maximum water content
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Wood Research ◽  
2021 ◽  
Vol 66 (6) ◽  
pp. 1046-1054
Author(s):  
ASLI GÖKÇE KILIÇ ◽  
NAMIK KILIÇ ◽  
CEM AKGÜN

In this study, three samples taken from the planks of the Yenikapı 29 shipwreck were analysed. Firstly, the maximum water content (MWC) and basic density values of the samples were calculated. MWC of the IK13-1 was 164% and the MWC of the SK6-1 was 87%. Because of these low MWC values, samples could be classified as non-degraded. When the SEM images of these two samples were examined, it was understood that the IK13-1 sample was non-degraded but the SK6-1 sample was penetrated with corrosion product and could not be classified as non-degraded. With these analyses, the XRF method was used to measure the iron amounts of the samples. The iron amount of the SK6-1 was 32.3% and the corrosion accumulation in this sample was also proved with XRF. In order to avoid incorrect results, multiple analysis techniques should be used for determining the physical condition of the waterlogged wood near the corroded parts.


Author(s):  
JA da Costa ◽  
A Akhavan-Safar ◽  
EAS Marques ◽  
RJC Carbas ◽  
LFM da Silva

In real practice, adhesively bonded structures are usually exposed to cyclic environmental conditions. However, cyclic ageing processes are relatively unexplored. The aim of this study is to consider the effect of cyclic ageing on the rate of water uptake and the drying process in an epoxy-based adhesive. Fick’s law was considered to estimate the water diffusion coefficients for the ageing and the drying steps at different cycles. Different cyclic ageing times have been considered in the ageing procedure. Dogbone shape specimens were also manufactured and subjected to cyclic aging to investigate the tensile properties of the tested adhesive as a function of aging cycles. The gravimetric results showed that the rate of water uptake and drying is mainly a function of the level of water uptake of the first ageing cycle. Tensile test results showed that the maximum water content increases with each subsequent ageing cycle. It was also found that the Young’s modulus and the tensile strength of the adhesive decreased significantly after the initial ageing cycle, but all subsequent ageing cycles have considerably less influence on the mechanical properties of the adhesive.


2020 ◽  
Vol 4 (2) ◽  
Author(s):  
Yayan Adi Saputro ◽  
Khotibul Umam ◽  
Shiska Fauziah

Concrete road works on the improvement of the Jepara - Kedungmalang - Pecangaan road are the activities of the Publick Works Department of Highways in Central Java Province. Quality control in a building structure work is very important to support the strength of the structure. In planning the road structure, it is necessary to have density of soil and foundation layers that meet the requirements. To get the value of the degree of density that is from the sandcone test where in the sandcone test there are several standart methods or references for example from AASHTO T 191 and ASTM D 1556 - 64. In this study the aims is to obtain the value of the degree of density, how big is the difference between the AASHTO T 191 standart and ASTM D 1556 - 64, and know the water content. From the test result, the optimum moisture content value is 6.5%, dry density is 2.17gr/cm3, the value of the degree of density mostly ranges from ">100%, and the minimum water content value is 5.00% maximum water content is 6.7%.


2020 ◽  
Author(s):  
Shoupeng Guan ◽  
Fang-Qing Chen ◽  
Jumei Zhou ◽  
Yongwen Huang ◽  
Dayong Fan

Abstract Background: The construction of the Three Gorges-Gezhou Dam altered the water level fluctuation pattern in the downstream habitat of the endangered species Myricaria laxiflora. This study investigated how branch and leaf growth traits of M. laxiflora remnant populations changed to adapt the environmental stress caused by human-altered water level fluctuations.Results:Due to such disturbance, branch and leaf growth traits of M. laxiflora populations exhibited significant differences across water level conditions. The number of secondary branches, plant height, and leaf number of the plants in the upper area of the habitat were significantly higher than that in the middle and lower river bank areas. The longest secondary branch length of the plants in the upper and middle region was significantly higher than that in the lower region. The branch and leaf volume of plants in the middle region was significantly higher than that in the upper and lower region. The maximum water content of plants in the middle and lower region was significantly higher than that in the upper region. Principal component analysis showed that the branch and leaf traits of plants changed with decreasing water level toward to decreasing plant height, leaf number and the number of secondary branches, and increasing maximum water content of branch and leaves. Conclusions: The phenotypic plasticity of M. laxiflora plants in branch and leaf growth traits alleviates the impacts of human-regulated water level fluctuations. However, the above ground growth of M. laxiflora plants distributed at the middle and lower areas of the fluctuation zone is still negatively affected.


