Responses of Water Holding Characteristic of Crown Debris and Litter in a Cunninghamia Lanceolata Stand to Ice-Snow Damage

2014 ◽  
Vol 937 ◽  
pp. 578-584
Author(s):  
Qin Jing Li ◽  
Yun Ting Hao ◽  
Li Xue ◽  
Xiao Li Hou
Keyword(s):  
Water Absorption ◽  
Absorption Rate ◽  
Water Holding Capacity ◽  
Cunninghamia Lanceolata ◽  
Water Absorption Rate ◽  
Maximum Water ◽  
Snow Damage ◽  
Stem Damage ◽  
Negative Exponential ◽  
Water Holding

Severe ice-snows caused break of many trees and a lot of crown debris in south China in 2008. Stem damage and crown debris. In order to determine the water holding characteristics of the crown debris, the water holding rate and water absorption rates of crown debris and litter were studied in a Cunninghamia lanceolata stand suffering from ice-snow damage occurring from January to February, 2008. The order of water-holding capacity of the components was leaves > litter > branches> stemwood > stembark in each stage of immersing water. The maximum water holding capacities of stemwood, branch, leaves, stembark and litter were 6.75, 8.13, 10.9, 2.72 and 8.22 t•ha 1, respectively. Maximum water holding rates of stemwood, branch, leaves, stembark and litter were 2271, 2144, 3199, 2800 and 3018 g•kg 1, respectively. Water absorption rate of each component sharply decreased with increasing immersed time from 0.5 to 4 hours, and then slowly decreased. The logarithm equation predicted water-holding capacity and water holding rates of crown debris and litter quite well and the negative exponential equation predicted water absorption rate within an 8.5% error.

scholarly journals Litter Ecohydrological Function Characteristics of Three Typical Plant Communities in The Core Area of Five-Hundred-Meter Aperture Spherical Radio Telescope from Guizhou, China

2021 ◽  
Author(s):  
Jianli Zhang ◽  
Ting Zhang ◽  
Lihua Pu ◽  
Lingbin Yan ◽  
Guojun Cai ◽  
...  
Keyword(s):  
Water Absorption ◽  
Plant Communities ◽  
Coniferous Forest ◽  
Water Holding Capacity ◽  
Litter Layer ◽  
Broad Leaved Forest ◽  
Maximum Water ◽  
And Storage ◽  
Water Holding ◽  
Leaved Forest

Abstract Taking the litter layer of three typical plant communities (broad-leaved forest, coniferous forest, and shrubs) as the research object, this study analyzed the hydrological function characteristics of the litter layers of different typical plant communities using the indoor immersion method in order to reveal the effects of the traits of the litter layer on the hydrological functions of typical plant communities in the core area. The results showed that: (1) the litter reserve change trend decreased in order as follows: broad-leaved forest (13.31 ± 1.54 t/hm2) > shrubs (12.62 ± 2.34 t/hm2) > coniferous forest (11.36 ± 1.43 t/hm2). The coniferous forest and shrub litter reserves increased significantly with the increase of decomposition degree (F = 19.36, P < 0.01; and F = 9.19, P < 0.01, respectively), while the broad-leaved forest litter reserves decreased first and then increased significantly with the increase of decomposition degree (F = 25.70, P < 0.01); (2) the litter natural moisture content change trends were as follows: shrubs (34.09 ± 4.31 t/hm2) > broad-leaved forest (31.32 ± 1.76 t/hm2) > coniferous forest (29.48 ± 7.02 t/hm2). The change trends of the maximum water-holding capacity, maximum interception amount, maximum interception rate, effective interception amount, and effective interception rate were in descending order as follows: broad-leaved forest > shrubs > coniferous forest. The maximum water-holding capacity, maximum interception amount, and effective interception amount of litter rose with the increase of decomposition degree. The broad-leaved forest community litter layer had the strongest rainfall interception function and the best hydrological service functions. The interception function was stronger with the increase of the decomposition degree of the litter layer; (3) the water-holding and water-releasing capacity variation of the litter layers manifested as reversed “J” features for the three typical plant communities. The water-holding capacity of different plant community litter layers (Qct) was significantly positively correlated with time (t) (P < 0.01), and the equation was Qct = b + alnt, whereas the water-releasing capacity of different plant community litter layers (Qst) was significantly positively correlated with time (t) (P < 0.01), and the equation was Qst = a t b; and (4) the water absorption and release rates of the litter layers had four periods. The water absorption rate (v) was significantly negatively correlated with time (t) (P < 0.01), and the equation was v = a t− b, while the water release rate was the same. The water absorption and release rates differed by one order of magnitude in the first 5 min, exhibiting the greatest regulation and storage function, while the rate differed by only 2.1–4.5 times during the last three periods. This shows that the litter layer has the strongest rainfall regulation and storage function for only a short period of time before declining.

