Wireless sensors networks consist of several tiny battery powered devices which are utilized to monitor and gather information of desired area, such as a net Zero energy Building. As there is no way to recharge the nodes’ energy and batteries, efficient energy consumption plays crucial role in prolonging nodes’ and network’ s lifetime. One of the most popular routing protocol is LEACH protocol, which suffers from drawbacks, despite several modifications have been deployed. This research aims to optimize the Leach protocol from three different aspects. Initially, the allocated energy of network is distributed to each nodes based on their distance with base station. The more distance between a node and BS, the more energy portion is allocated to the given node. Secondly, Genetic algorithm has been employed to select optimal cluster head set whose fitness function addresses number of CHs and distance between CHs and the BS. Lastly, sensor nodes are clustered by fuzzy clustering. Comparing the results with previous versions illustrates that the proposed modifications could prolong considering network and improve the energy consumption and the modified LEACH achieves 10% improvement in terms of survival rate of nodes.

Agriculture is a system exhibiting high levels of energy consumption. Thus, energy analysis is crucial for improving the energy efficiency of agricultural systems. In this research, the input energy of an irrigated wheat production system, including seeds, machinery, fertilizer, irrigation, electricity, diesel fuel and human labour, were determined and thereby the net output energy, energy efficiency and energy productivity were calculated for energetic system evaluation. For reaching this goal, 110 farmers were asked to complete the questionnaires in which cultivation information such as machinery, diesel fuel, grain produced per hectare, cultivation method, the method and the duration of water supply, workers, chemical materials which were used for plant treatment. The results showed that the total input energy for producing irrigated wheat was 42,481 MJ.ha-1. energy efficiency was achieved as 1.56, suggesting that the total output energy of the system was more than the input energy. The net output energy, indicating the rate of obtained net energy from the system, was 23,819 MJ.ha-1. Electricity and fertilizer were the inputs consuming the most energy in an irrigated wheat production system, in which 41% and 31% of the total consumed energy were devoted to electricity and fertilizer, respectively. Therefore, the appropriate management of electricity and fertilizer through advanced methods of irrigation and the precise calculation of plants’ required nutrient elements can result in the improvement of the energy efficiency of the system. Reducing seed bed preparing operations (decrease diesel fuel consumption) may also increase the energy efficiency of the wheat production system

Increasing demand for agricultural products and production of resource constraints- especially the limitation of cultivable areas - have made the highest yield per unit area the main goal of agricultural producers. Agriculture is a system exhibiting high energy consumption and production. Since energy has a direct impact on the efficiency of crop production, a sustainable agricultural system needs to be analyzed in terms of its input and output energy to determine the total consumed energy of production per unit area. The difference between input and output energy determines energy efficiency of an agronomical system. Input energy requires being well analyzed to reduce energy consumption and increase energy efficiency. This paper reviews energy efficiency indices based on energy consumption during planting and harvesting. To enhance energy efficiency of agronomical systems, some strategies are discussed in detail, including using high quality seeds, minimum tillage systems, direct seeded rice, weeds control especially in irrigation canals and plant nutrition through agronomical management. Although some agronomical strategies -like complementary irrigation in dry land farming systems- increase input energy, they increase crop yield. However, when output energy, resulting from the rise in crop yield, is higher than input energy, the system energy efficiency improves. Still, some inputs cannot be altered according to regional conditions which are often related to harvest stages operations.

IntroductionCommon pea is an annual crop of the legominosae family with the capability of biological nitrogen fixation, and as such it has an important role in increasing productivity of field soil and is commonly used in crop rotation programs. This crop has high nutritional value due to high concentrations of the essential amino acids lysine and tryptophan. Sustainability, in terms of obtaining maximum crop productivity from a system while maintaining conservation of its resources, is one of the most important components of an agricultural system. There is a close relationship between agriculture and energy, so that energy has a direct effect on the efficiency of crop production. Agricultural systems need to be evaluated in terms of input and output energy, so that based on that, the amount of energy consumed for product production per unit area can be determined. In essence, assessing the sustainability of production in agricultural systems involves considering the balance between energy input and output. Consequently, the identification and effective management of input energy become pivotal factors in enhancing the overall energy efficiency of a production system. The current research was carried out to evaluate energy consumption and production in a common pea dry land farming system to reach the best possible improvement of energy balance. Materials and MethodsEvaluation of the energy balance of a common pea dry land farming system and the effect of a complementary irrigation on total energy efficiency was determined from values for energy inputs and outputs including seed, pesticide (liquid herbicide), human labor (men and women), machinery, diesel fuel and grain yield per unit area. energy inputs were determined from questionnaires completed by farmers. Farmers were asked to provide the information on their cultivation system including technical specifications for type of machinery used, including motor capacity, total land area, planting and harvesting method, crop yield per unit area, number of workers, amount of seed, amounts of fertilizer and pesticides. energy efficiency of the system was evaluated by calculating the energy ratio and net output energy. Results and DiscussionResults showed that the highest energy input belonged to diesel fuel, followed by seed. Distances between the input of diesel fuel and other inputs were high, where 87% (12724 MJ.ha-1) of total consumed energy was allocated to diesel fuel. Grain yield of the common pea production system with and without complementary irrigation were 863 Kg.ha-1 and 645 Kg.ha-1, produced by consuming 14488 MJ.ha-1 and 14679 MJ.ha-1, respectively. In other words, complementary irrigation resulted in more input energy and grain yield. In the current research, complementary irrigation caused a considerable improvement in grain yield that resulted in higher output energy. Complementary irrigation increased input energy from 14589 MJ.ha-1 to 14679 MJ.ha-1 (60 MJ.ha-1was added) (Figure 2), but evaluations of energy ratio and net output energy revealed the positive effect of complementary irrigation on energy efficiency. ConclusionsThe dry land farming system for common peas exhibited low energy efficiency, primarily attributed to diminished grain production. Notably, diesel fuel consumption represented the highest energy input. While some essential production activities inevitably lead to increased input energy, it is recognized that managing inputs may not always guarantee improved energy efficiency. However, the experiment demonstrated that introducing complementary irrigation during the flowering stage of common peas resulted in an enhanced energy efficiency for the system.

