Continuous development and improvement of the modern disposable diaper is crucial for the optimization of product performance. Several methods are used for evaluation and improvements to sustain high quality diapers being produced. The aim of this thesis was to develop a new test method that follows liquid distribution in real time by combining two pre-existing measurement systems. Rewet is the amount of liquid that returns to the surface of diapers when subjected to pressure. Distribution of absorption material is examined by exposing the product core to radiation. These two measurement systems don’t convey anything about the course of the liquid in the diaper when tested separately. This method development is meant to be beneficial for research and development purposes at SCA, working as a complement to the pre-existing methods being used in the laboratory. The following questions are of interest: • Can the rewet test method be performed on a baby diaper while simultaneously exposing the product core to radiation so the course of the liquid can be followed in real time? • Is the liquid distribution (wet area) affected by different product compositions e.g. SAP or thickness? By modifying the current methods, rewet can be performed inside the x-ray equipment while studying the consistency of absorption material and following the liquid behavior in the product core. The developed method was verified by testing on handmade products with different compositions. The developed method’s rewet value has proved to be equivalent to the one tested outside, showing no significant difference between the two.

<p>Eksperimentalnim istraživanjem u okviru doktorske teze utvrđen je trend promene fizičko-hemijskih parametara: mutnoća, temperatura, provodljivost i pH vode, koncentracija katjona Cd2+, As3+, Hg2+ i Pb2+, ukupnog azota, fosfora i sulfatnog ajona u vodi i sedimentu, na lokalitetu Zapadne Srbije, slivno područje akumulacije Vrutci u 2003/2014. Rezultati istraživačkih aktivnosti predstavljali su osnovu za razvoj regresionog modela kojim se može predvideti koncentracija katjona teških metala u jezerskoj vodi. Primenom klaster analize, dendograma i PCA analize dobijena su tri faktora na osnovu kojih se posmatra uticaj ključnih fizičko-hemijskih parametara na kvalitet vode zatvorenog vodnog tela akumulacije pri čemu su dobijene visoko korespodentne funkcionalne zavisnosti sa realnim podacima u jezeru. Ovakva istraživanja su po prvi put sprovedena za selektovani lokalitet u Srbiji.</p> / <p>Experimental studies in the doctoral thesis established the trend of changes in the physico-chemical parameters: turbidity, temperature, conductivity and pH of the water, the concentration of cations Cd, As, Hg and Pb, total nitrogen, phosphorus and sulphate anion in water and sediment at the site of Western Serbia, the catchment area of the reservoir Vrutci in 2003/2014. Results of research activities constituted the basis for the development of a regression model which can predict the concentration of heavy metal cations in lake water. Cluster analysis, dendograms and PCA (principal component analysis) were resulted by three factors, which could be possible to registre the impact of key physical and chemical parameters on the water quality of the closed lake reservoirs.The obtained results by multivariance analysis has showen the highly correspondent functional dependence with real data in a lake. Such research investigations were for the first time carried out in selected localities in Serbia.</p>