نتایج جستجو برای: high temperature
تعداد نتایج: 2382321 فیلتر نتایج به سال:
in this thesis, a better reaction conditions for the synthesis of spirobarbiturates catalyzed by task-specific ionic liquid (2-hydroxy-n-(2-hydroxyethyl)-n,n-dimethylethanaminium formate), calcium hypochlorite ca(ocl)2 or n-bromosuccinimide (nbs) in the presence of water at room temperature by ultrasonic technique is provided. the design and synthesis of spirocycles is a challenging task becaus...
in this project, some new polyaspartimides, (pas)s, have been synthesized form michael addition reaction between new synthetic bismaleimide (bmi) and some aromatic diamines. a characteristic property of this polyaspartimides is a pendent carboxylic group, which introduced to these polymers from new bismaleimide. bismaleimides (bmi) is one of the interesting compounds, which can be self-polymeri...
abstract: mineral scaling in oil and gas production equipment is one of the most important problem that occurs while water injection and it has been recognized to be a major operational problem. the incompatibility between injected and formation waters may result in inorganic scale precipitation in the equipment and reservoir and then reduction of oil production rate and water injection rate. ...
the paper presents results of experimental studies on the methane and propane ignition process in various volumetric compositions of oxidizers heated to temperatures higher than ignition point of analyzed fuels (htac conditions–high temperature air combustion conditions). the increment of temperature dt and the ignition delay time tig are parameters characterizing the process of ignition under ...
چکیده : * در یک واکنش تک ظرفی و با استفاده از واکنش آلدهید های آروماتیک و 3- متیل 1- فنیل پیرازولین-5- ان با نسبت مولی 1:1، ساختارهای هتروسیکل پیرازول سنتز شد. از مزایای آن، انجام واکنش در دمای اتاق، عدم نیاز به کاتالیزور، بازده بالای واکنش، استفاده از آب بعنوان حلال سبز و بی خطر به جای حلال های آلی وسمی می باشد . * توانستیم با استفاده از ملدرام اسید ومشتقات 2- هیدروکسی بنزآلدهید، ترکی...
soft-sphere discrete element method (dem) and navier-stokes equations were coupled with equations of energy for gas and solids to investigate the process of agglomeration in fluidized bed of polyethylene particles at high temperature. the newton’s second law of motion was adapted for translational and rotational motion of particles and agglomerates. the cohesive force for polyethylene particles...
Abstract: A pulse-echo technique, based on ultrasonic "long-bar" mode (LBM) velocity measurements, working up to 1700°C is described. Magnetostrictive transducers and ultrasonic lines used in a 40-85 kHz frequency range are detailed. The conditions of choice of fundamental parameters (frequency, line geometry, sample size) are discussed in relation with the nature and the microstructure of ...
this paper aims at finding the long term coupled effect of high temperature and constant high relative humidity on the corrosion rehabilitated patches of chloride contaminated steel reinforced concrete. this paper is an extension of previous research in which the authors experimentally corroborated re-corrosion in the repaired reinforced concrete (rc) patches in the form of macro-cells. in prev...
run-out-table (rot) is located between last finishing stand and down coiler in a hot strip mill. as the hot steel strip passes from rot, water jets impact on it from top and bottom and strip temperature decreases approximately from 800-950 °c to 500-750°c. the temperature history that strip experience while passing through rot affects significantly the metallurgical and mechanical properties, s...
Dual phase steels with different martensite volume fraction and morphology were tensile tested at a temperature range of 25 to 5500C. Stress-strain curves of all steels showed serration flow at temperatures of 250 and 3500C, and smooth flow at the other temperatures. Both yield and ultimate tensile strengths increased with increasing testing temperature up to about 450<sup...
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