astrophysics is becoming now an integral part of general physics. considering the black hole theory ,which is a new and exciting branch of relativistic astrophysics, we see many connections between elementary particle physics and astrophysics. in this article we attempt to explain the development of star physics ,in an easy ,understandable manner. previous knowledge of relativistic theory or cl...

James P. Lantolf is George and Jane Greer Professor Emeritus of Language Acquisition and Applied Linguistics and former director of the Center for Advanced Language Proficiency Education and Research at the Pennsylvania State University, USA. He is currently Adjunct Professor of Applied Linguistics in the same academic unit at Xi’an Jiaotong University. He is founder of the Sociocultural Theory...

background: infant's transition is a challenge for parents and the health system that requires ongoing assessment and management to improve each newborn`s growth and development. the purpose of this study was to explore the management of infant` transition from neonatal intensive care unit (nicu) to home.materials and methods: we used a grounded theory study to explore and describe the man...

Many theoretical and practical problems arise at different stages of the design/manufacturing process during development of a pump. The experience obtained in pump development proves that the quality of a pump depends on many factors, which should he satisfied to receive good results. At the same time, the theory of engineering design principles exists, which is applicable to designing various ...

ibn khaldun has played a major role in the shaping of pre-modern population theories. he has proposed some important issues and perspectives on the interaction of population dynamics and development. thus, this paper attempts to explore ibn khaldun’s demographic perspectives and identify his approach to population and development interrelationship. the results indicate that ibn khaldun has intr...

These two problems remain fundamental in the classic theory of synchronization: the first one is on the behavior of oscillatory systems driven by a periodical force. The second focuses on the interaction between two coupled oscillatory systems. Both cases give a plethora of dynamical phenomena that exist at different values of control parameters which can either the amplitude and the frequency ...