Effects of Alkali Pretreatment on Surface Properties and Green Color Conservation of Moso Bamboo (Phyllostachys pubescens Mazel)

Holzforschung ◽  
2000 ◽  
Vol 54 (5) ◽  
pp. 487-491 ◽  
Author(s):  
Shang-Tzen Chang ◽  
Ting-Feng Yeh

SummaryStanding bamboo culms have an attractive greenish skin. Once harvested, however, they turn yellow and the color starts to decay. These adverse properties limit their applications and degrade their performance. Chromated copper arsenate (CCA) based preservatives have been reported to be good protectors for preserving the green color of bamboo culms. An alkali pretreatment was required before applying CCA. However, the mechanism of alkali pretreatment on color conservation is not fully understood. In this study, morphology, wettability, chemical and pigment changes of moso bamboo (Phyllostachys pubescensMazel) were studied after treating with four alkali reagents. The results showed that 2% KOH effectively removed the waxes and capes of silica cells on moso bamboo surface and also increased the surface wettability much better than treatments with 4% K2CO3, 10% K2CO3, 4% Na2CO3, or 4% NaHCO3. The KOH pretreatment also results in a better penetration and reaction with the green color protector (5% Boliden K-33, type-B CCA), and subsequently preserved the green color appearance of moso bamboo.

Holzforschung ◽  
2002 ◽  
Vol 56 (2) ◽  
pp. 130-134 ◽  
Author(s):  
Shang-Tzen Chang ◽  
Ting-Feng Yeh ◽  
Jyh-Horng Wu ◽  
David N.-S. Hon

Summary Standing moso bamboo (Phyllostachys pubescens Mazel) culm is attractive to many people for its green color, but it fades readily if it is not chemically treated. Chromated phosphate (CP)has beensuccessfully used to protect the green color of bamboo. In order to understand the mechanisms of such protection withCP, this study was performed using various surface analytical methods (FTIR,ESCA, and ESR) to examine the characteristic structures on the CP treated bamboo surface. The results revealed that pigments remaining in the bamboo epidermis did not affect the color of bamboo during subsequent green-color-protection treatment. After CP treatment, chromium and phosphorous from CP were located in the epidermisand cortical parenchymaofbamboo epidermaltissue. CPoxidized the chemical components on the bamboo surface and consequently generated a largenumber of carbonyl groups and radicals. Meanwhile, the valence states of Cr were reduced from Cr(VI) to Cr(V) and then to Cr(III).


2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Min Liao ◽  
Xuexiang Ren ◽  
Quan Gao ◽  
Niuniu Liu ◽  
Feng Tang ◽  
...  

AbstractMoso bamboo (Phyllostachys pubescens, Gramineae) is a well-known medicinal and edible plant found in China with various bioactivities, but few systematic studies address the utilization of its anti-fungal activity. The extract of moso bamboo leaf showed good anti-fungal activity to Phytophthora capsici, Fusarium graminearum, Valsa mali Miyabe et Yamada, Botryosphaeria dothidea, Venturia nashicola, and Botrytis cinerea Pers, with inhibitory rate of 100.00%, 75.12%, 60.66%, 57.24%, 44.62%, and 30.16%, respectively. Anti-fungal activity was different by the difference of samples picking time and location. The extract showed good synergistic effects with carbendazim at the ratios of 9:1 and 15:1 (extract : carbendazim), and the co-toxicity coefficients were 124.4 and 139.95. Compound 2 was isolated and identified as the main active component, with the EC50 value of 11.02 mg L−1. Then, the extract was formulated as a 10% emulsion in water, which was stable and had no acute toxic effects. Moreover, a field trial about this formulation was assayed to control pepper phytophthora blight, with the control effect of 85.60%. These data provided a better understanding of the anti-fungal activity and relevant active component of moso bamboo leaf extract. Taken together, our findings illustrated that bamboo leaf extract could be developed and utilized as a botanical fungicide or fungicide adjuvant.


Polymers ◽  
2021 ◽  
Vol 13 (8) ◽  
pp. 1264
Author(s):  
Teng-Chun Yang ◽  
Tung-Lin Wu ◽  
Chin-Hao Yeh

The influence of heat treatment on the physico-mechanical properties, water resistance, and creep behavior of moso bamboo (Phyllostachys pubescens) was determined in this study. The results revealed that the density, moisture content, and flexural properties showed negative relationships with the heat treatment temperature, while an improvement in the dimensional stability (anti-swelling efficiency and anti-water absorption efficiency) of heat-treated samples was observed during water absorption tests. Additionally, the creep master curves of the untreated and heat-treated samples were successfully constructed using the stepped isostress method (SSM) at a series of elevated stresses. Furthermore, the SSM-predicted creep compliance curves fit well with the 90-day full-scale experimental data. When the heat treatment temperature increased to 180 °C, the degradation ratio of the creep resistance (rd) significantly increased over all periods. However, the rd of the tested bamboo decreased as the heat treatment temperature increased up to 220 °C.


2019 ◽  
Vol 27 (01) ◽  
pp. 1950090
Author(s):  
HAIXIA YU ◽  
XIN PAN ◽  
WEIMING YANG ◽  
WENFU ZHANG ◽  
XIAOWEI ZHUANG

Bamboo material is widely used in outdoor applications. However, they are easily degraded when exposed to sunlight, their smooth surface will gradually turn to rough, and small cracks will appear and finally develop to large cracks. The paper presents a first-time investigation on the microstructure changes in the tangential section of Moso bamboo (Phyllostachys pubescens Mazel) radiated by artificial UV light. The results showed that the cracks mainly appeared at intercellular spaces of fibers where lignin content was high, the parenchyma cell walls and neighbor pits where the cell wall was very thin and more vulnerable than the other parts. In addition, the part of raised area and pit cavity tended to absorb more UV light radiation and showed more and larger cracks than the otherwhere. Cracks at the intercellular spaces of fibers were larger and bigger than those on the parenchyma cell walls. The cracks on the pits of the parenchyma cell walls normally appeared at one pit and then extended to the several surrounding pits. Bordered pits cavity showed more and larger cracks than the pits on the thin wall cells. The simple pits on the thick wall cells and the fiber cells were unaffected by UV radiation.


1995 ◽  
Vol 85 (1) ◽  
pp. 308-319 ◽  
Author(s):  
Jin Wang ◽  
Ta-Liang Teng

Abstract An artificial neural network-based pattern classification system is applied to seismic event detection. We have designed two types of Artificial Neural Detector (AND) for real-time earthquake detection. Type A artificial neural detector (AND-A) uses the recursive STA/LTA time series as input data, and type B (AND-B) uses moving window spectrograms as input data to detect earthquake signals. The two AND's are trained under supervised learning by using a set of seismic recordings, and then the trained AND's are applied to another set of recordings for testing. Results show that the accuracy of the artificial neural network-based seismic detectors is better than that of the conventional algorithms solely based on the STA/LTA threshold. This is especially true for signals with either low signal-to-noise ratio or spikelike noises.


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