scholarly journals METHODS FOR CALCULATING DYNAMIC SYSTEMS WITH ELASTOMERIC SUPPORTS UNDER SEISMIC IMPACTS OF THE "PROJECT EARTHQUAKE" LEVEL»

2020 ◽  
Vol 8 (3) ◽  
pp. 23-28
Author(s):  
Maksim Zubrickij ◽  
O. Ushakov ◽  
Linar Sabitov ◽  
A Sagabiev
Keyword(s):  
Surface Area ◽  
Dynamic Systems ◽  
Dynamic Method ◽  
Main Tool ◽  
Seismic Stability ◽  
Earthquake Resistant ◽  
The Difference ◽  
Seismic Impact ◽  
Isolated Systems ◽  
Seismic Impacts

The article provides a brief overview of methods for assessing the seismic stability of systems using elastomeric supports under seismic impacts of the "Project earthquake" level. As part of the study, a set of dynamic and static calculations was performed, and two methods for calculating earthquake-resistant systems were considered: the linear-spectral method (LSM) and the direct dynamic method (PDM). The purpose of the research is to assess the possibility of using LST for seismic impacts of the PZ level on systems with elastomeric supports. It was found that the difference in the results of calculations for the two methods does not exceed 12 %. Thus, the SHEET can be used as the main tool for calculating seismically isolated systems under the seismic impact of the earth's surface area.

scholarly journals Evaluation of the Vertical Producing Degree of Commingled Production via Waterflooding for Multilayer Offshore Heavy Oil Reservoirs

Energies ◽  
2018 ◽  
Vol 11 (9) ◽  
pp. 2428 ◽  
Author(s):  
Fei Shen ◽  
Linsong Cheng ◽  
Qiang Sun ◽  
Shijun Huang
Keyword(s):  
Heavy Oil ◽  
Flow Model ◽  
Dynamic Method ◽  
Theoretical Models ◽  
Oil Reservoirs ◽  
Sweep Efficiency ◽  
One Dimensional ◽  
Heavy Oil Reservoirs ◽  
The Difference ◽  
Important Form

Recently, commingling production has been widely used for the development of offshore heavy oil reservoirs with multilayers. However, the differences between layers in terms of reservoir physical properties, oil properties and pressure have always resulted in interlayer interference, which makes it more difficult to evaluate the producing degree of commingled production. Based on the Buckley–Leverett theory, this paper presents two theoretical models, a one-dimensional linear flow model and a planar radial flow model, for water-flooded multilayer reservoirs. Through the models, this paper establishes a dynamic method to evaluate seepage resistance, sweep efficiency and recovery percent and then conducts an analysis with field data. The result indicates the following: (1) the dynamic difference in seepage resistance is an important form of interlayer interference during the commingled production of an offshore multilayer reservoir; (2) the difference between commingled production and separated production is small within a certain range of permeability ratio or viscosity ratio, but separated production should be adopted when the ratio exceeds a certain value.

scholarly journals Effects of Hydraulic Gradient and Clay Type on Permeability of Clay Mineral Materials

Minerals ◽  
2020 ◽  
Vol 10 (12) ◽  
pp. 1064
Author(s):  
Masanori Kohno
Keyword(s):  
Hydraulic Conductivity ◽  
Specific Surface ◽  
Surface Area ◽  
Clay Mineral ◽  
Specific Surface Area ◽  
Hydraulic Gradient ◽  
Consistency Index ◽  
Hydrogen Energy ◽  
The Difference ◽  
Mineral Type

