No description available.

Thesis (Ph. D.)--Columbia University, 1929. / Vita. eContent provider-neutral record in process. Description based on print version record. Bibliography: p. 68.

The physical quantity of the square of tensile strength over Young’s modulus has been proposed as a criterion of comminution of rock by Oka and Majima. The value was determined for five different rocks, measuring tensile strength and Young's modulus. The testing method used to determine both rock properties was a point-load tensile strength test and measurement of propagation velocity of P-wave. In order to verify the applicability of the criterion thus obtained, the drop-weight impact test and ball mill grinding were carried out using the identical specimen used for tensile strength and Young's modulus test. The experimental result was obtained that the square of tensile strength is more applicable than the square of tensile strength over Young's modulus. In chapter 2, grinding tests were performed with a 12 inch batch mill. A torque meter was installed to estimate the energy consumption.necessary to achieve size reduction. From the torque measurement, the required torque for the mill turning remained almost constant regardless of the material being ground. A new concept, Energy Index, was introduced to evaluate grinding results and to study grinding problems. For each rock sample tested, the energy index was determined from torque measurements and the quantity of the products. It was found the energy index has a linear relationship with Bond work index under selected grinding condition. / Applied Science, Faculty of / Mining Engineering, Keevil Institute of / Graduate

Thesis (Ph.D.)--Hong Kong University of Science and Technology, 2008. / Includes bibliographical references.

QC 351 A7 no. 71 / Generalized ray tracing is a method of calculating the principal curvatures and directions of the wavefront associated with a ray as it is traced through an optical system. The results of such a ray trace provide important information about the structure of the image and have immediate application to lens design and image analysis. The caustic surface formed by an optical system can be easily determined from the results of a generalized ray trace. An examination of several caustic surfaces formed by different optical systems provides valuable information about the relative quality of the images and indicates some of the advantages of the generalized ray tracing method.

Call number: LD2668 .T4 1951 W3 / Master of Science

No description available.

No description available.

No description available.

No description available.