NUMERICAL STUDY OF COMPACTION OF THE EARTH DAM BODY IN THE POST-CONSTRUCTION PERIOD

2021 ◽  
pp. 66-72
Author(s):  
V.Ya. Zharnitsky ◽  
◽  
E. V. ANDREEV ◽  
Yu.V. Zaitsev
Keyword(s):  
Numerical Study ◽  
Subsequent Development ◽  
Physical And Mechanical Properties ◽  
Operational Reliability ◽  
The Body ◽  
Earth Dam ◽  
Hydraulic Structures ◽  
Construction Period ◽  
Degree Of Damage ◽  
Short Time

Ensuring the operational reliability of hydraulic structures is an important task at the stage of the life cycle of the structure. The main reasons of destructions of hydraulic structures in the course of research were identifi ed as errors in the design of such structures and their construction, or the absence of operating organizations and, as a result, the lack of proper maintenance for such structures. Such errors inevitably lead to the creation of defects in the body of hydraulic structures with the subsequent development of deformations and destruction of hydraulic structures because of a violation of the fi ltration strength. In this regard, standard methods for assessing operational reliability appear to be cumbersome and ineffi cient in the conditions of a short time allotted for assessing the degree of damage to the structure, obtaining reliable results on the current level of operational condition of hydraulic facilities, taking into account the physical and mechanical properties of the materials, the degree of damage and the characteristics of the operation.

MPACT OF SHOCK WAVES IN INERT MEDIA ON THE OPERATIONAL RELIABILITY OF LOW-PRESSURE EARTH DAMS

2021 ◽  
pp. 52-57
Author(s):  
E. V. ANDREEV ◽  
Keyword(s):  
Gas Dynamics ◽  
Degrees Of Freedom ◽  
Room Temperature ◽  
Hydraulic Structure ◽  
Operational Reliability ◽  
The Body ◽  
Hydraulic Structures ◽  
Safety And Reliability ◽  
Gas Molecules ◽  
Internal Degrees Of Freedom

During the operation of pressure hydraulic structures, there is an objective need to ensure their safety and reliability. In the case of non-stationary loads on hydraulic structures, they can be either seriously damaged or destroyed. One of the non-stationary effects can be considered a directed explosion on the body of a hydraulic structure or in the immediate vicinity of it. At significant Mach numbers, the processes of excitation of the internal degrees of freedom of molecules, ionization and dissociation of gas molecules, and their recombination occur behind the shock wave front. The course of these processes is due to the almost tenfold compression of the gas at the time of the explosion and it’s heating relative to the room temperature of the order of 104 K. The use of approximate and numerical methods is a consequence of the difficulties associated with the need to solve nonlinear equations of gas dynamics, with the simultaneous use of relaxation equations and equations of chemical kinetics at the same time.

NUMERICAL STUDY OF THE STATE OF SOIL DAMS AS A RESULT OF IMPACT OF SHOCK WAVES AND UNSTEADY LOADS

2021 ◽  
pp. 55-62
Author(s):  
E. V. ANDREEV ◽  
Keyword(s):  
Shock Waves ◽  
Numerical Study ◽  
Pressure Head ◽  
Operational Reliability ◽  
Hydraulic Structures ◽  
Time Interval ◽  
Short Time Interval ◽  
Urgent Task ◽  
Temperature Dependences ◽  
The Impact

At the stage of the life cycle, ensuring the operational reliability and safety of pressure head hydraulic structures is an urgent task. One of the serious threats at the present stage is the destruction of hydraulic structures by the impact of non-stationary loads, by directed explosions in the immediate vicinity of the structures or on their surface. Shock waves pose a serious threat to hydraulic structures. Impulse short-term impact on the solid surfaces of hydraulic structures or on the aquatic environment characterizes the specifi cs of the problem under consideration, as the nonstationary of the process of motion of continuous media into which, in a short time interval, a volume of energy can be released that can deform or completely destroy them. Scenarios of this kind can occur either in the immediate vicinity of a hydraulic structure or as a result of the collision of solid bodies on its surface. Water upstream of the hydro technical structure and its body is a complex liquid because many of its characteristics differ significantly in size from similar characteristics of other liquids or have so-called anomalies on pressure and temperature dependences.

scholarly journals Investigating the Influence of Penetration Length of Cut-off Wall on its Dynamic Interaction with Core and Foundation of Earth Dam

