Stormwater Management Ponds and Wetlands Sediment Maintenance

2000 ◽  
Vol 35 (3) ◽  
pp. 525-540 ◽  
Author(s):  
Edward I. Graham ◽  
Jian H. Lei
Keyword(s):  
Stormwater Management ◽  
Term Operation ◽  
Study Results

Abstract Effective long-term operation of Stormwater management ponds/wetlands requires maintenance. This study has evaluated many aspects related to such maintenance needs with respect to removal, methods of removal and disposal of removed sediments. This paper summarizes the study results that should be useful to owners/operators responsible for the maintenance of Stormwater management ponds/wetlands.

scholarly journals A varying comprehensive hydropower coefficient for medium/long-term operation of a single reservoir

2020 ◽  
Vol 51 (4) ◽  
pp. 686-698
Author(s):  
Wenting Gong ◽  
Pan Liu ◽  
Lei Cheng ◽  
He Li ◽  
Zhikai Yang
Keyword(s):  
Big Data ◽  
Hydropower Plant ◽  
Simulation Accuracy ◽  
K Value ◽  
Term Operation ◽  
Water Power ◽  
Hydropower Plants ◽  
Water Head ◽  
Study Results

Abstract In medium/long-term reservoir operation, the hydropower output is calculated from k × q × h, where q is the power discharge, h is the water head, and k is the comprehensive hydropower coefficient. k indicates the conversion efficiency from water power to electricity, however, it is standard practice to use a constant k. We developed a novel method to derive the varying k based on observed big data. The operational frequencies of different units for time (multiple periods) and space (multiple units) were accounted based on the observed big data from each unit, and then weights were obtained. Finally, k was derived by integrating the efficiency curves (hill charts) of the different units with their weights. The Three Gorges Project, China, was selected for a case study. Results indicated that: (1) the varying k value can improve hydropower simulation accuracy, (2) simulations using 10-day intervals have a higher accuracy for hydropower calculation than daily and monthly scales, (3) the evaluation of hydropower plant benefits is sensitive to k, and there is potential for producing more hydropower. These findings are highly relevant to the operation of hydropower plants and to the evaluation of medium/long-term hydropower generation for a hydropower plant.

scholarly journals Forecasting the durability of public transport bus bodies depending on operating conditions

2021 ◽  
Vol 4 (1(112)) ◽  
pp. 26-33
Author(s):  
Dmytro Ruban ◽  
Lubomir Kraynyk ◽  
Hanna Ruban ◽  
Andrii Sosyk ◽  
Andriy Shcherbyna ◽  
...  
Keyword(s):  
Public Transport ◽  
Operating Conditions ◽  
The Body ◽  
Body Frame ◽  
Operational Conditions ◽  
Term Operation ◽  
Study Results ◽  
Depth Study ◽  
Bus Body

This paper addresses the issue related to forecasting the durability indicators of public transport buses under operational conditions. It has been established that when buses are operated to transport passengers the bus bodies wear at different intensities. During operation, the strength of the body frame weakens under the influence of corrosion in combination with sites of fatigue destruction. As it was established, the intensity of corrosion of the bus body depends on the number of residents in the city where the bus is operated. The earlier established dependences were taken into consideration; the current study has identified two conditional variants of corrosion evolution based on the number of inhabitants: up to 1 million and exceeding 1 million. The expediency of repairs and their impact on the bus passive safety has been analyzed. It was found that the elements of the body frame, without external characteristic damage, no longer meet the specified conditions of strength as a result of sign-alternating loads and during long-term operation. Determining the durability of the bus body was made possible through the construction of a mathematical model. The model’s adequacy was confirmed by road tests of the bus. The devised model describes the movement of the bus over a road surface with different micro profiles, with different corrosion penetration, different loading by passengers, and bus speeds. It was established that the reason for the evolution of structural corrosion is the influence of salt mixtures preventing the icing of roads, as well as ignoring the washing of buses after such trips. It is recommended to use new software for the in-depth study into this issue addressing the combination of various factors of destruction: cyclic loads at variable bus speeds and the corrosion progress. The study results could make it possible to predict a life cycle of the body frame under factors that correspond to actual operating conditions.