scholarly journals Preliminary Study of Oil Palm Decanter Cake Natural Polymer Composite (OPDC-NPC)

2014 ◽  
Vol 911 ◽  
pp. 40-44 ◽  
Author(s):  
Muhammad Aqif Adam ◽  
Alawi Sulaiman ◽  
Che Mohd Som Said ◽  
Ayub M. Som ◽  
Azhari Samsu Bahruddin ◽  
...  
Keyword(s):  
Tensile Strength ◽  
Water Absorption ◽  
Polymer Composite ◽  
Palm Oil ◽  
Oil Palm ◽  
Absorption Rate ◽  
Natural Fiber ◽  
Natural Polymer ◽  
Water Absorption Rate ◽  
Decanter Cake

Palm oil industry produces huge amount of oil palm decanter cake (OPDC). Currently it is not yet commercialized however due to its characteristics, it can be used to produce oil palm decanter cake natural polymer composite (OPDC-NPC). NPC is a type of material made by combining natural fiber with polymer. Therefore the objective of this paper is to produce NPC from OPDC and then determine its mechanical and physical properties such as elasticity, stiffness, tensile strength and water absorption rate. The OPDC samples were collected from Felda Trolak Palm Oil Mill. Prior to NPC development, the oil was removed from OPDC using hexane soxhlet extraction method. OPDC-NPC was fabricated using molding method where the mixture of 95% polypropylene (PP) and 5% OPDC were mixed using twin-screw extruder. The results showed that OPDC-NPC has an elasticity of 2231 MPa, stiffness of 30 MPa, tensile strength of 32 MPa and water absorption rate of 0.16 % which was slightly better with the other types of fibers.

scholarly journals Analysis on the barrier properties of thin film PLA/PBAT reinforced with microcrystalline cellulose

2021 ◽  
Vol 2129 (1) ◽  
pp. 012059
Author(s):  
Sitti Fatimah Mhd Ramle ◽  
Aqilah Abdul Rahim ◽  
Nur Hafizzah Jusoh ◽  
Nurul Fazita Mohammad Rawi ◽  
Che Ku Abdullah Che Ku Alam
Keyword(s):  
Thin Film ◽  
Water Absorption ◽  
Microcrystalline Cellulose ◽  
Absorption Rate ◽  
Barrier Properties ◽  
Poly Lactic Acid ◽  
Plastic Pollution ◽  
Water Absorption Rate ◽  
Environmental Friendly ◽  
Hydrolysis Process

Abstract In recent times, awareness on plastic pollution had increase which brings innovation on new productions to be environmental friendly. Various polymers has been used to analyse the suitability to produce thin films. In this study, Poly lactic acid (PLA) and Polybutylene adipate terephthalate (PBAT) reinforced with microcrystalline cellulose (MCC) were investigated. MCC were produced from selected bamboo for obtaining cellulose, then followed by an acidic hydrolysis process for the processing of microcrystalline cellulose (MCC). In this study, the thin film are focusing on the barrier properties such as water absorption, solvent resistance and absorption test. From the results shows that, the lowest rate of water absorption rate is 1.9% by 1% B-MCC/PLA/PBAT, meanwhile, the highest rate of water absorption is 60.1% by 5% C-MCC/PLA/PBAT. The water absorption rate decrease gradually with the decreasing of amount of MCC in the samples. Lastly, the thin film samples can resist with oleic acid solvents as the condition of thin film samples is still remain but they were not resistance with xylene as the thin film samples were shrinked and degraded. This thin film have a potential to replace the non-biodegradable petrochemical polymer based on their properties such as food contact, availability and cost.

scholarly journals WATER ABSORPTION AND DRYING SHRINKAGE OF RECYCLED FOAMED AGGREGATE CONCRETE

2018 ◽  
Vol 30 (3) ◽  
Author(s):  
Chai Teck Jung ◽  
Tang Hing Kwong ◽  
Koh Heng Boon
Keyword(s):  
Water Absorption ◽  
Absorption Rate ◽  
Drying Shrinkage ◽  
Casting Process ◽  
Concrete Specimen ◽  
Sieve Analysis ◽  
Cement Ratio ◽  
Water Cement Ratio ◽  
Water Absorption Rate ◽  
Foamed Concrete