2018 ◽  
Vol 4 (12) ◽  
pp. 3019 ◽  
Author(s):  
Mehran Javanmard ◽  
Reza Mottaghi ◽  
S. M. Mir Mohammad Hosseini
Keyword(s):  
Numerical Study ◽  
Physical And Mechanical Properties ◽  
Earth Dam ◽  
Core Material ◽  
Length Variation ◽  
Cutoff Wall ◽  
Maximum Shear Strain ◽  
Penetration Length ◽  
The Core ◽  
Clay Core

Seepage and flow of water in the soil is one of the most important issue and effective elements in designing embankment dams. One of the methods to control seepage in alluvial foundation of earth dams is to use a plastic concrete cutoff-wall. For better seepage control, the cutoff-wall extends inside the clayey core as the one of common method of connection of cut-off wall and the core. Due to the stiffness difference of the core material and cutoff-wall, and also due to geological situation, physical and mechanical properties of rock and foundation, interaction of core and foundation with cut-off wall in different static and dynamic load cases is very considerable. Failure of cut-off wall occurs in cut-off wall and core joint.  So the study of their interaction, especially during an earthquake is very important. Karkheh dam cut-off wall with an area of about 150000 m2 is chosen for this study. FLAC software has been used to study the effect of cutoff-wall penetration length variation, inside the clay core of Karkheh earth dam under dynamic loading.  In numerical analysis of Karkheh earth dam model, all construction stages and seepage through dam are modelled. The model is first calibrated according to the results obtained from the dam instrumentations. After calibrating, according to available seismic studies of region, a suitable acceleration was selected and applied to the model. In this research, in order to find the optimum length, the effect of 0, 5, 10, 15 and 20 meters penetration length of cut-off wall in aforementioned conditions has been investigated. The results of the numerical study showed that the horizontal displacement and the maximum shear strain in the cutoff-wall is occurred adjacent to the clay core and the interface of core and foundation is a critical point for the cut-off wall, and also the stress in cut off wall joint increases with the elongation of penetration depth of the wall.

Numerical study of isotropic ocean swell

2019 ◽  
Vol 489 (5) ◽  
pp. 512-516
Author(s):  
V. V. Geogjaev ◽  
V. E. Zakharov ◽  
S. I. Badulin
Keyword(s):  
Numerical Study ◽  
Short Time ◽  
Kolmogorov Constant

A new algorithm is used for detailed numerical study of the evolution of isotropic swell in a homogeneous ocean. It is shown that the Zakharov-Filonenko spectrum occurs in an explosive manner in a short time. The Kolmogorov constant of the solution is estimated numerically.

scholarly journals A Computational Study on the Role of Parameters for Identification of Thyroid Nodules by Infrared Images (and Comparison with Real Data)

Sensors ◽  
2021 ◽  
Vol 21 (13) ◽  
pp. 4459
Author(s):  
José R. González ◽  
Charbel Damião ◽  
Maira Moran ◽  
Cristina A. Pantaleão ◽  
Rubens A. Cruz ◽  
...  
Keyword(s):  
Heat Transfer ◽  
Thyroid Nodules ◽  
Numerical Study ◽  
Computational Study ◽  
Internal Heat ◽  
Heat Transfer Process ◽  
The Body ◽  
Physical Parameters ◽  
Infrared Sensors ◽  
Wide Range

According to experts and medical literature, healthy thyroids and thyroids containing benign nodules tend to be less inflamed and less active than those with malignant nodules. It seems to be a consensus that malignant nodules have more blood veins and more blood circulation. This may be related to the maintenance of the nodule’s heat at a higher level compared with neighboring tissues. If the internal heat modifies the skin radiation, then it could be detected by infrared sensors. The goal of this work is the investigation of the factors that allow this detection, and the possible relation with any pattern referent to nodule malignancy. We aim to consider a wide range of factors, so a great number of numerical simulations of the heat transfer in the region under analysis, based on the Finite Element method, are performed to study the influence of each nodule and patient characteristics on the infrared sensor acquisition. To do so, the protocol for infrared thyroid examination used in our university’s hospital is simulated in the numerical study. This protocol presents two phases. In the first one, the body under observation is in steady state. In the second one, it is submitted to thermal stress (transient state). Both are simulated in order to verify if it is possible (by infrared sensors) to identify different behavior referent to malignant nodules. Moreover, when the simulation indicates possible important aspects, patients with and without similar characteristics are examined to confirm such influences. The results show that the tissues between skin and thyroid, as well as the nodule size, have an influence on superficial temperatures. Other thermal parameters of thyroid nodules show little influence on surface infrared emissions, for instance, those related to the vascularization of the nodule. All details of the physical parameters used in the simulations, characteristics of the real nodules and thermal examinations are publicly available, allowing these simulations to be compared with other types of heat transfer solutions and infrared examination protocols. Among the main contributions of this work, we highlight the simulation of the possible range of parameters, and definition of the simulation approach for mapping the used infrared protocol, promoting the investigation of a possible relation between the heat transfer process and the data obtained by infrared acquisitions.