2020 ◽  
Vol 13 (1) ◽  
pp. 6-12
Author(s):  
Dani Tri Wahyudi ◽  
Deni Shidqi Khaerudini

The rains will make a serious problem for the transportation sector in Indonesia, especially in areas that do not have permanent access roads (asphalt or concrete roads). Heavy vehicles such as oil palm trucks will go into the skid when crossing muddy dirt roads, and it makes an impact on the logistics delivery process. It is necessary for designing a support system, especially on the part of the wheel, to reduce the risk of skidding or rolling. Anti-slip shoe wheels of the colt diesel double (CDD) type truck is used on the rear-wheel-drive as a tool for handling slippage. Calculations and corrections are performed for maximum traction of the ground rolling resistance at ≥ 396 kg. Furthermore, the value of soil cohesion and soil shear angle was determined from the previous studies. In this study, a calculation simulation was carried out to obtain the design of the main components of an antislip wheel of a truck, which is in the form of a traction rod fin using steel UNP SNI 07-0052-2006 with a fin depth of 4.5 cm and a length of 20 cm. These dimensions are effective enough to increase the truck wheel traction of 8 tons when used to cross muddy roads with a maximum water content of 59.6% and a minimum cohesion value of land (C) of 0.108 kg/cm2


2017 ◽  
pp. 113
Author(s):  
Ernst Detlef Schulze ◽  
Harold A. Mooney ◽  
Stephen H. Bullock ◽  
Ana Mendoza

The maximum water content, the relative water content and the water depletion of wood were studied in 41 species of a tropical deciduous forest during the dry season. Ther is a significant correlation between the maximum water content and the specific wood weight. Also, water de pletion per wood weight is significantly correlated with the specific wood weight. On a wood volume basis, deciduous trees unse more stem water than water-storing trees. These data are discussed with respect to the dominance of life forms in this forest type


2016 ◽  
Vol 88 (10-11) ◽  
pp. 969-977 ◽  
Author(s):  
Emily McHale ◽  
Susan Braovac ◽  
Calin C. Steindal ◽  
Richard B. Gillis ◽  
Gary G. Adams ◽  
...  

AbstractThe development of new materials for the consolidation of waterlogged archaeological wood from sustainable sources is an important area of research, as the most widely used consolidant today is petroleum based. Ideally a new consolidant will interact with the existing wood structure, ensuring maximum compatibility. Lignin is often the major component remaining in archaeological wood, as it is less susceptible to degradation than holocellulose. Therefore, in order to maximise the potential for interaction with the wood cells, lignin-like oligomers have been synthesized from isoeugenol using a water soluble copper salen catalyst at pH 10, giving a weight average Mw of 1.6 kDa. Analysis by NMR spectroscopy has shown that the oligomers have a lignin-like structure with β-O-4′, β-β′ and β-5′ connections. A 10 w/w% solution of the oligomers in ethyl acetate was found to thoroughly penetrate 1 cm3 samples of waterlogged archaeological wood (density of 0.146 g/mL, maximum water content of 620%) after 14 days impregnation, as determined by FTIR spectroscopy. No impregnation material could be seen by SEM, suggesting that it coats the cell walls upon drying. This indicates that dehydrogenated polymers penetrate waterlogged archaeological wood well and have the potential to be developed into consolidants.


2012 ◽  
Vol 204-208 ◽  
pp. 552-556 ◽  
Author(s):  
Tie Hang Wang ◽  
Hui Zhang ◽  
Xing She Lu

Test equipments were designed and manufactured for producing moisture migration in unsaturated loess under freezing effect. The results showed that both the amount of freezing-thawing cycles and initial water content of soil samples affect the process of moisture migration. As the freezing front advanced in the sample, the water content in the unfrozen part significantly reduced and the water content in the freezing part significantly increased, with the maximum water content at the freezing front. Comparing to the moisture migration in the unfrozen part, the moisture migration to the freezing front in the freezing part was relatively slow. For soil samples with higher initial water content, the increment of water content at the freezing front was higher and sometimes ice could be formed. During a certain amount of freezing-thawing cycles, the water content at the freezing front kept increasing. However, as the amount of freezing-thawing cycles continued increasing, the freezing front started to move to the part with negative temperature and the maximum water content appears at the end with the lowest temperature.


2012 ◽  
Vol 457-458 ◽  
pp. 435-438
Author(s):  
Xue Dong Guo ◽  
Cao Jian ◽  
Xiang Yang Fang

In this paper,study water content and water stability of AC and SMA asphalt mixtures, and reach the following conclusions. In the normal saturated condition, the maximum water content of AC and SMA asphalt mixture is 0.28% and 0.32%.And in the vacuum saturated condition, the maximum water content of AC and SMA asphalt mixture is 0.8% and 0.78%.The water of AC and SMA asphalt mixture separately take 8 days and 9 days to drain completely in the normal saturated condition. But in the vacuum saturated condition, the time is more than two months. In different water content conditions, the splitting tensile strength of AC asphalt mixture is 0%> 100%> 25%> 75%> 50%.But the splitting tensile strength of SMA asphalt mixture is 0%> 100%> 25%> 50%> 75%.


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