scholarly journals The Dynamics of Water Wells Efficiency Reduction and Ageing Process Compensation

Water ◽  
2019 ◽  
Vol 11 (1) ◽  
pp. 117
Author(s):  
Krzysztof Polak ◽  
Kamil Górecki ◽  
Karolina Kaznowska-Opala
Keyword(s):  
Operation Time ◽  
Degradation Process ◽  
Ageing Process ◽  
Operating Parameters ◽  
Hydraulic Efficiency ◽  
Engineering Structures ◽  
Engineering Structure ◽  
Water Wells ◽  
Ageing Processes ◽  
The Moment

Water wells play an increasingly important role in providing water for the civilian population all over the world. Like other engineering structures, wells are subject to ageing processes resulting in degradation, which is observed as a reduction in hydraulic efficiency throughout their lifespan. To date, it has been found that the ageing process of a well is determined by a number of factors. The mathematical description of this process can be simplified. Drawing on Jacob’s equation, this paper presents the course of the degradation process as a variable depending on operation time, well loss and flow rate. To apply the determined relationships in practice, simplifying assumptions were adopted, which make it possible to determine the moment of ageing compensations of the degradation processes. It was also demonstrated that the degradation process may be slowed down by the appropriate selection of initial operating parameters. The presented discussion highlights the significance of parameters α, δ and exponent β. The relation between hydraulic resistances in an aquifer and in the engineering structure is closely connected with these values. The presented arguments indicate that step drawdown tests provide the necessary information which allows tracking changes in the ageing processes occurring in the engineering structure. The analysis of the drawdown test results makes it possible to determine the moment when the necessary adjustments in the operating parameters of a water well should be performed. Eventually, it allows maintaining the high hydraulic efficiency of the intake and extending the lifespan of the well in accordance with the principle of sustainability.

Review on Damage Identification and Diagnosis Research of Civil Engineering Structure

2014 ◽  
Vol 1006-1007 ◽  
pp. 34-37 ◽  
Author(s):  
Hong Ni ◽  
Ming Hui Li ◽  
Xi Zuo
Keyword(s):  
Structural Damage ◽  
Civil Engineering ◽  
Damage Identification ◽  
Engineering Structures ◽  
Engineering Structure ◽  
Civil Engineering Structure ◽  
Structure Damage ◽  
Development Direction ◽  
Structural Damage Identification ◽  
Civil Engineering Structures

This paper first describes the importance of structural damage identification and diagnosis in civil engineering, and introduces domestic and foreign status of damage identification and diagnosis methods, and on the basis of this, it also introduces all kinds of methods for damage identification and diagnosis of civil engineering structures, and finally puts forward the development direction of civil engineering structure damage identification and diagnosis.

Valuation of machinery and equipment subject to the Wiener degradation process

2021 ◽  
Vol 57 (3) ◽  
pp. 97
Author(s):  
Sergey Smolyak
Keyword(s):  
Service Life ◽  
Wiener Process ◽  
Market Value ◽  
Degradation Process ◽  
Average Value ◽  
Boundary State ◽  
Proposed Model ◽  
Negative Drift ◽  
The Mean ◽  
The Moment

We propose a model describing the decrease in the market value of machines (depreciation) with age. Usually it is characterized by the percent good factor, i.e. the ratio of machine’s value to the value of similar new machinery item. Often, appraisers know about a used machinery item only by its age, but not its performance. Therefore, for the valuation of the machinery item of a known age, they have to use the mean (for machines of this age) of percent good factor. In the proposed model, the state of the machine is characterized by the intensity of the benefits it brings. In this case, the benefits from using the machine in a certain period are defined as the market value of the work performed by it minus operating costs. We describe the change in the intensity of benefits over time by the Wiener process with negative drift. This allows us to take into account the tendency for the performance of machine to deteriorate during operation. The market value of a machine is defined as the maximum mathematical expectation of the sum of discounted benefits from its use. It is shown that it corresponds to the moment the machine reaches a certain boundary state. The parameters of the Wiener process (drift and volatility) are expressed through the known characteristics of the machine's durability, namely the average value and the coefficient of variation of the service life. The dependences of the mean percent good factor of machines on the relative age (the ratio of age to the average service life) are found. It turned out that these dependencies are almost independent of the discount rate and average service life.