Abstract: This paper presents some experimental results and discusses the used of recycled foamed aggregates as natural coarse aggregates replacement in producing concrete. The physical properties of recycled foamed aggregates concrete were investigated. The properties studied are water absorption and drying shrinkage from the concrete early ages until the periods of 56 days. The 100 mm x 100 mm cube specimen was used to study the water absorption at the age of 7, 28 and 56 days. Meanwhile, the 100 mm x 100 mm x 300 mm length prism had been casted and used for drying shrinkage test for recycled foamed aggregates concrete. The foamed aggregates was produced from crushing recycled foamed concrete blocks. It were coated with cement paste to reduce its water absorption ability during casting process. Superplasticizer was used to maintain the workability of fresh concrete with a slump vary between 50 mm to 100 mm. The physical tests were conducted on recycled foamed aggregates to determine their initial properties such as loose bulk density, sieve analysis and water absorption rate. Recycled foamed aggregate concretes were produced with varied water cement ratio. The results obtained indicated that the linear elastic relationship between water cement ratio and water absorption rate. The higher the water cement ratio of concrete specimen will obtained higher water absorption rate. Vice versa, the density is low for drying shrinkage. The water absorption decreased while drying shrinkage becomes more stabilized over curing period.

The influence of biochar particle size and concentration on bulk density and maximum water holding capacity of sandy vs sandy loam soil in a column experiment

Geoderma ◽  
2019 ◽  
Vol 347 ◽  
pp. 194-202 ◽  
Author(s):  
Frank G.A. Verheijen ◽  
Anna Zhuravel ◽  
Flávio C. Silva ◽  
António Amaro ◽  
Meni Ben-Hur ◽  
...  
Keyword(s):  
Particle Size ◽  
Bulk Density ◽  
Sandy Loam ◽  
Column Experiment ◽  
Water Holding Capacity ◽  
Sandy Loam Soil ◽  
Loam Soil ◽  
Maximum Water ◽  
Water Holding

scholarly journals Durability Studies on the Recycled Aggregate Concrete in China over the Past Decade: A Review

2019 ◽  
Vol 2019 ◽  
pp. 1-19 ◽  
Author(s):  
Zhiming Ma ◽  
Qin Tang ◽  
Dingyi Yang ◽  
Guangzhong Ba
Keyword(s):  
Water Absorption ◽  
Absorption Rate ◽  
Recycled Aggregate Concrete ◽  
Recycled Aggregate ◽  
Recycled Aggregates ◽  
Rapid Urbanization ◽  
Aggregate Concrete ◽  
The Past ◽  
Water Absorption Rate ◽  
Average Water

Since China hosted the Olympic Games in 2008, a mass of construction and demolition (C&D) wastes were produced with the rapid urbanization construction. Recycling the C&D waste into recycled aggregates (RA) is an effective method for reducing the amount of C&D wastes. Many studies on the properties of RA and the durability of recycled aggregate concrete (RAC) were conducted in China over the past decade. Due to the restrictions of various languages, some valuable studies on the durability of RAC are hard to be acquired by the scholars around the world. Therefore, this paper is developed to review the studies on the durability of RAC in China, and the shrinkage behavior, chloride permeability, carbonation behavior, and freeze-thaw resistance of RAC are, respectively, introduced. Considering the waste concrete, bricks, and ceramics used in preparing RA are frequently mixed together in China, this study proposes an index of average water absorption rate to quantify the effects of RA types, quality, and replacement percentages on the durability of RAC. Meanwhile, the relationship between the average water absorption rate of RA and the durability parameters of RAC is established. Finally, the improving methods of RAC durability are introduced, and the RA particle shaping and carbonation modification are emphasized.

The Influence of Different Hydrophobic Agent on the Water Absorptivity of Foam Concrete

2014 ◽  
Vol 665 ◽  
pp. 192-195 ◽  
Author(s):  
Yu Zheng ◽  
Chang Sheng Pan ◽  
Jian Li ◽  
He Chi Pan ◽  
Jun Yi Hu ◽  
...  
Keyword(s):  
Fatty Acids ◽  
Water Absorption ◽  
Thermal Performance ◽  
Absorption Rate ◽  
Foam Concrete ◽  
Organic Silicon ◽  
Water Absorption Rate ◽  
Hydrophobic Agent ◽  
High Absorption ◽  
High Fatty Acids

