فیلترها/جستجو در نتایج    

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اطلاعات دوره: 
  • سال: 

    1400
  • دوره: 

    52
  • شماره: 

    2
  • صفحات: 

    67-82
تعامل: 
  • استنادات: 

    0
  • بازدید: 

    170
  • دانلود: 

    16
چکیده: 

Identifying the constraining factors of production and yield gap is very important. Therefore; this research was performed to identify the production constraining factors of local rice cultivars. All management practices from nursery preparation to harvesting stages for 100 paddy fields of local rice cultivars were recorded through field studies, in Sari, from 2015-2016. In the CPA, the actual and calculated potential yield were 4495 and 5703 kg/ha, respectively and the gap was 1221 kg/ha. The yield gap caused by number of top-dressing variables was 324 kg/ha, equal to 27% of the total yield gap. The yield gap related to previous year of legumes cultivation was 218 kg ha-1, equal to 18% of the total yield variation. Among the 10 variables entered in the CPA model, the effects of top-dress fertilizer application and its application frequency and foliar application were remarkable, which could compensate a significant part of the yield gap (444 kg/ha, 37% of total) in the farmers’ fields by managing these variables. According to boundary line analysis (BLA) finding, actual yield mean on the basis of optimal limit related to 12 variables under study was 5369 kg/ha, with 881 kg/ha yield gap . Mean relative yield and relative yield gap for 12 variables (transplanting date, seedling age, number of seedlings per hill, planting density, nitrogen and phosphorous per hectare, nitrogen before transplanting, harvesting date, lodging problem, pest problem, diseases problem and weeds problem) were 83.64 and 16.35 kg/ha, respectively. Based on the finding, it can be stated that the model precision is appropriate and can be applied for both estimation of the quantity of yield gap and determining the portion of each restricting yield variables.

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نشریه: 

آمایش محیط

اطلاعات دوره: 
  • سال: 

    1389
  • دوره: 

    3
  • شماره: 

    10
  • صفحات: 

    137-160
تعامل: 
  • استنادات: 

    4
  • بازدید: 

    8716
  • دانلود: 

    4409
چکیده: 

امروزه شهرها از دو نماد جغرافیایی (محیط طبیعی، اجتماعی و اقتصادی) و مصنوعی (محیط انسان ساخت - معماری) بهره مند هستند. بشر امروزه در پی فعالیت های روزانه و در تکاپو برای گذران زندگی روزمره و معاش خود و در جهت احداث مسکن، چه به عنوان سرپناه و چه به منظور سرمایه گذاری، مسمترا این دو نماد را تغییر شکل می دهد و محیط زیست شهری را دگرگون می سازد. در این فرایند فضاهای سبز، باغ ها و جنگل ها تبدیل به آسمان خراش ها و شهرک های مسکونی می شوند. آهن و آجر، سیمان و سنگ جایگزین سیمای ساختمانی شهرها که روزگارانی علاوه بر تامین محل سکونت انسان چشم اندازی سبز و زیبا در اختیار وی قرار می داد شده است. شهرنشینان امروزی گاهی که به درون خود می نگرند با احساس خلائی عمیق از دستیابی به طبیعت خود را به دور از آسایش و آرامش راستین می یابند. در مقابله با این مشکل، بشر از گذشته های دور به ایجاد بام های سبز یا باغ بام ها به عنوان راه حلی مناسب برای آشتی دوباره با طبیعت و تغییر چشم انداز شهری روی آورده است. در واقع بام سبز استفاده از فضاهای بلا استفاده و بی روح ساختمان های شهری در جهت ایجاد لکه های سبز می باشد. این امر علاوه بر جنبه زیبائی شناختی شهر موجب تلطیف هوا (در مقیاس میکرو کلیما) و کاهش آلودگی هوا و نهایتا بهبود محیط زیست ساکنان شهر می گردد.

