توجه: محتویات این صفحه به صورت خودکار پردازش شده و مقاله‌های نویسندگانی با تشابه اسمی، همگی در بخش یکسان نمایش داده می‌شوند.
۱A Proposed Method for Reliable Scheduling in Deregulated Power Systems
نویسنده(ها): ، ، ،
اطلاعات انتشار: بیست و یکمین کنفرانس بین المللی برق، سال
تعداد صفحات: ۹
Electric power systems are typically scheduled at least cost subject to technical and reliability constraints. This paper presents a probabilistic approach for reliable scheduling in restructured power system. A competitive structure is proposed which includes a purchasing agency with centrally optimized scheduling (MaxISO structure). Spinning and non–spinning reserves are considered in the proposed approach. The value of risk is deduced from the generation model. The required generation model is constructed using the outage replacement rate (ORR) of units. The load forecast uncertainty is included in reliability evaluation. This is due to the increased uncertainty associated with competition. The concept of area risk curves is used to allow the inclusion of non–spinning reserve. The performance of the proposed approach is verified through numerical case studies using a test system.<\div>

۲AN OVERALL PROJECT CONCEPT OF 3x105 MW MONTAZERGHAEM COMBINED CYCLE POWER PLANT
نویسنده(ها): ، ، ،
اطلاعات انتشار: یازدهمین کنفرانس بین المللی برق، سال
تعداد صفحات: ۸
The project management of combined cycle power plant 3x105MW MONTAZERGHAEM, IRAN, paved the way for the manufacturing of first Iran's 125MVA, air cooled generator in the country. This paper presents an overall project concept, design selections, site layout problems, of CCPP major equipments like HRSG, Steam Turbine Generator, Power Supply schemes, I&C, Cooling Tower, W.T, etc. This conversion of power from the existing gas turbines model–GE 916IE would not only gain saving millions of dollars per year for this plant, but also preserves national wealth (fuel oil\gas).In addition, the CCPP would run at an efficiency of 48%.<\div>

۳LDPE\EPDM Blends with Unique Surface, Electrical and Mechanical Properties for Electrical Insulators
نویسنده(ها): ، ، ،
اطلاعات انتشار: پنجمین کنگره بین المللی مهندسی شیمی، سال
تعداد صفحات: ۱۰
The present paper reports about the result of testing the mechanical, thermal, morphological, dynamical mechanical and electrical properties of polymeric insulators. Low density polyethylene (LDPE), ethylene–propylene–diene monomer (EPDM) and blends of LDPE\EPDM are known polymers for use as low, medium and high voltage insulators. Studies illustrate that in LDPE\EPDM blends, tensile strength of the blends are higher than either polymer component alone. But the synergism effect in LDPE\EPDM compound is more than HDPE\EPDM. Also the blends of LDPE\EPDM show good break down voltage strength and heat resistance comparing to LDPE. The result of mechanical measurement shows that mechanical properties such as tensile strength, modulus and elongation at break of blends enhanced with increase in LDPE in formulation. Also testes were conducted to measure various properties (mechanical, surface, electrical) under accelerated ageing condition. Because the life time of these compounds are generally too long to wait for a verdict on their behavior in use. The ageing results show that mechanical properties follow same trend as before ageing.<\div>

۴SIMULATION OF HYDROGEN SULFIDE DECOMPOSITION PROCESS IN MEMBRANE REACTOR
نویسنده(ها): ، ، ،
اطلاعات انتشار: هشتمین کنگره ملی مهندسی شیمی ایران، سال
تعداد صفحات: ۹
A huge amount of H2S produces naturally in many gas wells and is often present in natural gas. H2S can be considered as resources for two salable, hydrogen and sulfur, production. The success in this field will result in waste minimization, resource utilization and environmental pollution reduction. Different technologies such as, thermal, thermo–chemical, electrochemical, photolytic and plasmolytic have been used in small scale for this purpose. In this study, firstly different processes for converting waste H2S to hydrogen and sulfur have been compared and the thermal–catalytic decomposition method followed by product removal by membrane is suggested to be one of the most practical and economical method for
industrialization. Hysys package was used for simulation of a large scale H2S conversion membrane reactor to investigate effect of various parameters on hydrogen production yield. Results are shown that hydrogen yield has been decreased with temperature and molar flow rate increasing. The optimum temperature is between 600 to 650oC. Increasing of pressure difference between permeate and reaction side lead better hydrogen yield. As the major capital cost is related to membrane reactor, it is found that if the reactor structure is modified in which the specific area is maximized, the process will be more economic.<\div>

۵Efficiency of Landsat ETM+ Thermal Band for Land Cover Classification of the Biosphere Reserve “Eastern Carpathians” (Central Europe) Using SMAP and ML Algorithms
نویسنده(ها): ، ،
اطلاعات انتشار: International Journal Of Environmental Research، چهارم،شماره۴، Autumn۲۰۱۰، سال
تعداد صفحات: ۱۰
Two different methods of Bayesian segmentation algorithm were used with different band combinations. Sequential Maximum a Posteriori (SMAP) is a Bayesian image segmentation algorithm which unlike the traditional Maximum likelihood (ML) classification attempts to improve accuracy by taking contextual information into account, rather than classifying pixels separately. Landsat 7 ETM+ data with Path\Row 186–26, dated 30 September 2000 for a mountainous terrain at the Polish – Ukrainian border is acquired. In order to study the role of thermal band with these methods, two data sets with and without the thermal band were used. Nine band combinations including ETM+ and Principal Component (PC) data were selected based on the highest value of Optimum Index Factor (OIF). Using visual and digital analysis, field observation data and auxiliary map data like CORINE land cover, 14 land cover classes are identified. Spectral signatures were derived for every land cover. Spectral signatures as well as feature space analysis were used for detailed analysis of efficiency of the reflective and thermal bands. The result shows that SMAP as the superior method can improve Kappa values compared with ML algorithm for all band combinations with on average 17%. Using all 7 bands both SMAP and ML classifications algorithm achieved the highest Kappa accuracy of 80.37 % and 64.36 % respectively. Eliminating the thermal band decreased the Kappa values by about 8% for both algorithms. The band combination including PC1, 2, 3, and 4 (PCA calculated for all 7 bands) produced the same Kappa as bands 3, 4, 5 and 6. The Kappa value for band combination 3, 4, 5 and 6 was also about 4% higher than using 6 bands without the thermal band for both algorithms. Contextual classification algorithm like SMAP can significantly improve classification results. The thermal band bears complementary information to other spectral bands and despite the lower spatial resolution improves classification accuracy.

