1,132 research outputs found
Transformation of the electricity market as a competitive factor for an energy intensive production plant
Abstract. The electricity market has been seen in transition due to climate change, increasing use of renewable energy sources, reduced use of fossil fuels and increased use of electricity. The purpose of this thesis is to analyse how the electricity market changes will affect to electricity prices and could major electricity users gain economically of the future changes. Thesis focuses mainly in the Nordic Electricity market, but the subject has also been studied from the global perspective.
Market changes and increased use of renewable energy sources are most likely affect a higher variation of market prices and increasing need of flexible demand due to intermittent nature of production of renewable energy sources. In the literature review, demand-side management (DSM) has presented as a possible solution for future electricity. This thesis focuses especially on the use of real-time pricing -model as a tool to implement DSM. Real-time pricing -model has been shown to be an economically efficient way to implement demand-side management. In the empirical section, the scenario analysis of demand-side management and real-time pricing model by using electricity intensive production plant consumption data. The effects of real-time pricing have been studied by optimising the consumption data with respect to electricity prices. According to previous related studies, the major electricity users can benefit economically of real-time pricing model if they can act in response to the market signals. Findings in this thesis are quite consistent with this view. According to the results of the empirical section, the electricity-intensive production plant can reduce its total and average electricity costs per MWh by using the real-time pricing model. The empirical study has been made by optimizing the historical and descriptive future data which does not necessarily describe the future or real life. Therefore, the results should be considered indicative due to the restrictions of the study
A mobile system for active otpical pollution monitoring
The remote monitoring of atmospheric pollutants can now be performed in several ways. Laser radar techniques have proven their ability to reveal the spatial distribution of different species or particles. Classical optical techniques can also be used, but yield the average concentration over a given path and hence no range resolution. One such technique is Differential Optical Absorption Spectroscopy, DOAS. Such schemes can be used to monitor paths that a preliminary lidar investigation has shown to be of interest. Having previously had access to a mobile lidar system, a new system has been completed. The construction builds on experience from using the other system and it is meant to be more of a mobile optical laboratory than just a lidar system. A complete system description is given along with some preliminary usage. Future uses are contemplated
Compact fiber-optic fluorosensor using a continuous-wave violet diode laser and an integrated spectrometer
A compact fluorosensor with a fiber-optic measurement probe was developed, employing a continuous-wave violet diode laser as an exciting source and an integrated digital spectrometer for the monitoring of fluorescence signatures. The system has the dimensions 22x13x8 cm(3), and features 5 nm spectral resolution and an excellent detectivity. Results from measurements on vegetation and human premalignant skin lesions are reported, illustrating the potential of the instrument. (C) 2000 American Institute of Physics. [S0034-6748(00)04508-1]
Photodynamic therapy using intravenous delta-aminolaevulinic acid-induced protoporphyrin IX sensitisation in experimental hepatic tumours in rats.
The efficacy of photodynamic therapy (PDT) using delta-aminolaevulinic acid (ALA)-induced protoporphyrin IX (PpIX) sensitisation and laser light at 635 nm was investigated in the treatment of experimental hepatic tumours. The model of liver tumours was induced either by local inoculation or by administration of tumour cells through the portal vein in rats. ALA at a dose of 60 mg kg(-1) b.w. was intravenously administered 60 min before PDT. PpIX accumulation in tumour, normal liver and abdominal wall muscle was detected by means of laser-induced fluorescence (LIF). Laser Doppler imaging (LDI) was used to determine changes in the superficial blood flow in connection with PDT. Histopathological examinations were performed to evaluate the PDT effects on the tumour and the surrounding liver tissue, including pathological features in the microvascular system. The accumulation of PpIX, as monitored by LIF, showed high fluorescence intensities at about 635 nm in both the hepatic tumour tissue and normal liver and low values in the abdominal wall. LDI demonstrated that the blood flow in the treated tumour and its surrounding normal liver tissue decreased immediately after the PDT, indicating an effect on the vascular system. A large number of thrombi in the irradiated tumour were found microscopically 3 h after the PDT. The tumour growth rate showed a marked decrease when evaluated 3 and 6 days after the treatment. These results show that the ALA-PDT is effective in the inhibition of growth of experimental hepatic tumours
Oil Slick Characterization Using an Airborne Laser Fluorosensor- Construction Considerrations
Differential Optical-absorption Spectroscopy (doas) System For Urban Atmospheric-pollution Monitoring
We describe a fully computer-controlled differential optical absorption spectroscopy system for atmospheric air pollution monitoring. A receiving optical telescope can sequentially tune in to light beams from a number of distant high-pressure Xe lamp light sources to cover the area of a medium-sized city. A beam-finding servosystem and automatic gain control permit unattended long-time monitoring. Using an astronomical code, we can also search and track celestial sources. Selected wavelength regions are rapidly and repetitively swept by a monochromator to sensitively record the atmospheric absorption spectrum while avoiding the detrimental effects of atmospheric turbulence. By computer fitting to stored laboratory spectra, we can evaluate the path-averaged concentration of a number of important pollutants such as NO2, SO2, and O3. A measurement of NH3 and NO close to the UV limit is also demonstrated
The FERRUM project: radiative lifetimes of the 3d(5)(S-6)4s4p(P-3)y P-6 degrees states of FeII measured with time-resolved vacuum ultra-violet laser spectroscopy
We report on lifetime measurements of the 3d(5)(S-6)4s4p(P-3)y P-6 degrees states of Fe II using time-resolved vacuum ultraviolet (VUV) laser spectroscopy. A laser-produced plasma has been used as the source of free Fe+ ions. The tunable VUV radiation was obtained employing resonantly enhanced sum-difference four-wave-mixing of short laser pulses. We obtained tau((6)P(3/2)degrees) = 3.90(20) ns, tau((6)P(5/2)degrees) = 3.80(20) ns and tau((6)P(7/2)degrees) = 3.65(20) ns
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