Marin Bica

Biodiesel Production and Sustainability Challenge

Today, energy is an indispensable factor for the developing of the societies and countries. However, most of the energy demand is supplied by fossil fuels which tend to dry up in the next few decades forcing all the authorities to find new alternative sources in order to stabilize their economies. Biodiesel has emerged as an alternative, biodegradable and renewable fuel which can be used in transportation sector without any modifications of internal combustion engines. Biodiesel is analyzed by environmental, social and economic criteria for sustainability analysis. The criteria for biodiesel sustainability are discussed by presenting different indicators, keeping in view the Romanian fuel market and Renewable energy directive. The paper concludes with perspectives and recommendations for biodiesel production and usage in Romania.

On the Cutting Tool and Workpiece Temperature in Turning of Titanium Parts Used in Automotive Industry

Although they have a high cost, titanium and its alloys have begun to be very used in automotive industry, due to the lightweight and high strength. As is known, an important role to increase the tool life and reduce the wear of cutting tool is the temperature during the cutting process. This paper presents the some researches on the cutting tool and workpiece temperature during the turning process of pure titanium.

Study on the Cutting Temperature and Chips Formation during the Milling of Pure Titanium

In this paper some experimental determinations on the temperature during the milling process of pure titanium is conducted, using different cutting conditions. The results are presented as graphical dependencies and also as a screen capture of the values obtained using an adequate technique for temperature of the cutting process. Some pictures of the chips shape captured during milling process of the pure titanium bare are presented.

Study of Emission of a Mono Cylindrical Diesel Engine Fueled with Biodiesel of Palm Oil

The demand of petroleum fuels which affect the air quality requires the use of alternative fuels to decrease the harmful emissions. In all the countries of European Union the biofuel production is stimulated and is a prime political and economic goal. The aim of this research is to evaluate the possibility to use biodiesel of palm oil in diesel engines with special emphasis on CO, CO2, HC and O2 emissions. Various blends of diesel and biodiesel of palm oil were mixed and evaluated on an experimental engine stand developed in the laboratory.

Different Approaches for Determination of Internal Combustion Engines Performances

The automotive industry represents one of the most important segments of the world economy that has to be in a continue development. The latest procedures for determination of an internal combustion engine performance have a big acquisition cost and demand special conditions even if the tested engine has smaller dimensions. The present paper presents other accessible solutions for this matter.

Solid Fuels Behavior Revealed by Thermo-Gravimetric Analysis

Thermogravimetric analysis is also used for the determination of mass composition changes of solid fuels caused by heating processes, coal, and wood or plant debris. Energy characteristics of coal depends on the age of their formation (geological age) and the transformations undergone by organic matter under the influence of geological chemistry (chemical age). Several classification criteria, excluding other problems that may arise in connection with the extraction, preparation and other use than combustion, several classifications have been proposed enabling the sharing of the multitude of solid fuels in groups so that each group members behave similarly during the combustion procedure. Wood and plant debris, combustible wastes, coal, have a heating value depending on their mass composition.

Research on the Processes of Gas-Air Mixtures Formation

The mixtures formation process based only on molecular diffusion proved to be the slowest. The mixing speed is reduced due to the collision of molecules of two or more gases which are subjected to the mixing process. The gases concentrations have an important role in mixture formation. Air is one of the combustion gases in the case of mixing in order to achieve the burning process.