Friction properties of fluorinated carbons

In boundary lubrication regime, friction reduction and antiwear processes are associated to the presence of additives in the lubricating oils or greases. These processes are due to the formation of protective tribofilms resulting from chemical reactions between the additives and the sliding surfaces, in the physico-chemical conditions of the sliding contact. Conventional antiwear additives mainly consist of transition metal organo phosphate or thiophosphates which present a remarkable efficiency in the case of contacts between ferrous alloys. In the case of non reacting surfaces, these additives become inactive. Recently developped lubrication strategies consist in the use of dispersion in oils of nano additives able to build the protective tribofilm in the sliding contact without reaction with the surfaces. Carbon fluorinated phases, due to their lamellar structure and their high chemical stability even at relatively high temperature (400°C) represent interesting candidates as lubricant nano-additives subjected to present friction reduction, anti wear and anti corrosion actions. This work presents the tribologic behaviour of some carbon fluorinated derivatives such as graphite fluorides, fluorinated carbon nanofibers, fluorinated carbon nanodiscs and fluorinated carbon blacks. The influence, on the tribologic performances, of the structure of the initial carbon phases, of the fluorination rate (0<F/C<1) and the structure of the fluorinated compounds is discussed

A note on the conservation characteristics of baled grass silages ensiled with different additives.

peer-reviewedThe effects of contrasting conventional silage additives on chemical composition, aerobic stability and deterioration, and mould development in baled silage were investigated. Herbage from a grassland sward was wilted for 24 h and treated with acid (formic or sulphuric), sugar (molasses), bacterial (Lactobacillus plantarum, L. plantarum + Serratia rubidaea + Bacillus subtilis, or L. buchneri) or sugar + bacterial (molasses + L. plantarum) additives prior to baling and wrapping. Silage made without an additive preserved well and had a low incidence of mould growth, and the effects of additives were minor or absent. It is concluded that little practical benefit was realised when conventional additives were applied to wilted, leafy, easy-to-ensile grass prior to baling and ensilage

Resin additive improves performance of high-temperature hydrocarbon lubricants

Paraffinic resins, in high temperature applications, improve strength of thin lubricant film in Hertzian contacts even though they do not increase bulk oil viscosity. Use of resin circumvents corrosivity and high volatility problems inherent with many chemical additives

Study Of Food And Energy Values Of New Gingerbread Types

The article deals with directions of the increase of the food value and decrease of the energetic value of gingerbread products. The results of the studies of the chemical composition of gingerbread products with food additives and changes in their composition were considered.The perspective of the use of vegetable additives in gingerbread technologies was substantiated on the base of the analysis and generalization of theoretical, experimental data and production studies, and the possibility of their use was proved.The use of food additives gives the possibility to raise the food and biological value, to widen the assortment of gingerbread products with prognosticated quality parameters, to form new consumption properties of a product to use the food potential of vegetable additives more full. It was proved, that new types of gingerbread products with vegetable additives have advantages over traditional ones.New types of gingerbread products has the balanced chemical composition, low energetic value, decreased content of sugar and saturated fatty acids and increased content of healthy ingredients of the functional and prophylactic destination.The addition of vegetable additives in the recipe of flour confectionary products leads to the increase of its food value at the expanse of protein quantity, change of food acids ratio in favor of unsaturated ones, enrichment with mineral substances and vitamins

Consumer Values of Health-Related Food Symbols and Chemical Food Additives - The Case of Breakfast Cereals

In this paper we analyze consumers’ revealed values of food symbols indicating nutritious and organic food, as well as consumers’ revealed values for chemical food additives. We do so by estimating a hedonic price function based on a rich data set on breakfast cereal purchases. Our findings suggest that consumers positively value chemical food additives in breakfast cereals, suggesting that the positive taste effect from e.g. chemical taste enhancers, emulsifiers, colourings and preservatives outweighs consumers’ health concerns regarding such additives. We find no evidence that consumers positively value the symbol indicating nutritious food. In addition, surprisingly enough, our results imply that consumers have a negative willingness-to-pay for the symbol indicating organic food.consumer economics; hedonic pricing; food labelling; food additives

