Many ant species have morphologically distinct worker sub-castes. This presumably increases colony efficiency and is thought to be optimized by natural selection. Optimality arguments are, however, often lacking in detail. In ants, the benefits of having workers in a range of sizes have rarely been explained mechanistically. In Atta leafcutter ants, large workers specialize in defence and also ...

The manufacturing of fitness equipment involves several processes, including the cutting and punching of iron tubes followed by welding. Welding operations produce hazardous gases and particulate matter, which can enter the alveolar, resulting in adverse health effects. This study sought to verify the particle size distribution and exposure concentrations of atmospheric air samples in various w...

The utilization of micro- and ultrafiltration with polymeric membranes for treatment of industrial cutting oil emulsion was investigated. The performance of 14 different membranes with pore sizes in the range of 1-800 nm, representing 8 different materials and varying hydrophobicity, was determined experimentally. Membrane permeances between 1.6 and 939 L m 2 h(-1) bar(-1) have been observed fo...

Parallel to the developments in the technology, a large number of cutting fluids were developed and used. Cutting fluids should contain suitable additions depending on the workpiece to be machined and the machining parameters. Their lubrication effects should be considered at the lower cutting speeds while their cooling effects should be considered at higher cutting speeds. In this study, descr...

The most emerging needs of the modern metal cutting operation are to increase the material removal rate with better surface finish and high machining accuracy. These objectives can be achieved by reducing cutting temperature in the cutting zone. In metal cutting process, high cutting temperature and its detrimental effects are generally reduced by proper selection of process parameters, proper ...

The use of cutting fluid in manufacturing industries has now become more problematic due to environmental pollution and health related problems of employees. Also the minimization of cutting fluid leads to the saving of lubricant cost and cleaning time of machine, tool and work-piece. The concept of minimum Quantity Lubrication (MQL) has come in to practice since a decade ago in order to overco...

The machine to be designed and developed with a view to resolve one ofthe irksome problems of this institute has been facing every year. This institute issurrounded by vast non- fertile land area of about 200 acres, which becomes widelyoccupied by numerous breads of bushes and shrubs during post-rainy season. Due tothis unwanted proliferation of such verdant institute gets abysmal look and that...

Sustainable agriculture can increase the efficiency of resource utilization, provide longer productivity and create a balance in the environment. A field experiment was conducted to study the use of organic and chemical fertilizers on biomass, essential oil content and essential oil yield as well as chemical compositions of Dracocephalum polychaetum Burnm in the first and second cutting. The tr...

A classical example of chatter prone machining is the boring operation. Turning under conditions with high vibrations in the cutting tool deteriorates the surface finish and may cause tool breakage. Severe noise is also a consequence of the high vibration levels in the boring bar. Active control is one possible solution to the noise and vibration problem in boring operations. In boring operatio...