Foam concrete products had high absorption rate due to a large number of bubbles dispersion in it.which has serious effects upon the overall thermal performance of material and the durability of construction.Three methods were studied which includes Organic Silicon hydrophobic agent、High fatty acids hydrophobic agent and hydrophobic agent F in order to reduce the water absorption rate.Results show that the water absorption rate was reduced significantly with mixed High fatty acids. The water absorption rate drops of 68.2%, and the organic silicon is in a second place , and the hydrophobic agent F is the worst.

scholarly journals The numerical simulation of Influence of Drying-wetting Cycles on the Deterioration Characteristics of Gypsum Rocks under Particle Flow Code

2020 ◽  
Vol 24 (1) ◽  
pp. 55-59
Author(s):  
Guopeng Wu ◽  
Wenwu Chen ◽  
Kai Cui
Keyword(s):  
Mechanical Properties ◽  
Numerical Simulation ◽  
Water Absorption ◽  
Absorption Rate ◽  
Early Stage ◽  
Particle Flow ◽  
Wetting And Drying ◽  
Water Absorption Rate ◽  
Gypsum Rock ◽  
Deterioration Characteristics

In order to study the influence of dry-wet cycling on the deterioration characteristics of gypsum rocks and solve the problems encountered in engineering construction, in this study, gypsum rocks are taken as the research object. With the combination of laboratory test and theoretical analysis, the numerical simulation of particle flow is carried out, and the deterioration characteristics of physical and mechanical properties of gypsum rock under dry-wet cycling are studied. The results show that gypsum, quartz, zeolite and dolomite are the main components of gypsum rocks. Gypsum occupies the most components in gypsum rocks, so the various characteristics of gypsum greatly affect the characteristics of gypsum rocks. The process of water absorption and loss of gypsum is similar, which shows that the rate of water absorption or loss of gypsum is faster in the early stage, and tends to be stable in the later stage. The curve of the whole process of water absorption and loss is fitted by negative exponential function, and the effect is better. The larger the porosity of gypsum rock is, the better its water absorption performance is. Intergranular pore, dissolution pore and dissolution pore are the main pore types of gypsum rock. Intergranular pore is the main water absorption channel of gypsum rock. The cumulative water absorption increases with the increase of wetting and drying cycles. The change of water absorption curve is mainly manifested in water absorption rate and time. The more the number of wet-dry cycles is, the higher the water absorption rate in the early stage of water absorption is, the closer the characteristic curve to the coordinate axis of water absorption is, and the shorter the water absorption time is. In contrast, the shape difference of water loss curve is very small. It can be seen from this that in the process of wetting and drying cycle, the hydrophysical and hydrochemical processes promote each other, which changes the crystal structure and pore structure of gypsum rocks, reduces the crystal strength and increases the porosity, thus leading to the deterioration of the mechanical properties of gypsum rocks.

Evaluation of Soya Bean Quality for Tofu Processing by near Infrared Spectroscopy

1998 ◽  
Vol 6 (A) ◽  
pp. A325-A328
Author(s):  
T.L. Hong ◽  
Samson C.S. Tsou ◽  
S.-J. Tsai
Keyword(s):  
Water Absorption ◽  
Absorption Rate ◽  
Near Infrared ◽  
Nir Spectroscopy ◽  
Soya Bean ◽  
Control Measures ◽  
Raw Material ◽  
Prolonged Storage ◽  
Tannin Content ◽  
Water Absorption Rate

Soya bean, as the raw material for tofu processing, is required to be of high quality. The variety characteristics, storage conditions and harvesting seasons of soya bean are the major contributors to soya bean quality. This study attempted to use near infrared (NIR) spectroscopy to evaluate the processing quality of soya bean. Evaluation models using NIR spectroscopy were developed for the analyses of tannin content, degrees of lipid oxidation, detection of harvest seasons and measurement of water absorption rate. Simulation experiments demonstrated that these models were not only able to analyse major compositions of soya bean, but also to sort out soya bean samples and their suitability for tofu making regardless of various defects, such as high tannin content, low water absorption rate, prolonged storage and unfavourable harvest seasons. Statistic analysis suggested that these models could be used as mass-screening techniques for breeding programmes and quality control measures in tofu-processing factories.

scholarly journals Analysis of Water Absorption Rate for Soybeans.

1996 ◽  
Vol 43 (3) ◽  
pp. 288-298 ◽  
Author(s):  
Jinfa RIE ◽  
Makoto MIURA ◽  
Shin-ichi TANEYA
Keyword(s):  
Water Absorption ◽  
Absorption Rate ◽  
Water Absorption Rate
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