1,721,056 research outputs found
A comprehensive review of environmental and operational issues of constructed wetland systems
No full textConstructed wetlands (CWs) are increasingly gaining ground
for the treatment of domestic and agricultural wastewaters,
coal mine drainage, and stormwater runoff, mainly because of
a set of beneficial features, including environmental quality
preservation, landscape conservation, and economic convenience.
These would not be possible without activities such as
monitoring and harvesting that can significantly contribute to
both pollutant removal efficiency and sustainability of CWs.
This review investigates this field of research by touching those
themes and close-related ones, to contribute to enhancing the
state of the art and the knowledge on CWs
Energy consumption of rainfed durum wheat cultivation in a Mediterranean area using three different soil management systems
No full textAn energy analysis comparing three different soil management systems was carried out in Southern Italy using data collected in a five-year field experiment, with the aim of identifying the most energy efficient system.
On average, because of a little more energy is demanded (13.3 GJ ha-1) and a higher grain yield is obtained (2.20 t ha-1) in the Intensive case than the other two practices, the total Energy Input required to produce 1kg durum wheat was higher in the No tillage-based system (11.05 MJ kg-1) than in the Intensive (6.80 MJ kg-1) and the Minimum one (6.78 MJ kg-1).
The highest contribution to Energy Input derived from nitrogen fertiliser followed by diesel fuel. In this regard, No-tillage allowed for reduction of diesel energy consumption by about 70% and 60% compared with Intensive tillage and Minimum tillage, respectively.
The Minimum tillage practice showed the best energy performance, because it determined the following results on an average base: the highest energy ratio (4.69) and the highest energy profitability (3.69); the lowest energy intensity (5.86 MJ kg-1). Therefore, MT may be considered as the practice exhibiting the best energy performance and representing the viable trade-off between IT and NT
Exploring Airports’ Landside Congestion Impacts on the dynamic of Passengers Satisfaction
No full text
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Synthesis and X-ray structure of a new sterically hindered cyclophane containing chiral spirobiindanol phosphonates and phosphate units
No full textThe synthesis, as well as the stereochemical and solid-state structure characterization of a novel sterically congested cleft-like receptor molecule, fully equipped for multipoint recognition and containing a chiral spirobiindanol phosphonate unit, is reported
Toughening effect of non-periodic fiber distribution on crack propagation energy of UHTC composites
Full text linkDifferent configurations of continuous carbon fiber-reinforced ultrahigh temperature ceramics (UHTCs), by combining coatings and matrix, were produced via electrophoretic deposition (EPD) and slurry infiltration. The toughening of non-periodic fiber distribution induced by the EPD process was investigated through work of fracture analysis. The results show that a non-periodic fiber distribution results in toughness increase from 8 MPa√m to 11 MPa√m with respect to a periodic fiber distribution. This toughness improvement does not strongly affect the flexural strength, which is mainly related to the fiber volumetric amount. It is shown that the assembling of carbon fibers into bundles (i.e. by dispersing the fibers with a non-periodic distribution) increases the crack propagation energy dissipated on the crack-wake from 0.5 kJ/m2 to 1 kJ/m2, which can be mainly ascribed to the fiber/bundle pull-out. On the other hand, the energy dissipated on the crack-tip (as fiber/matrix debonding) is fiber distribution-independent and increases from 0.3 kJ/m2 to 0.4 kJ/m2 with increasing the fiber amount from 33 vol% to 40 vol%. Finally, WoF analysis is proposed as test to evaluate pull-out toughening instead of push-in and push-out tests
Cure Kinetic and Properties of Epoxy Resins Containing a Phosphorous-Based Flame Retardant
No full textA fire retardant phosphorous-containing bisphenol compound,
bis(3-diethyl phosphono-4-hydroxyphenyl)-sulfide (DPHS), has been inserted in an epoxy network. In particular, a chain extension procedure has been used to incorporate DPHS into a standard bisphenol epoxy resin. Different amine catalysts have been tested to promote the reaction of DPHS with the epoxy oligomer. The cure kinetics of this chain-extended oligomer, using an aliphatic amine (triethylene-tetraamine, TETA) as hardener, has been studied with the aid of differential scanning calorimetry and compared with that of the standard stoichiometric epoxy/TETA formulation. For each formulation the activation energy of the curing reactions has been evaluated by the Kissinger method. The results of thermogravimetric and flammability tests indicate that DPHS promoted the formation of a char, leading to an improved fire resistance. Finally, a comparison of the thermal and mechanical properties of the standard stoichiometric formulation relative to those of the epoxy modified with DPHS, and cured with TETA, showed only marginal changes in the physical and mechanical properties
Dynamic stereochemistry of bis-β-diketonato-1,5-cyclooctadiene ruthenium(II) complexes
No full textTris(chelate)2(diene)ruthenium(II) complexes have been synthesized. All three possible diastereoisomers of Ru(bzac)2(cod) (where cod=1,5-cyclooctadiene and bzac=benzoylacetonato) have been isolated and diastereoisomerization processes were observed at elevated temperature. The energy barriers were found to be in the range of 35-36 kcal/mol. The DNMR behaviour of Ru(S2CNMe2)2(cod) and Ru(S2PMe2)2(L) complexes is also discussed. We synthesized a new Ru(N-isopropylsalicylaldiminato)2(cod) tris-chelate which was found to clathrate some solvents. © 1991
Variations on the Author
Full text link“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
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