Surface Runoff and Its Erosion Energy in a Partially Continuous System: An Ecological Hydraulic Model

2009 ◽  
Author(s):  
Huayong Zhang ◽  
Liming Dai
Keyword(s):  
Energy Dissipation ◽  
Plant Community ◽  
Surface Runoff ◽  
Ground Surface ◽  
Continuous System ◽  
Hydraulic Model ◽  
Dynamical Process ◽  
Erosion Process ◽  
The Relationship ◽  
Stable Development

Plant community and ground surface form a partially continuous ecosystem in conveying surface runoff and its erosion energy. It is one of the mechanisms for maintaining the stable development of a partially continuous ecosystem that the plant community and ground surface dissipate the erosion energy produced by surface runoff so as to control the soil erosion process of the ecosystem. Based on the energy fundamentals of hydraulics and by idealizing the structure of plant community, we obtain an ecological hydraulic model in this paper through a series of mathematical deductions, which includes three equations: (1) the equation on approaching energy balance of surface runoff moving across plant community and ground surface; (2) the equation on the process of dissipating energy of surface runoff by plant community and ground surface in an ecosystem; (3) the equation on the relationship among the pattern of plant community, ground surface and energy dissipation of surface runoff. Theoretically, the ecological hydraulic model can be used to calculate the dynamical process of energy dissipation of surface runoff by plant community and ground surface in a partially continuous ecosystem and to discuss the optimization of plant community pattern in a given section of the ecosystem.

scholarly journals Modeling the Temperature Field in the Ground with an Installed Slinky-Coil Heat Exchanger

Energies ◽  
2021 ◽  
Vol 14 (13) ◽  
pp. 4010
Author(s):  
Monika Gwadera ◽  
Krzysztof Kupiec
Keyword(s):  
Temperature Field ◽  
Heat Exchanger ◽  
Surface Temperature ◽  
Ground Surface ◽  
Heat Sources ◽  
Ground Surface Temperature ◽  
Coil Heat Exchanger ◽  
The Relationship ◽  
Temperature Responses ◽  
Coil Heat

In order to find the temperature field in the ground with a heat exchanger, it is necessary to determine temperature responses of the ground caused by heat sources and the influence of the environment. To determine the latter, a new model of heat transfer in the ground under natural conditions was developed. The heat flux of the evaporation of moisture from the ground was described by the relationship taking into account the annual amount of rainfall. The analytical solution for the equations of this model is presented. Under the conditions for which the calculations were performed, the following data were obtained: the average ground surface temperature Tsm = 10.67 °C, the ground surface temperature amplitude As = 13.88 K, and the phase angle Ps = 0.202 rad. This method makes it possible to easily determine the undisturbed ground temperature at any depth and at any time. This solution was used to find the temperature field in the ground with an installed slinky-coil heat exchanger that consisted of 63 coils. The results of calculations according to the presented model were compared with the results of measurements from the literature. The 3D model for the ground with an installed heat exchanger enables the analysis of the influence of miscellaneous parameters of the process of extracting or supplying heat from/to the ground on its temperature field.

LABORATORY FOOTING TEST ON PARTIALLY SATURATED SANDY SOIL

2016 ◽  
Vol 78 (5-5) ◽  
Author(s):  
J. D. Nyuin ◽  
M. J. Md Noor ◽  
Y. Ashaari ◽  
C. Petrus ◽  
A. Albar
Keyword(s):  
Sandy Soil ◽  
Ground Surface ◽  
Matric Suction ◽  
Shallow Foundation ◽  
Analysis And Design ◽  
Test Tank ◽  
Partially Saturated ◽  
Saturated Condition ◽  
Conventional Analysis ◽  
The Relationship