Analysis of crystallite size changes in a hematite and magnetite formed on steel used in the power idustry

2017 ◽  
Vol 1 (21) ◽  
pp. 65-73
Author(s):  
Monika Gwoździk
Keyword(s):  
Elevated Temperature ◽  
Oxide Layer ◽  
Cross Section ◽  
X Ray ◽  
Term Operation ◽  
Diffraction Line Profile ◽  
Crystallite Sizes ◽  
Scherrer Formula ◽  
Pipe Outlet

The paper presents results of studies on the crystallite sizes of oxide layer formed during a long-term operation on 10CrMo9-10 steel at an elevated temperature (T = 545° C, t = 200,000 h). This value was determined by a method based on analysis of the diffraction line profile, according to a Scherrer formula. The oxide layer was studied on a surface and a cross-section at the outer and inner site on the pipe outlet, at the fire and counter-fire wall of the tube. X-ray studies were carried out on the surface of a tube, then the layer’s surface was polished and the diffraction measurements repeated to reveal differences in the originated oxides layer.

Health Literacy and Long-Term Care Needs among Thai Elderly in Rural Communities

2020 ◽  
Vol 103 (12) ◽  
pp. 1315-1324
Keyword(s):  
Depressive Symptom ◽  
Health Literacy ◽  
Rural Communities ◽  
Long Term Care ◽  
Health Knowledge ◽  
Elderly Persons ◽  
Care Needs ◽  
Term Care ◽  
Study Results

Background: Factors related to long-term care needs have been studied widely, but there is limited research about the influence of health literacy on long-term care needs among the elderly in rural communities where the social context and care environment are uniquely different. Objective: To examine factors influencing long-term care needs among Thai elderly in rural communities. Materials and Methods: The present study used the cross-sectional design. The study sample included 477 elderly persons, who were members of the communities in Nakhon Ratchasima Province. Multi-stage random sampling was used to select participants. They were interviewed using the demographic and health information questionnaire, the Thai Geriatric Depression Scale (TGDS), the health literacy scale of Thai adults and long-term care needs questionnaire. The selected factors examined as independent variables included some demographic factors, depressive symptom, and health literacy. Results: The present study results revealed significant positive relationships existing between long-term care needs with age and depressive symptom, while negative relationships between income and health literacy were reported. A hierarchical multiple regression analysis indicated that four of nine determinants of long-term care needs: age, depressive symptom, health knowledge and understanding, and ability managing their health condition significantly predicted long-term care needs at a level of 18% (R² adjusted=0.18, p<0.001). Conclusion: The present study results showed associations between personal and health literacy factors with long-term care needs. These findings prove that it is vitally important for healthcare professionals to consider the rural elderly’s mental health status and health literacy when providing care and planning treatment. Keywords: Health literacy, Long-term care needs, Rural community

Retention and expression of recombinant plasmids in suspended and biofilm-bound bacteria degrading trichloroethene (TCE)

1997 ◽  
Vol 36 (10) ◽  
pp. 1-8 ◽  
Author(s):  
James D. Bryers ◽  
Robert R. Sharp
Keyword(s):  
Biofilm Reactor ◽  
Bacterial Biofilm ◽  
Laboratory Evaluation ◽  
Recombinant Bacteria ◽  
Suitable Host ◽  
Term Operation ◽  
Open Environment ◽  
Recombinant Microorganisms ◽  
Extracellular Polymer

Exposure of plasmid recombinant microorganisms to an open environment, either inadvertently or intentionally, requires research into those fundamental processes that govern plasmid retention, transfer and expression. In the open environment, a majority of the microbial activity occurs associated with an interface, within thin biological layers consisting of cells and their insoluble extracellular polymer, layers known as biofilms. Current toxic wastewater or wastegas treatment reactors exploit bacterial biofilm systems for certain system operating advantages. Using recombinant bacteria within a biofilm reactor to degrade xenobiotic wastes requires finding a suitable host to harbor and express the desired plasmid phenotype. Suitable host characteristics include: the ability to produce copious amounts of biofilm, resistance to waste-related injury and toxicity, and the ability to retain and express the desired plasmid during long term operation. This paper reports on a laboratory evaluation of factors governing plasmid retention and the expression of trichloroethene (TCE) degradative capacity in both suspended and biofilm cultures.

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