فهرست مقالات Energy use

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  1 - مطالعه عوامل موثر بر انتشار دی‏اکسیدکربن در کشور (با رویکرد تحلیل تجزیه لاسپیرز اصلاح شده)
  هدیه علیشیری شهرزاد محمد خانلی اعظم محمدباقری
  10.22034/jest.2017.10625
  زمینه و هدف: اقدامات جاری در زمینه تثبیت و کاهش انتشار گازهای گل خانه ای به ویژه دی اکسیدکربن (CO2) در راستای دستیابی به توسعه پایدار در سطح قابل قبولی نبوده و تلاش بیشتری نیاز است. از این رو شناخت عوامل موثر بر انتشار CO2 جهت ارزیابی سیاست ها و راهبردها ضروری است. مقی چکیده کامل

  زمینه و هدف: اقدامات جاری در زمینه تثبیت و کاهش انتشار گازهای گل خانه ای به ویژه دی اکسیدکربن (CO2) در راستای دستیابی به توسعه پایدار در سطح قابل قبولی نبوده و تلاش بیشتری نیاز است. از این رو شناخت عوامل موثر بر انتشار CO2 جهت ارزیابی سیاست ها و راهبردها ضروری است. مقیاس فعالیت اقتصادی، تغییرات ساختاری، ضریب انتشار و شدت انرژی را می توان به عنوان مهم ترین عوامل مؤثر در نظر گرفت که البته با توجه به تفاوت میزان اثر گذاری ها در هریک از بخش ها، اقتصاد ایران به چهار بخش خانگی و تجاری، صنعت، حمل و نقل و کشاورزی تقسیم شدند و در دوره زمانی 1380-1391مورد بررسی قرار گرفتند . روش بررسی: روش بررسی این مطالعه شیوه "تحلیل تجزیه لاسپیرز اصلاح شده" است. یافته ها: نتایج حاکی از آن است که در تمامی بخش های مورد بررسی اثر ساختار بیشترین نقش را در انتشار CO2 داشته است. بحث و نتیجه گیری: براساس نتایج به دست آمده، مثبت بودن اثر مقیاس بیان گر آن است که با شیوه کنونی صنعتی شدن کشور به علت مصرف بیشتر سوخت های فسیلی، افزایش انتشار CO2 امری اجتناب ناپذیر است . هم چنین اثر شدت انتشار به جزء در بخش حمل و نقل در سه بخش دیگر در تمام دوره مورد بررسی به سبب اهتمام مسئولان در راستای افزایش کارایی انرژی، بهبود کیفیت سوخت منفی می باشد ولی در بخش حمل و نقل رشد بیشتر میزان مصرف انرژی سبب خنثی شدن این سیاست ها و مثبت شدن اثر شده است. اجرای سیاست سهمیه بندی بنزین و هدف مندی یارانه ها را می توان از مهم ترین علل روند نامنظم اثر شدت انرژی در بخش ها دانست. پرونده مقاله
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  2 - Energy Flows Modeling and Economic Evaluation of Watermelon Production in Fars Province of Iran
  Sajad Rostami Maryam Lotfalian Bahram Hosseinzadeh مهدی قاسمی ورنامخستی
  This study aimed to evaluate the efficiency of energy consumption and economic analysis of different watermelon cultivation systems in Fars Province of Iran. Watermelon production systems were classified into five systems, namely, custom tillage (group 1), conservation چکیده کامل

