scholarly journals Stability study of rock slope in fractured quartzite at right side of spillway, Middle Marsyangdi Hydroelectric Project, Nepal

2003 ◽  
Vol 28 ◽  
Author(s):  
Kaustubh Mani Nepal ◽  
Roger Olsson
Keyword(s):  
Rock Slope ◽  
Stability Study ◽  
Cut Slope ◽  
Stability Studies ◽  
Hydroelectric Project ◽  
The Stability ◽  
The Right ◽  
Cut Slopes

A 120 m long and 68 m high rock cut slope is designed at the right side of spillway of Middle Marsyangdi Hydroelectric Project. This paper describes the stability studies performed for the rock cut slopes in jointed quartzite for foundation of spillway.

scholarly journals Assessment of Slope Instability and Risk Analysis of Road Cut Slopes in Lashotor Pass, Iran

2014 ◽  
Vol 2014 ◽  
pp. 1-12 ◽  
Author(s):  
Mohammad Hossein Taherynia ◽  
Mojtaba Mohammadi ◽  
Rasoul Ajalloeian
Keyword(s):  
Rock Mass ◽  
Risk Analysis ◽  
Rock Slope ◽  
Classification Systems ◽  
Slope Instability ◽  
Rock Slope Stability ◽  
Rock Slopes ◽  
The Stability ◽  
Cut Slopes ◽  
Road Cut Slopes

Assessment of the stability of natural and artificial rock slopes is an important topic in the rock mechanics sciences. One of the most widely used methods for this purpose is the classification of the slope rock mass. In the recent decades, several rock slope classification systems are presented by many researchers. Each one of these rock mass classification systems uses different parameters and rating systems. These differences are due to the diversity of affecting parameters and the degree of influence on the rock slope stability. Another important point in rock slope stability is appraisal hazard and risk analysis. In the risk analysis, the degree of danger of rock slope instability is determined. The Lashotor pass is located in the Shiraz-Isfahan highway in Iran. Field surveys indicate that there are high potentialities of instability in the road cut slopes of the Lashotor pass. In the current paper, the stability of the rock slopes in the Lashotor pass is studied comprehensively with different classification methods. For risk analyses, we estimated dangerous area by use of the RocFall software. Furthermore, the dangers of falling rocks for the vehicles passing the Lashotor pass are estimated according to rockfall hazard rating system.

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 Influence of Implant Surfaces on Osseointegration: A Histomorphometric and Implant Stability Study in Rabbits

2015 ◽  
Vol 26 (5) ◽  
pp. 451-457 ◽  
Author(s):  
Priscilla Barbosa Ferreira Soares ◽  
Camilla Christian Gomes Moura ◽  
Marcela Claudino ◽  
Valessa Florindo Carvalho ◽  
Flaviana Soares Rocha ◽  
...  
Keyword(s):  
Surface Characteristics ◽  
Analysis Data ◽  
Stability Study ◽  
Histomorphometric Analysis ◽  
Resonance Frequency Analysis ◽  
Bone Implant ◽  
Bone Integration ◽  
The Stability ◽  
The Right ◽  
The Sacrifice

Abstract: The aim of this study was to evaluate the stability and osseointegration of implant with different wettability using resonance frequency analysis (RFA) and histomorphometric analysis (bone implant contact, BIC; and bone area fraction occupied, BAFO) after 2 and 4 weeks in rabbit tibiae. Thirty-two Morse taper implants (length 7 mm, diameter 3.5 mm) were divided according to surface characteristics (n=8): Neo, sandblasted and dual acid-etched; and Aq, sandblasted followed by dual acid-etched and maintained in an isotonic solution of 0.9% sodium chloride. Sixteen New Zealand rabbits were used. Two implants of each group were installed in the right and left tibiae according to the experimental periods. The RFA (Ostell(r)) was obtained immediately and after the sacrifice (2 and 4 weeks). The bone/implant blocks were processed for histomorphometric analysis. Data were analyzed using two-way ANOVA followed by Tukey's test and Pearson's correlation for ISQ, BIC and BAFO parameters (p=0.05). No significant effect of implant, period of evaluation or interaction between implant and period of evaluation was found for BIC and BAFO values (p>0.05). Only period of evaluation had significant effect for RFA values at 4 weeks (p=0.001), and at 2 weeks (p<0.001). RFA values were significantly higher at the final period of evaluation compared with those obtained at early periods. There was a significant correlation between BIC values and BAFO values (p=0.009). Both implant surfaces, Aq and Neo, were able to produce similar implant bone integration when normal cortical bone instrumentation was performed.

