scholarly journals A new method for the conservation of ancient colored paintings on ramie textiles

2021 ◽  
Vol 9 (1) ◽  
Author(s):  
Jiaojiao Liu ◽  
Yuhu Li ◽  
Daodao Hu ◽  
Huiping Xing ◽  
Xiaolian Chao ◽  
...  

AbstractTextiles are valuable cultural heritage items that are susceptible to several degradation processes due to their sensitive nature, such as the case of ancient ma colored-paintings. Therefore, it is important to take measures to protect the precious ma artifacts. Generally, ″ma″ includes ramie, hemp, flax, oil flax, kenaf, jute, and so on. In this paper, an examination and analysis of a painted ma textile were the first step in proposing an appropriate conservation treatment. Standard fiber and light microscopy were used to identify the fiber type of the painted ma textile. Moreover, custom-made reinforcement materials and technology were introduced with the principles of compatibility, durability and reversibility. The properties of tensile strength, aging resistance and color alteration of the new material to be added were studied before and after dry heat aging, wet heat aging and UV light aging. After systematic examination and evaluation of the painted ma textile and reinforcement materials, the optimal conservation treatment was established, and exhibition method was established. Our work presents a new method for the conservation of ancient Chinese painted ramie textiles that would promote the protection of these valuable artifacts.

2021 ◽  
Author(s):  
Jiaojiao Liu ◽  
Yuhu Li ◽  
Daodao Hu ◽  
Huiping Xing ◽  
Xiaolian Cao ◽  
...  

Abstract Textiles are valuable cultural heritage items that are susceptible to several degradation processes due to their sensitive nature, such as the case of ancient ma colored-paintings. Therefore, it is important to take measures to protect the precious ma artifacts. Generally, ″ma″ includes ramie, hemp, flax, oil flax, kenaf, jute, and so on. In this paper, an examination and analysis of a painted ma textile were the first step in proposing an appropriate conservation treatment. Standard fiber and light microscopy were used to identify the fiber type of the painted ma textile. Moreover, custom-made reinforcement materials and technology were introduced with the principles of compatibility, durability and reversibility. The properties of tensile strength, aging resistance and color alteration of the new material to be added were studied before and after dry heat aging, wet heat aging and UV light aging. After systematic examination and evaluation of the painted ma textile and reinforcement materials, the optimal conservation treatment was established, and exhibition method was established. Our work presents a new method for the conservation of ancient Chinese painted ramie textiles that would promote the protection of these valuable artifacts.


2020 ◽  
Author(s):  
Jiaojiao Liu ◽  
Yuhu Li ◽  
Huiping Xing ◽  
Daodao Hu ◽  
Xiaolian Chao ◽  
...  

Abstract As a kind of textile, hemp artifact is a valuable cultural heritage. Suffering from several degradation factors in the preservation of cultural relics, some ancient hemp colored-paintings have been damaged, further affected their ornamental values. Therefore, it is urged to take the suitable conservation measures to protect the precious hemp artifacts for the historical culture succession. In this paper, an examination and analysis of the hemp colored paintings were the first step to propose an appropriate conservation treatment. Ultra-depth-of-field microscope was used to identify the kinds of fiber, and scanning electron microscope (SEM) was utilized to observe their condition and surface morphology. The element distribution and composition were identified by SEM, energy disperse spectroscopy (EDS) and X-ray fluorescence spectroscopy (XRF). Gas chromatography-mass spectrometer (GC-MS) was applied to identify the kinds of binding media and amino acid composition. Moreover, novel reinforcement materials and technology were proposed with the principle of compatibility and feasibility. The properties of tensile strength, aging resistance and chromatic aberration were tested before and after dry heat aging, wet heat aging and UV light aging. After systematic examination and evaluation of the hemp colored paintings and reinforcement materials, the optimal conservation treatment was finally established, and the Chinese hemp painting as an example has been protected successfully. This paper provides new methods and ideas for the restoration and protection of the linen cultural relics, which would promote the progress of protecting valuable cultural heritages.


