One main drawback of electrical discharge machining (EDM) is related to the dielectric fluid, since it impacts both the environment and operator health and safety. To resolve these issues, recent research has demonstrated the technical feasibility and qualitative performance of vegetable oils as substitutes for hydrocarbon-based dielectric and synthetic oils in EDM. However, due to the higher content of unsaturated fatty acids, vegetable oils lose their stability, due to several factors such as heating or exposure to light or oxygen. The present study is a first attempt to analyze the extent to which the physic-chemical properties of vegetable oils change during EDM processing. Refractive index, dynamic viscosity and spectra analyses were conducted for sunflower and soybean oils. The results revealed that, under the applied processing conditions, no structural changes occurred. These findings are very promising from the perspective of EDM sustainability.

The present paper presents our attempts concerning the development of an extraction method for catecholamines. In order to achieve the extraction of all the selected solutes using a single SPE cartridge, several types of support were tested, among them: cation exchange supports, hydrophilic-lipophilic supports, C18 supports and PGC supports. As unfortunately none of the supports tested offered us the possibility of carrying out the extraction of 12 catecholamines from our standard mixture, we chose to use a coupling of two different cartridges: Oasis HLB and PGC which together ensure the extraction of all the compounds of the mixture with good extraction yields and with simple protocols. The selected cartridges were successfully tested for the extraction of a sample spiked from sheep brain with the 12 catecholamines in our mixture. The SPE method that we have developed allows the purification of the samples (a significant part of the components of the matrix is eliminated during this step) and also a preconcentration of the samples.

The aim of the paper is to present the actual state of techniques regarding the influence of cryogenic cooling in turning and milling process. Processing some materials is impossible without cooling the tool or the processed material. Hard-to-cut materials are increasingly used in industry, so new methods of cooling these materials had to be researched. Cryogenic cooling is the most efficient method to cool down the turning, milling or cutting tools. There are a lot of materials that are not affected by the low temperature of the liquid nitrogen (LN2), on the contrary, they behave better and have better proprieties after being cooled with LN2. On the other hand, there are materials that do not behave very well after cooling them with LN2 because their properties are changed, but with the right equipment, the amount of cooling liquid can be controlled, so that the temperature could be maintained at an optimal level. This paper highlights the advantages of the cryogenic cooling systems compared to the classic cooling systems (cooling and lubricating in the same time) industrially used.

This paper presents the optimization of a hydrophilic interaction chromatographic method for the separation of eleven catecholamines, indolamines and their precursors and metabolites. The studied parameters are: the organic modifier nature and percentage, the salt nature and concentration, the mobile phase pH and the column temperature. The best results in terms of separation were obtained using a mobile phase composed of acetonitrile and ammonium formate (150 mM pH 3) 85:15 v:v.