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اطلاعات دوره: 
  • سال: 

    1403
  • دوره: 

    13
  • شماره: 

    4
  • صفحات: 

    135-150
تعامل: 
  • استنادات: 

    0
  • بازدید: 

    40
  • دانلود: 

    9
چکیده: 

A B S T R A C T Green city is one of the approaches to sustainable development. “green city” is an environmentally friendly city compatible with the concept of sustainable development and can be used for the welfare and security of its inhabitants. Based on the concept of a “green city,” urban managers try to have the least destructive effect on the ecosystems upon which cities rely. Green city is one of the sustainable development approaches that reduce the environmental footprint of cities. The purpose of this study is to evaluate the situation of Mashhad metropolis in terms of the objective characteristics of the green city. In this study, 14 indicators of electricity consumption per capita, green space per capita, population density, water availability, sewage availability, superior public transportation network, urban mass transportation, traffic reduction, annual production waste per capita, carbon monoxide, concentration nitrogen dioxide, sulfur dioxide concentration, particulate matter concentration, and air quality were exerted. To determine the importance of research indicators, the Shannon entropy method, and the status of Mashhad city areas in terms of green city indicators, the VIKOR multi-criteria decision-making method has been applied. The results showed that most areas of Mashhad are average and below average in terms of green city characteristics, and only District 9 is in very good condition (0.636). Also, based on the results of this part of the research, District 5, with the value of VIKOR index of 0.969, is in the last rank in terms of objective characteristics of the green city Extended Abstract Introduction Green city is one of the approaches to sustainable development. A “Green city” is an environmentally friendly city compatible with the concept of sustainable development and can be used for the welfare and security of its inhabitants. Based on the concept of a “green city,” urban managers try to have the least destructive effect on the ecosystems upon which cities rely. Green cities constantly try to manage their environmental effects by reducing waste, increasing recycling, reducing air pollution, increasing population density, developing open urban spaces, and encouraging the development of sustainable local businesses. Green cities were first used to evaluate 30 European cities by the Economist Intelligence Unit (EIU) in 2009 with the financial support of Siemens and the aim of reducing the environmental effects of human activities in cities. In that study, eight indices of carbon dioxide, energy, construction, transportation, water, recycling and land use, air quality, and environmental governance were used. Later, the Economist Intelligence Unit, with the financial support of Siemens, evaluated the status of the green city index in 17 Latin American cities, 15 African cities, 22 major Asian cities, and 27 cities in United States, Canada, Australia, and New Zealand. In recent years, even some Western Islamic scholars have, in various publications, shown that Islam is an ecological religion. In Iran, the issue of protecting the environment has not received much attention regardless of its rich cultural and religious background and its confirmation in Article 50 of the Constitution of the Islamic Republic of Iran. Mashhad is the second metropolis of Iran, located in North-East of Iran, and is one of the counties of Khorasan Razavi Province. According to the 2016 Iranian Population and Housing Census, its population was 3057679 people (The Vice-Presidency of Planning and Development of Mashhad Municipality). In Mashhad, due to several reasons including the presence of Imam Reza Shrine (PBUH) and arrival of millions of pilgrims per year, population growth, increased garbage production (production of 896534 tons of garbage in 2016 (The Vice-Presidency of Planning and Development of Mashhad Municipality), air pollution (increased number of unhealthy days from 46 days per year in 2015 to 88 days in 2016 for sensitive groups and 4 days of unhealthy air for all groups in 2016 (Center for Monitoring Environmental Pollutants of Mashhad Municipality) the 2025 vision of the city has paid attention to the environment in the form of five general objectives; however, just like the national level, no specific pattern for environmentally-compatible urban development, such as green city, is determined. Analysis of the green city index in Mashhad metropolis can considerably contribute to urban managers and planners in addition to providing a pattern for evaluating the present situation in other cities of Iran and improving the quality of life regardless of the current status of the urban environment in Iranian cities; we can preserve these environments as parts of the natural environment for future generations.   Methodology In terms of its goal, the present study is an applied one; in the study, drawing upon other studies and library sources and considering the conditions of Iran and the metropolis of Mashhad in terms of green city, 14 quantitative indices were exerted. To this end, the required data for the quantitative indices was gathered by library research from the relevant institutions. Next, the weights of quantitative indices were determined using Shannon's entropy. Then, using the VIKOR method of multi-criteria decision-making, the status of various districts of the metropolis of Mashhad in terms of quantitative indices of green city was determined. Finally, the map of the spatial distribution of quantitative indices was drawn using the ARC GIS software package.   Results and discussion In this study, to analyze the status of the metropolis of Mashhad in terms of green city features, 14 quantitative indices were used. Considering the value of the VIKOR index ranges from 0 to 1, various districts of Mashhad can be classified into five categories; very satisfactory, satisfactory, average, unsatisfactory, and very unsatisfactory in terms of quantitative indices of green city. The results of the current situation of Mashhad showed that in terms of objective indicators of the green city, District 9 of Mashhad metropolis with a value of VIKOR index of 0.056 is in first place, and the seventh region with a value of VIKOR index of 0.433 is in second place. Also, based on the results of this part of the research, District 5, with the value of VIKOR index of 0.969, is in the last rank in terms of objective characteristics of the green city.   Conclusion Similarly, the results of studies by Afshar (2011) and Shabani et al. (2017) on Tehran metropolis are indicative of the unsatisfactory situation of Tehran (the biggest metropolis of Iran) in terms of green city features. Comparing the results of the studies by Afshar (2011) and Shabani et al. (2017) with the present study on Mashhad (the second biggest metropolis of Iran) reveals the necessity for a comprehensive plan toward achieving green cities. It should be mentioned that, due to the specific conditions of Mashhad metropolis and availability or unavailability of the required data, the indices used in the present study are somewhat different from the ones used by Afshar (2011) and Shabani et al. (2017).   Funding There is no funding support.   Authors’ Contribution All of the authors approved the content of the manuscript and agreed on all aspects of the work.     Conflict of Interest Authors declared no conflict of interest.   Acknowledgments We are grateful to all the scientific