scholarly journals Stability Assessment of the Excavated Rock Slope at the Dagangshan Hydropower Station in China Based on Microseismic Monitoring

2018 ◽  
Vol 2018 ◽  
pp. 1-16 ◽  
Author(s):  
K. Ma ◽  
N. W. Xu ◽  
Z. Z. Liang
Keyword(s):  
Rock Mass ◽  
Slope Stability ◽  
Monitoring System ◽  
Rock Slope ◽  
Rock Slope Stability ◽  
Hydropower Station ◽  
Bank Slope ◽  
The Stability ◽  
The Right ◽  
Dagangshan Hydropower Station

A high-resolution microseismic (MS) monitoring system was implemented at the right bank slope of the Dagangshan hydropower station in May 2010 to analyse the slope stability subjected to continuous excavation. The MS monitoring system could real-time capture a large number of seismic events occurring inside the rock slope. The identification and delineation of rock mass damage subject to excavation and consolidation grouting can be conducted based on the analysis of tempospatial distribution of MS events. However, how to qualitatively evaluate the stability of the rock slope by utilizing these MS data remains challenging. A damage model based on MS data was proposed to analyse the rock mass damage, and a 3D finite element method model of the rock slope was also established. The deteriorated mechanical parameters of rock mass were determined according to the model elements considering the effect of MS damage. With this method, we can explore the effect of MS activities, which are caused by rock mass damage subjected to excavation and strength degradation to the dynamic instability of the slope. When the MS damage effect was taken into account, the safety factor of the rock slope was reduced by 0.18 compared to the original rock slope model without considering the effect. The simulated results show that MS activities, which are subjected to excavation unloading, have only a limited effect on the stability of the right bank slope. The proposed method is proven to be a better approach for the dynamical assessment of rock slope stability and will provide valuable references for other similar rock slopes.

scholarly journals Evolution of the Stabilis® Database: Creation of a Level of Evidence for Stability Studies

2018 ◽  
Vol 3 (1) ◽  
pp. 3-12 ◽  
Author(s):  
Elise D’Huart ◽  
Pauline Lider ◽  
Jean Vigneron ◽  
Béatrice Demoré
Keyword(s):  
Analytical Method ◽  
Antiviral Drugs ◽  
Stability Study ◽  
Antifungal Drugs ◽  
Quality Level ◽  
Stability Studies ◽  
Level Of Evidence ◽  
Stability Data ◽  
The Stability

AbstractBackgroundStabilis®is an international database on stability and compatibility of drugs. The stability data comes mainly from publications of pharmaceutical journals. As the quality of the published stability studies is not equivalent, the objective of this work was to propose a level of evidence for the physico-chemical stability studies selected for the database.MethodsAt first, we evaluated the main pharmacological class consulted by the users. This work was then divided into 5 steps: (1) updating of the criteria to validate a stability study, (2) creating a grid rating articles, (3) rating of the articles of stability studies for anticancer, antifungal and antiviral drugs by 2 evaluators, (4) creation of new screens in the database to enter rating, to visualize the pictograms and commentaries by the users, (5) creation of a guideline to explain the different levels of evidence.ResultsThe main pharmacological class consulted by Stabilis®users is the anticancer drugs and then antiinfectives. We have selected anticancer, antifungal and antiviral drugs for our study. Two hundred and forty publications were evaluated. The highest level attributed was A for anticancer and antifungal drugs and C for antiviral drugs. This difference can be explained by the fact that the majority of publications about antiviral drugs were older.The most frequent anomalies in the rating of articles were an incomplete or imperfect validation of the analytical method (high value of the coefficient of variation) and a defect in the evaluation of the stability indicating capacity.It must be noted that the level of evidence is not the quality level of the analytical method but the mixture of the quality of the method validation and of the results. This aspect was a choice of the Stabilis®team and seems important because the security of the patient is impacted by both aspects.ConclusionsThis new function contributes to help the Stabilis®users to evaluate the stability data published and to take a decision for their use in daily practice. This function will be progressively extended to other pharmacological classes of injectable drugs and then for non-injectable preparations.