Fire safety of steel wall systems using enhanced plasterboards

Fire safety design is important to eliminate the loss of property and lives during fire events. Gypsum plasterboard is widely used as a fire safety material in the building industry all over the world. It contains gypsum (CaSO4.2H2O) and Calcium Carbonate (CaCO3) and most importantly free and chemically bound water in its crystal structure. The dehydration of the gypsum and the decomposition of Calcium Carbonate absorb heat, which gives the gypsum plasterboard fire resistant qualities. Currently plasterboard manufacturers use additives such as vermiculite to overcome shrinkage of gypsum core and glass fibre to bridge shrinkage cracks and enhance the integrity of board during calcination and after the loss of paper facings in fires. Past research has also attempted to reduce the thermal conductivity of plasterboards using fillers. However, no research has been undertaken to enhance the specific heat of plasterboard and the points of dehydration using chemical additives and fillers. Hence detailed experimental studies of powdered samples of plasterboard mixed with chemical additives and fillers in varying proportions were conducted. These tests showed the enhancement of specific heat of plasterboard. Numerical models were also developed to investigate the thermal performance of enhanced plasterboards under standard fire conditions. The results showed that the use of these enhanced plasterboards in steel wall systems can significantly improve their fire performance. This paper presents the details of this research and the results that can be used to enhance the fire safety of steel wall systems commonly used in buildings

Development of New Crispy Breads with the Inclusion of Vegetable Additives and Evaluation of Their Quality

Spelt-based crispy breads with the inclusion of herbal supplements (powders of milk thistle, mountain ash, wild rose and green tea extract) and the results of assessing the quality of new products by organoleptic and physico-chemical indicators are presented. For a tasting evaluation, a point scale has been developed for the organoleptic evaluation of sugary-grain crispy breads. On the basis of which the organoleptic analysis of crispy breads, enriched with herbal supplements, has been carried out It is established that the introduction of vegetable additives in the composition of crispy bread leads to an improvement in the organoleptic characteristics of finished products. These products are characterized by a crispy, porous structure, an attractive light cream color, a harmonious taste, a pronounced smell of used additives. According to the results of the tasting evaluation, samples enriched with herbal supplements received the highest score in relation to the control sample, which meets the requirements of potential consumers. On the basis of physico-chemical indicators, it has been established that the introduction of grain additives to crispy breads does not impair the physic-chemical properties of these products.On the basis of the obtained data, the expediency of the production of new spelt-based crispy breads with the inclusion of enriching additives with improved organoleptic properties is substantiated

The effects of carboxylic acids in aluminum anodizing

Hard-anodized alumina coatings were formed in sulfuric acid at low temperature and high current density in the presence of carboxylic acid additives. Citric acid, trimesic acid, mellitic acid and ethylenediaminetetraacetic acid (EDTA) were utilized in varying concentrations. The additives were chosen for their capacity to form complexes with tri-valent aluminum and hence impart chemical stability to the coatings. The coatings were sealed in boiling water, and corrosion resistance was observed in a high pH solution of potassium hydroxide. The coatings were examined using scanning electron microscopy (SEM) to assess coating thickness and pore dimensions. Thicker coatings were produced when the additive inhibited oxide coating dissolution, increasing corrosion resistance. Overall, carboxylic acid additives showed a positive impact on corrosion resistance when coupled with sealants. More research in this field could improve products used in cleaning and cooking environments to withstand conditions of high and low pH

The Study of Influence of Aronia Additives on Functional-technological Properties of Wheat Flour

The expedience of the use of aronia in technology of short dough products as a source of vitamins, mineral, pectin substances, phenol compounds, easily assimilated sugars, organic acids and so on was substantiated. To study the influence of aronia additives on the main receipt component of short dough (wheat flour) there was elaborated an algorithm of the study that includes theoretical analysis and physical-chemical experiment. The expedience of introduction of aronia as a powder directly into wheat flour was theoretically grounded. The methods of estimation of the content of polyphenol compounds, influence of aronia additives on amylolytic and proteolytic activity of wheat flour, its sugar-creating ability, were selected. The methods of experiment planning and mathematical processing of experimental data were realized using computer program MS Excel 97 2003.In was established, that the aronia additive weakens the gluten of wheat flour and prevents the swelling of gluten proteins. It positively influences the process of short dough formation and provides a possibility of its storage during the long time until baking. The use of aronia additives in technology of short dough products allows not only raise their food value but also improve the quality of short dough