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AbstractThis paper lists in chronological order all the nuclear detonations which have been announced by the six countries which have conducted nuclear detonations. The numbers of such detonations and the cumulative yield are underestimates for reasons presented and discussed. In a 30-yr span, begin

ABSTRACT This study aimed to evaluate the energy efficiency of a center pivot irrigation system operating in a terrain of variable topography. Values of Pumping Energy Efficiency (PEE), Supply Energy Efficiency (SEE), Global Energy Efficiency (GEE) and Specific Energy (Es in kWh m-3) computed at 18 different angular positions of the lateral line were used as energy efficiency indicators. An ultrasonic flow meter, digital pressure transducers and a power quality analyzer were used in order to evaluate hydraulic (total system flow-Q and total dynamic head-TDH) and electrical parameters (active electrical power - AEP) of the center pivot pumping unit that were required for evaluating the selected energy efficiency indictors. Topographic elevations of the water source, the pumping unit and of the center lateral line were also determined. For the center pivot lateral line, it was necessary to determine, at the 18 angular positions considered, the altitude of the track of each center pivot support tower. Results indicated that currently, even after more than 10000h of use, the center pivot system operates with satisfactory energy efficiency, as indicated by an average GEE value equal to 42.5%, that is classified as “good”. Statistical analysis indicated that the topographic disposition of the center pivot lateral line, as characterized by a uphill or downhill disposition, resulted on different PEE, SEE and GEE values, while the average Es value (0.42 kWh m-3) was not affected by the lateral line disposition.

Abstract Several environmental accounting methods exist to evaluate the rate of ecosystems resource exploitation and to strengthen the comparison among human production systems in terms of renewability and sustainable use of resources. However, their application rarely refers to the environmental work that is necessary to produce natural resources. The aim of this research is to advance the characterization of different wood biomass species by using the emergy principles and thus to estimate the geobiosphere work required to generate wood resources. The analysis has been conducted applying the classical emergy methodology and a recently developed life cycle-based embodied energy approach. This latter is implemented with the support of Life Cycle Assessment (LCA) principles and tools to disclose as a result vectors of Unit Embodied Energy Value ( UEEV → ) , composed by three components: the Embodied Solar, Tidal and Geothermal Energy. Differently from emergy evaluation, the life cycle-based embodied energy approach does not consider the baseline concept and the emergy algebra, but the Solar, Geothermal and Tidal sources are independently quantified, keeping them separated and not weighted. The present paper shows that the latter method can provide a consistent framework to trace and evaluate the primary provision of energy throughout the formation of resources. Regionalized UEVs (Unit Emergy Values) and ( UEEVs → ) have been obtained and compared with regard to Fagus spp., Quercus spp., Picea spp., Pinus spp., Pseudotsuga spp., Fraxinus spp., Populus spp., Castanea spp., and other grouped conifers (Larix spp., Cupressus spp. and Abies spp.) and other deciduous species (Carpinus spp., Betulus spp., Alnus spp. and Robinia spp.). The trend of output values per unit of resource species obtained by means of the two methods was very similar when looking at the Solar Embodied Energy contribution, meaning that this flow has the main direct (with the life cycle-based embodied energy approach) and indirect (with the emergy one) influence on the generation of wood biomass. Results obtained by means of both methods can fill out the life cycle of products based on wood biomass, providing the natural contribution to wood species formation and thus embedding this information in the technosphere processes.

We examine technological progress in the US and Canada to answer the question: has the efficiency (e.g., the edible energy efficiency, or EEE) for producing agricultural products in the US and Canada increased in recent decades? Specifically, we determined the energy efficiency of agriculture at the farm gate in recent decades by dividing the outputs (the total annual crop and animal output in energy units minus the feed used for animal production and the grain used for ethanol production) by the energy inputs: all the energy used by the nation to produce food (the energy used to generate and apply the fertilizer, pesticides, seed and to operate machinery) minus the energy inputs to produce grain for ethanol. Our data comes primarily from national and international agricultural censuses. Our study found that the energy efficiency of US agriculture has more than doubled from 0.8:1 in 1970 to 2.2:1 by 2000, then increased more slowly to 2.3:1 by 2009. The energy efficiency of the agricultural sector in Canada has not changed appreciably since 1980, and has varied about a mean of 2:1 from 1981 to 2009. Our study found that EEE improvements in the US could be attributable in part to advancements in crop production per hectare, and lower direct fuel consumption, but also a greater proportion of less energy-intensive corn and changes to the diet of livestock (e.g., increased use of meals and other by-products which have increased the availability of grain). Thus increases due to technological progress alone for the last several decades appear small, less than one percent a year.

Abstract In this article we have described the development of solar-powered gas metering units including modern ultrasonic and vortex flowmeters for volume and mass measurement of natural gas, associated petroleum gases, inert gases, oxygen, hydrogen, air, nitrogen, carbon dioxide and any other single and multicomponent gases that are not aggressive to the flowmeter materials. We have shown implementation of such units in the existing gas producing stations in the desert of Kara-Kum. Confirmed was the ability of our gas metering units to operate more than a year without network power supply and staff intervention. Also pictured was creation of telemetry system for collecting and transmitting metrological information, including gas flow rate, temperature, pressure, humidity to the central terminal. Different physical layers have been used to transfer data from the metering units, including radio channels at 433 MHz frequency between units and central station. This telemetry system implemented selfmaintenance and self-monitoring features, facilitating remote control of metering unit, so important in rigid conditions of solar-rich deserts and semi-deserts.