Conventional analysis and design of shallow foundation are based on the assumption that the soil is under fully saturated condition. However, shallow foundations are typically constructed near the ground surface where the soil is under partially saturated condition. Therefore, more research to investigate the behaviour of shallow foundation in unsaturated soil is very essential in order to aid engineers in making good analysis and design. This paper presents a series of laboratory footing tests conducted on unsaturated sandy soil. A specially designed test tank was fabricated for the test. Square footings of two different sizes (100 mm x 100 mm and 150 mm x150 mm) were used and loaded on Rawang sand which has residual suction value of 10 kPa. The measured values of matric suction of the soil in the test tank were in the range of 0 to 30 kPa. Based on the results, it was observed that bearing capacities of shallow foundation under fully saturated condition were the lowest compared to soil under unsaturated conditions. The highest values were measured at matric suction equals to residual suction (i.e 10 kPa). Furthermore, the relationship between the bearing capacities of shallow foundation with the matric suction was observed to be non-linear.    

Experimental Research on the Relationship between Surface Polishing and Fracture Strength for Ground Ceramics

2013 ◽  
Vol 770 ◽  
pp. 433-436
Author(s):  
Xin Li Tian ◽  
Jian Quan Wang ◽  
Bao Guo Zhang ◽  
Peng Xiao Wang
Keyword(s):  
Residual Stress ◽  
Fracture Strength ◽  
Ground Surface ◽  
Residual Tensile Stress ◽  
Residual Stress Field ◽  
Polishing Process ◽  
Machined Surface ◽  
X Ray ◽  
Surface Polishing ◽  
The Relationship

Fracture strength is one of the key mechanics performances for engineering ceramics products, greatly influenced by the microscopic topography and residual stress field of ground surface. In this work, several testing equipments, such as the metallurgical microscope, surface profiler and X ray residual stress tester were introduced to investigate the relationships between microscopic topography, surface roughness, residual stress and fracture strength of ground ceramics, after the surface grinding and mechanical polishing. The experimental results show that a smoother machined surface with low roughness and residual stress is obtained through polishing with absolute alcohol for 20 minutes; the fracture strength of Si3N4SiC and Al2O3 are increased by 6.64%8.18% and 6.58% respectively, comparing to the ceramics without polishing; the surface stress concentration and residual tensile stress of polished ceramics are both reduced after an appropriate time of polishing process, which causes a certain improvement of ground fracture strength.

scholarly journals The Effects of Landscape Elements on the Breeding Sites of Bloodsucking Midge

2021 ◽  
Vol 13 (5) ◽  
pp. 2863
Author(s):  
Kaowen Grace Chang ◽  
Hungju Chien
Keyword(s):  
Ground Surface ◽  
Preventive Strategies ◽  
Careful Selection ◽  
Public Concern ◽  
Breeding Sites ◽  
Algae Growth ◽  
Potential Habitats ◽  
Landscape Factors ◽  
The Relationship ◽  
Selection Of

Forcipomyia taiwana, a bloodsucking midge that is one of the most irritating biting pests in Taiwan, has raised widespread public concern. However, we have little information about the extent to which landscape factors affect their potential habitats. As a result, landscape professionals do not have enough information to implement preventive strategies to control midges. The purpose of this study is to investigate the relationship between landscaping and algae growth for larval breeding sites of Forcipomyia taiwana. The intent is to determine the environmental strategies that make the planned landscape unsuitable for midges to breed. GIS based on data collected from 16 constructed landscape sites (317,187 m2 in total) was utilized to spatially examine the relationship between the occurrence of the algae for midge breeding sites and the ground surface types and planting characteristics in each landscape. The results revealed that the potential midge habitats can be controlled through careful selection of the ground surface, the improvement of the site drainage, and choosing plants with the appropriate characteristics. Apart from choosing the appropriate type of paving surface, the integrity of the paving installation and the coverage of the ecological surface also influence prevention efficacy.

scholarly journals Analysis of Differentiation of Regions in the Conditions of Sustainable Development

