The influence of nanofillers on the properties of dental acrylic composites

W rehabilitacji układu stomatognatycznego dysponujemy szeroką gamą materiałów polimerowych, w tym akrylowych. Częste uszkodzenia płyt protez mogą jednak świadczyć o zbyt małej wytrzymałości mechanicznej tworzyw akrylowych, z których są wykonywane. W pracy omówiono próbę modyfikacji materiału protetycznego Vertex R.S hydrofobizowanym bentonitem/montmorylonitem, w celu poprawy wytrzymałości protezy. Hydrofobizowany bentonit rozpraszano w metakrylanie metylu (MMA) przez sonifikację, a następnie przeprowadzano polimeryzację metodą roztworowo-strąceniową. Przebadano właściwości mechaniczne i optyczne polimerowych kompozytów stomatologicznych zawierających zmodyfikowany montmorylonit.A wide range of polymer materials may be used in the rehabilitation of the stomathognatic system. However, frequent damage of denture plates indicates rather low mechanical strength of acrylic materials. In this article we describe an attempt to modify a prosthetic material Vertex R.S. with hydrophobized bentonite/montmorilonite in order to improve the mechanical strength of the denture. Hydrophobized bentonite was dispersed in methyl methacrylate (MMA) by sonification, and then polymerized by solution - precipitation method. Mechanical and optical properties of the polymer composites containing the modified montmorillonite were evaluated

Importance of catch crops end microelements in potato cultivation

Badania prowadzono w latach 2010-2012, których celem była ocena działania obornika, międzyplonów ścierniskowych (gorczycy białej, grochu siewnego i facelii) oraz mikroelementów w aspekcie wysokości plonu i wybranych cech jakościowych bulw ziemniaka. Stwierdzono, że istotnie najwyższe plony uzyskano z obiektów, na których stosowano obornik lub uprawiano międzyplon peluszki łącznie z mikroelementami. Zawartość białka ogólnego w bulwach ziemniaka, a także jego plon oraz plon skrobi istotnie zależały od wszystkich badanych czynników, a największe ich średnie wartości, za wyjątkiem koncentracji białka ogólnego, uzyskano na obiektach z obornikiem. Wykazano pozytywny aspekt uprawy badanych międzyplonów w przypadku plonów: bulw ziemniaka, skrobi oraz białka ogólnego. Stwierdzono, że uprawa międzyplonów, stosowanie obornika oraz aplikacja mikroelementów wpłynęły istotnie na obniżenie zawartości azotanów (V) w bulwach ziemniaka w porównaniu do ich koncentracji po zastosowaniu nawożenia mineralnego. Istotnie najmniejsze zawartości uzyskano na obiekcie gdzie stosowano obornik i uprawiano międzyplony łącznie z mikroelementami.Due to the shortage of manure due to a reduction of livestock population, the potato cultivation in the form of stubble catch crop is becoming increasingly important, especially on light soils. Therefore, studies were undertaken, which aim was to evaluate the effect of manure, stubble catch crop (white mustard, field pea and phacelia), and the application of microelements in terms of height and selected quality of potato tuber yield. The experiment was conducted at the Research Station Wierzchucinek University of Technology and Life Sciences, in 2010-2012, on a lessive good rye complex. Forecrop was winter wheat, and the tested plant was potato variety 'Bila'. The experiment was a randomized block design in three replications and two-factors, where I factor were the variants of fertilizer: NPK - control, manure 30 t∙ha-1, white mustard catch crop plowing, field pea or phacelia. The second factor was microelements fertilization: without fertilization or application of microelements in the form of Symphony Micro PLUS fertilizer. After the harvest in each year of the study the amount of potato tuber yield was determined and the representative samples were collected in which the content of starch (polarimetrically using Evers method) and total nitrogen (using Kjeldahl method) were determined. Based on the obtained results, the protein content and yield of starch and protein were determined. The obtained results were analyzed statistically. In addition, the relationships between the nitrates(V) content and the studied qualitative characteristics of potato tubers were studied. Correlation coefficients were calculated using MS Excel 2002 software. It was found that the use of mineral fertilizers, manure, and crop stubble catch crop (white mustard, phacelia, field pea) and the application of microelements, significantly determined the potato tuber yield. Indeed, the highest yields were obtained from facilities where manure was applied or field pea catch crop grown together with microelements. The content of protein in potato tubers as well as the yield and the yield of depended starch significantly on all the tested agents and their average maximum value, except for the concentration of total protein, were obtained on objects where manure application. It has been demonstrated the positive aspect of the studied catch crop on the yield of potato tubers, starch and total protein, which were generally significantly higher on average, compared to the values obtained from the objects where mineral fertilization was used. It was found that the catch crop, manure and microelements application have significant impact on the reduction of nitrate(V) in potato tubers compared to its concentration found after the mineral fertilizers (control) application. Indeed, the lowest contents were obtained on a object where the manure was applied and catch crop were grown together with microelements