Considering the relevance of clay mineral-bearing geomaterials in landslide/mass movement hazard assessment, various engineering projects for resource development, and stability evaluation of underground space utilization, it is important to understand the permeability of these clay mineral-based geomaterials. However, only a few quantitative data have been reported to date regarding the effects of the clay mineral type and hydraulic gradient on the permeability of clay mineral materials. This study was conducted to investigate the permeability of clay mineral materials based on the clay mineral type, under different hydraulic gradient conditions, through a constant-pressure permeability test. Comparative tests have revealed that the difference in the types of clay mineral influences the swelling pressure and hydraulic conductivity. In addition, it has been found that the difference in water pressure (hydraulic gradient) affects the hydraulic conductivity of clay mineral materials. The hydraulic conductivity has been found to be closely associated with the specific surface area of the clay mineral material. Furthermore, the hydraulic conductivity value measured is almost consistent with the value calculated theoretically using the Kozeny–Carman equation. Moreover, the hydraulic conductivity is also found to be closely associated with the hydrogen energy, calculated from the consistency index of clay. This result suggests that the hydraulic conductivity of clay mineral materials can be estimated based on the specific surface area and void ratio, or consistency index of clay.

scholarly journals 520 Weight-based vs. BSA-based Fluid Resuscitation Predictions in Pediatric Burn Patients

2021 ◽  
Vol 42 (Supplement_1) ◽  
pp. S107-S107
Author(s):  
Jan V Stevens ◽  
Nina Prieto ◽  
Elika Ridelman ◽  
Justin D Klein ◽  
Christina M Shanti
Keyword(s):  
Surface Area ◽  
Fluid Resuscitation ◽  
Normal Weight ◽  
Overweight Children ◽  
Obese Children ◽  
Post Injury ◽  
Pediatric Burns ◽  
The Difference ◽  
Parkland Formula ◽  
Total Fluid

Abstract Introduction Current practice for major pediatric burns includes fluid resuscitation using formulas that estimate fluid requirements based on weight and/or body surface area (BSA) along with percent total burn surface area (TBSA). Adult studies have shown that these formulas can cause fluid overload in obese patients and increase risk of complications. These findings have not been validated in pediatric patients. This study aims to evaluate whether a weight-based resuscitation formula increases the risk of complications in obese children following burn injuries and compares fluid estimates to those that incorporate BSA. Methods A retrospective review was conducted on 110 children (≤ 18 years old) admitted to an ABA-verified urban pediatric burn center from October 2008 to May 2020. Patients had ≥15% TBSA, were resuscitated with the weight-based Parkland formula, and had fluids titrated to urine output every two hours (1 ml/kg/hr if ≤ 30kg; 0.5 ml/kg/hr if > 30kg). Demographics, burn type, and TBSA were collected on admission. BSA-based Galveston and BSA-incorporated Cincinnati formula resuscitation predictions were also calculated. Output and input volumes were collected at 8h and 24h post-injury. Complications were collected throughout the hospital stay. Patients were classified into CDC-defined weight groups based on percentile ranges. Statistical analysis was conducted using SPSS Statistics version 10.0. Results This study included 11 underweight, 60 normal weight, 18 overweight, and 21 obese children. Our patients had a mean age-based weight CDC percentile of 62.2%, and mean TBSA of 25.4%. Predicted resuscitation volumes increased as CDC percentile increased for all three formulas (p=0.033, 0.092, 0.038), however there were no significant differences between overweight and obese children. Total fluid administered was higher as CDC percentile increased (p=0.023). However, overweight children received more total fluid than obese children. The difference between total fluids given and Galveston predicted resuscitation volumes were significant across all groups (p=0.042); however, the difference using the Parkland and Cincinnati formulas were not statistically significant. There were more children in the normal weight group who developed complications compared to other groups, but these findings were not significant. Conclusions The Parkland formula tended to underpredict fluid needs in the underweight, normal weight, and overweight children, and it overpredicted fluid needs for the obese. Further research is needed to determine the value of weight-based vs BSA-based or incorporated formulas in terms of their risk of complications.

scholarly journals Correlation between clinical risk factors and tracheal intubation difficulty in infants with Pierre-Robin syndrome: A systematic review

