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[en] Highlights: • A technical solution to the power supply of wireless sensor networks is presented. • The low voltage produced by device is boosted from around 1 V to more than 4 V. • An output current and voltage of the device is acquired as 343 mA and 1057 mV. • The device provides output power 362.56 mW in no electricity conditions. • The economic value of device is demonstrated. - Abstract: Solar thermoelectric power generation has been widely used to solve the power supply limitation issue for low-power wireless sensors because of its light weight, high reliability, low cost, lack of noise, and environmental friendliness. A solar thermoelectric power generation system based on gravity-assisted heat pipes and solar radiation is devised in this paper, and its behavior is continuously measured in realistic outdoor circumstances. The effects of key parameters, including solar luminous flux, load resistance, a proportional coefficient, and a relative Seebeck coefficient, are analyzed. Related experimental results show that the device can output a voltage of 1057 mV and an electrical current of 343 mA, resulting in an output power of 362.56 mW. With a stable external energy conversion module under aluminous flux of 7.81 × 10"4 lx, the voltage converted from the nature solar radiation is boosted from 1057 mV to 4.40 V, which meets the rated operating voltage of low power consumption components, such as low-power wireless sensors and ZigBee modules. An economic analysis of the system shows that the solar thermoelectric power generation device is both economically and technically competitive when it is applied in a low-voltage wireless sensor network.
[en] Magnetic heat pumps have been successfully used for refrigeration applications at near absolute-zero-degree temperatures. In these applications, a temperature lift of a few degrees in a cryogenic environment is sufficient and can be easily achieved by a simple magnetic heat-pump cycle. To extend magnetic heat pumping to other temperature ranges and other types of applications in which the temperature lift is more than just a few degrees requires more involved cycle processes. This paper investigates the characteristics of a few better-known thermomagnetic heat-pump cycles (Carnot, Ericsson, Stirling, and regenerative) in extended ranges of temperature lift. The regenerative cycle is the most efficient one. For gadolinium operating between 0 and 7 T (Tesla) in a heat pump cycle with a heat-rejection temperature of 320 K, our analysis predicted a 42% loss in coefficient of performance at 260 K cooling temperature, and a 15% loss in capacity at 232 K cooling temperature for the constant-field cycle as compared with the ideal regenerative cycle. Such substantial penalties indicate that the potential irreversibilities from this one source (the additional heat transfer that would be needed for the constant-field vs. the ideal regenerative cycle) may adversely affect the viability of certain proposed MHP concepts if the relevant loss mechanisms are not adequately addressed
[en] The european market showed all of its strength and soundness in 2005. The 2005 installed cells growth could have been even greater if the market had not been continually curbed by a lack of raw materials. Germany remained the leading photovoltaic market in the world in 2005, positioned far ahead of Japan and the USA. This unabashed success inspired both Spain and Italy, which set up conditions in order to rapidly develop their photovoltaic sectors. (A.L.B.)
[en] In the coherent-state representation the quantum mechanical calculation of thermomagnetic current fluctuations in a non-degenerate parabolic quantum film is conducted using method of effective Hamiltonian. The results obtained are applicable for study of noise in electron instruments
[en] The procedure for determination of individual statical characteristic (ISC) of high accuracy thermoelectric converters has been developed. The research for metrological characteristics of the ISC determination procedure has been carried out. The application of ISC determination procedure during production of thermal converters suitable for use in higher accuracy measuring systems has been justified
[ru]Разработана методика определения индивидуальной статической характеристики (ИСХ) термопреобразователей высокой точности. Проведены исследования метрологических характеристик методики определения ИСХ. Обоснована применимость методики определения ИСХ при производстве термопреобразователей, пригодных для использования в измерительных системах повышенной точности
[en] This paper determines a concept for analyzing the thermoelectric expansion by mineral coal in Brazil, as an alternative of integrated energy supply for a national strategic. The main issues relating with thermoelectric generation by mineral coal, a historical way of coal in the Brazilian view and the condition of their reserves and potentiality are presented. The political and economical directress of federal government, the environmental subject, the technological options and the investment costs are also discussed. (C.G.C.)
[en] The Seebeck coefficient and electrical resistivity have been measured for the La/sub 3-//sub x/ M/sub x/ S4 alloys with the Th3 P4 -type structure for M = Sm, Eu, Yb, and x = 0.1 to 0.9 in order to determine their potential as high-temperature thermoelectric energy conversion materials. An analysis of the lattice parameters of these alloys suggests that Sm has a valence of 2.2 over the entire composition range. Furthermore, the variation of the Seebeck coefficient and electrical resistivity as a function of electron concentration is different for the Sm-doped alloys than for the Eu- and Yb-doped alloys, which are all different from that of the pure binary LaS/sub y/ alloys. A maximum in the electrical power factor at 1000 0C is found to occur at x ≅ 0.3, but when a reasonable estimate is made of the thermal conductivity the maximum in the figure-of-merit at 1000 0C shifts to larger x values (∼0.7) in all alloy systems. The long term stability of the Sm and Eu ternaries is also reported
[en] Radioisotope thermoelectric generators (RTGs) have successfully provided power for space missions since the early 1960's. Their safety, reliability, long-life performance and survivability have been thoroughly demonstrated for multiple applications of earth orbital flying, lunar scientific experiments and planetary exploration. With regard to the energy conversion systems, the static isotope power system has been continuously improved and the dynamic isotope power system combining the general purpose heat source modules with closed Brayton cycle has been started to develop in recent years so as to increase the efficiency of thermo-electric conversion. The launch schedule of spacecraft powered by isotope energy system in the 1990's is given in this paper, and the application prospects of isotope power system are also forecasted here
[en] This publication presents in a series of graphs the situation of development of photovoltaic energy in France and in the whole world: New production capacities in France, Europe, USA and the rest of the world; connected capacities in the world; production costs of new capacities; photovoltaic share of power consumption in France; cumulative connected loads; annual flux of connected capacities; evolution of residential and large roof connections and feed-in tariffs for different roof surfaces or power; pending projects; evolution of feed-in tariffs in continental France; extra costs induced by new connections with respect to roof size.