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اطلاعات دوره: 
  • سال: 

    1400
  • دوره: 

    40
  • شماره: 

    3 (پیاپی 101)
  • صفحات: 

    361-371
تعامل: 
  • استنادات: 

    0
  • بازدید: 

    235
  • دانلود: 

    546
چکیده: 

استفاده از سورفکتانت های شیمیایی مانند سدیم لوریل سولفات در شوینده ها باعث ایجاد مشکل های گوناگونی مانند تحریک پوست و چشم، اختلال دستگاه عصبی و سرطان می باشد. بنابراین استفاده از بیوسورفکتانت ها به دلیل سمیت کم و تجزیه پذیر بودن مورد توجه فراوانی قرار گرفته اند. در این پژوهش تولید یک نمونه آزمایشگاهی شامپوی سبز با استفاده از بیوسورفکتانت رامنولیپید مورد بررسی قرار گرفت. نخست بیو سورفکتانت رامنولیپید از باکتری سودموناس آرژینوزا PTCC 1340 با استفاده از منبع کربنی روغن سویا در مقیاس آزمایشگاهی در حدود 4/1 گرم بر لیتر تولید و اثبات آن با آنالیزهای کروماتوگرافی لایه نازک (TLC) و طیف سنجی تبدیل فوریه فروسرخ (FT-IR) تأیید شد. نتیجه های فاکتورهای تاخیر در کاغذTLC نشان داد که مخلوطی از رامنولیپید های نوع 1 و 3 تولید شدند. با جایگزین کردن رامنولیپیدهای تولید شده به جای سدیم لوریل سولفات خواص ظاهری، شیمیایی و میکروبی شامپوهای سبز تولیدی بررسی شدند. با مقایسه نتیجه های به دست آمده با مقدارهای مرجع استاندارد، مشخص شد ویژگی های نمونه شامپوهای سبز تهیه شده بر اساس فرمولاسیون ارایه شده در این پژوهش در بازه استاندارد می باشند. این نتیجه ها می تواند گامی در راستای بهبود کیفیت زندگی افراد جامعه باشد.

