The purpose of the present study is to compare three factors of job retention (JRF) including work balance conditions, recognition of colleague support, and inclusiveness between PE and non-PE teachers. Out of 1963 high school teachers in Rasht, 71 PE teachers (4%) and 213 non-PE teachers (13%) were selected. To measure the 3 factors, a standard questionnaire (JRF) designed by Sue Ingles, Pastor and Banyl Chuk (1996) was used. The reliability of the questionnaire was estimated by Ramezani Nejad (2001) with Cronbach Alpha coefficient of 0.83. 81% of the questionnaires (231) were returned (57 PE and 17 non-PE teachers). After collecting the data, T-student test, analysis of variance (ANOVA) and Tukey test were used in the level of P<0.05. The results of the study indicated that from PE teachers and non-PE teachers point of view, the first priority is work balance conditions, and the last ong is inclusiveness. But for al the teachers, the first priority is the recognition of colleague support, and the last one is inclusiveness. A comparison 3 main factors between PE and non-PE teachers showed that there was a significant difference in recognition fo support between high-educated PE teachers and experienced ones. There was also a significant difference in work balance conditions between single and married female non-PE teachers in general. PE teachers had a better condition in recognition of support. Comparing to other teachers the same was true for non-PE teachers regardinginclusiveness.

The effects of three different mixers, two different feeding orders and nanoclay content on the structure development and rheological properties of PE/nanoclay nanocomposite samples were investigated. Fractional Zener and Carreau– Yasuda models were applied to discuss the melt linear viscoelastic properties of the samples. Moreover, scaling law for fractal networks was used to quantify the clay dispersion, which depends on the PE matrix structure. A better dispersion and a higher melt intercalation of nanoclay particles were obtained by simultaneous feeding compared to compatibilizer/nanoclay masterbatch feeding. A twin-screw extruder (Brabender DSE 25 model) showed a greater potential for melt intercalation of PE/nanoclay as compared to internal mixers (Brabender W50 and Haake Rheomix 3000 batch mixers). Comparing the thermal analysis of PE, PE/PE-g-MA and PE/nanoclay samples by DSC technique showed an opposite effect for the compatibilizer versus the nanoclay on the crystallization behavior of PE. PE/nanoclay cast film samples were produced at three different draw ratios. The X-ray diffraction structural analysis in conjunction with the melt linear viscoelastic measurements confirmed that the PE/nanoclay cast film produced at higher draw ratio had a more effective melt intercalation. The tensile test showed that the machine direction modulus and yield strength of both PE and PE/nanoclay cast film samples reduced with increase of the draw ratio.

Polyethylene (PE) nanocomposites containing Cellulose Nano Crystal (CNC) were prepared via melt blending in a twin screw extruder. The evaluation of PE/CNC nanocomposites was studied for food packaging applications. The nanocomposites were investigated by thermal, mechanical analyses. Addition of CNC particle while having no effect on melting and crystallization temperature had intensive effect on the degree of crystallinity of the polyethylene. It is shown that due to the weak interfacial bonding between CNC and PE matrix, a decrease in yield stress and modulus of elasticity was observed for PE/CNC nanocomposites. According to the x-ray diffraction analyses, incorporation of the CNC into PE matrix induced a preferred crystalline orientation for PE crystallites.