Structure Investigations of Radiation-modified Polymers Polyethylene and Polymethylmethacrylate

the underlying structure of language proficiency and the proficiency level

هدف از انجام این تخقیق بررسی رابطه احتمالی بین سطح مهارت زبان خارجی (foreign language proficiency) و ساختار مهارت زبان خارجی بود. تعداد 314 زبان آموز مونث و مذکر که عمدتا دانشجویان رشته های زبان انگلیسی در سطوح کارشناسی و کارشناسی ارشد بودند در این تحقیق شرکت کردند. از لحاظ سطح مهارت زبان خارجی شرکت کنندگان بسیار با هم متفاوت بودند، (75 نفر سطح پیشرفته، 113 نفر سطح متوسط، 126 سطح مقدماتی). کلا ...

Infrared Spectra of High Polymers . II . Polyethylene *

The infrared spectrum of polyethylene has been obtained between about 3000 cm-1 and 70 em-I, polarization measurements on oriented specimens having been obtained to about 350 em-l. Assignments of the fundamentals are made with the help of a group theory analysis. The assignment of the controversial CH. wagging mode is discussed in detail and especially in terms of new evidence from the spectra ...

Rheological properties of modified Bitumen: Comparison of waste polymers’ performance

In this investigation, rheological properties of three different polymer-modified bitumen compounds containing recycled polyethylene terephthalate (R-PET), crumb rubber (CR) and poly (styrene-butadiene-styrene) (SBS) are evaluated and compared. The modified samples were tested by a dynamic shear rheometer (DSR) where complex modulus (G*), phase angle (δ) and rutting resistance (G*/Sinδ) of spec...

Investigations of Positron Annihilation Radiation

By combining OSSE, SMM and TGRS observations of the galactic center region, Purcell et al. (1997) and Cheng et al. (1997) produced the first maps of galactic positron annihilation. That data-set has been augmented with additional data, both recent and archival, and re-analyzed to improve the spectral fitting. The improved spectral fitting has enabled the first maps of positronium continuum emis...

Polyethylene bags and solar ultraviolet radiation.