State Monitoring of Civil Engineering Structures Based on Wireless Network Sensor

2014 ◽  
Vol 926-930 ◽  
pp. 2574-2577
Author(s):  
Lin Wang
Keyword(s):  
Monitoring System ◽  
Health Monitoring ◽  
Civil Engineering ◽  
Wireless Sensor ◽  
State Monitoring ◽  
Structure Health Monitoring ◽  
Engineering Structures ◽  
Engineering Structure ◽  
Health Monitoring System ◽  
Civil Engineering Structure

State monitoring is one of the important part of the structure healthy monitoring system, the dynamic characteristics of structures are evaluated rather frequently by measuring their vibrations. With the research and application going in deep, wireless sensor is a perfect way to expand the range of the structure health monitoring system. This dissertation started with a concept design of a wireless sensor that could be used in the structure health monitoring system. In this paper, the state monitoring of civil engineering structure by using wireless sensor technology has been gave out based on monitoring technology and network protocol analysis. Design and hand make the front-end measurement circuit board and software for secondary development based on the monitoring equipment of company. The monitoring network has been set up and experiments were carried out about the structure deformation in the standard steel beam of civil engineering structure laboratory.

scholarly journals Key Operating Parameters Affecting Partial Nitritation Efficiency in the Nitritation Reactor Packed with PVA/Alginate Carrier

2020 ◽  
Vol 42 (5) ◽  
pp. 251-258
Author(s):  
Daehee Choi ◽  
Jinyoung Jung
Keyword(s):  
Operation Time ◽  
Selective Inhibition ◽  
Microbial Community Analysis ◽  
Ammonium Concentration ◽  
Operating Parameters ◽  
Ammonia Oxidizing Bacteria ◽  
Partial Nitritation ◽  
Reject Water ◽  
Nitrite Production ◽  
Do Concentration

Objectives:The purpose of this study was to investigate key operating parameters for partial nitritation in the nitritation reactor packed with PVA (polyvinyl alcohol)/alginate carrier.Methods:Partial nitritation was conducted in a 2 L reactor packed with PVA/alginate carrier of 30%. Dissolved oxygen (DO) concentration was considered as the main operating parameters. Raw reject water was used as the influent, and the ammonium concentration of the influent was adjusted with dilution at the beginning of operation. The DO concentration in the reactor was maintained at 3~4 mg O<sub>2</sub>/L. The activity test of ammonia oxidizing bacteria (AOB) and nitrite oxidizing bacteria (NOB) was conducted periodically. The effect of the operating parameters applied in this study was verified through analysis of microbial community.Results and Discussion:The stable performance for partial nitritation was achieved at operation time of 17 days. Thereafter, the reject water containing 683.6±73.5 mg NH4<sup>+</sup>-N/L was introduced without dilution. Although the DO concentration was maintained at 3~4 mg O<sub>2</sub>/L, stable partial nitritation was achieved for a long time, resulting in effluent NO<sub>2</sub>-N/NH<sub>4</sub><sup>+</sup>-N of 0.94±0.07 and maximum nitrite production rate of 2.24 kgN/m<sup>3</sup>/d. This was confirmed to be due to DO diffusion limitation inside PVA/alginate carrier, whereby the NOB activity could be effectively inhibited. Microbial community analysis also showed that NOB fraction inside the carrier was reduced to 0.09%. It indicated that partial nitritation using the PVA/alginate carrier was effective for selective inhibition of the NOB.Conclusions:In the case of using the whole cell entrapment technique, effective inhibition of NOB was possible by keeping the DO concentration inside the carrier low despite the fluctuation of DO in the reactor. The results of these findings may help improve the stability of the process in the field.

scholarly journals Research and Analysis of Damping Control Technology in Civil Engineering Construction Process

2014 ◽  
Vol 8 (1) ◽  
pp. 406-406
Author(s):  
Yonggang Bao ◽  
Qingwei Meng ◽  
Ki Bae Seo
Keyword(s):  
Active Control ◽  
Passive Control ◽  
Civil Engineering ◽  
Control Method ◽  
Rapid Development ◽  
Rational Approach ◽  
Engineering Structures ◽  
Engineering Construction ◽  
Engineering Structure ◽  
Civil Engineering Structure