  This study aimed to evaluate the efficiency of energy consumption and economic analysis of different watermelon cultivation systems in Fars Province of Iran. Watermelon production systems were classified into five systems, namely, custom tillage (group 1), conservation tillage (group 2), traditional planting (group3), semi mechanized planting (group 4), and mechanized planting (group 5). Data were collected from 317 watermelon producers from different parts of the province through face to face interviews. Multi-Layer Perceptron artificial neural networks were used to model the energy flows of watermelon production. The results showed that the greatest energy consumption belonged to mechanized planting system with the value of 81317.72 MJha-1 and with the productivity of 0.61 kgha-1and energy use efficiency of 1.17. Clustering function with three inputs (human resources, machines and diesel fuel) showed that the difference between groups 2 and 4 is more than the other groups. The least energy consumption belonged to the conservative agriculture as78163.86 MJha-1and the energy productivity and energy use efficiency about 0.64 kgha-1 and 1.22, respectively. The results of energy modeling showed that an ANN model with 9-10-1 structure was determined to be optimal for energy flow modeling of this system. Generally, it was concluded that the artificial neural network models can be applicable to prognosticate the energy flows of watermelon production. From an economic point of view, the least net profit belonged to traditional planting with the value of 2618.14$, and the most net return belonged to mechanized planting with the value of 2752.88$/ha. پرونده مقاله
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  3 - Life cycle of energy-economic analysis for different cultivation scenarios of paddy production (Case study: Khuzestan Province)
  محمد غلامی پرشکوهی Heidar Molaee Jafrodi Hamed Afshari Davood Mohammad Zamani
  In this study, energy and economic analysis of paddy production in Khuzestan province of Iran were studied. Paddy production in this province was analyzed under three scenarios of multiple cultivation system including (Paddy-Transplanting System) PTS, (Paddy Direct Seed چکیده کامل

  In this study, energy and economic analysis of paddy production in Khuzestan province of Iran were studied. Paddy production in this province was analyzed under three scenarios of multiple cultivation system including (Paddy-Transplanting System) PTS, (Paddy Direct Seeding Flooding System) PDSFS and (Paddy-Upland Cultivation System) PUCS. The highest total input (87993.14 MJ ha-1) and output (105400 MJ ha-1) energies were related to PTS. Diesel fuel and nitrogen fertilizer had the uppermost energy use shares. Depending on the type of cultivation in PUCS, human labor has a large share of energy. Estimation of the energy ratio of PUCS method (1.34) indicates that the amount of output energy is much higher than the input energy. Productivity energy index also showed that there is no significant difference between the three methods in terms of amount of paddy relative to input energy. The specific energy of PTS method (14.19 MJ kg-1) indicates large amounts of input energy relative to the amount of paddy produced. Based on the high revenue and low cost, the benefit to cost ratio at the expense of PTS method is significant. The productivity of the PUCS method was reported to be 212.65 kg $−1 due to the high production of paddy compared to the lowest costs. پرونده مقاله
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  4 - Modeling energy use and economic productivity of different fish production systems using artificial neural networks
  محمد غلامی پرشکوهی محسن رسولی بابک بهشتی محمد قهدریجانی
  This study aimed to use artificial neural networks (ANNs) to predict output energy and economic indicators. So, data on two fish breeding sites were collected with a questionnaire, directly from the site owners and administrators, and from the records. Then, the input a چکیده کامل

  This study aimed to use artificial neural networks (ANNs) to predict output energy and economic indicators. So, data on two fish breeding sites were collected with a questionnaire, directly from the site owners and administrators, and from the records. Then, the input and output energy of cold-water and hot-water fish were calculated. The cold-water fish were found to have a more favorable energy ratio (ER) (2.24), energy productivity (EP) (0.04 kg MJ−1), specific energy (SE) (26.83 MJ kg-1), and net energy gain (NEG) (33222.16 MJ kg-1). According to the results, fish feed and electricity are two factors among energy consumption inputs whose proper management will increase energy efficiency. The benefit-to-cost ratio was positive for cold-water fish (1.54) and hot-water fish (2.45). The productivity of cold-water and hot-water fish was 0.58 kg $-1 and 0.52 kg $-1, respectively. The results of ANNs showed that R2 varied from 0.947 to 0.993 overall, from 0.912 to 0.964 for the training stage, and from 0.978 to 0.980 for the testing stage in the case of cold-water fish. Regarding hot-water fish, these values were 0.885-0.998, 0.923-0.952, and 0.952-0.995, respectively. So, ANNs can be used to predict output energy and economic productivity. پرونده مقاله