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[en] The purpose of this report is to evaluate data from measurements of physico-chemical parameters and microbiological parameters. Because of sources of contamination like petroleum residues, and derivated products are out of the limits accepted at international level. In addition to this contaminatio was found high levels of microbiological load that are causing harms to ecosystems of the river Dulce
[en] Since 1980's the world market for crude oil and oil products has faced significant changes that are going to have a grate influence on the supply and consumption of crude oil derivatives in Macedonia. The knowledge of these changes would have a grate contribution in planning the future development of this part of the energetic system of Macedonia. The purpose of this paper (which is a short version of the introductory report for the ZEMAK session with a theme 'Energetic policy and development of energetics in Macedonia') is to present the actual situation on the market for crude oil products, as well as to give the main factors that would have influence on this market in the future. (author). 4 refs., 3 ills
[en] A series of experiments concerning the toxicity of certain crude oil fractions to selected aquatic and terrestrial species were carried out to gain information on the fate and transport and the potential ecological and human health impacts of these hydrocarbon contaminants. Paraffinic, asphaltic, and napthenic crudes were fractionated and the fractions were analyzed by flame ionization gas chromatography for a semi-quantitative assessment of how the fractionation affects the distribution within the C to C6 range (which is typical for total extractable hydrocarbons). Artificial and field soil samples were then spiked with the fractions and crudes. Standard worm and seed test were done on the spiked soils and microbial, plant, and invertebrate test on soil and extracts of the crude fractions. Details of the results achieved were described
[en] In this paper the application of the exergy method to a crude oil atmospheric distillation tower is presented. The fundamentals and procedures are presented as well as the main parameters used to describe the thermodynamic performance of the system, such as Exergy Losses, Effectiveness and Improvement Potential. A parametric analysis of the influence on the effectiveness of the tower is then performed as a function of the number of trays, the amount of stripping steam, the use of reboilers and the operation pressure. The results obtained are discussed. As expected, the effectiveness of the tower increases with the overall number of trays in the tower and in the stripping columns for a constant operation pressure and a constant amount of stripping steam but there is a limit at which the pressure drop across the trays and the stripping steam requirements make the effectiveness decrease. The use of reboilers in the stripping columns adjacent to the main tower allows an increase in the effectiveness basically due to a greater heat integration. Finally, the increase in the operation pressure of the tower produces an increase of the effectiveness but also an increase in the stripping steam requirements
[en] This project focuses on the synthesis of mesoporous aluminophosphate (AlPO) catalysts for application in the acid catalyzed conversion of large petroleum feedstock compounds to Useful middle distillates and naphtha transportation fuels
[en] This paper presents a simple treatment of elastic wave scattering at periodically structured surfaces and interfaces of solids, and the existence and nature of surface acoustic waves (SAW) and interfacial (IW) waves at such structures. Our treatment is embodied in phenomenological models in which the periodicity resides in the boundary conditions. These yield zone folding and band gaps at the boundary of, and within the Brillouin zone. Above the transverse bulk wave threshold, there occur leaky or pseudo-SAW and pseudo-IW, which are attenuated via radiation into the bulk wave continuum. These have a pronounced effect on the transmission and reflection of bulk waves. We provide examples of pseudo-SAW and pseudo-IW for which the coupling to the bulk wave continuum vanishes at isloated points in the dispersion relation. These supersonic guided waves correspond to embedded discrete eigenvalues within a radiation continuum. We stress the generality of the phenomena that are exhibited at widely different scales of length and frequency, and their relevance to situations as diverse as the guiding of seismic waves in mine stopes, the metrology of periodic metal interconnect structures in the semiconductor industry, and elastic wave scattering by an array of coplanar cracks in a solid
