Preliminary Experimental Study on Double Fuel HCCI Combustion

Abstract This paper regards an experimental study on a particular internal combustion engine process which combines Double Fuel combustion with Homogeneous Charge Compression Ignition (HCCI) using mixtures of natural gas (NG) and gasoline. The tests performed on a CFR engine demonstrate that HCCI combustion can be achieved using NG-gasoline mixtures without knocking occurrence for low to medium engine load varying the proportion between the two fuels. The main advantage of this new combustion process relies on the noticeable higher engine efficiency obtained with respect to conventional spark ignition operation, and on the strong reduction of NO X emissions

Il "Panegirico di Costantino" di Optaziano Porfirio

La colección de poesía de Optatianus Porfirio está configurado como un elogio poético dirigido a Constantino. El trabajo de Porfirio asume las características externas de la poética panegírico, pero es una pátina sólo aparente, limitado a epítetos, apóstrofes cortos, alabanza retórica, más justificada por el fin de obtener el regreso del exilio, que no es por convicción personal real. Además una retórica semejante es una de las principales cargas por el lector moderno, si va a entrar en la obra de Optatianus, cuya principal razón de la atracción es y sigue siendo las innovadoras características a nivel de artificio-icónica visual y métrica.

Experimental Model-Based Linearization of a S.I. Engine Gas Injector Flow Chart

Experimental tests previously executed by the authors on the simultaneous combustion of gasoline and gaseous fuel in a spark ignition engine revealed the presence of strong nonlinearities in the lower part of the gas injector flow chart. These nonlinearities arise via the injector outflow area variation caused by the needle impacts and bounces during the transient phenomena that take place in the opening and closing phases of the injector and may seriously compromise the air-fuel mixture quality control for the lower injection times, thus increasing both fuel consumption and pollutant emissions. Despite the extensive literature about the operation and modelling of fuel injectors, there are no known studies focused on the nonlinearities of the gas injector flow chart and on the way they can be reduced or eliminated. The authors thus developed a mathematical model for the prediction of mass injected by a spark ignition (S.I.) engine gas injector, validated through experimental data. The gas injector has been studied with particular reference to the complex needle motion during the opening and closing phases, which may strongly affect the amount of fuel injected. In this work, the mathematical model previously developed has been employed to study and determine an appropriate injection strategy in order to linearize the injector flow chart to the greatest degree possible. The injection strategy proposed by the authors is based on minimum injection energy considerations and may be easily implemented in current engine control units (ECU) without any hardware modification or additional costs. Once calibrated by means of simulation, this strategy has been validated by experimental data acquired on an appropriately equipped injector test bench. As a result, the real injector flow chart has been substantially improved, reducing its deviation from linearity to one third of the original flow chart, which is an excellent result, especially if the typical measurement dispersion of the injected mass is taken into account. The injection strategy proposed by the authors could extend the linear behaviour of gas injectors and improve the fuel supply by means of a simple software update of the ECU, thus obtaining higher engine efficiency and lower pollutant emissions

Fishery reserves in the Mediterranean Sea: the Gulf of Castellammare case study

The effects of fisheries management based on artificial reefs and on trawl banning are explored in the Gulf of Castellammare fishery reserve by means of biological (from trammel and trawl survey) data collected during several research programs between 1990 and 2001. The artificial reefs have caused an increase of diversity but not of biomass, as suggested by the comparison between the associated fish assemblage and that of nearby sandy bottoms. The associated species however do not have any trophic relation to the boulders, except the twobanded seabream, Diplodus vulgaris. An overall increase of experimental trammel net yields in the artificial reef area was observed from 1990 to 1998, due mainly to pelagic species associated with the boulders. The trawl ban caused a dramatic increase of groundfish biomass in the protected area (+711% after four years, total species). Different species had different increase rates, from 2-fold for the musky octopus, Eledone moschata to 127-fold for the gurnard, Lepidotrigla cavillone. Eight and ten years after the ban started, the yields did not vary significantly in the overall area, but decreased near to (both outside and inside) the protected area, probably due to increased legal and illegal trawling. The mean size did not increase in three studied species, except for the monkfish, Lophius budegassa. In conclusion the Gulf of Castellammare fishery reserve is considered a positive example of marine coastal fisheries management, especially considering the effects of the trawl ban on the abundance of groundfish stocks, although the cooperation between scientists and administrative bodies is still far from optimal

Towards the sustainable hydrogen production by catalytic conversion of C-laden biorefinery aqueous streams

An extensive screening of representative molecules of a post-hydrothermal process side stream has been performed with the aim of producing a gas mixture rich in hydrogen by catalytic aqueous phase reforming. The survey enlightens possible routes of valorisation of these by-products, scarcely investigated with other processes so far. The influence of reaction temperature was studied in the 230–270 °C range, looking at both the composition of the gas phase and the characterization of the liquid products. Indeed, the information coming from the condensed phase may provide relevant insights on the components that are not easily reformed, and that should be studied to improve the performance of the process. Binary and ternary mixtures of four selected compounds were tested to investigate synergistic and inhibiting effects, going towards the direction of a real biorefinery stream. The spent alumina-supported catalyst was characterized, outlining possible deactivation mechanisms of the catalytic system, and reused in two successive tests

Aqueous phase reforming of lignin-rich hydrothermal liquefaction by-products: a study on catalyst deactivation

The water fraction derived from the hydrothermal liquefaction of a lignin-rich feedstock was subjected to aqueous phase reforming to produce hydrogen. Deactivation of the catalyst was observed, and it was ascribed to fouling phenomena caused by phenolic oligomers. Simple aromatics like guaiacol and phenol, as well as in-organics, were proved not to be the cause of the deactivation thanks to the use of a multi-component synthetic mixture. The influence of using activated carbon as a pretreatment was studied, leading to a strong improvement of the performance when it was carried out at high temperature. The extent of deactivation was assessed using aqueous phase reforming of glycolic acid as a model reaction test. The results were found to be correlated with the surface area of the catalyst. A thermal regeneration in inert conditions was evaluated as a mode of catalyst regeneration. While the textural properties were partially recovered, the performance of the catalyst only slightly improved. A spectroscopic analysis of the solids in the aqueous solution was carried out, highlighting the structural similarities between their nature and the lignin residue. The results obtained in this study helped to enlarge the knowledge on the aqueous phase reforming of real complex mixtures, looking at indicators of paramount importance for a possible industrial application such as the stability of the catalyst

A Case of Fatal Drug Rash Eosinophilia and Systemic Symptoms from Allopurinol

Hypereosinophilia is a systemic condition that has several possible etiologies: allergies, medications, infectious, autoimmune or other systemic diseases, and finally idiopathic forms. Skin involvement seems to relate to subcutaneous inflammatory infiltration in this condition, as can be observed in parasitic, autoimmune and bullous diseases, as well as in drug reactions. Generalizing, a severe adverse drug-induced reaction may cause a systemic inflammatory disease: Drug Rash with Eosinophilia and Systemic Symptoms (DRESS). Its diagnosis requires the application of a complex diagnostic algorithm and immediate identification to prevent inauspicious evolution. The prognosis is severe; drug discontinuation is sometimes not enough and so far the proposed therapies are not always valid. We describe a case of fatal DRESS in which we report: a) difficulties in the management and therapy of the syndrome in its most severe form, and b) need for caution in prescribing drugs potentially inducing DRESS, especially in elderly patients