Energy Efficiency of a Wooden House

An exemplary construction project developed in a commune close to Constanta, Romania, aims to build wooden houses for families with low income. The study focuses on their energy performance, aiming to determine simple technical solutions for the improvement of energy efficiency. The original house is a duplex ground floor building. The energy assessment was performed in accordance with the Romanian methodology for the original house, for the reference one and for a variant of the original house whose ground floor is insulated. The study showed that appropriate insulation of the ground floor which covers 30% of the thermal envelope area results in a heating energy saving of 17%. Furthermore, the original horizontal duplex was compared to its similar vertical version (ground floor and one storey) which is more compact, at the same heated volume and the same heated area. The reference vertical version saves 3% of heating energy.

High pressure microwave-assisted flow digestion system using a large volume reactor-feasibility for further analysis by inductively coupled plasma-based techniques

Food and biological samples were digested automatically in a high pressure (40 bar) flow digestion system with a large volume reactor (13.5 mL heated volume).

First observations of SPEAR-induced artificial backscatter from CUTLASS and the EISCAT Svalbard radars

Results are presented from the first two active experimental campaigns undertaken by the new SPEAR (Space Plasma Exploration by Active Radar) high-power system that has recently become operational on Spitzbergen, in the Svalbard archipelago. SPEAR's high-power beam was used to excite artificial enhancements in the backscatter detected by the ESR (EISCAT Svalbard Radar) parallel to the geomagnetic field, as well as coherent backscatter detected by both of the CUTLASS (Co-operative UK Twin Located Auroral Sounding System) coherent radars, in directions orthogonal to the geomagnetic field. The ESR detected both enhanced ion-lines as well as enhanced plasma-lines, that were sustained for the whole period when SPEAR was transmitting ordinary mode radio waves, at frequencies below the maximum F-region plasma frequency. On a number of occasions, coherent backscatter was also observed in one or in both of the CUTLASS radars, in beams that intersected the heated volume. Although the levels of enhanced backscatter varied considerably in time, it appeared that ion-line, plasma-line and coherent backscatter were all excited simultaneously, in contrast to what has typically been reported at Tromsø, during EISCAT heater operations. A description of the technical and operational aspects of the new SPEAR system is also included.

Predicted and observed characteristics of small-scale field-aligned irregularities generated in the F-region by low power HF heating

Simultaneous HF scattering from the different regions of the heated volume is used to investigate characteristics of the small-scale field-aligned irregularities in the F-region. Time of growth, decay rate and saturation level for different pump powers are deduced from the observations and are compared with their behaviour predicted by the thermal parametric instability model. As a result, the estimates of the density and of the temperature modifications inside of the irregularities are obtained.Key words. Ionosphere (ionospheric irregularities)

<i>Letter to the editor</i>CUTLASS observations of a high-m ULF wave and its consequences for the DOPE HF Doppler sounder

The CUTLASS (Co-operative UK Twin Located Auroral Sounding System) Finland HF radar, whilst operating in a high spatial and temporal resolution mode, has measured the ionospheric signature of a naturally occurring ULF wave in scatter artificially generated by the Tromsù Heater. The wave had a period of 100 s and exhibited curved phase fronts across the heated volume (about 180 km along a single radar beam). Spatial information provided by CUTLASS has enabled an m-number for the wave of about 38 to be determined. This high-m wave was not detected by the IMAGE (International Monitor for Auroral Geomagnetic Efects) network of ground magnetometers, as expected for a wave of a small spatial scale size. These observations over the first independent confirmation of the existence of the ground uncorrelated ULF wave signatures previously reported in measurements recorded from an HF Doppler sounder located in the vicinity of Tromsö. These results both demonstrate a new capability for geophysical exploration from the combined CUTLASS-EISCAT ionospheric Heater experiment, and provide a verification of the HF Doppler technique for the investigation of small scale ULF waves.Key words. Ionosphere (ionosphere – magnetosphere interactions) . Magnetospheric physics (magnetosphere – ionosphere interactions; MHD waves and instabilities)

The formation of a blast wave by a very intense explosion. - II. The atomic explosion of 1945

Photographs by J. E. Mack of the first atomic explosion in New Mexico were measured, and the radius, R , of the luminous globe or ‘ball of fire’ which spread out from the centre was determined for a large range of values of t , the time measured from the start of the explosion. The relationship predicted in part I, namely, that R* would be proportional to t , is surprisingly accurately verified over a range from R = 20 to 185 m. The value of R" t-1 so found was used in conjunction with the formulae of part I to estimate the energy E which was generated in the explosion. The amount of this estimate depends on what value is assumed for y , the ratio of the specific heats of air. Two estimates are given in terms of the number of tons of the chemical explosive T.N.T. which would release the same energy. The first is probably the more accurate and is 16,800 tons. The second, which is 23,700 tons, probably overestimates the energy, but is included to show the amount of error which might be expected if the effect of radiation were neglected and that of high temperature on the specific heat of air were taken into account. Reasons are given for believing that these two effects neutralize one another. After the explosion a hemispherical volume of very hot gas is left behind and Mack’s photographs were used to measure the velocity of rise of the glowing centre of the heated volume. This velocity was found to be 35 m./sec. Until the hot air suffers turbulent mixing with the surrounding cold air it may be expected to rise like a large bubble in water. The radius of the ‘equivalent bubble’ is calculated and found to be 293 m. The vertical velocity of a bubble of this radius is 2/3 √(g 29300) or 35.7 m./sec. The agreement with the measured value, 35 m./sec., is better than the nature of the measurements permits one to expect.