Recently there has been interest in DWDM-based optical networks that are assumed to employ exactly two working fibers uniformly on every span (or “link”). At the fiber level such networks are referred to as homogeneous networks. An interesting and highly efficient strategy for protection of such networks is to use a single dark-fiber pcycle formed on a Hamiltonian cycle (if it exists). We show ...

The energy efficiency, greenhouse gas (GHG) emissions, and carbon efficiency of paddy rice production were analysed in Sari in the Mazandaran province of Iran during 2011–2012. Data was collected through questionnaires and interviews with paddy producers. The results showed that the net energy gain was 27,932 MJ ha-1 and energy efficiency was 1.83 during production. The results o...

This study was conducted to compare the methods of seed bedpreparation in rangelands of Khash region in Sistan and Baluchestan province inIran. A split plot design was conducted based on Randomized complete blockdesign with three replications in 1999. Five seed bed preparation methods wereused as main plot as: 1) Seed sown by passing livestock. 2) Seed sown machinery.3) Seeds sown as drilled in...

Land leveling is one of the most important steps in soil preparation and cultivation. Although land leveling with machines requires considerable amount of energy, it delivers a suitable surface slope with minimal soil deterioration as well as damage to plants and other organisms in the soil. Notwithstanding, in recent years researchers have tried to reduce fossil fuel consumption and its delete...