The paper presents achievements in gluing technique in steel and aluminium structures. Adhesives currently in use and available on the market are characterized from the point of view of their mechanical properties. Design rules of adhesive connections and basic methods for their calculations are mentioned. The most significant examples of the applications of those joints in steel as well as aluminium structures are shown.

A complete parametric approach is proposed for the design of the Luenberger type function Kx observers for descriptor linear systems. Based on a complete parametric solution to a class of generalized Sylvester matrix equations, parametric expressions for all the coefficient matrices of the observer are derived. The approach provides all the degrees of design freedom, which can be utilized to achieve some additional design requirements. An illustrative example shows the effect of the proposed approach.

Chemical bonded resin sand mould system has high dimensional accuracy, surface finish and sand mould properties compared to green

sand mould system. The mould cavity prepared under chemical bonded sand mould system must produce sufficient permeability and

hardness to withstand sand drop while pouring molten metal through ladle. The demand for improved values of permeability and mould

hardness depends on systematic study and analysis of influencing variables namely grain fineness number, setting time, percent of resin

and hardener. Try-error experiment methods and analysis were considered impractical in actual foundry practice due to the associated cost.

Experimental matrices of central composite design allow conducting minimum experiments that provide complete insight of the process.

Statistical significance of influencing variables and their interaction were determined to control the process. Analysis of variance

(ANOVA) test was conducted to validate the model statistically. Mathematical equation was derived separately for mould hardness and

permeability, which are expressed as a non-linear function of input variables based on the collected experimental input-output data. The

developed model prediction accuracy for practical usefulness was tested with 10 random experimental conditions. The decision variables

for higher mould hardness and permeability were determined using desirability function approach. The prediction results were found to be

consistent with experimental values.