۶Prediction of the Operating Conditions in a Batch Distillation Column Using a Shortcut Method
نویسنده(ها): ،
اطلاعات انتشار: Iranian Journal of Chemistry and Chemical Engineering (IJCCE)، بيست و يکم،شماره۲(پياپي ۲۸)، ۲۰۰۲، سال
تعداد صفحات: ۸

۷Biodesulfurization of Tabas Coal in Pilot Plant Scale
نویسنده(ها): ، ، ،
اطلاعات انتشار: Iranian Journal of Chemistry and Chemical Engineering (IJCCE)، بيست و نهم،شماره۴(پياپي ۵۶)، ۲۰۱۰، سال
تعداد صفحات: ۴
Sulfur emission from coal combustion presents many environmental problems. The techniques used to reduce the amount of sulfur in coal before combustion, include physical, chemical and biological processes. Biological processes based on degradation of sulfur compounds by microorganisms offer many advantages over the conventional physical and chemical processes. The processes are performed under mild conditions with no harmful reaction products and the value of coal is not affected. In this article the progress achieved to date in biodesulfurization of Tabas coal in pilot plant is reviewed. Effect of particle size and pulp density at constant temperature on coal biodesulfurization investigated in this research. The best results obtained was 45% of pyritic sulfur and 20% of total sulfur in reduction at pulp density of 10% and 0–0.5 mm particle size within 14 days.

۸Microwave Assisted Synthesis of Nano Zeolite Seed for Synthesis Membrane and Investigation of its Permeation Properties for H2 Separation
نویسنده(ها): ، ، ، ، ،
اطلاعات انتشار: Iranian Journal of Chemistry and Chemical Engineering (IJCCE)، بيست و نهم،شماره۴(پياپي ۵۶)، ۲۰۱۰، سال
تعداد صفحات: ۶
MFI–type zeolite membranes (ZSM–5) were prepared on α–alumina tubular supports and tested for separation of H2\CO mixtures. The effect of pressure and temperature on H2 and CO flows and selectivity was investigated. The best results in this work were obtained with a ZSM–5 membrane prepared over a porous α–alumina tube seeded with zeolite nanocrystals synthesized with microwave technique. In this case the H2 permeance was obtained 2.8 × 10–6 mol\ (m2.s.Pa) with a H2\CO ideal selectivity of 4.9 at 373 K. The permeation results of four gas (H2, CO, N2, CH4) on the synthesized membrane were also investigated.

۹Kinetic Study of Ethyl Mercaptan Oxidation in Presence of Merox Catalyst
نویسنده(ها): ، ، ، ، ، ، ،
اطلاعات انتشار: Iranian Journal of Chemistry and Chemical Engineering (IJCCE)، سي و دوم،شماره۲(پياپي ۶۶)، ۲۰۱۳، سال
تعداد صفحات: ۱۰
Mercaptans are commonly present in petroleum products. Their foul odor and highly corrosive nature make them the most undesirable sulfur compounds so they should be removed because of environmental issues. Merox process is used for oxidation of mercaptans to disulfide using air in the presence of alkaline solution and Merox catalyst. In this paper، due to lack of information about the kinetic of mercaptan oxidation، the kinetic of conversion of ethyl mercaptan in gasoline and kerosene is studied in order to be able to model and simulate this process. The experiments were carried out in a semi–batch bubble column reactor and it was proved that increasing the temperature، improves the rate of the reaction. The obtained results were analyzed and a correlation for the rate of reaction is suggested. The suggested equation is first–order with respect to mercaptan concentration.

۱۰Modeling of Oxidative Coupling of Methane over Mn\Na2WO4\SiO2 Catalyst Using Artificial Neural Network
نویسنده(ها): ، ، ، ، ،
اطلاعات انتشار: Iranian Journal of Chemistry and Chemical Engineering (IJCCE)، سي و دوم،شماره۳(پياپي ۶۷)، ۲۰۱۳، سال
تعداد صفحات: ۸
In this article, the effect of operating conditions, such as temperature, Gas Hourly Space Velocity (GHSV), CH4 \O2 ratio and diluents gas (mol% N2) on ethylene production by Oxidative Coupling of Methane (OCM) in a fixed bed reactor at atmospheric pressure was studied over Mn\Na2WO4 \SiO2 catalyst. Based on the properties of neural networks, an artificial neural network was used for model development from experimental data. In order to prevent network complexity and effective data input to network, principal component analysis method was used and the numbers of output parameters were reduced from 4 to 2. A feed–forward back–propagation network was used for simulating the relations between process operating conditions and aspects of catalytic performance, which include conversion of methane, C2+ products selectivity, yield of C2+ and C2H4 \C2H6 ratio. Levenberg– Marquardt method is presented to train the network. For first output, optimum network with 4–9–1 topology and for second output, optimum network with 4–6–1 topology was prepared.
نمایش نتایج ۱ تا ۱۰ از میان ۱۰ نتیجه