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The YK 1 shipwreck, found at Yenikapı, Istanbul, is one of 37 shipwrecks dating to the medieval era. This paper describes the studies and the processes which were conducted to conserve the YK 1. Firstly, the level of physical and chemical degradation of the wood from the YK 1 was examined, which revealed that the wood was highly degraded. Therefore, PEG 2000 was chosen for the impregnation process before vacuum freeze-drying. In addition, the ASE values confirmed that the PEG 2000 impregnation and vacuum freeze-drying method together were successful in conserving the YK 1, with values higher than PEG 2000 impregnation and vacuum freeze-drying methods alone. The concentration of the PEG solution in the tank was monitored throughout the impregnation process. Following this, samples taken from the wood cores were analysed using FTIR to evaluate the effectiveness of the impregnation process. Finally, SEM was used to examine the effectiveness of the PEG 2000 impregnation and vacuum freeze-drying method. The SEM images showed that the PEG 2000 was uniformly distributed, and the wood had no deformation after freeze-drying. [ABSTRACT FROM AUTHOR]

Background/Study Context: Older adults exhibit an age-related deficit in item memory as a function of the length of the retention interval, but older adults and young adults usually show roughly equivalent benefits due to the spacing of item repetitions in continuous memory tasks. The current experiment investigates the seemingly paradoxical effects of retention interval and spacing in young and older adults using a continuous recognition memory procedure. Methods: Fifty young adults and 52 older adults gave memory confidence ratings to words that were presented once (P1), twice (P2), or three times (P3), and the effects of the lag length and retention interval were assessed at P2 and at P3, respectively. Results: Response times at P2 were disproportionately longer for older adults than for younger adults as a function of the number of items occurring between P1 and P2, suggestive of age-related loss in item memory. Ratings of confidence in memory responses revealed that older adults remembered fewer items at P2 with a high degree of certainty. Confidence ratings given at P3 suggested that young and older adults derived equivalent benefits from the spacing between P1 and P2. Conclusion: Findings of this study support theoretical accounts that suggest that recursive reminding and/or item retrieval difficulty promote item retention in older adults. [ABSTRACT FROM PUBLISHER]