scholarly journals Bio-analytical Approach for Stability Studies of Bendroflumethiazide Materials

2021 ◽  
pp. 195-203
Author(s):  
B. Veeraswami ◽  
V. M. K. Naveen
Keyword(s):  
Stability Study ◽  
Stability Studies ◽  
Dry Extract ◽  
Long Term Stability ◽  
Analytical Stability ◽  
Ich Guidelines ◽  
The Stability ◽  
Efficacy Prediction

In this paper a comprehensive study of stability related, and evidence based best practices of Bio-analytical stability on Bendroflumethiazide drug samples are studied. The proposed approach is very significant and essential for the drugs development process address the specify the acceptancy, purity, efficacy, prediction of strength and quality of the drugs. The stability study constituents several methods like Bench-Top, Auto-sampler, Freeze-Thaw, Dry-extract, Wet-extract, Short-term, long-Term stability studies at relative intervals results the complete stability information about the drug under the proposed and validated method. There ported out comes of this methos shows this drug have good stability according to ICH guidelines.

scholarly journals Seismic stability analysis of rock slopes by yield design theory using the generalized Hoek-Brown criterion

2018 ◽  
Vol 149 ◽  
pp. 02026
Author(s):  
Mounir Belghali ◽  
Zied Saada
Keyword(s):  
Rock Mass ◽  
Stability Analysis ◽  
Design Theory ◽  
Rock Slope ◽  
Numerical Solutions ◽  
Stability Study ◽  
Seismic Stability ◽  
Rock Slopes ◽  
The Stability ◽  
Kinematic Approach

The stability of rock slope is studied using the kinematic approach of yield design theory, under the condition of plane strain and by considering the last version of the Hoek-Brown failure criterion. This criterion, which is suitable to intact rock or rock mass highly fractured regarded as isotropic and homogeneous, is widely accepted by the rock mechanics community and has been applied in numerous projects around the world. The failure mechanism used to implement the kinematic approach is a log-spiral rotational mechanism. The stability analysis is carried out under the effects of gravity forces and a surcharge applied along the upper plateau of the slope. To take account of the effects of forces developed in the rock mass during the passage of a seismic wave, the conventional pseudo-static method is adopted. This method is often used in slope stability study for its simplicity and efficiency to simulate the seismic forces. The results found are compared with published numerical solutions obtained from other approaches. The comparison showed that the results are almost equal. The maximum error found is less than 1%, indicating that this approach is effective for analyzing the stability of rock slopes. The relevance of the approach demonstrated, investigations are undertaken to study the influence of some parameters on the stability of the slope. These parameters relate to the mechanical strength of the rock, slope geometry and loading.

Rock Slope Stability Study for Yujian River Dam Site Based on Kinematic Analyses

2012 ◽  
Vol 446-449 ◽  
pp. 2048-2055
Author(s):  
Liang Qing Wang ◽  
P.H.S.W. Kulatilake ◽  
Hui Ming Tang ◽  
Ye Liang
Keyword(s):  
Slope Stability ◽  
Rock Slope ◽  
Failure Modes ◽  
Stability Study ◽  
Rock Slope Stability ◽  
Field Investigations ◽  
Kinematic Analyses ◽  
Dam Site ◽  
Dip Angle ◽  
The Stability

Lithological information, rock mass fracture data and discontinuity shear strength obtained through field investigations have been used in conducting kinematic analyses for the rock slopes that exist in the Yujian River dam site to evaluate the stability of the slopes. Results given in the paper can be considered as conservative because of several conservative assumptions used in the analyses. Dam site slopes seem quite stable up to 40º dip angle. Out of the three basic failure modes, possible wedge sliding seems to be the most likely one followed up with possible plane sliding as the second. Irrespective of the considered slope regions, slope dip direction ranges 270-315º and 200-210º seem to be the worst cases for possible instability of slopes in the dam site. Regional slopes in the dam site can be ranked with respect to safety from the lowest to highest in the following order: R-c-1, R-e-2, R-c-2, R-d-1, R-b, R-a, R-d-2 and R-e-1. Note that the dam site slopes are currently stable and the existing slope angles agree well with the results obtained from the rock slope stability analyses.