With the rapid development of society and the economy, people's life and property safety importance is also more and more high. Especially the occurrence of the Wenchuan earthquake, people on whether the application of civil engineering construction damping scientific and rational approach was questioned. How to ensure the quality of civil engineering construction, to avoid in the event of earthquakes and other natural disasters, the emergence floor crash event, is an issue for all engineering designers and builders focus on. Because of the relationship with all life safety, so how to use rational scientific method damping to the construction of civil engineering structures is very important and necessary. This study from the passive control, active control, semi-active control and hybrid control methods start with four damping research and analysis, combining their research status. The Benchmark problem of structure control has carried on the simple introduction. Focusing on civil engineering structure vibration control method of systematic review, so as to the future of civil engineering structure suspension construction provides the certain reference function

EVALUATION OF ENGINEERING STRUCTURES DEFORMATION (ACCURACY)

2019 ◽  
pp. 77-82
Author(s):  
T. Malik ◽  
Ya. Bryk ◽  
V. Zatserkovnyi ◽  
V. Belenok
Keyword(s):  
Real Time ◽  
Monitoring System ◽  
Structure Prediction ◽  
Optoelectronic Devices ◽  
Deformation Monitoring ◽  
Automated System ◽  
Control Panel ◽  
Engineering Structures ◽  
Engineering Structure ◽  
Accuracy Of Measurements

The construction of the model of accuracy of the measuring processes of the automated monitoring system of engineering structures deformations from the point of the theory of accuracy is considered in the article. From the point of view of the generalization of the accuracy of measurements by the automated system of engineering structures monitoring, the construction of the model of the measuring process is considered, resulting in separate characteristics and properties of the object to be investigated. In this case these are values of deformations of engineering constructions' structures. The brief acquaintance with the automated system of monitoring of engineering structures deformations, which represents a chain of optoelectronic devices-deformation marks, which are installed on constructions of structures and fix the created line is given. The use of this system allows to solve the problem of the preventive assessment of the dynamics of local technogenic deformation in the engineering structure and thus to increase the level of technogenic safety of the personnel of the engineering structure. Compared with modern well-known methods and means for determining the engineering structures deformation, an automated deformation monitoring system has the following advantages: 1. Cross-section geodetic control of deformations (position) of elements of the full volume of engineering structure with increased accuracy. 2. Automated control of engineering structures deformations in real time, including in limited or inaccessible for visual measurements places. 3. Control of the technogenic safety of the engineering structure, prediction of the moment of the emergency, warning about the upcoming critical state (moment) of the engineering structure in real time with the accurate definition of a certain area. 4. Installation of the entire monitoring system occurs during the construction of the structure, pre-installation sites of optoelectronic devices - deformation marks are agreed with the designers and architects. 5. The mean square error of measurement of relative deviations of deformations is not less than 0,1-0,5 mm at distances between optoelectronic devices up to 10 m. 6. Information on the magnitude of deviations from the nominal (initial) position goes to the remote central control panel of the system in real time scale. 7. In the case of upcoming moment of dangerous deviation (deformation), the command from the main control panel receives a signal for rapid response with the accurate designation of the place of dangerous deformation.

Helicopter Landing Ship: Undercarriage Strength and the Role of the Human Factor

2009 ◽  
Vol 132 (1) ◽  
Author(s):  
E. Suhir
Keyword(s):  
Human Factor ◽  
Operation Time ◽  
Extreme Value Distribution ◽  
Mean Value ◽  
Helicopter Landing ◽  
The Times ◽  
The Moment ◽  
Normal Law ◽  
Time Required

We address, using probabilistic modeling and the extreme-value-distribution technique, the helicopter undercarriage strength in a helicopter-landing-ship situation. Our analysis contains an attempt to quantify, on the probabilistic basis, the role of the human factor in the situation in question. This factor is important from the standpoint of the operation time that affects the likelihood of safe landing during the lull period in the sea condition. The operation time includes (1) the time required for the officer-on-ship-board and the helicopter pilot to make their go-ahead decisions and (2) the time of actual landing. It is assumed, for the sake of simplicity, that both these times could be approximated by Rayleigh’s law, while the lull duration follows the normal law with a high enough ratio of the mean value to the standard deviation. Safe landing could be expected if the probability that it occurs during the lull time is sufficiently high. The probability that the helicopter undercarriage strength is not compromised can be evaluated as a product of the probability that landing indeed occurs during the lull time and the probability that the relative velocity of the helicopter undercarriage with respect to the ship’s deck at the moment of encounter does not exceed the allowable level. This level is supposed to be determined for the helicopter-landing-ground situation. The developed model can be used when developing specifications for the undercarriage strength, as well as guidelines for personnel training. Particularly, the model can be of help when establishing the times to be met by the two humans involved to make their go-ahead decisions for landing and to actually land the helicopter. Plenty of additional risk analyses (associated with the need to quantify various underlying uncertainties) and human psychology related efforts will be needed, of course, to make such guidelines practical.

