The minimum quantity of lubricant (MQL) technique in the surface grinding of steel

This research aimed to analyze the viability of the minimum quantity of lubricant (MQL) technique towards different methods of lubri-refrigeration in surface grinding of steel, considering process quality, wheel life and the viability of using cutting fluids The proposal methods were the conventional (abundant fluid flow), the minimum quantity lubrication (MQL) and the optimized method with Webster nozzle (rounded) This analysis was carried out in equal machining conditions, through the assessment of variables such as grinding force, surface roughness, G ratio (volume of removed material/volume of wheel wear), and microhardness The results showed the possibility of improvement of the grinding process Besides, there is the opportunity for production of high quality workpieces with lower costs The MQL technique showed efficiency in machining with lower depths of cut The optimized method with Webster nozzle applies the fluid in a rational way, without considerable waste Hence, the results show that industry can rationalize and optimize the application of cutting fluids, avoiding inappropriate disposal, inadequate use and consequently environment pollution

Costs estimates and rentability of the guava culture {psidium guajava l. patuma cv.) in monte alto county, Sao Paulo state

This work intended to calculate the rentability of the guava culture Paluma cv. in Monte Alto region-SP, estimating the costs of the implantation, maintenance, production and the gross income of this culture in the first three years of cultivation. The production system utilized refers to the cultural treatments usually used in this culture in the region. The costs estimates were based on the total operational costs methodology used by the Agricultural Economics Institute (I.E.A.). The results obtained showed that the implantation and maintenance costs of the culture, in the two first years was Rs7.402,31/alqueire. Considering the possibility that in guava orchard, on irrigated conditions, reach in the fourthy year a productivity of 80t/alqueire and that the current price is Rs0,20/kg, it is possible to estimate the gross income around of Rs16.000,00/alqueire, resulting in a net income of Rs9.497,06/alqueire.

The sugar cane vegetal residues unloaded in the sugar mill: Operational costs and physical characteristics

Brazil produced in 2002/03 season 317.87×106tons of sugar cane stalks and 36.88×106tons of vegetal residues (green leaves, dry leaves and tops) in a planted area of 4.61×106 hectares (ha). These residues have a useful heat of 3,613.14Mcal.t-1. Currently most of this biomass is burned as a pre-harvest practice. The doubt persists in the system type that it must be adopted to pick up, load, transport and unload this biomass at the sugar mill boilers. This study analyzed 22 variables related to operational costs and physical characteristics of these residues in a field situation using a JOHN DEERE® 6850 forage harvester with two different treatments: T1 and T2 (two types of rakes) with 6 repetitions each one. The geographic location of the studied area that belongs to COSTA PINTO MILL (COSAN® Group) is: Latitude 22°40'30S and Longitude 47°36'38W. The adopted methodology was proposed by Ripoli et al. (2002). The obtained results at a 5% level of significance showed that both treatments did not differed significantly between them. Some of the results were, where EBP stands for Oil Equivalent Barrel: Windrowing (T1=US$0.17.EBP-1 and US$9.59.ha-1, T2=US$0.08.EBP-1 and US$4.27.ha-1); Pick up (T1=US$1.31.EBP-1 and US$44.29.ha-1, T2 =US$1.37.EBP-1 and US$48.36.ha-1); Transportation (T1=US$1.27.EBP-1 and US$14,30.ha -1, T2=US$1.33.EBP-1 and US$14,80.ha -1), Unloading at the sugar mill (T1=US$0.30.EBP-1 and US$3.39.ha-1, T2=US$0.32.EBP-1 and US$3.51.ha-1); Total (T1=US$3.05.EBP-1 and US$71.57.ha-1, T2=US$3.10.EBP-1 and US$70.94.ha-1). Confronting the obtained data with the ones in the bibliography, this system revealed itself more expensive than the baling system or the integral harvest system using combines.

Spinning reserve opportunity cost in hydroelectric plants

Starting from the deregulated process of the Electric Sector, there was the need to attribute responsibilities to several agents and to elaborate appropriate forms of remuneration of the services rendered by the same. One of the services of great importance within this new electric sector is the Ancillary Services. Among the various types of Ancillary Services, Spinning Reserve is a service necessary for maintaining the integrity of the transmission system from either generation interruptions or load variations. This paper uses the application of the Economic Dispatch theory with the objective of quantifies the availability of Spinning Reserve supply in hydroelectric plants. The proposed methodology utilizes the generating units as well as their efficiencies so as to attend the total demand with the minimum water discharge. The proposed methodology was tested through the data provided by the Água Vermelha Hydroelectric Power Plant. These tests permitted the opportunity cost valuation to the Spinning Reserve supply in hydroelectric plants. © 2005 IEEE.

Sustainable development 20 years on from the earth summit: progress, gaps and strategic guidelines for Latin America and the Caribbean

Includes bibliography

World food price increases and Brazil: an opportunity for everyone?

Includes bibliography.

Economics of climate change in Latin America and the Caribbean: summary 2009

Includes bibliography

Economics of climate change in Latin America and the Caribbean: summary 2010

Spanish version available at the Library

Forum for East Asia-Latin America Cooperation (FEALAC): new biregional trade and investment relations in a changing world economic environment$c

Includes bibliography

India and Latin America and the Caribbean: opportunities and challenges in trade and investment relations

Includes Bibliography

Climate Change and Development in Latin America and the Caribbean. Overview 2009

Includes bibliography

SMEs in the environmental goods and services market: identifying areas of opportunity, policies and instruments: case studies: Argentina, Chile, Colombia and Mexico

Includes bibliography

Biofuels potential in Guyana

Includes bibliography

Contribution of energy services to the Millennium Development Goals and to poverty alleviation in Latin America and the Caribbean: executive summary

Includes bibliography