Fruit and vegetables constitute an essential part of human diet and that is why they should be “safe”.
Chemical contaminants of plant origin in food, including the pesticide residues, are defined as critical differentiators of quality and food safety. Pesticide residues are found in fruits, vegetables, cereals and herbs chemically
protected at low concentrations, but they are one of the elements that affect the quality of healthcare.
The aim of this study was to assess the pesticide residues in apples from the north-eastern Poland (Lubelskie,
Podlaskie and Warmińsko-Mazurskie provinces) and get an answer whether any contamination in fruit from the
region is similar to that in other countries and whether it can lead to exposure of consumer’s health. Also assessed compliance of used pesticides with applicable law and found residues were compared with the Maximum
Residue Levels (MRLs). The study showed that 59% of the samples of apples from the north-eastern Poland
contain pesticide residues below the MRL, and 7% above the limits. The estimated dietary intake has shown
the chronic dietary exposure of the most vulnerable groups - children and adults to the pesticide residues in
Polish apples was relatively low and does not constitute a health risk to. The results show that apples from
north-eastern Poland are safe.
Following paper is focused on experimental and numerical studies of the behavior and energy absorption for both: quasi-static and dynamic axial crushing of thin-walled cylindrical tubes filled with foam. The experiments were conducted on single walled and double walled tubes. Unfilled profiles were compared with tubes filled with various density polyurethane foam. All experiments were done in order to possibility of the safety of the elements absorbing collision energy which can applied in car body. The dynamic nonlinear simulations were carried out by means of PAM-CRASH™ explicit code, which is dedicated calculation package to modelling of crush. Computational crushing force, plastic hinges locations and specimens post-crushed geometry found to be convergent with the real experiments results. Conducted experiments allowed to draw conclusion, that crashworthiness ability is directly proportional to foam density. The investigation of the experimental data revealed, that double walled tubes have greater energy absorbing ability. A proposed investigation enable to analyze and chosen of optimal parameters of these elements, which can use in automotive industry as an absorption energy components.
The paper covers the research on the process of solutionizing of 7075 aluminum alloy in cold tools during the stamping of a high-strength structural element (B-pillar’s base). For technological reasons, in order to obtain high strength parameters of the 7075 alloy, it is necessary to carry out a solutionization process, which allows to obtain dispersion strengthening during ageing process. Properly performed heat treatment of the alloy increases the strength of the material to approx. 600 MPa. The combination of the process of solutionization with simultaneous shaping is aimed at improving and simplifying technological operations of aluminum alloy stamping, shortening the duration of the manufacturing process and reducing production costs. The manufactured lower part of the B-pillar will be used for the verification of the validity of the developed method. During the experiment, a series of stamping tests were carried out, in which the lubricants, pressure and position of the upper and lower blankholders were the variables. The obtained results allow to estimate the influence of the cooling conditions on the strength of the drawpieces obtained after the process of artificial ageing. In order to verify and analyse the results more quickly, a numerical simulation was carried out.