Damage Mechanics-Finite Element Method for Vibrational Fatigue Life Prediction of Engineering Structures with Damping

2014 ◽  
Vol 472 ◽  
pp. 17-21 ◽  
Author(s):  
Lin Lin Sun ◽  
Wei Ping Hu ◽  
Miao Zhang ◽  
Qing Chun Meng
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Fatigue Life ◽  
Life Prediction ◽  
Damage Mechanics ◽  
Fatigue Crack Initiation ◽  
Engineering Structures ◽  
Engineering Structure ◽  
Crack Initiation Life ◽  
Element Method

This paper provides a new method which is damage mechanics to predict the fatigue life of engineering structure with damping under resonant loading. The material parameters are obtained by the results of the fatigue test of standard specimens. And based on the further development of APDL language, damage mechanics-finite element method for vibration life prediction under resonant loading is used in ANSYS. Finally, the vibrational fatigue crack initiation life of an aluminum alloy beam with damping carrying load of various frequencies is calculated. Whats more, this research provides a feasible way to predict the fatigue live of an engineering structure by means of damage mechanics.

scholarly journals C3c intrathecal synthesis evaluation in patients with multiple sclerosis

2007 ◽  
Vol 65 (3b) ◽  
pp. 800-802 ◽  
Author(s):  
Bárbara Padilla-Docal ◽  
Alberto J Dorta-Contreras ◽  
Hermes Fundora-Hernández ◽  
Elena Noris-García ◽  
Raisa Bu-Coifiu-Fanego ◽  
...  
Keyword(s):  
Multiple Sclerosis ◽  
Complement System ◽  
Progressive Disease ◽  
Degradation Process ◽  
Intrathecal Synthesis ◽  
Brain White Matter ◽  
The Central Nervous System ◽  
The Moment ◽  
The Complement System ◽  
The Brain

INTRODUCTION: Multiple sclerosis (MS) is a chronic, inflammatory and progressive disease of the central nervous system in which local inflammatory injuries of the brain white matter appears, being the most outstanding feature the myeline loss (demyelination). OBJECTIVE: To determine if the complement system might be involved in the MS immunopathogeny favouring the mechanism intervening in the myelin destruction. METHOD: Samples of sera and CSF from twelve patients with a diagnosis of MS obtained at the moment of the admission to the hospital at the beginning of the break out, were collected. Levels of C3c and albumin in sera and in CSF were quantified using radial immunodiffusion plates. RESULTS: High values over 80% of intrathecal synthesis were obtained except in one of the patients. CONCLUSION: Intrathecal synthesis of C3c and its liberation to the CSF means that the activation of the complement system in any of the two ways has taken place, and that once performed its biological functions, has suffered a degradation process.

Spatial Autocorrelation Test of Engineering Deformation Data

2015 ◽  
Vol 744-746 ◽  
pp. 1701-1704
Author(s):  
Song Lin Zhang ◽  
Xiao Meng Yang ◽  
Kun Zhang
Keyword(s):  
Environmental Factors ◽  
Spatial Autocorrelation ◽  
Spatial Association ◽  
Engineering Structures ◽  
Engineering Structure ◽  
Safe Behavior ◽  
Spatial Dependencies ◽  
The Relationship ◽  
Vertical Deformations

Deformation of engineering structures is often measured in order to ensure that the structure is exhibiting a safe behavior. The relationship between deformation and environmental factors is often studied through regression to pick out ambient factors which have major impact on the deformation of the engineering structure. One of the regression assumptions is independence of observations. However, when observations are closer to each other, there is spatial autocorrelation in the observations and the assumption does not hold. Thus it is necessary to test for spatial dependencies before regression. Through the study of a deformation data of a viaduct in Shanghai, China, we find that there exists significant spatial autocorrelation in horizontal and vertical directions, and the vertical deformations exhibit especially strong spatial association.

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