Essex Rock

All landscapes are built on rock: from hard stone for building with, to the softest clay or sand. Each piece of rock is a storehouse of prehistorical information; even a simple pebble from the garden has its own complex tale to tell. Geology is the great detective science that can unlock these secrets. In this entertaining and eye-opening book, the authors take a deep dive – quite literally – into their home county of Essex. We are all living in an ice age, an ongoing event that has hugely affected Essex over the last 3 million years. Yet this county was born more than 500 million years ago. Our story begins when the land we know as Essex was part of a large continent close to the South Pole, tracing the geological processes that continue to shape the countryside around us. The form of the land, boulders on village greens, road cuttings, cliffs, stones in church walls – they can all bring geology to light in unexpected and fascinating ways. Aimed at a general readership with no scientific background, chapters progress from fundamentals to intricate details of geological investigations and cutting-edge research. Richly illustrated with photographs and colour diagrams, here the geology of a county is visualised and brought to life as never before, along with pertinent environmental insights in the light of climate change that is happening now.

The Effect of Coatings on Cutting Force in Turning of C45 Steel

This article focuses on the development of a mathematical model of a cutting force that is applicable for coated and uncoated cutting tool inserts and aims to enable more accurate calculation of the cutting force. Two common PVD coatings, AlTiN and TiAlCrN, were used. Firstly, a mathematical model of the cutting force based on the specific cutting force and cutting area is proposed. This mathematical model considers the cutting speed and coating correction factor as well as the real cutting edge geometry, i.e., it includes both the straight and rounded parts of the cutting edge. For this proposed model, material constants for C45 steel, which was machined with uncoated inserts, were obtained. Before determining an equation for a coating correction factor and implementing it into the model, experimental cutting force data for coated and uncoated inserts were compared using a paired t-test. The result was that the difference between them was statistically significant. Their percentage difference was found to be up to 4%. The correction factor equation that was obtained and implemented into the mathematical model was applied to compare the calculated and experimental data of the coated inserts, also using a paired t-test. The result was that the difference between them was insignificant. Moreover, their percentage difference was found to be up to 0.6%.

Review on Study Methods for Reciprocally Enwrapping Surfaces

The processing of the piece surfaces involves the transformation of the blank into a piece, the defining characteristics of the surfaces (the form, dimensions, deviations, etc.), depending to a large extent on the parameters of the generated processes of the surfaces. Generating surfaces by enveloping represents a complex problem, this mode of generating being a constant concern of researchers due to its advantages. A very important issue is the cutting edge profiling of the future tool, which will generate the wanted profile of the piece. Throughout time, researchers have studied the problems of enveloping surfaces and stated theorems related to them, based on which practical solutions have been conceive to determine the generating and generated surfaces form. The paper presents an overview on study methods for reciprocally enwrapping surfaces, as well as methods for profiling tools for generating helical surfaces by the kinematic method and by the method of decomposing the helical movement. This review can represent a basis for future research articles and projects.

Light People: Professor Jianhua Jiang

EditorialRecently, Prof. Jianhua Jiang from Soochow University of China accepted an interview from Light: Science & Applications. Prof. Jiang works on topological photonics, topological phononics, and nonequilibrium physics. On this issue, he discusses the challenges and opportunities in topological photonics, topological phononics, and other topological synthetic systems. He also shares his experiences in cutting-edge research, the education of graduate students, and other challenges faced by junior researchers. Finally, he gives remarks and suggestions for Light: Science & Applications. Light People is a featured column of high-end interviews with outstanding scientists. It is our great honor to invite Prof. Jianhua Jiang, an outstanding young scientist, to showcase his research life and the story behind his success.