نتایج جستجو برای: Insulation properties

تعداد نتایج: 876888  

Journal: :iranian journal of chemistry and chemical engineering (ijcce) 2014
tohid farajpour yadollah bayat mohammad hossein keshavarz ebrahim zanjirian

polysulfide resins,with trade name of  g4 and g112, with short and long chain lengths respectively, were used as reactive modifiers to toughen epoxy resin. the effects of molecular weights of g4 and g112 on impact resistance, dielectric constant, thermal conductivity as well as decomposition  heat and adhesion properties of toughened epoxy were investigated. the impact strength and the dielectr...

Journal: :جنگل و فرآورده های چوب 0
کژال مرادیان کارشناس ارشد صنایع خمیر و کاغذ، دانشکدة منابع طبیعی، دانشگاه تهران، کرج، ایران محمد آزادفلاح استادیار، گروه علوم و صنایع چوب و کاغذ، دانشکدة منابع طبیعی، دانشگاه تهران، کرج، ایران امیر عباس شایگانی اکمل استادیار، گروه مهندسی برق، دانشکدة مهندسی برق و کامپیوتر، دانشگاه تهران، تهران، ایران علی عبدالخانی دانشیار، گروه علوم و صنایع چوب و کاغذ، دانشکدة منابع طبیعی، دانشگاه تهران، کرج، ایران

the oil-paper insulation is a type of an inexpensive combination insulation system in oil-filled power transformers. in this study the dielectric and strength properties of canola oil and mineral oil impregnated hand-sheet papers were investigated. all hand sheets were made of unbleached bagasse soda pulp with two different freeness levels of 200 ± 25 ml, csf and 400± 25 ml,csf. after drying th...

ژورنال: مواد پرانرژی 2015

Thermal insulation materials protects internal surface of the motor casing in contact with the hot produced gases, extreme turbulence flow and high pressure due to combustion propellant. Insulation Materials in the rocket motor covers the inner surface of the motor casing and protect the body against the damage caused by extreme and short-term heat, intense turbulent flow and high pressure. O...

ژورنال: مواد پرانرژی 2014
غفوری, مرتضی, نوآموز, مرتضی,

In order to preserve structure and also achieve the desired thrust rocket motor, engine Case temperature should be prevented increase excess.This operation the can be done by Insulation. EPDM rubber because of advantages such as low specific weight, improve aging properties, as long as thermal insulation for solid propellant motors case bond Introduced and its properties are investigated in thi...

Ebrahim Zanjirian Mohammad Hossein Keshavarz Tohid Farajpour, Yadollah Bayat

Polysulfide resins,with trade name of  G4 and G112, with short and long chain lengths respectively, were used as reactive modifiers to toughen epoxy resin. The effects of molecular weights of G4 and G112 on impact resistance, dielectric constant, thermal conductivity as well as decomposition  heat and adhesion properties of toughened epoxy were investigated. The impact strength and the diel...

ژورنال: مواد پرانرژی 2019

Aerogel is a unique nanoparticle that has grown dramatically in the world of chemistry over the past few decades. Aerogel features: Very low density, ultra-porous surface, sound and heat absorber, and super hydrophobic. Depending on the type of aerogels and their synthesis methods, different applications in military industries such as: Explosives, Rocket fuels, thermal insulation, sound insulat...

2011
Jian Li Lijun Yang

Oil-impregnated paper is widely used in power transmission equipment as a reliable insulation. However, copper sulphide deposition on oil-paper insulation can lead to insulation failures in power transformers. This paper presents the influences of copper sulfur corrosion and copper sulphide deposition on copper wires and oil-paper insulation in power transformers. Thermal aging tests of paper-w...

2014
J. Zach J. Hroudova J. Brozovsky

Abstract—Thermal insulation materials based on natural fibers represent a very promising area of materials based on natural easy renewable row sources. These materials may be in terms of the properties of most competing synthetic insulations, but show somewhat higher moisture sensitivity and thermal insulation properties are strongly influenced by the density and orientation of fibers. The pape...

2017
Bitao Fan Shujun Chen Qiufang Yao Qingfeng Sun Chunde Jin

Cellulose nanofiber/AlOOH aerogel for flame retardant and thermal insulation was successfully prepared through a hydrothermal method. Their flame retardant and thermal insulation properties were investigated. The morphology image of the cellulose nanofiber/AlOOH exhibited spherical AlOOH with an average diameter of 0.5 μm that was wrapped by cellulose nanofiber or adhered to them. Cellulose nan...

2002
W. Sun J. T. Tzeng

An analytical model and numerical approach to predict the effective mechanical properties of a composite conductor consisting of metallic core and insulation layers are presented in this paper. The analytical model was developed based on a two-step homogenizations and mechanics analysis for composite unit cell. The Step 1 homogenization derives the effective properties of the out-wrapped compos...

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