Toxicity and Biodegradability Behavior of Xenobiotic Chemicals Before and After Ozonation: A Case Study with Commercial Textile Tannins

Ozonation of a natural tannin (NT; COD_o?=?1195 mg/L; TOC_o?=?342 mg/L; BOD_5,o?=?86 mg/L) and a synthetic tannin ST; COD_o?=?465 mg/L; TOC_o?=?55 mg/L; BOD_5,o?=?6 mg/L) being frequently applied in the polyamide dyeing process was investigated. Synthetic wastewater samples containing these tannins individually were prepared and subjected to ozonation at varying ozone doses (625– 1250 mgO₃/L wastewater), at pH?=?3.5 (the application pH of tannins) and pH?=?7.0 at an ozone dose of 1125 mgO₃/L wastewater. The collective environmental parameters COD, TOC, BOD₅, UV₂₅₄ and UV₂₈₀ (UV absorbance at 254 nm and 280 nm, representing aromatic and unsaturated moieties, respectively) were followed during ozonation. Changes in the biodegradability of the tannins were evaluated in terms of BOD₅ measurements conducted before and after ozonation. In addition, activated sludge inhibition tests employing heterotrophic biomass were run to elucidate the inhibitory effect of raw and ozonated textile tannins towards activated sludge biomass. Partial oxidation (45% COD removal at an ozone dose of 750 mg O₃/L wastewater and pH?=?3.5) of ST was sufficient to achieve elimination of its inhibitory effect towards heterotrophic biomass and acceptable biodegradability improvement, whereas the inhibitory effect and biodegradability of NT could not be reduced via ozonation under the same reaction conditions.     

A spectral Integral method (SIM) for layered media

A spectral integral method is presented for electromagnetic scattering from dielectric and perfectly electric conducting (PEC) objects with a closed boundary embedded in a layered medium. Two-dimensional layered medium Green's functions are computed adaptively by using Gaussian quadratures. The singular terms in the Green's functions and the non-smooth terms in their derivatives are handled appropriately to achieve exponential convergence. Numerical results, compared with the ones obtained by using other methods, demonstrate the spectral accuracy and high efficiency of the proposed method. They also confirm that the spectral integral method (SIM) is applicable to concave objects.     

Mechanochemical processing and microstructural characterization of pure Fe2B nanocrystals

The results of current investigation demonstrate that mechanochemical processing can be used to synthesize high purity Fe₂B nanocrystals by selecting well-optimized milling conditions, reaction paths and proper starting materials. Microstructure, phase analyses, specific surface area, and magnetic properties of the synthesized nanocrystals were examined by using X-ray diffraction/spectroscopy, electron microscopy, nitrogen adsorption–desorption methods following Brunauer-Emmett-Teller equation and vibrating sample magnetometer techniques, respectively. Removal of MgO impurity phase by leaching the resulting powder in the acetic acid solution yielded single phase Fe₂B nanocrystals with the crystallite size and specific surface area of 12.5 nm and 29 m²/g, respectively. Magnetization results clearly indicated the ferromagnetic behavior of Fe₂B nanocrystals with saturation magnetization observed around 96.26 emu·g^?1. Electron microscope images revealed coaxial/spherical powder shape and morphology of the single-phase Fe₂B nanocrystals.     

Sulfurized Co-Mo Alloy Thin Films as Efficient Electrocatalysts for Hydrogen Evolution Reaction

Catalysis Letters - Here, we successfully fabricated sulfurized Co-Mo alloy thin film electrodes with different compositions and studied their catalytic properties for hydrogen evolution reaction...     

An unusual insertion of accessory biceps brachii muscle

Nutritional intake appears to be an important factor contributing to aging. In the present study we describe changes in physical health related to nutritional intake among elderly persons in a 10-y longitudinal study. Among 304 healthy elderly participants (median age 72 y on entry into the study in 1980), 97 (34.2%) are still in good health 10 y later in 1990, 74 (26.5%) have become frail or sick, 54 (19.1%) have died, and 57 (20.1%) have dropped out of the study. Women with lower or higher energy intakes (in 1980 and 1981) than the current Recommended Daily Allowance (RDA; between 25 and 30 kcal/kg) were more likely to become frail or sick or to die in 1990 than those with energy intake in the midrange (below RDA, odds ratio (OR) = 3.3, confidence interval (CI) = 1.2-8.6; above RDA, OR = 3.4, CI: 1.1-10.7). Moreover, women with protein intakes greater than the midrange of 0.8-1.2 g/kg of body weight (1.20-1.76 g/kg in 1980 and 1981) tended to have fewer health problems over the next 10 y than those with protein intakes < 0.8 g/kg, suggesting that the mean protein requirement in elderly adults is greater than that established by the 1985 joint World Health Organization/ FAO/UNU Expert Committee. Moreover, a decrease in energy intake was greater in elderly persons who died or dropped out of the study because of illness.     

Determining optimum tilt angles and orientations of photovoltaic panels in Sanliurfa, Turkey

The performance of a photovoltaic (PV) panel is affected by its orientation and its tilt angle with the horizontal plane. This is because both of these parameters change the amount of solar energy received by the surface of the PV panel. A mathematical model was used to estimate the total solar radiation on the tilted PV surface, and to determine optimum tilt angles for a PV panel installed in Sanliurfa, Turkey. The optimum tilt angles were determined by searching for the values of angles for which the total radiation on the PV surface was maximum for the period studied. The study also investigated the effect of two-axis solar tracking on energy gain compared to a fixed PV panel. This study determined that the monthly optimum tilt angle for a PV panel changes throughout the year with its minimum value as 13° in June and maximum value as 61° in December. The results showed that the gains in the amount of solar radiation throughout the year received by the PV panel mounted at monthly optimum tilt angles with respect to seasonal optimum angles and tilt angel equal to latitude were 1.1% and 3.9%, respectively. Furthermore, daily average of 29.3% gain in total solar radiation results in an daily average of 34.6% gain in generated power with two-axis solar tracking compared to a south facing PV panel fixed at 14° tilt angle on a particular day in July in Sanliurfa, Turkey.     

Scalar estimation and control with noisy binary observations

We consider a simple one-dimensional system whose observations are sent to a state estimator over a noisy binary communication link. The interesting thing about the system is that it is unstable. The problem is to design an encoding scheme and a decoder such that the estimation error is stable. We explicitly construct a simple but efficient estimator for the binary symmetric channel (BSC). We are not aware of any such previous "codes" for the BSC. We compare our results to the nonconstructive bounds of Sahai.