A NUMERICAL STUDY ON THE HEMODYNAMIC AND SHEAR STRESS OF DOUBLE ANEURYSM THROUGH S-SHAPED VESSEL

2015 ◽  
Vol 27 (04) ◽  
pp. 1550033 ◽  
Author(s):  
Mahdi Halabian ◽  
Alireza Karimi ◽  
Borhan Beigzadeh ◽  
Mahdi Navidbakhsh
Keyword(s):  
Blood Flow ◽  
Mechanical Behavior ◽  
Numerical Study ◽  
Flow Characteristics ◽  
Flow Simulation ◽  
The Body ◽  
Sweep Angle ◽  
Abdominal Aortic ◽  
Hemodynamic Characteristics ◽  
Refined Meshes

Abdominal aortic aneurysm (AAA) is a degenerative disease defined as the abnormal ballooning of the abdominal aorta (AA) wall which is usually caused by atherosclerosis. The aneurysm grows larger and eventually ruptures if it is not diagnosed and treated. Aneurysms occur mostly in the aorta, the main artery of the chest and abdomen. The aorta carries blood flow from the heart to all parts of the body, including the vital organs, the legs, and feet. The objective of the present study is to investigate the combined effects of aneurysm and curvature on flow characteristics in S-shaped bends with sweep angle of 90° at Reynolds number of 900. The fluid mechanics of blood flow in a curved artery with abnormal aortic is studied through a mathematical analysis and employing Cosmos flow simulation. Blood is modeled as an incompressible non-Newtonian fluid and the flow is assumed to be steady and laminar. Hemodynamic characteristics are analyzed. Grid independence is tested on three successively refined meshes. It is observed that the abrupt expansion induced by AAA results in an immensely disturbed regime. The results may have implications not only for understanding the mechanical behavior of the blood flow inside an aneurysm artery but also for investigating the mechanical behavior of the blood flow in different arterial diseases, such as atherosclerosis.

scholarly journals Electrochemotherapy Effectiveness Loss due to Electric Field Indentation between Needle Electrodes: A Numerical Study

2018 ◽  
Vol 2018 ◽  
pp. 1-8 ◽  
Author(s):  
José Alvim Berkenbrock ◽  
Rafaela Grecco Machado ◽  
Daniela Ota Hisayasu Suzuki
Keyword(s):  
Electric Field ◽  
In Silico ◽  
Treatment Effectiveness ◽  
Numerical Study ◽  
Specific Treatment ◽  
The Body ◽  
Membrane Selectivity ◽  
Chemotherapy Drugs ◽  
Mast Cell Tumor ◽  
Anticancer Treatment

Electrochemotherapy is an anticancer treatment based on applying electric field pulses that reduce cell membrane selectivity, allowing chemotherapy drugs to enter the cells. In parallel to electrochemotherapy clinical tests, in silico experiments have helped scientists and clinicians to understand the electric field distribution through anatomically complex regions of the body. In particular, these in silico experiments allow clinicians to predict problems that may arise in treatment effectiveness. The current work presents a metastatic case of a mast cell tumor in a dog. In this specific treatment planning study, we show that using needle electrodes has a possible pitfall. The macroscopic consequence of the electroporation was assessed through a mathematical model of tissue electrical conductivity. Considering the electrical and geometrical characteristics of the case under study, we modeled an ellipsoidal tumor. Initial simulations were based on the European Standard Operating Procedures for electrochemotherapy suggestions, and then different electrodes’ arrangements were evaluated. To avoid blind spots, multiple applications are usually required for large tumors, demanding electrode repositioning. An effective treatment electroporates all the tumor cells. Partially and slightly overlapping the areas increases the session’s duration but also likely increases the treatment’s effectiveness. It is worth noting that for a single application, the needles should not be placed close to the tumor’s borders because effectiveness is highly likely to be lost.

