نتایج جستجو برای: tref

تعداد نتایج: 66  

2012
B. Monrabal

The introduction of single site catalysts and multiple reactor technology allows the design of new Polyolefin resins with improved properties for each particular application, and the Chemical Composition Distribution (CCD) has become the most discriminating microstructure parameter in these polymers. The proper analysis of the CCD necessarily requires a fractionation process, typically done acc...

2011
Benjamín Monrabal Pilar del Hierro

The introduction of single-site catalysts in the polyolefins industry opens new routes to design resins with improved performance through multicatalyst-multireactor processes. Physical combination of various polyolefin types in a secondary extrusion process is also a common practice to achieve new products with improved properties. The new resins have complex structures, especially in terms of ...

Journal: Polyolefins Journal 2014

In this work, the role of comonomer content of 1-hexene-medium density polyethylene (MDPE) copolymer, synthesized using Phillips catalyst, on thermal behavior parameters such as: crystallization, melting temperature and thermal degradation was investigated in detail. The copolymer was fractionated to homogenous short-chain branching (SCB) fractions by "preparative temperature rising elution fra...

Journal: :Sensors 2023

After surgery for ovarian cancer or colorectal cancer, residual tumors are left around. A practical way to treat is destroy them with heat by injecting high-temperature drugs into the abdominal cavity. The injected medicinal substances induced flow out of cavity; then, spilled drug flows back cavity through feedback. During this process, starts decrease; thus, treatment performance reduces. To ...

Journal: :Journal of bacteriology 2006
Arnim Weber Stephanie A Kögl Kirsten Jung

Escherichia coli lives in the mammalian gastrointestinal tract anaerobically at high osmolarity as well as in the soil aerobically at varying osmolarities. Adaptation to these varying environmental conditions is crucial for growth and survival of E. coli. Two-dimensional protein gels were used to visualize global time-dependent changes (10 to 60 min) in the proteome of cells responding to osmot...

Journal: :Dalton transactions 2013
Ilya E Nifant'ev Pavel V Ivchenko Vladimir V Bagrov Sandor M Nagy Linda N Winslow Jean A Merrick-Mack Shahram Mihan Andrei V Churakov

A general and efficient approach toward new zirconium and hafnium complexes based on 2-aryl-8-arylaminoquinoline ligands was developed. These precursors, when activated with MAO/borate cocatalyst and supported on silica, result in active olefin polymerization catalysts. The ethylene copolymers produced under industrially relevant conditions show very high molecular weights and unique microstruc...

2017

The vast majority of commercial polyolefins are semi-crystalline materials. Depending on the chemical composition and tacticity, their melting temperatures range from ambient to temperatures exceeding 160 C. Polyolefins form various crystalline structures that can be investigated with microscopic, spectroscopic and scattering techniques. When a semi-crystalline polyolefin is dissolved in a solv...

پایان نامه :وزارت علوم، تحقیقات و فناوری - پژوهشگاه پلیمر و پتروشیمی ایران - پژوهشکده پتروشیمی 1394

هدف از انجام این رساله دکتری بررسی نقش تعداد شاخه کوتاه (scb) در رفتار حرارتی دما پایین و دما بالای کوپلیمرهای اتیلن/?-اُلفین بوده است. به این منظور کوپلیمرهای اتیلن/1-بوتن، اتیلن/1-هگزن و اتیلن/1-اُکتن دارای شاخه های کوتاه به ترتیب اتیلی، بوتیلی و هگزیلی انتخاب گردیدند. از آنجائیکه این کوپلیمرها هر یک دارای یک توزیع ناهمگن از تعداد شاخه کوتاه در ساختار خود می باشند، جهت بررسی نقش تعداد شاخه کوتا...

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