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Abstract Natural yellow plant dyes and traditional medicines were used widely on historical papers in ancient China for religious reasons and conservation considerations. This study aims to evaluate some traditional yellow botanical sources of dyes that contain different chemical colorant compositions in order to understand their effects on the properties of traditional handmade paper. The physical and chemical changes in paper specimens treated with plant dyes were studied by examining properties such as the color, pH, thermogravimetric (TG) characteristics, tensile strength, folding endurance and microstructure by scanning electron microscopy (SEM). The results indicated that different colorants had different toning effects and that the main components, including carboxyl and ketone groups, could affect the paper stability at high temperatures. The results also revealed that the mechanical properties of paper specimens were improved after treatment with plant dyes. The significant improvements in the tensile strength and folding endurance and the slightly higher decomposition temperature of Amur cork tree-dyed paper could be ascribed to the strong interaction between the colorants’ main components and the fibers. The scientific evaluation of the property changes is therefore valuable information for weighing the advantages and disadvantages of the various yellow toning materials for paper conservation treatment.

Natural yellow plant dyes and traditional medicines were used widely on historical papers in ancient China for religious reasons and conservation considerations. This study aims to evaluate some traditional yellow botanical sources of dyes that contain different chemical colorant compositions in order to understand their effects on the properties of traditional handmade paper. The physical and chemical changes in paper specimens treated with plant dyes were studied by examining properties such as the color, pH, thermogravimetric (TG) characteristics, tensile strength, folding endurance and microstructure by scanning electron microscopy (SEM). The results indicated that different colorants had different toning effects and that the main components, including carboxyl and ketone groups, could affect the paper stability at high temperatures. The results also revealed that the mechanical properties of paper specimens were improved after treatment with plant dyes. The significant improvements in the tensile strength and folding endurance and the slightly higher decomposition temperature of Amur cork tree-dyed paper could be ascribed to the strong interaction between the colorants' main components and the fibers. The scientific evaluation of the property changes is therefore valuable information for weighing the advantages and disadvantages of the various yellow toning materials for paper conservation treatment. [ABSTRACT FROM AUTHOR]

The results of measuring elastic wave velocities in the rock mass of the base of the Inguri HPP dam at minimum and maximum upper pool levels (UPLs) are presented. A substantial difference in the change in longitudinal and transverse wave velocities during a rise of the UPL in the right- and left-bank abutments both in horizontal and vertical sections is established. [ABSTRACT FROM AUTHOR]

The results of research on the consequences of cryopreservation of fungi testifying to stability of their morphology are reviewed, and a number of facts indicating changes in the properties of fungi and the mutagenicity of cryopreservation are presented. The investigations of the last decade confirm Rozanov’s hypothesis that cryopreservation must increase the resource of hereditary variation in the organisms. [ABSTRACT FROM AUTHOR]

This study implements a supercritical CO 2 (scCO 2) sequestration environment in a laboratory and investigates the geochemical effects of scCO 2 on the properties of rock specimens. Shale specimens constituting caprock were kept in a laboratory reactor chamber with scCO 2 for 63 days. Chemical interaction between rock surface and the scCO 2 was then induced, and the changes in the properties were inspected before and after the reaction through various tests. The non-destructive tests comprised measurement of elastic wave velocity, shore hardness followed by investigation using the inductively coupled plasma mass spectrometer, and scanning probe microscope. The destructive tests include uniaxial compressive strength, Brazilian tensile strength, and X-ray fluorescence tests. Results show that mechanical properties are significantly weakened when shale specimens are exposed to both scCO 2 and brine. The specimens reacting with only scCO 2 induced a self-healing effect by precipitation of secondary sediments, becoming a more intact rock with increased strength and elastic modulus. The results denote that the geochemical alteration of shale occurs in a short time and are highly dependent on the reaction conditions. These results provide fundamental information for the stability of CO 2 storage sites regarding the physical and chemical reactions between rocks under geological sequestration conditions. • Geochemical and mechanical changes were analyzed in detail by a series of tests. • The coexistence of brine with scCO 2 has a significant effect on shale properties. • Mechanical properties are severely weakened when brine coexists with scCO 2. • Conversely, the properties are enhanced when reacted only with scCO 2. • Dissolution exceeds precipitation in CO 2 -dissolved brine; and vice versa in scCO 2. [ABSTRACT FROM AUTHOR]