88,237 research outputs found
Gallucci site_Río Negro, Patagonia, Argentina
No full text3D model of Gallucci site.Full reference: Béguelin M., Vazquez R.C., Citton P. and Otero F. 2024. Sitio Gallucci: primer hallazgo arqueológico de restos óseos humanos en el valle superior del Río Negro, Patagonia Argentina. Comechingonia. Revista de Archeologia, 28, https://revistas.unc.edu.ar/index.php/comechingonia/article/view/42379</p
Bioenergy–Intensified Biomass Utilization
No full textA major objective of European energy policy is to move towards more sustainable development based on diverse mix of resources, in particular, renewable resources including biomass. This chapter addresses broad field of power and combined heat and power (CHP) generation from biomass: more specifically, advances in biomass gasification technology aimed at increasing the overall conversion and efficiency and hence in a decreased cost of electricity. Poly-generation strategies are also considered, with particular reference to recent technological innovations in hot gas cleaning and conditioning; these have been developed to achieve the required improvements in syngas quality and have been validated under industrially relevant conditions. Biomass gasification is a thermo-chemical conversion process for the production of a fuel gas. Various combinations of air, oxygen and steam may be used as the gasification agent. This chapter focuses on steam gasification processes carried out in fluidized bed reactors for the production of H2-rich syngas. © 2015 John Wile
Un nuovo sottosistema penale
No full textin BALDI F., GALLUCCI E., GARUTI G., MATTEVI E., PANIZZO F., PICOTTI L., PONGILUPPI C., Le definizioni alternative del processo penale davanti al giudice di pace. Conciliazione, irrilevanza del fatto e condotte riparatori
Il pioppo conservato intero è fra i migliori in caldaia
No full textSe l'utilizzo finale del pioppo è la conversione energetica in caldaia la forma di stoccaggio preferibile rispetto a cippatura e pezzatura è la pianta intera, che raggiunge un livello di umidità finale del 17,8
EFFECT OF DIVALENT CATIONS ON PORIN INCORPORATION IN PLANAR BLM
No full textBiological membranes contain as a basic structural unit a phospholipid bilayer.
Phospholipid membranes in the form of bilayer films (BLM) are currently used as experimental models for transport phenomena of the biological membranes. In particular, bilayers made of acidic phospholipids, present the advantage to investigate the bioelectrical phenomena across the biological membranes.
This class of phospholipids by having a fixed charge might bind ions that play an important role on many physiological processes. It is known that Ca++ and other alkaline cations change the electrostatic potential of the negatively charged bilayer membranes either absorbing to the phospholipids or accumulating in the aqueous diffuse double layer, and this potential change may induce conductance variation (1).
Cd++ another divalent cation has been shown to exert influence on the permeability of some anaelectrolytes across BLM made of negatively charged phospholipids, but not on the zwitterionic phospholipids (2).
We have studied the effect of divalent cations as Ca++ and Ba++ that exert a cross linking together with a screening effect respectively, on the kinetics of incorporation of the mithocondrial porin in bimolecular lipid membranes made with phosphatydilinositol.
In order to understand how lipids of the bilayer affect protein incorporation at the molecular level we must consider that protein crossing the bilayer has to surmount different regions characterized by different properties as interfacial region, head groups, lipid backbone and hydrocarbon core.
In this study we focused our attention to the role of the interface and head group regions of the BLM in the porin incorporation.
The artificial membranes were made of phosphatydilinositol cromatografically pure in n-decane (1% w/w). The bathing media were KC1 1M and KC1 1M plus CaC12 or BaCl2 10 mM. Porin was added at membrane "black" on the two aqueous bathing solutions. Bilayers conductivity and capacitance measurements were carried out at temperature of 25 ± 2 °C and studied by means of alternate current (f = 1 Hz) recording the voltage after a current to voltage converter in series with the membrane; simultaneously electrical capacitance was measured at 1 KHz before and during porin incorporation (3) .
We noticed that when the membranes are in the presence of Ca++ or Ba++ there was an exceptional stability.
With the different bathing solutions no significant differences were observed in membrane conductance values whereas small capacitance variations were recorded.
Once the membrane has became black porin, at a fixed concentration, was added to the aqueous solutions, and after a lag time due to the diffusion of the protein in the solutions and of the time to overcome the membrane barriers, an increase of the voltage output due to the channels formation was recoded. This phenomenon shows a "S-shaped" kinetics. In contrast to the kinetics of incorporation of the porin in oxidized cholesterol lipid membranes (4), showing an hyperbolic shape. These different kinetics may be explained by the different interface barrier; in fact when the experiment were conducted with porin already present in the bathing solutions before membrane formation, the different kinetics persisted in the phosphatydilinositol and in oxidized cholesterol BLM.
The S shaped kinetics persists also when porin is incorporated in phosphatydilinositol membranes in the presence of Ca++ or Ba++; but the curve in presence of the Ca++ is shifted to the right.
This shift is much more pronounced in the presence of Ba++.
It is known that Ca++ affects the surface potential of BLM containing negatively charged lipids. The protein incorporation into BLM can be regarded as a two steps process: I) the interaction at the surface barrier, and II) the penetration into hydrocarbon region.
In the first step the protein encounter an higher resistance in phosphatydilinositol membrane because it has to overcome the interface region consisting of a diffuse double layer, the membrane surface and the polar head groups.
