat higher for a ∼22,000 Mv sample, as might be expected from the dependence of other properties on molecular weight. The dyeing rate is shown to be linearly related to 1/√ d, where d is the denier per filament. The molecular size of the acid molecule used in the acid dyebath was investigated, and no effect was found for formic, acetic, propionic, and hexanoic acids. An effect is found on both rate and saturation, however, if the larger and more polarizable napthoic acid is used. Sodium chloride and sodium sulfate, when added to the dyebath, decrease both the dye absorbed at saturation and the rate of dye diffusion, although they offer benefits as leveling agents. The effect of sodium chloride is considerably greater than for sodium sulfate.