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اطلاعات دوره: 
  • سال: 

    2015
  • دوره: 

    5
  • شماره: 

    2
  • صفحات: 

    59-69
تعامل: 
  • استنادات: 

    0
  • بازدید: 

    395
  • دانلود: 

    0
چکیده: 

The fast depletion of petroleum crude oil reserves and the serious consideration of environmental issues make the implementation of sustainable energy sources a crucial issue worldwide. Biofuel derived from vegetable oils is receiving a great attention as one of the most suitable and logical alternatives of fossil fuels. Therefore, the production of petroleum-like fractions from nonedible oil extracted from jojoba seeds is the main objective of this study.Hydrocracking technique has been applied here, using a fixed bed high pressure flow reactor system and using zeolite as a catalyst. A series of experiments were carried out in the temperature ranges from 350-425oC at the pressure of 1.0-5.0 MPa, liquid hour space velocity (LHSV) of 1-5 hr-1, and H2 to oil feed ra6o of 1600 l/l in order to elucidate the influence of operating conditions on the quantity and quality of the biofuel attained.The major products obtained from hydrocracking of jojoba oil feedstock were organic liquid products contaminated with some water and gases .The yield and conversion were estimated. The cracked products were analyzed and compared with that of the feed via FTIR, GC, ASTM distillation, and some routine testes. The organic liquid layers were fractionated to gasoline, kerosene, and gas oil. The results reveal that the main constituent lies in the gasoline range, which was favored at high temperature and pressure and low LHSV.

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نویسندگان: 

Razavi Marzie

اطلاعات دوره: 
  • سال: 

    2025
  • دوره: 

    2
  • شماره: 

    1
  • صفحات: 

    14-19
تعامل: 
  • استنادات: 

    0
  • بازدید: 

    22
  • دانلود: 

    0
چکیده: 

As oil resources become increasingly scarce, the need to transition to renewable energy sources is ‎critical for sustainable living. The United Nations first emphasized the importance of sustainable ‎development in 1987, highlighting the "central role" of energy in this effort. After years of research, ‎innovative solutions for sustainable energy have emerged, with energy production from wastewater ‎showing significant potential. Wastewater can be converted into biogas through anaerobic digestion, ‎where microorganisms break down organic matter in the absence of oxygen to produce methane, which ‎can be used for electricity, heat, or fuel. This process not only aids in reducing greenhouse gas ‎emissions but also supports environmental protection and waste management. The growing demand for ‎renewable energy has sparked significant interest in these techniques, which utilize bacteria to generate ‎electricity, further demonstrating the potential of wastewater as a sustainable energy source. Using ‎wastewater for energy not only lowers operational costs but also allows treatment plants to generate ‎energy on-site, reducing reliance on external energy sources and lowering carbon emissions. Exploring ‎these renewable energy sources is crucial, particularly given the large volumes of wastewater generated ‎from agricultural, industrial, and domestic activities. This paper reviews the potential of wastewater as a ‎green energy source, discussing specific technologies for treating various wastewater types and the ‎associated challenges and opportunities. By examining successful case studies and emerging trends, it ‎aims to advance green energy solutions that promote both environmental sustainability and economic ‎growth‎‎.

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اطلاعات دوره: 
  • سال: 

    1402
  • دوره: 

    20
  • شماره: 

    37
  • صفحات: 

    93-120
تعامل: 
  • استنادات: 

    0
  • بازدید: 

    156
  • دانلود: 

    8
چکیده: 

