in the present study, an attempt has been made to use data envelopment analysis (dea) for assessing the technical efficiency and return-to-scale for greenhouse cucumber production in iran. for this purpose, the data from greenhouses in esfahan province, during one period of plant cultivation in one year including spring plants were randomly collected. the results indicated that total input ener...

The characteristics of the electron-photon showers initiated by 2 to 10 GeV electrons aligned along the < 111 >-axis of tungsten crystals are compared with those for the amorphous tungsten. In this energy range, as known, the positron yield at the optimal target thicknesses is larger in a crystal case only by several percent. However, the amount of the energy deposition in a crystal turns out t...

Past efforts to achieve selective bond scission by vibrational excitation have been thwarted by energy thermalization. Here we report resonant photodesorption of hydrogen from a Si(111) surface using tunable infrared radiation. The wavelength dependence of the desorption yield peaks at 0.26 electron volt: the energy of the Si-H vibrational stretch mode. The desorption yield is quadratic in the ...

The energy gain and motion of electrons can quantitatively describe the mechanism of electron multipacting in a long-bunched proton machine. Strong multipacting usually happens around the bunches' tails due to the high energy of electrons when they hit the chamber surface. We investigated several important parameters of electron multipacting, proving that it is sensitive to the beam's intensity...

The yields of dibaryon (ΩΩ)0+ in relativistic heavy ion collisions at three energies (AGS, SPS and RHIC energies) are calculated in the framework of statistical model. It’s yield at full RHIC energy, √ sNN = 200 GeV, is predicted by means of extrapolation. In the RHIC energy region (RHIC to full RHIC energies), it is in order of magnitude 10−4 − 10−3. The yields of hyperon Ω− and the ratios of ...

1. In two experiments measurements were made of food intake, live-weight change, milk yield and milk composition in early lactation when dairy cows were given diets containing varying proportions of protein as fish meal (low rumen degradability) or as groundnut meal (high rumen degradability). In a preliminary trial measurements were also made with cows given supplements of either fish meal or ...

In Europe, the perennial C4 grass miscanthus is currently mainly cultivated for energy generation via combustion. In recent years, anaerobic digestion has been identified as a promising alternative utilization pathway. Anaerobic digestion produces a higher-value intermediate (biogas), which can be upgraded to biomethane, stored in the existing natural gas infrastructure and further utilized as ...

The characteristics of the electron-photon showers initiated by 2 to 10 GeV electrons aligned along the < 111 >-axis of tungsten crystals are compared with those for the amorphous tungsten. In this energy range, as known, the positron yield at the optimal target thicknesses is larger in a crystal case only by several percent. However, the amount of the energy deposition in a crystal turns out t...

In this analysis energy inputs to crop production, emphasizing corn or maize, is compared for a series of agricultural systems of increasing complexity. Solar energy captured in corn yield is 2 to 8 times higher under intensive modern management systems than in hand or animal powered systems. The ratio of energy output to energy input is 2.14 to 1 for a modern tractor system and decreases to 0....