Dyed and un-dyed polyurethane elastomers have been synthesized via the prepolymer method and analyzed by using different analytical techniques such as Fourier transform infrared (FTIR) spectroscopy, Proton nuclear magnetic resonance ( 1 H-NMR) and Carbon-13 nuclear magnetic resonance ( 13 C-NMR) spectroscopy, scanning electron microscopy (SEM), X-ray diffraction (XRD), differential scanning colorimetery (DSC) and thermogravimetric and differential thermal analysis (TG/DTA), tensile testing, contact angle measurement, water absorption percentage (%), density and hardness. FTIR and NMR techniques were used to confirm the chemical structure of the synthesized PUEs. While XRD was executed to determine the extent of crystallanity as a function of chain extenders, diisocyanates and for the dye (Disperse Red 5/1,4- butanediol) as chain extender. Which also have shown that the dye molecule becomes the part of the polymeric chain of the PUEs. Scanning electron microscopy was employed to analyze the surface morphology of PUEs with variation of chain extenders, diisocyantes and dye content. SEM images of PUEs have shown that hard segments are completely dispersed in the soft segment matrix. Other methods like contact angle measurement and water absorption percentage (%) were also used to determine the surface properties. The results have shown that the samples of PUEs based on HTPB were hydrophobic and this nature was increased as the chain extender length was increased. The same trend was observed in the variation of aromatic to aliphatic diisocyanates as well as the content of DR5 dye was increased. Thermal analysis was performed to analyze the thermal behavior of the PUEs by using TG/DTA and DSC which show that all the PUEs were stable up to 215 o C and all the samples were degraded to constant mass at 470 o C. Mechanical properties of the PUEs were studied by tensile testing, it is revealed that chain extender length and diisocyantes affect the mechanical properties while dyed polyurethane had represented the inverse mechanical behaviour with respect to un- dyed PUEs. The present study gave us reliable results for dyed and un-dyed PUEs and it was found that the dye had been incorporated in the polymeric chains and the effect was significant on surface morphology, thermal and mechanical properties such as tensile strength, modulus and elongation at break.
نوکر جدوں تیک رہیا ہاں تیرے ہو نزدیک رہیا ہاں عمر نہیں اینویں ضائع کیتی تیری وچ اڈیک رہیا ہاں کرچی کرچی ہوئی روح نوں درداں نال دھریک رہیا ہاں اوسے در دا خادم ہاں میں اوتھوں منگ دا بھیک رہیا ہاں جس رستے تے مجنوں ٹریا اوہو لبھدا، لیک رہیا ہاں غیراں نوں میں دُکھ دِتے نیں تیرے نال تے ٹھیک رہیا ہاں
Economic causes of social insecurity describes the risk of economic loss faced by workers and households as they encounter the unpredictable events of social life. This review suggests a nine-part framework for studying the distribution and trends in these economic risks. Empirical research in these areas reveals high levels of economic insecurity among low-income households and suggests an increase in economic insecurity with the growth in economic inequality in the Country. The solution of social insecurity because of Economic causes is also discussed in the light of Teachings of Holy Prophet.
Vocabulary has been found to be a predictor of later language development (Lee, 2011). Research indicates stories to be great stimulators of language, especially in enhancing children’s vocabulary. Pakistan’s National Curriculum for Early Childhood Education (2007) also emphasizes on the importance of supporting children’s vocabulary development. Through a collaborative action research, I explored the role of stories, told monolingual and bilingually, to support vocabulary development of two years old bilingual children at a private English-medium school in Karachi, Pakistan. Two teachers, facilitating this age group and four randomly chosen children from the classroom participated with me in the study. Data was gathered through various tools including, interviews, classroom teaching, and reflective conversations. Anecdotes of the four participant children were also maintained throughout the study. Findings revealed that stories supported children’s vocabulary development. Children enjoyed both monolingual (English or Urdu) and bilingual stories (Urdu and English). Moreover, vocabulary development can further be supported by reinforcing the key vocabulary through play and language games. A change in the teachers’ and my perception regarding the power of stories and storytelling, both monolingual and bilingual stories, was seen as a result of the intervention. The study also brings to light the importance of having bilingual stories to support language development in both the home and classroom languages. It also raises questions about assessing progress in both languages. It also highlights that along with stories, the storyteller, in this case the teacher helps support vocabulary development in children. It also raises questions about supporting the professional development of these teachers, about the use of stories as a teaching pedagogy as well as different strategies of telling stories.