This research, conducted in Gotvand, southwest Iran, evaluated the energy balance of a field system which watermelon produced in it. In the current research, energy inputs of watermelon planting were measured. To reach this goal, questionnaires were given to the farmers to record the amount of energy input to their watermelon planting field. Statistical analysis of the data revealed that nitrogen was the input with the highest consumption of energy (4175 MJ.ha-1) followed by diesel fuel. About 90% of the consumed energy of watermelon planting system was seen for energies which cannot be renewed. The results showed that the efficiency of energy consumption was positive, indicating that the amount of output energy was higher than that of input energy. With each unit of energy was consumed, 4.86 units of energy were produced, which indicates high energy efficiency. For improving the efficiency of energy usage in the watermelon planting system, nitrogen application to the system should be reduced and it can be reached by suitable rotation which diminish the nitrogen needs.

Castor bean (Ricinus communis L.) with a capability to withstand harsh conditions, low nutritional needs, 50 percent of oil content and high- quality, is one of the best crop used to produce biodiesel. The first step toward introduction and widespread cultivation of this crop is to investigate the energy balance for its cultivation. To do so, energy input (include renewable and nonrenewable) and output were calculated through an examination of all inputs during two consecutive years of cultivation (2012-2014) in Varamin county in Tehran province. energy indicators were also assessed. Result showed Indirect, non-renewable sources of energy with 59.68 and 80.86 percent of 11245.64 MJ energy consumption, comprise the major part of the consumable energy in castor bean cultivation. Moreover, among inputs fertilizers and pesticides with the share of 55.26 percent of the total consumable energy considered as the highest energy inputs. Fuels with the share of 21.28 percent formed placed at the second rank of consumable energy. energy use efficiency in seed production was calculated to be 3.81, which is a considerable amount when compared with other crops used to produce biodiesel. Therefore, in order to expand the cost efficient and mechanized system of castor production, breeding of the current local ecotypes is recommended.

The law of Targeted Subsidies on energy carriers has been implemented for seven years. There are still many uncertainties about the effectiveness of this law, which has raised many questions for energy economists. One of the main questions in this regard is the estimation of embodied energy subsidy for net export of goods and services at the level of the economic sectors that has not been taken into consideration by Iranian researchers. To answer this fundamental question, we measure the net exports of embodied energy subsidy for goods and services with using the price-gap approach and applying Iranian Input-output table for year 2011. In addition, for assuming the differences of embodied energy in unit of Iran’ s imported and exported commodities, it is measured according to the ratio of the world average energy intensity to Iran’ s energy intensity. The results of this study show that while some sectors of the economy such as basic metals are faced net exports of embodied energy, the net value of the embodied energy subsidy in the content of exporting goods and services is not consistent with the net export of embodied energy, and policy makers cannot employ pricing policies, such as increasing the price of energy carriers, to manage and control the implicit energy subsidy. Accordingly, the government has recommended adjusting the prices of energy carriers in line with international prices as well as improving technology by creating an efficient financing market.

With the outbreak of the coronavirus in countries around the world and its rapid spread, governments have decided to impose restrictions and social distancing. Restrictions and closures of businesses and economic activities, and changes in supply and demand patterns during this period, have exacerbated concerns among economists. This article deals with the issue of changing primary energy consumption in 18 countries in the MENA region. To this end, 10 different scenarios of the future state of the disease and its limitations have been considered. The results show that according to the best scenario (rapid and complete improvement of the epidemic), Libya with 4. 38% and Iraq with 3. 39% will have the largest decrease, and according to the worst-case scenario (explosive disease exacerbation and complete quarantine), Libya with 12. 6% and Syria with 12. 3% will have the greatest reduction in primary energy consumption. The three countries, Syria, Lebanon, and Iran, also had the most differences in the pessimistic and optimistic scenario. Also, taking into account the total changes in the primary energy consumption of these 18 countries, according to the most optimistic scenario, the primary energy consumption will be reduced by 1. 5% and according to the worst-case scenario, it will be reduced by 8. 8%.