2020 ◽  
Author(s):  
Yanli Liu ◽  
Jiashuo Wang ◽  
Shan Zhong
Keyword(s):  
Computed Tomography ◽  
Tracheal Intubation ◽  
Surface Area ◽  
Body Surface ◽  
Pierre Robin Syndrome ◽  
Intubation Difficulty ◽  
Computed Tomography Images ◽  
The Difference ◽  
And Gender ◽  
Pierre Robin

Abstract Background: Difficult tracheal intubation is a problem commonly encountered by anesthesiologists in the clinic. Methods: In this retrospective study, case-level clinical data and computed tomography images of 96 infants with Pierre-Robin syndrome were included in the analysis. First, computed tomography images were labeled by a clinically experienced physician. Then color space conversion, binarization, contour acquisition, and area calculation processing were performed on the annotated files. Finally, we calculated the correlation coefficient between the seven clinical factors and tracheal intubation difficulty, and the difference in each risk factor under tracheal intubation difficulty. Results: The absolute value of the correlation coefficient between throat area and tracheal intubation difficulty is 0.54, and the difference of throat area under tracheal intubation difficulty is significant. Body surface area, weight and gender also show significant difference under tracheal intubation difficulty. Conclusions: There is a significant correlation between throat area and tracheal intubation difficulty in infants with Pierre-Robin syndrome. Body surface area, weight and gender may have an impact on tracheal intubation difficulty in infants with Pierre-Robin syndrome.

Miskonsepsi Siswa pada Pemahaman Konsep Bangun Ruang

2020 ◽  
Vol 5 (2) ◽  
pp. 72-86
Author(s):  
Arif Muchyidin ◽  
Lefi Nurlatif ◽  
Indah Nursuprianah
Keyword(s):  
Surface Area ◽  
Causal Factors ◽  
Descriptive Research ◽  
8Th Grade ◽  
Qualitative Descriptive ◽  
The Difference ◽  
Research Students ◽  
Understanding Pictures ◽  
Area And Volume

The purpose of this study is to describe 8th-grade students’ misconceptions in solving surface area and volume of beam and cube problems and their causal factors. This is qualitative descriptive research. Based on the research, students’ misconceptions in solving surface area and volume of beam and cube problems are misconceptions on the concept of a beam, misconceptions on the concept of the cube, misconceptions on the concept of prerequisite material, misconceptions on unit comprehension, misconceptions on the understanding of meaning, and misconceptions on sign and number operations. While the causal factors of misconception are students’ assumptions about the lack of importance of concepts so students only memorize formulas, students are not able to associate one concept with other concepts, lack of understanding concepts in prerequisite material, misunderstanding the meaning of words in a problem, students have difficulty understanding pictures., misunderstanding the difference in the size of area and length.

Influence of underground mass explosion on protected objects of the industrial site in case of collapse of the interstory whole

2020 ◽  
pp. 368-382
Author(s):  
V. A. Kutuev ◽  
S. N. Zharikov
Keyword(s):  
Large Scale ◽  
Physical And Mechanical Properties ◽  
Underground Mine ◽  
Seismic Stability ◽  
Experimental Measurements ◽  
Industrial Site ◽  
Close Proximity ◽  
Ground Conditions ◽  
Seismic Vibrations ◽  
Seismic Impact

Within the boundaries of the mining branch of JSC Kyshtymsky MCC the underground large-scale blast was made to cave in the interstorey pillar with the maximum explosive weight 963 kg at the spacing stage. The Institute of Mining of Ural Branch of RAS has received a task to study the seismic impact of the underground large-scale blast on the protected objects of the industrial site of Kyshtymsky underground mine located in the close proximity to the sites of blast works. The aim of the work is to determine the seismic stability of grounds on sites of the protected objects and the permissible values of vibration velocities for buildings of JSC Kyshtymsky MCC. It is also necessary to determine the permissible distances from the blast to the protected objects for 5 engineering-geological elements on the basis of physical and mechanical properties of deposit rocks. On the basis of the initial data, according to the method of the Institute of Mining of Ural Branch of RAS, the authors have performed a complex of calculations of seismic stability of grounds on sites of the objects to determine the permissible values of vibration velocities for buildings of JSC Kyshtymsky MCC. The authors have also performed a multiversion calculation of permissible distances from the blast to the protected objects for 5 engineering-geological elements (EGE) depending on the the explosive weight at the spacing stage, the coefficient of ground conditions and the permissible velocity of seismic vibrations. As a result of comparison of the calculated values and experimental measurements, the recommendations have been given to establish the limitation of the explosive weight at the spacing stage to the level of minimum hazardous values during the large-scale blasts in the underground mine.