2021 ◽  
Vol 295 ◽  
pp. 01017
Author(s):  
Margarita Bykova ◽  
Sergey Grachev ◽  
Oleg Donichev
Keyword(s):  
Dynamic Assessment ◽  
Development Models ◽  
Digital Development ◽  
Interregional Differentiation ◽  
Development Processes ◽  
The Russian Federation ◽  
Decoupling Effect ◽  
Relationship Of ◽  
The Relationship ◽  
Stable Development

This article is devoted to the analysis of the factors aimed at ensuring the sustainability of development, as well as certain markers of the presence of the stable development of the Russian Federation regions. As part of the work, it is planned to analyze the relationship of digital development in the country and its effective effects for the process of interregional differentiation in modern conditions of a prolonged economic crisis, aggravated by an unfavorable epidemiological situation. In this case, particular importance should be given to the analysis of the ecological component as a factor that predetermines the possibility of the development and implementation of certain technologies. Due to the dynamic assessment of the decoupling effect, the differentiation of regions is assumed, the analysis of the tendency towards a decrease in the inconsistency of the development models of territories. Herewith, special attention is focused on the factor of a potential further decrease in differentiation based on an increase in the sustainability of economic and environmental development processes.

On the Mechanism and the Rate of Sub-Ground Erosion in the Loess Material

2011 ◽  
Vol 233-235 ◽  
pp. 2528-2531 ◽  
Author(s):  
Xi An Li ◽  
Qiang Xu ◽  
Hong Zhou Lin ◽  
Wan Jun Ye
Keyword(s):  
Critical Condition ◽  
Theoretical Basis ◽  
Field Survey ◽  
Influential Factors ◽  
The Other ◽  
Initial Water Content ◽  
Key Factors ◽  
Erosion Process ◽  
Initial Water ◽  
The Relationship

Sub-ground erosion often resulted in severe problems in various engineering constructions, most of which is due to the sub-erosion in loess. In this paper, the critical condition of “soil bursting” was analyzed and the formula describing the critical condition of soil bursting was derivated by the analytical method. Furthermore, the velocity of tunnel-erosion in loess and its influential factors were studied. A set of tests are designed to study the relationship between the tunnel-erosion velocity and the key influential factors. The key factors considered in the test include soil density as well as the initial water content. The other purpose is to reveal the characteristics of the tunnel-erosion process. Phenomena observed during the tests together with the data from field survey revealed the mechanism of tunneling in loess very well, and the work in this paper formed a theoretical basis for further study about sub-ground erosion in loess.

Experimental Study for Highly Plastic Material Damper

2003 ◽  
Author(s):  
C. S. Tsai ◽  
T. T. Wei ◽  
W. S. Chen
Keyword(s):  
Energy Dissipation ◽  
Mechanical Behavior ◽  
Structural Control ◽  
Passive Control ◽  
Base Isolation ◽  
Plastic Material ◽  
New Technology ◽  
Seismic Responses ◽  
New Energy ◽  
The Relationship

Earthquakes can result in terrible disasters. The new technology of structural control has been acknowledged as the better way to reduce the seismic responses of structures during strong ground motions. The passive control that belongs to the structural control technology can be classified into the base isolation and energy dissipation systems. In this study, a new energy dissipation device called as highly plastic material damper has been proposed. This study focuses on testing and exploring the mechanical behavior of the highly plastic damper proposed by the research group in Feng Chia University, Taichung, Taiwan. The damper was tested in the MTS System to sustain cyclic loadings. The tests include the material stability, durability, the relationship between the force and velocity, and the temperature effect on energy dissipation capacity, etc. From experimental results, it is shown that the force-deformation hysteresis loop of the highly plastic material damper looks like an ellipse in shape for small amplitudes, and a quadrilateral shape for large amplitudes. These results express that the mechanical behavior of the highly plastic material damper depends on the velocity in small amplitudes, and on the displacement in large amplitudes. Based on these observations, the highly plastic material damper could be suitable not only for resisting wind loads but also for controlling seismic responses of a structure during earthquakes.