Ca++, by exerting a cross-linking and screening effect on negatively charged membranes, retards the porin incorporation.
At the moment we are not able to distinguish which of the two effect is prevalent; but results in presence of Ba++, that exerts a screening effect only seem to indicate that the latter effect is prevalent. In order to establish the pure cross-linking effect experiments are in progress.
The influence of the divalent cations on the protein incorporation into BLM, that are sensitive to changes in environmental conditions, make this study appealing in order to provide a better knowledge in the molecular mechanism of the protein incorporation and channel formation.
Work supported by 40% grant from MURST 1991
1) S. G. A. McLaughlin, G. Szabo and G. Eisenman, 1971: J. Gen. physiol., 58, 667.
2) S. Micelli, E. Gallucci and C. Lippe, 1978: Arch. Intern. Physiol. Biochim., 86, 755-759.
3) G. Monticelli, E. Gallucci and S. Micelli, 1990: Proc. X School on Biophysics of Membrane Transport, 1: 328-343, Poland.
4) S. Micelli, G. Monticelli and E. Gallucci, 1990: IBST 1: 221
L'essiccazione naturale del cippato di pioppo
No full textStoccare cippato di dimensioni grossolane (10-25 mm per il 65% del peso totale del cumulo) e senza compattamenti in fase di accumulo permette di essiccare il materiale più rapidamente e con minori perdite di sostanza secca a causa dei fenomeni fermentativ
On the measurement of solids circulation rates in interconnected fluidized beds: Comparison of different experimental techniques
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Powder Technology
Volume 302, 1 November 2016, Pages 81-89
On the measurement of solids circulation rates in interconnected fluidized beds: Comparison of different experimental techniques (Article)
Medrano, J.A.a,
Nordio, M.ab,
Manzolini, G.b,
van Sint Annaland, M.a,
Gallucci, F.a
a Chemical Process Intensification, Department of Chemical Engineering and Chemistry, Eindhoven University of Technology, De Rondom 70, Eindhoven, Netherlands
b Group of Energy Conversion Systems, Department of Energy, Politecnico di Milano, Via Lambruschini 4, Milano, Italy
View references (31)
Abstract
Membrane assisted Chemical Looping Reforming (MA-CLR) is a novel concept recently proposed for efficient hydrogen production with integrated CO2 capture. This novel technology is based on the circulation of a solid (an oxygen and heat carrier) between two different reactors, an air reactor and a membrane assisted fuel reactor. The solids circulation rates (SCR) between the two reactors determine the oxygen and heat transfer rate and temperature difference between the reactors and hence the overall performance of the new concept. However, the prediction of the SCR is still based on empirical correlations while many different techniques have been used in the literature to measure it. In this work a comparison of three different experimental techniques for the SCR is presented. A pseudo 2D interconnected circulated fluidized bed system has been constructed and the SCR have been measured using an optical technique, a pressure difference technique and a particles extraction technique. The three methods have been compared for different experimental conditions by varying superficial gas velocities, particle diameter and particle type. Results show that the SCR can be well predicted with the pressure drop method as the results are in good agreement with both the optical technique and the particle extraction technique for both spherical particles and non-spherical particles. The fact that the optical and pressure methods are not intrusive represents the main advantage for both. However, while the optical technique gives more information on the distribution of the solids hold-up along the riser of the chemical looping system, it can only be applied to 2D systems as optical access is required. On the other hand, the pressure drop technique is much cheaper and easier to be applied and can also be used for 3D high temperature systems
Metal Supported and Laminated Pd‐Based Membranes
No full textmetal supported and laminated Pd-based membranes;Pd-H system, applications of Pd alloys - to production of membrane devices for producing hydrogen;diffusion welding technique, applied - for preparing two kinds of Pd-based composite membranes;metal support use, for Pd-based membranes - overcoming drawbacks given by ceramic supports;thermomechanical press, used for preparing metal-supported membranes via diffusion welding;Pd-Ag foil, supported by steel grid after the peel test;Scheme of device, for preparing the Ni-supported membrane tube;laminated membranes - use of low-cost metals instead of Pd - its alloy, way to reduce costs of metal permeators for producing pure hydrogen;cold rolling of metal alloys, different than Pd ones - new types of dense metal membranes;preparation of laminated membranes - using low costs metals as bulk material for Pd-based membrane
Cynara cardunculus exploitation for energy applications : development of a combine head for theshing and concurrent residues collecting and utilization
Full text linkThe CRA-ING took part to the Cynara cardunculus harvesting tests organized in Spain in 2007, where UPM has experimental cultivations in the Instituto Madrileño de Investigación y Desarrollo Rural, Agrario y Alimentario (IMIDRA) de la Consejería de Economía y Innovación Tecnológica de la Comunidad de Madrid in El Encìn, near
Alcalà De Henarez. The harvesting tests were carried out in week 33 (August 13th-17th); the cultivation was found
part in good condition of maturity, part still not ready for harvesting. The project concept, supplied to a firm that already
builds heads for maize, wheat, sunflower, soybean and so on, included the upper devices of a maize head and a
classic wheat head (without the paddle wheel) in the lower part, to obtain capitula detachment and effective threshing
and, at the same time, the stalk cut. The basic concept of the machine, to separate and thresh the capitula and to drop
in windrow the biomass and then pick it up with a baler with a minimum soil presence, was proved to be feasible. The effective working capacity was good, so the costs should be sustainable
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