The present paper studied the chemical composition of recent and historical oak wood comparing the extractive, holocellulose, α-cellulose, lignin, and ash contents. Comprehensive knowledge of the chemical components in recent and historical oak wood will facilitate the use of conservation agent in the restoration and conservation process of the investigated artifacts. The cyclohexane–ethanol extract of historical oak wood was significantly lower compared to recent wood, which can be explained by the leaching of extractives into the soil. No significant differences in the holocellulose and α-cellulose content of recent and historical oak wood were found. The lignin and the ash contents were significantly higher in the historical samples. The EDX analysis of the ash of historical oak wood showed remarkably higher iron content compared to the recent material. The result indicated the degradation of hemicelluloses in the historical sample. The significant difference in the amount of ash between the samples was explained by sediment materials that have been introduced into the wood from the soil. SEM imaging made these materials clearly visible as depositions in the cell lumens.

The context of the COVID-19 pandemic required the implementation of special measures to ensure the continuity and quality of teaching in higher education. The study presented here aims to identify the differences of opinion between the age categories of students in the first year of the Faculty of Physical Education and Sports in Galati, Romania, regarding teaching, learning and assessment activities on online platforms. A total of 147 students divided into three age groups (under 20 years, 20–30 years and over 30 years) filled out a questionnaire composed of items with closed and free answers, structured on four factors (attractiveness, accessibility, motivation and efficiency), after participating in the online teaching and evaluation act during the first semester of the academic year 2020–2021. Multivariate and univariate tests were applied, identifying the influence of the independent age variable on the dependent variables (aspects measured by the items of the questionnaire). Values were obtained at significant thresholds of F for some of the investigated aspects: boredom induced by online activities, stress value, participation, involvement, motivation and adaptation to the online program, usefulness and quality of teaching process, value of professional training and involvement in disruptive activities. The analysis of the differences between the average scores of the items for the pairs formed by age categories highlighted insignificant values between those under 20 and those aged 20–30, but multiple significant differences between the group of those over 30 and the other two groups. The centralization of free answers by environment (rural and urban) identified the advantages perceived by the students about the online activities (increasing the amount of free time, low financial costs, high accessibility, personal learning pace), the reported disadvantages (technical problems, low concentration, poor socialization) and contradictory proposals to improve activities (continuing online, returning to classical teaching, simplifying the subject, using video materials, involving all students in activities). The paper aims to evaluate the performance of teaching activities performed in the first year of study for the students of physical education and sports, in the context of the COVID-19 pandemic, involving questionnaires validated by the specialty center at the university. The analysis of the results highlighted a series of extremely important aspects that have a role in the future design of activities and courses.

Wood is usually stable under relatively dry conditions but may still undergo slow deterioration. The type of deterioration and how these processes affect the wood are important questions that need consideration if old wooden structures are to be studied and properly preserved. The aim of this paper is to establish the main structural and morphological differences between new and naturally aged European spruce (~ 150–200 years) and silver fir wood (~ 150 years). Naturally aged European spruce (a) was sourced from an outdoor part of a building constructed in the seventeenth century and naturally aged European spruce (b) were obtained from a furniture item located in a historical building from the eighteenth century. The principal age-induced changes in fir are the degradation of C–O and C=O groups in hemicellulose, according to the FTIR analysis. Degradation of cellulose and hemicelluloses was observed for spruce, with a greater effect seen in the indoor aged sample. X-ray photoelectron spectroscopy (XPS) showed that after aging C–C/C–H peaks were smaller in the spruce and fir samples, while C–O and O–C–O peaks were larger. The crystallinity index (CrI) obtained by X-ray diffraction showed that due to weathering the CrI of naturally aged spruce (a) increased compared to the new wood. The CrI of the aged spruce (b) and aged fir was lower than in the new woods. The ratios for the spruce sample, which aged indoors, were higher than those for the one aged outdoors. According to the observations made in this study, hemicellulose and cellulose are easily degraded under environmental conditions.