An ideal surface produced in machining has typical roughness due to these feed marks which can be modeled and quantitatively predicted from the geometry of the cutting tool and its relative path or feed rate. The associated mechanism of surface generation can be termed as deterministic and intrinsic to the process. However the real or practical surface has considerable variation from the ideal ...

BACKGROUND There is concern that, despite the fall in air pollution levels since the 1950s, there may still be adverse effects at current levels. A study was carried out to investigate the association between air pollution and respiratory symptoms in 23 year old subjects in 1981. METHODS Data on cough, phlegm, and wheeze were available on 11,552 members of the 1958 national birth cohort. Coun...

the built up layer thickness in secondary deformation zone is one of the important parameters in metal cutting process. the built up layer (bul) is formed in second deformation zone near the tool-chip interface in the back of the chip. this parameter influences the tool life and machined surface quality. this bul should not be confused with the built up edge (bue). the deformation of the bul in...

& This paper presents a methodology for practical estimation of cutting force and cutting power. Based on a previously proposed definition, the power spent in metal cutting is the summation of four components: the power spent on the plastic deformation of the layer being removed by both major and minor cutting edges, the power spent on the tool-chip interface, the power spent on the tool-workpi...

In this paper, FEM modeling and simulation of orthogonal cutting of AISI 1045 steel is studied by using dynamics explicit Arbirary Lagrangian Eulerian method. The simulation model utilizes the advantages offered by ALE method in simulating plastic flow around the round edge of the cutting tool and eliminates the need for chip separation criteria. JohnsonCook work material model is used for elas...

Black and white plastic rowcovers were established over field-grown ‘Jersey Giant’ asparagus (Asparagus officinalis L.). Spears were cut for 7 weeks. Season soil temperatures were lowest under white plastic and highest without plastic covering. Night air temperature under plastic covers was ≈ 1.4C higher than without plastic covering (control), but day air temperature was typically 10C higher u...

This paper uses quasi-steady molecular statics model and diamond tool to carry out simulation temperature rise of nanoscale orthogonal cutting single-crystal silicon. It further qualitatively analyzes temperature field of silicon workpiece without considering heat transfer and considering heat transfer. This paper supposes that the temperature rise of workpiece is mainly caused by two heat sour...

This study was conducted in perennial alfalfa farm infected by weeds located at Km 7 Hamadan-Tehran road in the spring of 2014 and 2015 in a randomized complete block design with 11 treatments and 4 replications compared with control to investigate the effects of different harvest times of first cutting on the increase or decrease in percentage of dry weight of weeds and also alfalfa in second ...