2020 ◽  
Vol 90 (5-6) ◽  
pp. 439-447 ◽  
Author(s):  
Andrew Hadinata Lie ◽  
Maria V Chandra-Hioe ◽  
Jayashree Arcot

Abstract. The stability of B12 vitamers is affected by interaction with other water-soluble vitamins, UV light, heat, and pH. This study compared the degradation losses in cyanocobalamin, hydroxocobalamin and methylcobalamin due to the physicochemical exposure before and after the addition of sorbitol. The degradation losses of cyanocobalamin in the presence of increasing concentrations of thiamin and niacin ranged between 6%-13% and added sorbitol significantly prevented the loss of cyanocobalamin (p<0.05). Hydroxocobalamin and methylcobalamin exhibited degradation losses ranging from 24%–26% and 48%–76%, respectively; added sorbitol significantly minimised the loss to 10% and 20%, respectively (p < 0.05). Methylcobalamin was the most susceptible to degradation when co-existing with ascorbic acid, followed by hydroxocobalamin and cyanocobalamin. The presence of ascorbic acid caused the greatest degradation loss in methylcobalamin (70%-76%), which was minimised to 16% with added sorbitol (p < 0.05). Heat exposure (100 °C, 60 minutes) caused a greater loss of cyanocobalamin (38%) than UV exposure (4%). However, degradation losses in hydroxocobalamin and methylcobalamin due to UV and heat exposures were comparable (>30%). At pH 3, methylcobalamin was the most unstable showing 79% degradation loss, which was down to 12% after sorbitol was added (p < 0.05). The losses of cyanocobalamin at pH 3 and pH 9 (~15%) were prevented by adding sorbitol. Addition of sorbitol to hydroxocobalamin at pH 3 and pH 9 reduced the loss by only 6%. The results showed that cyanocobalamin was the most stable, followed by hydroxocobalamin and methylcobalamin. Added sorbitol was sufficient to significantly enhance the stability of cobalamins against degradative agents and conditions.


1964 ◽  
Vol 12 (01) ◽  
pp. 119-125 ◽  
Author(s):  
Y Shamash ◽  
A Rimon

SummaryA new method for the assay of plasmin inhibitors in human plasma is described. The method consists of determination of the caseinolytic activity of a standard plasmin solution before and after incubation with the inhibitor, with lysine added to the mixture as a stabilizer of plasmin. Using this method, it was found that plasma contains enough inhibitors to inactivate 30 caseinolytic units of plasmin, or 10 times the normal amount of plasminogen in human plasma.


2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Javier Caviedes-Bucheli ◽  
Nestor Rios-Osorio ◽  
Diana Usme ◽  
Cristian Jimenez ◽  
Adriana Pinzon ◽  
...  

Abstract Background The purpose of this study was to evaluate the changes in canal volume after root canal preparation in vivo with 3 different single-file techniques (Reciproc-Blue®, WaveOne-Gold® and XP-EndoShaper®), with a new method using CBCT and 3D reconstruction. Methods In this prospective study, thirty human lower premolars from healthy patients were used, in which extraction was indicated for orthodontic reasons. All the teeth used were caries- and restoration-free with complete root development, without signs of periodontal disease or traumatic occlusion, and with only one straight canal (up to 25º curvature). Teeth were randomly divided into three different groups: Reciproc-Blue, WaveOne-Gold and XP-EndoShaper. CBCT scans before root canal preparation were used to create a 3D reconstruction with RHINOCEROS 5.0 software to assess the initial canal volume, and then compared with 3D reconstructions after canal preparation to measure the increase in canal volume. Student’s t test for paired data were used to determine statistically significant differences between the before and after canal volumes. Anova test was used to determine statistically significant differences in the percentage of canal volume increase between the groups and Tukey's post-hoc test were used to paired comparison. Results Reciproc-Blue showed the higher increase in canal volume, followed by WaveOne-Gold and XP-EndoShaper (p = 0.003). XP-EndoShaper did not show a statistically significant increase in canal volume after root canal preparation (p = 0.06). Conclusion With this model, Reciproc-Blue showed higher increase in root canal volume, followed by WaveOne-Gold, while XP-EndoShaper did not significantly increase root canal volume during preparation.


