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The static series compensator (SSC) has shown a significant capability to mitigate voltage dips, which are the most severe problem to sensitive loads. Also, it has been declared that the function of the SSC can be extended to work as a series active filter. This work proposes a moving-average filter to detect the fundamental component of the measured voltages and currents (needed to control the SSC) while using a double vector control algorithm to improve the transient performance of the SSC. This is made in order to accurately control the fundamental voltage component at the load terminals in the case of distorted grid voltage. Furthermore, a selective harmonic compensation strategy is applied to filter out the grid harmonics. The operation of the SSC under distorted utility conditions and voltage dips is discussed. The validity of the proposed controller is verified by experiments, carried out on a 10-kV SSC laboratory setup. Experimental results have shown the ability of the SSC to mitigate voltage dips and harmonics. It is also shown that the proposed controller has improved the transient performance of the SSC even under distorted utility conditions.

Responses to recent climatic changes in the sediment of subarctic Lake Saanajärvi in northwestern Finnish Lapland are studied by comparison of various biological and sedimentological proxies with the 200-year long climate record, specifically reconstructed for the site using a data-set of European-wide meteorological data. The multi-proxy evidence of simultaneously changing diatom, Cladocera, and chrysophyte assemblages along with the increased rates of organic matter accumulation and pigment concentrations suggest that the lake has undergone a distinct typological change starting from the turn of the 20th century. This change, indicating an increase in lake productivity, parallels a pronounced rise in the meteorologically reconstructed mean annual and summer temperatures in the region between ca. 1850 and 1930's. We postulate that, during the Little Ice Age, the lake was not, or was only weakly, thermally stratified during summer, whereas the subsequent increase in air and hence epilimnetic water temperatures resulted in the development of the present summer stratification. The increased thermal stability of the lake created more suitable conditions for the growth of phyto- and zooplankton and changed the overall primary production from benthos to plankton. Mineral magnetic and carbonaceous particle records suggest long-distance pollution, particularly since the 1920's, yet the observed changes in lake biota and productivity can hardly be explained by this very minor background pollution; the 20th century species configurations are typical of neutral waters and do not indicate any response to pollution.

Chemical looping combustion allows a simple separation of CO2 during the combustion of fossil fuels, thanks to the use of regenerable oxygen carriers. In this work, novel materials containing manganese and iron/manganese oxides have been developed via geopolymerization, and characterized in thermogravimetric apparatus and fixed bed reactor. The materials demonstrated suitable characteristics for chemical looping combustion (CLC). The tests conducted in the temperature range 800-900 °C revealed the good performance of the developed oxygen carriers, which also exhibited the ability to release O2 in inert conditions. Efficiencies in CO conversion up to 99% were achieved, as well as some synergies between Fe and Mn oxides gave a beneficial effect toward the oxygen yield. X-ray diffraction analyses of the samples confirmed the effective reduction/oxidation behavior of the materials, as well as the morphological characterization did not reveal dramatic changes of the internal microstructure up to 900 °C

The most widely used process for hydrogen production is steam methane reforming. It can be carried out using a membrane reactor in which simultaneous hydrogen production and purification occur. Mathematical modeling of these reactors plays a key role in the selection of the design and operating parameters that yield high performance for the reactor. This review study discusses, synthesizes, and compares different mathematical modeling studies on the packed bed membrane reactors for hydrogen production from methane found in the literature. Different approaches used in these modeling studies for the hydrogen permeation steps, reaction kinetic expressions, phases involved (pseudo-homogeneous and heterogeneous), and spatial dimensions (one, two, and three dimensional) are given.

En afprøvning af pc-værktøjet BEAT 2000's viser, at BEAT 2000 er et velegnet værktøj, der umiddelbart kan anvendes til energi- og miljøvurdering af renoveringssager. BEAT 2000 er afprøvet dels på renovering med energibesparende foranstaltninger i form af solfangere, solvægge og ventilationsanlæg med varmegenvinding, dels på mere traditionel renovering af små, utidssvarende lejligheder. En udbygning af datagrundlaget, især for alternative energibesparende løsninger og de materialer, der indgår, vil kunne reducere tidsforbruget ved definition af de utraditionelle og usædvanlige bygningsdele, der optræder ved renovering. Tests show that BEAT 2000, a simulation program for energy and environmental assessment is a tool well suited for direct energy and environmental assessments of renovation projects. BEAT 2000 has been tested on renovation projects which included energy saving measures such as solar collectors, solar walls and ventilation systems with heat recovery. The tool was also tested on more traditional renovation of small out-of-date flats. Particularly for alternative energy saving solutions and the materials they incorporate, an extended basis for the data would reduce time consumption by defining untraditional and unusual building elements that occur in renovation.

The reversible dissociation/carbonation of metal carbonates, performed in fluidized bed reactors, is one of the most promising technological solution for thermochemical energy storage (TCES) in concentrating solar power plants (CSP). In this framework, the SrCO3/SrO system is receiving increasing interest due to its high energy density (4 GJ/m3) and working temperatures (up to 1200 ?C). As the more investigated CaCO3/CaO couple, also SrO undergoes a dramatic drop of reactivity over multiple carbonation/calcina- tion cycles due to sintering. Even though the potentiality of this system has already been proved by thermo-gravimetric analyses, its actual reaction performances in a fluidized bed are strongly dependent on the gas-solid contact efficiency and heat/mass transfer between the gaseous and solid phase. In this work, the cyclic carbonation/calcination of the SrO/SrCO3 system for TCES-CSP has been investigated by thermo-gravimetric analysis and, for the first time, in a lab-scale fluidized bed rig, thus providing useful applicative insights. A new Al2O3-stabilized composite has been synthesized, i.e. Al2O3 has been added to SrO/SrCO3 system as both sintering inhibitor and flow conditioner. In particular, composite materials with different Al2O3/SrO composition have been synthesized to investigate the ef- fect of the inhibitor amount on both the fluidizability and energy storage performances.

Intention of this work is to investigate the opportunity and feasibility of energy efficient networking in Home and Building automation protocols. Wired HBAS have traditionally devoted a relatively little attention to this point, especially if compared to wireless networks. This paper will try to address the issue by evaluating the introduction of power state switching in a real scenario and proposing the concept of functional and spatial adjacency among packets.