the investigation was conducted on wet and dry seasons of ethiopia during the year 2012/2013 at wondo genet agricultural research center nursery site. four levels of cutting size and three levels of cutting positions were arranged in randomized complete block design with three replications. data on seedling height, branch number/seedling, root number/seedling, root weigh/seedling, root length/s...

This paper discusses a number of discrete models used for optimization of cutting condition during NC machining. The models can be broadly placed into two categories: 1. volumetric models in which feedrate is proportional to either average or instantaneous volumetric removal rate, 2. vector force models in which feedrate is set to values which keep either average or instantaneous cutting forces...

Noncontact anterior cruciate ligament (ACL) injuries often occur during lateral cutting maneuvers, in which extension, adduction, and external rotation create high loads on the ACL. The aim of this study was to examine knee moments and foot strike patterns during lateral cutting when shod (SD) and barefoot (BF). Fifteen NCAA Division III athletes (7 female and 8 male; age 20.2 ± 1.5 years; mass...

Quality improvements in laser cutting of mild steel have been achieved by a newly developed model-based optimisation strategy. The specific aims of such efforts are to assure quality of cut right up to pre-cut sections and boundaries, which are inherent in intricate part programs. Such boundaries frustrate heat transfer and result in bulk heating of the workpiece. This in turn leads to a degrad...

The paper presents results of an analysis of acoustic emission (AE) measurement in laser cutting of a DC04 steel plate. Laser cutting was evaluated on the basis of monitoring the acoustic emission in the course of cutting and of an analysis of events occurring in the material after the completion of laser cutting. It was found that the cutting oxygen flow was the primary source of AE in laser c...

Chatter vibrations, occurring during cutting process, cause vibration between the cutting tool and workpiece, which deteriorates surface roughness and reduces tool life. The purpose of this study is to investigate the influence of cutting parameters and tool construction on surface roughness and vibration in turning of aluminum alloy AA2024. A new design of cutting tool is proposed, which is fi...

High speed machining of hardened steels for manufacturing dies and molds offers various advantages, but the productivity often limited by mainly tool life. This study investigates the influence of edge preparation in cubic boron nitrite (CBN) cutting tools on process parameters and tool performance by utilizing practical finite element (FE) simulations and high speed orthogonal cutting tests. T...

Introduction: A bullet type sampler is sometimes used to obtain a sample from an asteroid on samplereturn missions [1]. On the other hand, in-situ analysis is demanded for the investigation of more amount of rock samples. Many drilling or coring devices have been developed [2-5]. Slicing the rock sample is preferable to observe its interior rather than shaving [6]. Because coolant cannot use in...

* Corresponding author – [email protected] Tel: 414-229-4126 Fax:414-229-6958 ABSTRACT Understanding the fundamental tribology associated with the cutting of rock under extremely high pressure and high temperature (HPHT) conditions are extremely important in mining and drilling operations. In this paper, a rock fragmentation process is simulated during mechanical cutting of rock using an explicit...

Residual stresses in a surface layer determine many exploitation characteristics of machined surface. Depending on their kind and the type of applied loading, the influence of residual stresses can be negative or positive. Tensile residual stresses usually exert highly detrimental impact on several functional aspects such as strength, fatigue life, corrosion, wear resistance, etc., whereas comp...