Exploratory data analysis on the Upper-Tisza section using single and multi-variate data analysis methods

Abstract The River Tisza is one of Central Europe's most important rivers. In the last one and a half century numerous anthropogenic activities have influenced its watershed. As a result measures need to be taken to protect its water quality, necessitating a comprehensive picture of the spatial and temporal variability of its processes, which this study aims to extend further. In this study five sampling locations were analyzed in the upper section of the Tisza over the time interval 1974–2005, dealing with 24 parameters using multi-variate data analysis methods. Employing time series analysis and taking the river's tributaries into account, the strong influence of the River Szamos was pointed out, while stochastic connections indicated the influence of the Tiszalök Water Barrage System on the spatial variation of the Tisza's processes. Finally, by using principal component analysis (PCA), the different background factors were revealed in space and time (seasonal separation) as well. During summer the processes tended to be nitrogen-related, while during winter inorganic compounds play a greater role. Most importantly, spatial variety was observable in the factors

Effect of temperature and plasticizer content of polypropylene and polylactic acid on migration kinetics into isooctane and 95 v/v% ethanol as alternative fatty food simulants

Plasticizers are commonly used plastic additives. Deep understanding of their effect on the migration of other substances is essential, especially for food contact materials. The migration kinetics of four stabilizer-type additives from polypropylene (PP) and polylactic acid (PLA) with different tributyl acetyl citrate plasticizer content were investigated. The results confirm that the presence of plasticizer in the plastics enhances swelling, and thus the migration of additives. The plasticizer content is in strong correlation with migration rate for all additives, except for PLA-Irgafos 168 samples. Migration kinetic experiments conducted at different contact temperatures showed that the role of temperature apparently exceeds that of plasticization. Nevertheless, hierarchical cluster analysis revealed similarity in the migration mechanisms of stabilizers from plastics with low plasticizer content at high temperature, to that at low temperature from plastics with high plasticizer content

Borravalóadási szokások Magyarországon = Tipping habits in Hungary

Célunk a magyar fogyasztók borravalóadási szokásainak vizsgálata, különös tekintettel a nők és férfiak borravalóadási különbségeire. A primer kutatás során csaknem 500 személyt kérdeztünk meg. Legfőbb eredményeink szerint a jövedelmi helyzet és a borravaló nagysága mindkét nem esetében negatív korrelációban van egymással. A leginkább adott borravaló mértéke 5-10% között van. A fogyasztók borravalóadási hajlandóságát elsősorban a társadalmi elvárások (a szokásjog és jó színben feltűnni egy társaságban) határozzák meg. | Our aim is to examine the tipping habits of Hungarian consumers, with a special focus on the differences between men and women. Almost 500 people were surveyed in the primary research. Our main results show a negative correlation between income status and tip size for both sexes. The most common tipping rates are between 5-10%. Consumers' propensity to tip is primarily determined by social expectations (customary law and make a good impression on a group of friends)