Alok Sharma

The purpose of research in this book is to cut a 1mm thick Carbon fibre reinforced polymer (CFRP) by using a low power CO2 laser cutting speed (1-2mm/sec) and assist gas pressure (1-2bar). Main objective of this research work is to lower production cost of cutting by using lower laser power. A Composite of Carbon Fibre (carbon fibre + epoxy resin) with initial dimensions of 120mm 100mm 1mm was used as a material for laser cutting. A CO2 laser machine of maximum laser power 150 watt was used for laser cutting. Rectangle cuts of 50mm 40mm were cut through CFRP sheets. Samples size was determined according to response surface methodology (RSM). Factorial design was used to determine number of experiments. According to this design, number of experiment was eight. Experiments were conducted according to this design. Experiments were conducted by changing process parameters (laser power, cutting speed and assist gas pressure) simultaneously. After laser cutting, scanning electron microscope was used to see effect of process parameters on material surface in the form of microstructure. Optimization was done by the use of MINITAB software.The purpose of research in this book is to cut a 1mm thick Carbon fibre reinforced polymer (CFRP) by using a low power CO2 laser cutting speed (1-2mm/sec) and assist gas pressure (1-2bar). Main objective of this research work is to lower production cost of cutting by using lower laser power. A Composite of Carbon Fibre (carbon fibre + epoxy resin) with initial dimensions of 120mm 100mm 1mm was used as a material for laser cutting. A CO2 laser machine of maximum laser power 150 watt was used for laser cutting. Rectangle cuts of 50mm 40mm were cut through CFRP sheets. Samples size was determined according to response surface methodology (RSM). Factorial design was used to determine number of experiments. According to this design, number of experiment was eight. Experiments were conducted according to this design. Experiments were conducted by changing process parameters (laser power, cutting speed and assist gas pressure) simultaneously. After laser cutting, scanning electron microscope was used to see effect of process parameters on material surface in the form of microstructure. Optimization was done by the use of MINITAB software.

The first trimester of pregnancy is a period of major development for a foetus. It can also be a dangerous time with the highest risk of miscarriage during the first few months. This book is a comprehensive guide to the first trimester of pregnancy for obstetricians and gynaecologists. Beginning with the basics of physiology, the following chapters describe changes in the body, screening, dietary advice, exercise, travel and the effects of smoking and alcohol. The book covers the management of numerous disorders that may be associated with first trimester pregnancy, including ectopic pregnancy, recurrent miscarriage, breast diseases, sepsis and gynaecological problems. The final chapters examine termination and medicolegal aspects. Key points Guide to first trimester pregnancy for obstetricians and gynaecologistsCovers management of numerous associated disordersIncludes surgical procedures and anaesthesia during the first trimesterNearly 170 images, illustrations and tables