Thermal insulation of wet shielded metal arc welds
Thesis (Nav. E.)--Massachusetts Institute of Technology, Dept. of Ocean Engineering, 1994, and Thesis (M.S.)--Massachusetts Institute of Technology, Dept. of Materials Sciences & Engineering, 1994.
Zastosowanie izolacji cieplnej przy wykonywaniu złączy w warunkach spawania izobarycznego
Artykul dotyczy badan nad zastosowaniem izolacji cieplnej jako metody ograniczenia chlodzącego wplywu wody, na spawalnośc stali o podwyzszonej wytrzymalości. Wykazano, ze odizolowanie plyty spawanej w warunkach izobarycznych od wody warstwą izolatora w postaci styropianu, powoduje znaczący spadek twardości maksymalnej badanych zlączy ze spoiną czolową i pachwinową. Wskazano kierunki dalszych badan, ktore mogą przyczynic sie do poprawy spawalności stali spawanej w rozpatrywanych warunkach.  Application of thermal insulation for carrying out welded joints under isobaric welding conditions  The article concerns investigations on the application of thermal insulation as a method of limitation of cooling effect of water on weldability of high strength steel. It was found that under isobaric conditions, isolation of welded plate from water by a layer of styrofoam results the significant reduction of maximum hardness of examined welded joints for both, butt and fillet welds. Directions of future researches, which can contribute to improvement of weldability of steel welded in considered conditions were indicated.
Novel polymeric hydrogel composites: Synthesis, physicochemical, mechanical and biocompatible properties
In this research study, novel hydrogel composite films were constructed using different ratios of poly (vinyl alcohol) (PVA)/kappa-carrageenan (KC) (PVA90/KC10%, PVA80/KC20%, PVA70/KC30%, PVA60/KC40%) crosslinked with glutaraldehyde (0.025%) and investigated their physicochemical characteristics such as mechanical, thermal, morphological, swelling behaviour, and cell viability. SEM and FTIR revealed that surface morphology changed to heterogeneous and the presence of molecular interaction among the polymers. PVA90KC10 and PVA60KC40 exhibited smaller and larger pores on surface respectively. The change in the proportion of PVA and KC also triggered the tensile strength (Ts) of the film and the highest Ts observed were 21.60 MPa for PVA60KC40. Moreover, the thermal analysis showed three-phase degradation, and an increase in KC40 concentration results inversely proportional to a decrease in the rate of thermal degradation. Further, swelling and in-vitro biodegradation study confirmed the enhanced perseverance of water uptake for PVA60KC40 (286%) due to pores structure of the hydrogel film and PVA and KC alone degraded faster as compare to other films results suggested higher concentration of PVA90KC10 showed lower degradation rate and highest for PVA60KC40 about 6% and 22% respectively. Further, the cell viability was studied with MTT assay method by using NIH3T3 and HEK-293 cells for biocompatibility study revealed NIH3T3 cells were more biocompatible than HEK-293 and cell viability percent for PVA60KC40 showed the highest cell attachment about 99%. Overall corroborating data obtained from the study attested to the average swelling, appreciable mechanical characters, good interaction between molecules, and cell viability of the constructed PVA/KC hydrogel film, these all characters pave to be used as a potential template for biomedical applications such as tissue engineering and drug delivery.