scholarly journals Stability Study Using Numerical Analysis for the Panel Method Applied to the Weathered Rock Section below the National Highway

2021 ◽  
Vol 21 (5) ◽  
pp. 213-220
Author(s):  
Ji-Sun Kim ◽  
Ja-Yeon Kim ◽  
Ki-Young Eum ◽  
KookHwan Cho
Keyword(s):  
Numerical Analysis ◽  
Soil Layer ◽  
Stability Study ◽  
Panel Method ◽  
Measuring Instruments ◽  
Tunneling Method ◽  
Ground Conditions ◽  
Natm Tunnel ◽  
The Stability ◽  
National Road

In sections with poor ground conditions, it is difficult to apply the commonly used NATM tunnel method; thus, applications of the non-open cut tunneling method are increasing. This section is a tunnel crossing area under the national road in which the Panel method is to be applied to the section where a deeply buried layer and a loose weathered soil layer are distributed. Therefore, the stability of the upper road, the amount of settlement, and the stability of the tunnel structure were reviewed for each construction stage by using MIDAS GTX. Through the installation of measuring instruments in the tunnel area, the results of the numerical analysis were reviewed and the stability during and after construction was evaluated. Therefore, it is likely that the Panel method is an appropriate countermeasure in the downtown area and in areas with soft ground sections where the application of the general tunnel excavation method is difficult.

Calculation of Static Safety Coefficient about Loess Cave

2011 ◽  
Vol 189-193 ◽  
pp. 2366-2370
Author(s):  
Jun Hong Li
Keyword(s):  
Finite Element ◽  
Yield Criterion ◽  
Soil Layer ◽  
Engineering Application ◽  
Static Stability ◽  
Strength Reduction ◽  
Engineering Practice ◽  
Stability Calculation ◽  
Safety Coefficient ◽  
The Stability

For the loess cave characteristics, such as the thin coverage soil layer at the hole top, the poor self-stabilizing capacity, the large disturbance deformation after excavation and the easy collapse, thus in this paper, the loess cave safety factor is obtained by the method of strength reduction. And the stability calculation analysis is much more perfect. The Northwest Area Lishi loess cave is used in this paper, and the idea of strength reduction finite element method is applied, based on the Drucker-Prager yield criterion, the loess cave static stability analysis is made by the software of ANSYS.The results show that the actual situation can be reflected by the method of finite element strength subtraction. And the obtained loess cave stability coefficient is much closer to the actual steady state, thus showing the certain advantages of stability analysis.The method is also adopted in this paper. And its feasibility can be applied to the engineering practice, also a theoretical basis of reference is provided for engineering application.

scholarly journals An integral equation formulation of the N-body dielectric spheres problem. Part 1: Numerical analysis

2020 ◽  
Author(s):  
Muhammad Hassan ◽  
Benjamin Stamm
Keyword(s):  
Integral Equation ◽  
Numerical Analysis ◽  
Error Analysis ◽  
Convergence Rates ◽  
A Priori ◽  
Approximation Error ◽  
Spherical Particles ◽  
Integral Equation Formulation ◽  
Dielectric Spheres ◽  
The Stability

In this article, we analyse an integral equation of the second kind that represents the solution of N interacting dielectric spherical particles undergoing mutual polarisation. A traditional analysis can not quantify the scaling of the stability constants- and thus the approximation error- with respect to the number N of involved dielectric spheres. We develop a new a priori error analysis that demonstrates N-independent stability of the continuous and discrete formulations of the integral equation. Consequently, we obtain convergence rates that are independent of N.

scholarly journals Limitations and Challenges in the Stability of Cysteamine Eye Drop Compounded Formulations

2021 ◽  
Vol 15 (1) ◽  
pp. 2
Author(s):  
Cristina Martín-Sabroso ◽  
Mario Alonso-González ◽  
Ana Fernández-Carballido ◽  
Juan Aparicio-Blanco ◽  
Damián Córdoba-Díaz ◽  
...  
Keyword(s):  
Shelf Life ◽  
Stability Study ◽  
Eye Drops ◽  
Microbiological Analysis ◽  
Nitrogen Gas ◽  
Long Term Stability ◽  
Main Degradation Product ◽  
The Stability ◽  
Unstable Molecule

Accumulation of cystine crystals in the cornea of patients suffering from cystinosis is considered pathognomonic and can lead to severe ocular complications. Cysteamine eye drop compounded formulations, commonly prepared by hospital pharmacy services, are meant to diminish the build-up of corneal cystine crystals. The objective of this work was to analyze whether the shelf life proposed for six formulations prepared following different protocols used in hospital pharmacies is adequate to guarantee the quality and efficacy of cysteamine eye drops. The long-term and in-use stabilities of these preparations were studied using different parameters: content of cysteamine and its main degradation product cystamine; appearance, color and odor; pH and viscosity; and microbiological analysis. The results obtained show that degradation of cysteamine was between 20% and 50% after one month of storage in the long-term stability study and between 35% and 60% in the in-use study. These data confirm that cysteamine is a very unstable molecule in aqueous solution, the presence of oxygen being the main degradation factor. Saturation with nitrogen gas of the solutions offers a means of reducing cysteamine degradation. Overall, all the formulae studied presented high instability at the end of their shelf life, suggesting that their clinical efficacy might be dramatically compromised.