Forests ◽  
2021 ◽  
Vol 12 (5) ◽  
pp. 567
Author(s):  
Hong Yang ◽  
Mingyu Gao ◽  
Jinxin Wang ◽  
Hongbo Mu ◽  
Dawei Qi

In the absence of high-quality hardwood timber resources, we have gradually turned our attention from natural forests to planted fast-growing forests. However, fast-growing tree timber in general has defects such as low wood density, loose texture, and poor mechanical properties. Therefore, improving the performance of wood through efficient and rapid technological processes and increasing the utilization of inferior wood is a good way to extend the use of wood. Densification of wood increases the strength of low-density wood and extends the range of applications for wood and wood-derived products. In this paper, the effects of ultrasonic and vacuum pretreatment on the properties of high-performance wood were explored by combining sonication, vacuum impregnation, chemical softening, and thermomechanical treatments to densify the wood; then, the changes in the chemical composition, microstructure, and mechanical properties of poplar wood before and after treatment were analyzed comparatively by FT-IR, XRD, SEM, and mechanical tests. The results showed that with ultrasonic pretreatment and vacuum impregnation, the compression ratio of high-performance wood reached its highest level and the MOR and MOE reached their maximums. With the help of this method, fast-growing softwoods can be easily prepared into dense wood materials, and it is hoped that this new material can be applied in the fields of construction, aviation, and automobile manufacturing.


Materials ◽  
2021 ◽  
Vol 14 (5) ◽  
pp. 1080
Author(s):  
Clever Aparecido Valentin ◽  
Marcelo Kobelnik ◽  
Yara Barbosa Franco ◽  
Fernando Luiz Lavoie ◽  
Jefferson Lins da Silva ◽  
...  

The use of polymeric materials such as geosynthetics in infrastructure works has been increasing over the last decades, as they bring down costs and provide long-term benefits. However, the aging of polymers raises the question of its long-term durability and for this reason researchers have been studying a sort of techniques to search for the required renewal time. This paper examined a commercial polypropylene (PP) nonwoven geotextile before and after 500 h and 1000 h exposure to ultraviolet (UV) light by performing laboratory accelerated ultraviolet-aging tests. The state of the polymeric material after UV exposure was studied through a wide set of tests, including mechanical and physical tests and thermoanalytical tests and scanning electron microscopy analysis. The calorimetric evaluations (DSC) showed distinct behaviors in sample melting points, attributed to the UV radiation effect on the aged samples. Furthermore, after exposure, the samples presented low thermal stability in the thermomechanical analysis (TMA), with a continuing decrease in their thicknesses. The tensile tests showed an increase in material stiffness after exposition. This study demonstrates that UV aging has effects on the properties of the polypropylene polymer.


2018 ◽  
Vol 33 (4) ◽  
pp. 592-602
Author(s):  
Amanda Mattsson ◽  
Tetsu Uesaka

Abstract In end-use, containerboard is subjected to a variety of loading histories, such as seconds of loading/unloading, hours of vibration, days of creep load. The fundamental question is whether the commonly measured static strength represents “strength” under these conditions. Another question is, since those time-dependent failures are notoriously variable, how to describe the probabilistic aspect. This study concerns the characterisation of these different facets of “strength”. In our earlier work, we have investigated the theoretical framework for time-dependent, probabilistic failures, and identified three material parameters: (1) characteristic strength, {S_{c}}, representing short-term strength, (2) brittleness/durability parameter, ρ, and (3) reliability parameter, β. We have also developed a new method that allows us to determine all these parameters much faster than typical creep tests. Using the new method, we have started investigating effects of basic papermaking variables on the new material parameters. Among the samples tested, the parameter ρ varied from 20 to 50, and β from 0.5 to 1.0. This suggests that, even within the current papermaking practice, there is a wide operating window to tune these new material parameters. The future work is, therefore, to find specific manufacturing variables that can systematically change these new material parameters.


2011 ◽  
Vol 11 (3) ◽  
pp. 253-257 ◽  
Author(s):  
Winarti Andayani ◽  
Agustin N M Bagyo

Degradation of humic acid in aqueous solution containing TiO2 coated on ceramics beads under irradiation of 254 nm UV light has been conducted in batch reactor. The aim of this experiment was to study photocatalytic degradation of humic acid in peat water. The irradiation of the humic acid in aqueous solution was conducted in various conditions i.e solely uv, in the presence of TiO2-slurry and TiO2 beads. The color intensity, humic acid residue, conductivity and COD (chemical oxygen demand) of the solution were analyzed before and after irradiation.  The compounds produced during photodegradation were identified using HPLC. The results showed that after photocatalytic degradation, the color intensity and the COD value of the solution decreased, while the conductivity of water increased indicating mineralization of the peat water occurred. In addition, oxalic acid as the product of degradation was observed.


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