scholarly journals GPR Signal Processing with Geography Adaptive Scanning using Vector Radar for Antipersonal Landmine Detection

10.5772/5696 ◽  
2007 ◽  
Vol 4 (2) ◽  
pp. 22 ◽  
Author(s):  
Toshio Fukuda ◽  
Yasuhisa Hasegawa ◽  
Yasuhiro Kawai ◽  
Shinsuke Sato ◽  
Zakarya Zyada ◽  
...  
Keyword(s):  
Ground Penetrating Radar ◽  
Ground Surface ◽  
Landmine Detection ◽  
Image Objects ◽  
Kirchhoff Migration ◽  
Surface Image ◽  
Buried Object ◽  
Ground Penetrating ◽  
The Relationship ◽  
Object Imaging

Ground Penetrating Radar (GPR) is a promising sensor for landmine detection, however there are two major problems to overcome. One is the rough ground surface. The other problem is the distance between the antennas of GPR. It remains irremovable clutters on a sub-surface image output from GPR by first problem. Geography adaptive scanning is useful to image objects beneath rough ground surface. Second problem makes larger the nonlinearity of the relationship between the time for propagation and the depth of a buried object, imaging the small objects such as an antipersonnel landmine closer to the antennas. In this paper, we modify Kirchhoff migration so as to account for not only the variation of position of the sensor head, but also the antennas alignment of the vector radar. The validity of this method is discussed through application to the signals acquired in experiments.

Dynamic response of plant chlorophyll fluorescence to light, water and nutrient availability

2015 ◽  
Vol 42 (8) ◽  
pp. 746 ◽  
Author(s):  
M. Pilar Cendrero-Mateo ◽  
A. Elizabete Carmo-Silva ◽  
Albert Porcar-Castell ◽  
Erik P. Hamerlynck ◽  
Shirley A. Papuga ◽  
...  
Keyword(s):  
Energy Dissipation ◽  
Thermal Energy ◽  
Plant Stress ◽  
Nutrient Deficiency ◽  
Light Response ◽  
Response Curves ◽  
Light Response Curves ◽  
Thermal Energy Dissipation ◽  
Response To Water ◽  
The Relationship

Chlorophyll molecules absorb photosynthetic active radiation (PAR). The resulting excitation energy is dissipated by three competing pathways at the level of photosystem: (i) photochemistry (and, by extension, photosynthesis); (ii) regulated and constitutive thermal energy dissipation; and (iii) chlorophyll-a fluorescence (ChlF). Because the dynamics of photosynthesis modulate the regulated component of thermal energy dissipation (widely addressed as non-photochemical quenching (NPQ)), the relationship between photosynthesis, NPQ and ChlF changes with water, nutrient and light availability. In this study we characterised the relationship between photosynthesis, NPQ and ChlF when conducting light-response curves of photosynthesis in plants growing under different water, nutrient and ambient light conditions. Our goals were to test whether ChlF and photosynthesis correlate in response to water and nutrient deficiency, and determine the optimum PAR level at which the correlation is maximal. Concurrent gas exchange and ChlF light-response curves were measured for Camelina sativa (L.) Crantz and Triticum durum (L.) Desf plants grown under (i) intermediate light growth chamber conditions, and (ii) high light environment field conditions respectively. Plant stress was induced by withdrawing water in the chamber experiment, and applying different nitrogen levels in the field experiment. Our study demonstrated that ChlF was able to track the variations in photosynthetic capacity in both experiments, and that the light level at which plants were grown was optimum for detecting both water and nutrient deficiency with ChlF. The decrease in photosynthesis was found to modulate ChlF via different mechanisms depending on the treatment: through the action of NPQ in response to water stress, or through the action of changes in leaf chlorophyll concentration in response to nitrogen deficiency. This study provides support for the use of remotely sensed ChlF as a proxy to monitor plant stress dynamics from space.

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