scholarly journals FORMULATION, CHARACTERIZATION AND STABILITY STUDY OF FAST DISSOLVING THIN FILM CONTAINING ASTAXANTHIN NANOEMULSION USING HYDROXYPROPYLMETHYL CELLULOSE POLYMER

2021 ◽  
pp. 17-22
Author(s):  
LUSI NURDIANTI ◽  
IYAN SOPYAN ◽  
TAOFIK RUSDIANA
Keyword(s):  
Thin Film ◽  
Mechanical Characteristics ◽  
Storage Conditions ◽  
Stability Study ◽  
Matrix System ◽  
Stability Studies ◽  
Casting Method ◽  
Hydroxypropylmethyl Cellulose ◽  
The Stability ◽  
Physical And Mechanical Characteristics

Objective: The present study was conducted to formulate and characterize the thin film containing astaxanthin nanoemulsion (TF-ASN) using Hydroxypropylmethyl Cellulose (HPMC) polymer as a film matrix system. The stability studies in different storage conditions were also performed. Methods: Astaxanthin nanoemulsion (As-NE) was prepared by using self-nanoemulsifying method, followed by incorporation into the HPMC matrix system by solvent casting method to forming TF-ASN. Evaluation of TF-ASN was performed by physical and mechanical characterizations. Stability study was carried out in both of accelerated (temperature of 40±2 °C/75±5% RH) and non-accelerated (at ambient temperature) conditions. Assay of astaxanthin in individual TF-ASN was determined compared to pure astaxanthin. Results: TF-ASN had good physical and mechanical characteristics that suitable for intraoral administration. Conclusion: For the study of stability under different storage conditions, it was proven that nanoemulsion form was packed in a HPMC matrix could enhance the stability of the astaxanthin.

scholarly journals The stability study of a plane engine

2000 ◽  
Vol 27 (1) ◽  
pp. 35-44
Author(s):  
Rafał Kołodziej ◽  
Tomasz Nowicki
Keyword(s):  
Stability Study ◽  
The Stability

scholarly journals Hydraulic Tests and Interpretation of Test Data for Reno Mattresses in Open Channel Flow

2021 ◽  
Vol 930 (1) ◽  
pp. 012025
Author(s):  
P D Pietro ◽  
M Lelli ◽  
A Rahman ◽  
Serkandi
Keyword(s):  
Soil Erosion ◽  
Control Systems ◽  
Soil Layer ◽  
Erosion Control ◽  
Wire Mesh ◽  
Unit Weight ◽  
Research Results ◽  
Colorado State University ◽  
Soil Erosion Control ◽  
The Stability

Abstract The efficacy of erosion control systems depends on preventing soil loss underneath and maintaining its integrity under the effects of the water flow. The paper presents the research results at the Colorado State University on the performance of double twisted wire mesh products, known as Reno Mattresses, used as soil erosion control systems. Mattresses were subjected to various flow conditions on a 10 m long flume placed on a soil layer. The performance against erosion was evaluated by assessing the effect of the stone motion inside the mattress combined with the condition of incipient soil erosion underneath, in relationship to the mattress thickness, the filling stone properties, and under variable hydraulic flow regimes. At the same time, confirming the stability obtained using the conventional tractive force design approach, the research results allowed to introduce a new performance limit based on incipient soil erosion underneath the revetment. Based on the research results, the authors propose to express the shear resistance of mattresses used as soil erosion control systems as a function of the filling stones’ size, uniformity, unit weight, mattress thickness, and the presence of vertical strengthening elements.

scholarly journals Physicochemical Properties and Stability of Microencapsulated Betacyanin Pigments from Red Dragon Fruit Peels and Flesh

2020 ◽  
pp. 141-148
Author(s):  
Rosalinda C Torres ◽  
Rowelain Mae G Yumang ◽  
Chelsea Kate F Jose ◽  
Danielle Camille P Canillo
Keyword(s):  
Moisture Content ◽  
Physicochemical Properties ◽  
Morphological Characterization ◽  
Stability Study ◽  
Natural Colorant ◽  
Hygroscopic Moisture ◽  
Dragon Fruit ◽  
The Stability ◽  
Spray Dried ◽  
Hylocereus Polyrhizus

Dragon fruit (Hylocereus polyrhizus) is known for its purple-coloured peels and pulp, which can be attributed to the presence of betalains. In this study, the potential of red dragon fruit as a source of natural colorant was investigated. Betacyanins were extracted from red dragon fruit peels and flesh in 1:3 ratio with water. Microencapsulation by spray-drying was done by adding 5% and 10% (w/v) maltodextrin (DE 11.8) to peels and flesh extracts, respectively. The spray-dried colorant powders all obtained <10% moisture content, 5.261-6.409 g/100g hygroscopic moisture content, and 5.317-7.349(mg/100L) betacyanin content. Morphological characterization revealed spherical, agglomerated particles with visible cracks on the surface. The stability study conducted showed that pigment retention was lowest at 70°C and highest at 4°C. Keywords: Hylocereus polyrhizus; Red dragon fruit; Betacyanin; Microencapsulation; Physicochemical properties

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