POLYNUCLEAR AROMATIC COMPOUNDS IN COAL AND OIL SHALE WASTEWATER: AN ENVIRONMENTAL CONCERN

ABSTRACT

A solvent refining coal liquefaction process recycle water (No. 3) from Du Pont, Washington, a true in-situ oil shale retort water (Omega-9) from Rock Springs, Wyoming, and a ten-ton unit simulated in-situ oil shale retort water (No, 16) from Laramie, Wyoming, were subjected to solvent extraction procedure and subsequent instrumental analysis including: (a) high performance liquid chromatography (HPLC) of polynuclear aromatics (PNA's) having more than four rings; (b) capillary gas chromatography (GC) of low molecular weight volatile PNA's; and (c) gas chromatography-mass spectrometry (GC-MS) for complementary identification of PNA's having functional and heterocyclic modifications.

A total of 41 PNA's were identified. Identification of 28 PNA's in the coal derived water (No. 3) was attained, whereas that of the true in-situ retort water (Omega-9) and the simulated retort water (No. 16) were 24 and 18, respectively. Thirteen PNA's were found to be common to all three wastewater samples. Thirteen PNA's were exclusively found in sample No. 3 whereas that of samples Omega-9 and No. 16 were 8 and 4, respectively. It was estimated that the concentration of PNA's in all samples ranged from traces to 30.0 ppb.     

Environmental and economic assessment of sugarcane first generation biorefineries in Brazil

The majority of current sugarcane mills in Brazil are annexed plants, producing both ethanol and sugar; the other plants are dedicated only to ethanol production (autonomous distilleries). This study focuses on the technical, environmental, and economic impacts of these first generation sugarcane processing facilities in Brazil using an innovative framework, the so called Virtual Sugarcane Biorefinery. Results showed that optimization technologies presents potential for reducing environmental impacts and improve economic results in comparison to base scenarios for both annexed and autonomous plants. It was also observed that annexed plants that diverted more sugarcane juice for sugar production were more profitable, considering the average prices for the past 10?years in Brazil. In addition, results indicate that scenarios considering more flexibility in annexed plant are more profitable than the conventional annexed one (diverting 50% of the sugarcane juice to sugar and 50% to ethanol production) if increases in prices were to occur. This study shows quantitatively the benefits of optimization techniques and allows understanding the real benefits of the sugarcane plant flexibility in the Brazilian context.     

Oxidized low‐density lipoprotein and lipoprotein(a) levels in chronic kidney disease patients under hemodialysis: Influence of adiponectin and of a polymorphism in the apolipoprotein(a) gene

Chronic kidney disease (CKD) has been associated with an abnormal lipid profile. Our aim was to study the interplay between oxidized low‐density lipoprotein (ox‐LDL), adiponectin, and blood lipids and lipoproteins in Portuguese patients with CKD under hemodialysis (HD); the influence of the pentanucleotide repeat polymorphism in the apolipoprotein(a) (apo [a]) gene upon lipoprotein(a) (Lp[a]) levels in these patients. We studied 187 HD patients and 25 healthy individuals. ox‐LDL and adiponectin were measured using enzyme‐linked immunoassays. Apo(a) genotyping was performed by polymerase chain reaction, followed by electrophoresis in polyacrylamide gel. Compared with controls, patients presented with significantly higher levels of adiponectin, Lp(a), and ox‐LDL/low‐density lipoprotein cholesterol (LDLc) ratio; significantly lower levels of total cholesterol (TC), LDLc, apo A‐I, apo B, ox‐LDL, and TC/high‐density lipoprotein cholesterol (HDLc) ratio were also observed. Similar changes were observed for patients with or without statin therapy, as compared with controls, except for Lp(a). Multiple linear regression analysis showed that body mass index, HDLc, time on HD, and triglycerides (TG) were independent determinants of adiponectin levels, and that apo B, TG and LDLc were independent determinants of ox‐LDL concentration. Concerning the apo(a) genotype, the homozygous (TTTTA)8/8 repeats was the most prevalent (50.8%). A raised proportion of LDL particles that are oxidized was observed. Adiponectin almost doubled its values in patients and seems to be an important determinant in HDLc and TG levels, improving the lipid profile in these patients. Apo(a) alleles with a lower number of repetitions are more frequent in patients with higher Lp(a).     