[en] Highlights: • Cross-sectional study in Milan, Italy. • Bipolar patients hospitalized for manic episode between 2007 and 2019. • PM10 exposure associated with a lower severity of manic episodes. • Severity found higher in psychotic patients and lower in those with mixed features. • PM10 also associated with a higher risk of manic episodes with mixed features. Bipolar Disorder (BD) alternates depressive, manic or hypomanic phases. A manic episode (ME) is the main psychopathological condition of BD and it often requires hospitalization. Air pollution is thought to play a role in onset and exacerbation of several psychiatric disorders. We aimed to verify the association between exposure to particulate matter ≤10 μm (PM10) and ME severity, assessed through the Young Mania Rating Scale (YMRS). We evaluated clinical records regarding 414 hospital admissions of 186 patients residing in Milan (Italy), hospitalized for ME in the Psychiatry Unit of the Policlinico Hospital from 2007 to 2019. Patients were assigned mean daily PM10 and apparent temperature levels of the Milan municipality. As exposure windows, we considered single days preceding hospitalization (lag0 to 7) and their average estimates (lag0-1 to 0-7). We applied mixed effect models, adjusted for relevant confounders. Short-term PM10 exposure was associated with a reduction in YMRS, both when considering daily lags [β: −0.43 (95% Confidence Interval: −0.83; −0.03) at lag0] and their average [−0.47 (−0.90; −0.04) at lag0-1]. YMRS was higher in psychotic patients (24.8) and lower in ME with mixed components (15.5) if compared to episodes characterized by neither mixed nor psychotic features (17.4, p < 0.001). While PM10 did not influence the risk of psychotic symptoms at admission, it was associated with a higher risk of ME with mixed features, with Odds Ratios ranging from 2.43 (1.02; 5.76) at lag0 to 3.60 (1.22; 10.7) at lag0-2. Our findings show that increasing levels of PM10 move the ME towards the depressive pole of the BD spectrum and augment the probability of hospitalization for ME with mixed components. These results have important clinical implications, as mixed features worsen the course of ME and make the management of bipolar patients challenging.
[en] We present that the presence of dark energy in our universe is causing space to expand at an accelerating rate. As a result, over the next approximately 100 billion years, all stars residing beyond the Local Group will fall beyond the cosmic horizon and become not only unobservable, but entirely inaccessible, thus limiting how much energy could one day be extracted from them. Here, we consider the likely response of a highly advanced civilization to this situation. In particular, we argue that in order to maximize its access to useable energy, a sufficiently advanced civilization would chose to expand rapidly outward, build Dyson Spheres or similar structures around encountered stars, and use the energy that is harnessed to accelerate those stars away from the approaching horizon and toward the center of the civilization. We find that such efforts will be most effective for stars with masses in the range of , and could lead to the harvesting of stars within a region extending out to several tens of Mpc in radius, potentially increasing the total amount of energy that is available to a future civilization by a factor of several thousand. Lastly, we also discuss the observable signatures of a civilization elsewhere in the universe that is currently in this state of stellar harvesting.
[en] In this study we present an analytical investigation on the propagation characteristics of electro-kinetic wave modified through quantum correction term and charge imbalance parameter using quantum hydrodynamic model for an ion-implanted semiconductor plasma. The dispersion relation has been analyzed in two distinct velocity regimes. We found that as the number of negative charges resides on the colloids increases, their role become increasing effective. The present investigation is important for understanding of wave and instability phenomena and can be put to various interesting applications
[en] The product slate of a simple refinery consists mainly of liquefied petroleum gas, leaded and unleaded gasoline, jet fuel, diesel fuel, extra light heating oil and fuel oil. The quality of the oil products (fuels) for sale has to comply with the adopted standards for liquid fuels, and the produced quantities have to be comply with the market needs. The oil products are manufactured by blending two or more different fractions which quantities and physical-chemical properties depend on the crude oil type, the way and conditions of processing, and at the same time the fractions are used to blend one or more products. It is in producer's interest to do the blending in an optimal way, namely, to satisfy the requirements for the oil products quality and quantity with a maximal usage of the available fractions and, of course, with a maximal profit out of the sold products. This could be accomplished by applying linear programming, that is by using a linear model for oil products blending optimization. (Author)