Developmental stages in the Digenea

Parasitology ◽  
1964 ◽  
Vol 54 (2) ◽  
pp. 295-312 ◽  
Author(s):  
Elon E. Byrd ◽  
William P. Maples
Keyword(s):  
Body Wall ◽  
Developmental Stages ◽  
Snail Host ◽  
The Body ◽  
Body Movements ◽  
Hatching Enzyme ◽  
Apical Papilla ◽  
Short Time ◽  
Membranous Body ◽  
Egg Capsule

The naturally oviposited egg of Dasymetra conferta is fully embryonated and it hatches only after it is ingested by the snail host, Physa spp.Hatching appears to be in response to some stimulus supplied by the living snail. The stimulus causes the larva to exercise a characteristic series of body movements and to liberate a granular sustance (hatching enzyme) from the larger pair of its cephalic glands. This enzyme reacts with the vitelline fluid to create pressure within the egg capsule, and with the cementum of the operculum, so that it may be lifted away. The larva's escape from the shell, therefore, is due to a combination of pressure and body movements.The hatched larva has a membranous body wall, supporting six epidermal plates, an apical papilla, two penetration glands and a central matrix (the presumptive brood mass).It lives for about an hour within the snail and during this time there is a reorganization of the central matrix which terminates in the formation of an 8-nucleated syncytial brood mass.The miracidial ‘case’, consisting of the body wall and the epidermal plates, ultimately ruptures to liberate the brood mass. Once the brood mass is free it penetrates through the gut wall in an incredibly short time.

Isolation of myosalvarsan'a

1930 ◽  
Vol 26 (9) ◽  
pp. 942-942
Author(s):  
H. Bauer
Keyword(s):  
Maximum Amount ◽  
The Body ◽  
Drug Excretion ◽  
Clinical Observations ◽  
Short Time ◽  
Detailed Technique ◽  
Cessation Of Treatment

Abstracts. Venereology and Dermatology. Hugo Bauer (D. Z. Bd. 57, H. 4, 29), aiming to study the secretion of myosalvarsan'a, took under observation 4 syphilitics treated with injections of the drug. Excretion of myosalvarsan'a, as well as its absorption, is similar to 'neo' and sulfoxylsalvarsan'y. Most of the arsenobenzol'a introduced into the body is released within a "short time" after injection; four weeks after the cessation of treatment, the body is freed from the maximum amount of introduced As. The author believes that the clinical observations, on the basis of which it is argued that if certain intervals are observed between courses, the cumulative action of As does not occur, are completely fair. The author gives a detailed technique for determining As in selections and supplies the article with visual tables and curves of his own observations.

LEGAL REGULATION IN THE IMPLEMENTATION OF A SET OF MEASURES AIMED AT ENSURING THE OPERATIONAL RELIABILITY AND SAFETY OF OWNERLESS HYDRAULIC STRUCTURES

2020 ◽  
Vol 3 (82) ◽  
pp. 81-88
Author(s):  
Z.M. Kadiev ◽  
◽  
A.N. Kochetov ◽  
Keyword(s):  
Legal Regulation ◽  
Operational Reliability ◽  
Hydraulic Structures

На территориях, поднадзорных Федеральной службе по экологическому, технологическому и атомному надзору, территориальными Управлениями в рамках возложенных полномочий, проводятся регулярные работы, направленные на выявление и сокращение количества бесхозяйных гидротехнических сооружений. Статус гидротехнического сооружения в качестве бесхозяйного, являющегося объектом, создающими повышенную опасность для населения, требует принятия незамедлительных мер по постановке их на учет и передаче в собственность и/или оперативное управление эксплуатирующей организации для обеспечения безопасности с целью предотвращения чрезвычайных ситуаций и стихийных бедствий. Законодатель уделил особое внимание вопросу соблюдения обязательных требований безопасности бесхозяйных ГТС. И отнес их к наиболее вероятно опасным объектам хозяйственного права. Отсутствие собственника и/или эксплуатирующей организации, подготовленного и аттестованного штата обслуживающих сооружения специалистов, не может не отразиться на потенциальной опасности самого сооружения и, как следствие, территории его расположения. Эти события могут послужить причиной возникновения ситуаций, влекущих за собой негативные последствия, ввиду наличия опасности для жизни и здоровья людей, проживающих на данной территории.

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