Quality traits and lipid composition of meat from Nellore young bulls fed with different oils either protected or unprotected from rumen degradation

The qualitative characteristics, lipids and chemical composition of the meat of 35 Nellore young bulls were analyzed. These bulls had an average slaughter weight and fat thickness of 532.17 ± 30.2 kg, and 7.00 mm, respectively. Significant differences were found only in the meat's water holding capacity (WHC), which was higher for animals fed with fresh linseed oil. More conjugated linoleic acid (CLA) was found in the meat of animals fed with unprotected soybean oil, while better omega-6/omega-3 ratios were noted for those fed unprotected linseed oil. The addition of different vegetable oils to the bulls' diet (soybean or linseed, either protected or not protected from rumen digestion) did not interfere with the qualitative characteristics of their meat while improving the lipid composition of the longissimus muscle. Of the oils examined, unprotected linseed oil most improved the omega-6/omega-3 ratio, thus producing the healthiest meat for human consumption.     

Investigation of the pH effect and UV radiation on kinetic degradation of anthocyanin mixtures extracted from Hibiscus acetosella

The major anthocyanin pigments extracted from Hibiscus acetosella flower were investigated by UV–Vis spectroscopy and multivariate curve resolution-alternating least squares (MCR-ALS). Pure spectra and kinetic of the species present at different pH values were recovered for anthocyanins transformation and degradation products, found with and without UV radiation exposure. In the absence of UV radiation, up to seven different species were detected and by UV radiation exposure, this number increased to up to nine. The species detected in the absence of radiation were also detected when pigments samples were exposed to UV radiation, where degradation occurred faster and two new species appear. The kinetic profiles obtained at different pH values allowed the proposal of a reaction mechanism and pathway.     

Primary neurogenesis in Xenopus embryos regulated by a homologue of the Drosophila neurogenic gene Delta

X-Delta-1, a Xenopus homologue of the Drosophila Delta gene, is expressed in the early embryonic nervous system in scattered cells that appear to be the prospective primary neurons. Ectopic X-Delta-1 activity inhibits production of primary neurons and interference with endogenous X-Delta-1 activity results in overproduction of primary neurons. These results indicate that the X-Delta-1 protein mediates lateral inhibition delivered by prospective neurons to adjacent cells, and that commitment to a neural fate in vertebrates is regulated by Delta-Notch signalling as in Drosophila.     

Operational failure experience of fault-tolerant digital control systems

Fault-tolerant digital control systems (F-T DCSs) can theoretically achieve extremely high reliability, i.e. high mean time between failures (MTBFs). However, in actual applications theoretical MTBFs are idealized goals, and even the more modest goals can only be achieved with great effort at the design stage (particularly software design) and with excellence in operation/maintenance throughout the life of the system. This paper discusses the reliability performance of F-T DCSs, including a presentation of actual failure experience from 20 different computer system installations. Particular emphasis is given to identifying major contributors to system unreliability and comparing different types of F-T DCS architectures.     

Characterization of MAO‐Modified Silicas for Ethylene Polymerization

A series of methylaluminoxane (MAO)‐modified PQ and EP 12 silicas, calcined at 110, 250, and 450°C, were prepared. The resulting MAO‐modified supports were characterized by a set of complementary techniques: Fourier transform infrared spectroscopy (FT‐IR), scanning electron microscopy‐energy dispersive X‐ray spectroscopy (SEM‐EDX), small angle X‐ray scattering (SAXS), and thermal gravimetric analysis (TGA). The Al/Si ratios of the MAO‐modified PQ and EP12 silicas were in the ranges of 0.19–0.27 wt % and 0.17–0.30 wt %, respectively. MAO‐modified silicas were used in the polymerization of ethylene using an Et₂IndZrCl₂ catalyst. The MAO‐modified PQ silica showed higher activity in comparison to the MAO‐modified EP12. © 2013 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 130: 4568–4575, 2013     

Optimized orthonormal wavelet filters with improved frequency separation

This paper proposes an optimization-based method to design orthonormal wavelet filters with improved frequency separation. The proposed approach adopts a parameterization of orthogonal filter banks which ensures that the resulting wavelets have at least two vanishing moments. The filter parameters are adjusted by a numerical optimization algorithm in order to minimize a cost function associated to cut-off sharpness. In comparison with standard orthonormal filters, the proposed method is shown to provide better trade-off between frequency selectivity and time resolution. For illustration, the optimized filters are employed in an application example involving the use of a wavelet-packet system identification scheme. As a result, the identification errors are smaller than those obtained by using a non-optimized filter with the same length.     

Evaluating two implementations of the component responsible for decoding video and audio in the Brazilian digital TV middleware

The project Ginga Code Development Network (GingaCDN) was created to implement a reference version of Ginga, the Brazilian Digital Television System (SBTVD) middleware, supporting the declarative GingaNCL and the procedural GingaJ environments in the same middleware. To reach that, a common core is being implemented, named Ginga Common Core (GingaCC). One of the main components of the GingaCC is the one responsible to decode audio and video streams, called Media Processing. In this work, two Media Processing implementations using libVLC and Xine graphical libraries are investigated. Performance tests and results of both Media Processing implementations running in two different desktop architectures are discussed.