The lack of Quranic approaches in the production of Quran-based humanities is still felt, despite the predominance of the philosophical approach in critical approaches to modern humanities, which has become very common in the Islamic world and in Iran for several decades. It seems that the capacity of the method of thematic exegesis (al-Tafsīr al-mawdū'ī, Arabic: التفسیر الموضوعیّ) in this regard, can be used to bring the Holy Quran into the field of humanities. Thematic exegesis, according to whether its subject is inside or outside the Qur'an, has several functions in criticizing the structure of modern knowledge and scientific research, as well as the production of Islamic humanities. It is possible to make use of thematic exegesis of the inside of the Holy Book of Quran in order to “fundamental criticism” of the general fundamentals of humanities -the fundamentals of epistemology, axiology, ontology and anthropology- and it is also possible to use thematic exegesis for constructing and producing foundation of humanities obtained from the Holy Quran. It is used by thematic interpretation exegesis of the outside of the Holy Book of Quran -such as Shahīd (martyr) Sadr’s interrogational approach- to answer the problems of humanities and this process faces challenges such as the complexity and multiplicity of the “subject” of the humanities that exist in modern terminology of this field. It can be used in order to solve this issue in some cases to know the process of the change of the components of the modern of the conceptual history’s approach and also by analyzing the issue into several components can be shown that the components are not necessarily a product of the modern era and can be followed up in the Holy Quran and can be found up in the Holy Quran. The perspective of the Holy Quran, after that, regarding the modern subject in the desired field by the “combining” of the results obtained based on the thematic interpretation.

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نویسندگان: 

MELIS A. | HAPPE T.

اطلاعات دوره: 
  • سال: 

    2001
  • دوره: 

    127
  • شماره: 

    3
  • صفحات: 

    740-748
تعامل: 
  • استنادات: 

    1
  • بازدید: 

    136
  • دانلود: 

    0
کلیدواژه: 
چکیده: 

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اطلاعات دوره: 
  • سال: 

    1389
  • دوره: 

    3
  • شماره: 

    12
  • صفحات: 

    19-24
تعامل: 
  • استنادات: 

    0
  • بازدید: 

    2014
  • دانلود: 

    0
چکیده: 

مهم ترین منبع پنتوزان در طبیعت لیگنوسلولز موجود در زیست توده است. پنتوزان در اسید های معدنی رقیق به پنتوز هیدرولیز می شود. محصول آبگیری در این محیط از، پنتوز فورفورال خواهد بود. فورفورال از پوسته میوه های مختلف، به عنوان ضایعات کشاورزی، تولید می شود. پوسته سبز پسته از درخت پسته (Pistachio vera) به دست آمده که از ضایعات کشاورزی می باشد. این ضایعات از مواد لیگنوسلولزی فراوان و ارزان قیمت بوده و پتانسیل خوبی برای تولید فورفورال دارد. در این مطالعه عوامل موثر بر هیدرولیز اسیدی پوسته سبز پسته از جمله دمای واکنش (425 تا 545 کلوین)، غلظت سولفوریک اسید (0.5 تا 4 مول بر لیتر) و زمان آن (30 تا 600 ثانیه) بررسی شده و بازده واکنش بر اساس لیگنوسلولز، پنتوز و فورفورال به دست آمده است.

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بازدید 2014

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اطلاعات دوره: 
  • سال: 

    2014
  • دوره: 

    43
  • شماره: 

    SUPPLEMENT 2
  • صفحات: 

    129-129
تعامل: 
  • استنادات: 

    0
  • بازدید: 

    244
  • دانلود: 

    0
چکیده: 

Background: Due to rising world population, energy consumption in industrialized countries is increasing. For commercial production of biofuel, the using of fermentable organic waste such as algae is proposed. In this study, cheap carbon sources including green algae Spirogyra, Cladofora and Azolla were consumed for ethanol production by isolated Zymomonas spp.Methods: Green algae were collected from shores of the Caspian Sea. Algae were dried using sun light then treated with dilute acids and bases. Liquid medium including 12% of the treated algae were prepared then Zymomonas ssp. were inoculated in aerated and non-aerated conditions at 30-35oC.Results: The results demonstrated that Zymomonas spp was produced about 14% ethanol using Cladofora that hydrolyzed with sodium hydroxide.Conclusion: The result of this study revealed that xylose of green algae could introduce as a suitable and cheap carbon sources for bioethanol production.

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