scholarly journals Notes on the behaviour of trajectories of polynomial dynamic systems

2020 ◽  
Vol 313 ◽  
pp. 00014
Author(s):  
Irina Andreeva
Keyword(s):  
Dynamic Systems ◽  
Wide Spectrum ◽  
Modern Science ◽  
Seismic Stability ◽  
Phase Portraits ◽  
Main Task ◽  
Physical Processes ◽  
Science And Engineering ◽  
Research Stage

Dynamic systems play a key role in various directions of modern science and engineering, such as the mathematical modeling of physical processes, the broad spectrum of complicated and pressing problems of civil engineering, for example, in the analysis of seismic stability of constructions and buildings, in the fundamental studies of computing and producing systems, of biological and sociological events. A researcher uses a dynamic system as a mathematical apparatus to study some phenomena and conditions, under which any statistical events are not important and may be disregarded. The main task of the theory of dynamic systems is to study curves, which differential equations of this system define. During such a research, firstly we need to split a dynamic system’s phase space into trajectories. Secondly, we investigate a limit behavior of trajectories. This research stage is to reveal equilibrium positions and make their classification. Also, here we find and investigate sinks and sources of the system’s phase flow. As a result, we obtain a full set of phase portraits, possible for a taken family of differential dynamic systems, which describe a behavior of some process. Namely polynomial dynamic systems often play a role of practical mathematical models hence their investigation has significant interest. This paper represents the original study of a broad family of differential dynamic systems having reciprocal polynomial right parts, and describes especially developed research methods, useful for a wide spectrum of applications.

scholarly journals Seismic stability of reinforced-soil wall by pseudo-dynamic method

2006 ◽  
Vol 13 (3) ◽  
pp. 111-119 ◽  
Author(s):  
S. S. Nimbalkar ◽  
D. Choudhury ◽  
J. N. Mandal
Keyword(s):  
Dynamic Method ◽  
Reinforced Soil ◽  
Seismic Stability ◽  
Reinforced Soil Wall

Effects of Carbonation on the Specific Surface BET of Cement Mortar Measured by Two Different Methods: Nitrogen Adsorption and Water Adsorption

2014 ◽  
Vol 931-932 ◽  
pp. 421-425 ◽  
Author(s):  
Son Tung Pham ◽  
William Prince
Keyword(s):  
Specific Surface ◽  
Surface Area ◽  
Specific Surface Area ◽  
Water Adsorption ◽  
Cement Mortar ◽  
Nitrogen Adsorption ◽  
Accelerated Carbonation ◽  
Molecular Sizes ◽  
The Difference ◽  
Adsorption Desorption

The objective of this work was to examine the microstructural changes caused by the carbonation of normal mortar. Samples were prepared and subjected to accelerated carbonation at 20°C, 65% relative humidity and 20% CO2concentration. The evolutions of the pore size distribution and the specific surface area during carbonation were calculated from the adsorption - desorption isotherms of water vapour and nitrogen. Conflicts observed in the results showed that the porous domains explored by these two methods are not the same due to the difference in molecular sizes of nitrogen and water. These two techniques therefore help to complementarily evaluate the effects of carbonation. The study also helped to explain why results in the literature diverge greatly on the influence of carbonation on specific surface area.

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