Simplified Descriptive Scheme and Classification System for the Logging of Cut Slope Faces

1986 ◽  
Vol 2 (1) ◽  
pp. 253-260 ◽  
Author(s):  
T. I. Gamon ◽  
R. P. Finn
Keyword(s):  
Hong Kong ◽  
Classification System ◽  
Site Investigation ◽  
Granitic Rocks ◽  
Site Formation ◽  
Cut Slope ◽  
Weathered Granite ◽  
Soil Slopes ◽  
The Stability ◽  
Cut Slopes

AbstractA simplified descriptive scheme and classification system is currently being used for the systematic logging of cut slopes for a 22 ha site formation project in weathered granitic rocks in Hong Kong.The site formation comprises the removal of some 1.5 million m3 of soft granitic soil and 3.5 million m3 of sound rock, and the formation of approximately 60,000 m2 of slope face. The cut slope faces are logged as they are exposed, and the slope protection and stabilisation works designed and installed as the site is lowered.A simplified descriptive scheme was considered essential to reduce the time for logging and eliminate the need for specialist logging personnel.Existing descriptive schemes were compared and the most useful, compatible indices selected. Additional indices from other authors were added where appropriate. This descriptive scheme was simplified after the site investigation stage of the works and the resultant scheme checked against the faces exposed during the excavation of 300,000 m3 of weathered granite as part of the advanced works.The finalised simplified scheme was documented as a manual, which has been used on site to standardise the descriptions, abbreviations and presentation. Once logged, the exposed weathered profile is classified into zones, and the distribution of the zones compared with a number of standard profiles to rapidly assess the stability of the ‘soil’ slopes.To date, 40,000 m2 of slope face have been logged at a scale of 1:100, and appropriate slope protection and stabilisation works designed and installed.

scholarly journals Stabilizing effect of chitosan-poly vinyl alcohol complex on simvastatin loaded nanoformulation

2019 ◽  
Vol 10 (3) ◽  
pp. 2265-2279
Author(s):  
Irisappan Sarathchandiran ◽  
Nandakumar Selvasudha ◽  
Kailasam Koumaravelou ◽  
Kandasamy Ruckmani
Keyword(s):  
High Performance ◽  
Freezing Temperature ◽  
Simulation Method ◽  
Stability Study ◽  
Poly Vinyl Alcohol ◽  
Forced Degradation ◽  
Stability Studies ◽  
Drug Molecules ◽  
Accelerated Stability ◽  
The Stability

Biopolymers are attractive new and general means of presenting more stable drug delivery system. This is accomplished by encapsulation of polymers to respective drug molecules which offer formation of bonds between them.  In this work, chitosan-coated simvastatin nanoformulation was formulated using a method named solvent evaporation technique, and various stability studies were performed. The steadiness of preparation was evaluated by accelerated stability method and forced degradation method. High-performance thin-layer chromatography (HPTLC) was utilized to detect the degradant present in formulation after subjecting it in different stress condition. Simulated annealing process for the prediction of nanoformulation stability was also performed. The accelerated stability study was performed at three altered temperature conditions, (i.e.) accelerated temperature (40 ± 2 °C/75 ± 5% RH), room temperature (25 ± 2 °C/60%) ± 5% RH, and freezing temperature (4°C) and change in drug content, solubility, % cumulative drug release, moisture content and molecular weight were calculated. Standard sample and nanoformulation were exposed to different stress conditions (thermal, base, acid, and light). Finally, the percentage of decomposition was calculated by HPTLC method. All stability studies, along with the simulation method, represented the stability of simvastatin in nanoformulation.  Establishment of adequate shelf life also was achieved. This work evidenced the extensive stability offered by chitosan polymers to the prodrug simvastatin. Also, give insight when the problem of poor stability of drug molecules limits its practical applicability.

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