By Mrs. Krupaliny R C Assistant Professor of English, Seshadripuram Degree College, MysoreWith over 14 years of teaching experience across India and Singapore, Mrs. Krupaliny R C brings her expertise to this indispensable guide for first-year undergraduate commerce students. This companion is meticulously crafted to enrich your understanding of English literature, serving as an invaluable aid throughout your academic journey. Whether you are delving into classic texts or exploring contemporary perspectives, this book is your trusted partner in achieving academic excellence.

The book describes the problem of dynamic behaviour of a mass being dragged on a dry surface is studied in detail in the light of proposed sigmoid and exponential function family based stiction model. The objective of this work is to identify relevant parameters and determine their range in which the dynamic behaviour of the system is optimum or acceptable. Numerical simulation is used to investigate this range using a model that consists of a spring-mass system being pulled on a rough surface at constant velocity with and without viscous damping. Relevant parameters such as stiffness, damping ratio, driving velocity, and the ratio of static to kinetic friction are varied to conduct the investigation. The range of these parameters and their combinations that result in the least number of friction-induced disturbances while a mass is being pulled on a rough surface at a constant speed is the study's conclusion. The response of the system for different set of combination of the systems parameters are obtained in form of displacement and velocity v/s time plots and the results are tabulated for different characteristics of motion like velocity peak, freezing time, frequency of vibration, sticking time, ratio of sticking time to total time for a cycle percentage amplitude decay in velocity etc. It is concluded that Damping has a negative effect on stick-slip since it reduces sticking time exponentially with increasing damping ratio; yet it can be used to reduce viscous friction even at the expense of power loss. Sticking time increases linearly with an increase in the Fs/Fc ratio; so, stick-slip is encouraged by a low Fs/Fc ratio, which should be maintained to completely remove stick-slip from the system. This might be achieved by inserting certain unique materials in between the rubbing surfaces, although doing so could raise material costs. Driving the system at a faster velocity can reduce stick-slip since the sticking time lowers as driving velocity increases. However, it may not always be possible because of some system contains and moreover it may lead to high wear causing high temperature at rubbing surfaces. That indeed may deteriorate the overall life of the system. Friction plays a beneficial role in stick-slip because the sticking time increases as the coefficient of friction between the rubbing surfaces increases. Therefore, the coefficient of friction between the rubbing surfaces should be kept as low as possible to minimize stick-slip. But it will result in higher manufacturing costs. In order of influence, the velocity, coefficient of friction, viscous damping, and ratio Fs/Fc are the dominant parameters that affect sticking time.

Prof. Woldeamlak Araia holds a PhD in Cropping Systems/Agronomy and Production Ecology from Wageningen Agricultural University (2001) and an MSc and BSc in Agronomy and Plant Science from Alemaya University (1982-83, 1972-73). With extensive experience in leadership roles, teaching, research, outreach, and consultancy, he has served as Dean, Associate Dean, Head of Research and Publication, and Head of Agronomy at Hamelmalo Agricultural College and University of Asmara. He has taught courses like Seed Production Technology, Cropping Systems, and Dryland Agronomy for over 32 years and advised numerous undergraduate, MSc, and PhD students. Prof. Woldeamlak has authored 8 teaching manuals, 35 journal articles, 8 proceedings articles, and 5 book chapters.Dr. Fathi Ibrahim A. Brima, an Assistant Professor in the Department of Agronomy at Hamelmalo Agricultural College, Eritrea, holds a BSc from Upper Nile University (2001), an MSc from the University of Khartoum (2008), and a PhD from Cairo University. Since 2003, he has served in various academic and administrative roles, including department head, Registrar, and Chief Inspector. He has published numerous research articles and a practical manual book. His teaching excellence earned him a Certificate of Merit at an international conference organized by the Agricultural Technology Development Society (ATDS) and C.C.S. University. He is a member of several professional organizations, including the ATDS, where he is a life member.Dr. Gangapuram Sethumadhava Rao is an Associate Professor at Hamelmalo Agricultural College with over 28 years of experience in teaching, training, and research. He holds degrees from Osmania University and a PhD in Mycology and Plant Pathology. He has worked as a lecturer and Assistant Professor in India, Eritrea, and Ethiopia, contributing significantly to agricultural sciences. Dr. Rao has mentored students from Ph.D. to diploma levels, focusing on fungal flora research. His publication record includes about 30 research papers, book chapters, and monographs. Active in the scientific community, he reviews for research journals and participates in national and international seminars. Dr. Rao's dedication and contributions are widely recognized in academia and research.