Search results for "power"
showing 10 items of 5099 documents
Photocatalytic degradation of dyes by using a membrane reactor
2004
Abstract Dyes are organic compounds used in textile, food and drug industries, and their abatement represents one of the main problems in the treatment processes because generally they are very stable toxic compounds. In this work, two commercial azo-dyes, i.e. Congo Red (C32H22N6Na2O6S2) and Patent Blue (C27H31N2NaO6S2), in aqueous solution were degraded in a photocatalytic membrane reactor by using TiO2 Degussa P25 as the catalyst. Different system configurations and irradiating sources were studied, and the influence of some operational parameters such as the pressure in the membrane cell and the initial concentration of the substrates was determined. A comparison between suspended and e…
Photocatalytic formation of H2 and value-added chemicals in aqueous glucose (Pt)-TiO2 suspension
2016
Abstract Commercial and home prepared bare and Pt-supported TiO2 samples were used as the photocatalysts for the aqueous photo-conversion of glucose at ambient pressure and temperature. Aerobic and anaerobic conditions were used to study the products of glucose degradation both in the liquid (arabinose, erythrose, gluconic acid, glucaric acid, fructose and formic acid) and gaseous (H2 and CO2) phases. The distribution of these molecules was different in the presence of the various powders, depending on the structural and physico-chemical properties of the materials, and Pt resulted essential for the anaerobic production of H2. The home prepared samples resulted more active than the commerci…
The President of the gold diggers: Sources of power in a gold mine in Burkina Faso
2003
The article provides an example of how 'formal' and 'informal' modes of power and legitimacy, as well as material and symbolic leadership resources, may intersect and interrelate. It analyses the sources of power that a Big Man in West Africa mobilised in order to appropriate mining rights and to establish leadership in a gold mining camp. As an entrepreneur in an economic field directly regulated by state laws and authorities, he has to operate within these structures while at the same time subverting them by creating a 'system of personal power' that resembles Sahlins' classic model of the Big Man in Melanesia. Although he is elected to represent the gold diggers, his leadership position …
Energy management of multi-carrier smart buildings for integrating local renewable energy systems
2016
The proposed paper aims at defining a Building Management System (BMS) able to control energy flows inside a smart building integrated with various energy networks and Renewable Energy Resources (RES). The smart building envisaged in this work interacts with different energy carriers and is equipped with cogeneration and RES systems, as well as storage devices, which enable a certain degree of flexibility in the energy usage. The smart building is modelled as a multi-carrier hub, by defining the graphical and mathematical model of the building system. Moreover, the control criteria of the BMS are explained and the implementation of the BMS itself is depicted, along with some early results. …
Improvement of Energy Efficiency for Indoor Lighting in a Big Shopping Center
2018
As the progressive diffusion of shopping centers in Italy, the paper analysis the potential energy savings in the indoor lighting plant, thanks to new technologies as LED lamps and Building Automation System. The case study, applied to a big shopping mall in the middle of Italy, shows great results, thanks to the high efficiency of LED technology, high number of operating hours and the implementation of a control system. An economic and environmental evaluation is reported.
Słabości eksplanacyjne teorii inteligentnego projektu
2021
Artykuł powstrzymuje się od polemiki merytorycznej z teorią inteligentnego projektu, dalej TIP, a jedynie wskazuje na jej niedostatki metodologiczne. Dowodzi, że wbrew twierdzeniom jej zwolenników TIP nie jest falsyfikowalna. W odróżnieniu od teorii ewolucji nie może pełnić nawet roli metafizycznego programu badawczego w sensie Poppera. Co jednak ważniejsze, TIP nie pełni żadnych funkcji eksplanacyjnych. W grę wchodzą jedynie wyjaśnienia intencjonalne, TIP zaś nie jest w stanie zidentyfikować motywów domniemanego projektanta. Argument jest zilustrowany przykładami zaczerpniętymi od Stanisława Lema, które pokazują, że możliwych jest wiele alternatywnych hipotez na temat celów domniemanego pr…
Memory effects and coverage dependence of surface diffusion in a model adsorption system
1999
We study the coverage dependence of surface diffusion coefficients for a strongly interacting adsorption system O/W(110) via Monte Carlo simulations of a lattice-gas model. In particular, we consider the nature and emergence of memory effects as contained in the corresponding correlation factors in tracer and collective diffusion. We show that memory effects can be very pronounced deep inside the ordered phases and in regions close to first and second order phase transition boundaries. Particular attention is paid to the details of the time dependence of memory effects. The memory effect in tracer diffusion is found to decay following a power law after an initial transient period. This beha…
Statistical modeling, simulation, and experimental verification of wideband indoor mobile radio channel
2018
This paper focuses on the modeling, simulation, and experimental verification of wideband single-input single-output (SISO) mobile fading channels for indoor propagation environments. The indoor reference channel model is derived from a geometrical rectangle scattering model, which consists of an infinite number of scatterers. It is assumed that the scatterers are exponentially distributed over the two-dimensional (2D) horizontal plane of a rectangular room. Analytical expressions are derived for the probability density function (PDF) of the angle of arrival (AOA), the PDF of the propagation path length, the power delay profile (PDP), and the frequency correlation function (FCF). An efficie…
Assessment of the Operating Temperature of Crystalline PV Modules Based on Real Use Conditions
2014
Determining the operating temperatureTcof photovoltaic panelsPVis important in evaluating the actual performance of these systems. In the literature, different correlations exist, in either explicit or implicit forms, which often do not account for the electrical behaviour of panels; in this way, estimatingTcis based only on the passive behaviour of thePV. In this paper, the authors propose a new implicit correlation that takes into account the standard weather variables and the electricity production regimes of aPVpanel in terms of the proximity to the maximum power points. To validate its reliability, the new correlation was tested on two different PV panels (Sanyo and Kyocera panels) and…
Biologinen sosiaalisen mallina. Valintoja uuden hedelmöityshoitolain kentällä.
2007
Tarkastelen artikkelissa hedelmöityshoitoja koskevan lakiprosessin aikaista kamppailua, joka realisoitui Laiksi hedelmöityshoidoista (1237/2006). Analysoin tarkemmin lain viidettä pykälää (1237/2006, 5§) sekä siitä lakiesityksessä HE 3/2006 esitettyjä perusteluja. Pykälän mukaan lääkärin tulee valita sukusolujen luovuttajista hoitoa saavan parin osapuolia muistuttavat henkilöt, sillä lapsen tulee saada muistuttaa myös sosiaalista vanhempaansa. Analysoin lain viidennen pykälän sisältämiä vanhempien ja lapsen asemaa koskevia lausumia modaalisuusanalyyttisesti käyttäen apuna semioottista neliötä. Neliön kautta ilmennän hoitoihin osallistuvien positioiden modaalista astevaihtelua, joka osoittaa…