Study on Stability of Dayantang Landslide under the Engineering Disturbance and Rainfall

2012 ◽  
Vol 594-597 ◽  
pp. 415-418
Author(s):  
Jian Jun Zhou ◽  
Hua Deng ◽  
Hao Peng
Keyword(s):  
Steady State ◽  
Anthropogenic Disturbance ◽  
Safety Monitoring ◽  
Numerical Results ◽  
Long Period ◽  
Unstable Failure ◽  
Before And After ◽  
Project Construction ◽  
The Stability

Dayantang slope was stable before Shuibuya project construction. Based on the long-term safety monitoring, it has appeared the obvious deformation during the project construction. According the monitoring datas, the stability of the landslide before and after the construction was discussed and analyzed. Considering the rainfall effect on landslide after it has been strongly anthropogenic disturbance, the numerical results show that it is in critical steady state without rainfall, while get worse and even unstable failure under the influence of the intensive rain and the long period of rainfall.

Numerical Simulation on Deformation Features and Filling Efficiency of Channel Goaf Foundation

2013 ◽  
Vol 353-356 ◽  
pp. 3707-3712
Author(s):  
Zhi Dong Zhou ◽  
Hong Bo Zhang ◽  
Xiu Guang Song ◽  
Hong Ya Yue
Keyword(s):  
Numerical Simulation ◽  
Comparative Analysis ◽  
Comprehensive Analysis ◽  
Obvious Effect ◽  
Before And After ◽  
Check Gate ◽  
Deformation Features ◽  
Natural Foundation ◽  
The Stability

For analyzing and evaluating the deformation features of channel goaf foundation and its effect on superstructure, according to the foundation reinforcement engineering of Ji-Liang Channel Check Gate, the comparative analysis on the differential settlement between the unfavorable foundation and natural foundation was performed by numerical simulation with FLAC3D. The computer results showed that the present foundation had obvious effect on the stability and security of the superstructure, so the engineering treatment are needed. Based on technical-economic comprehensive analysis among three treatment methods for strengthening the channel golf foundation with different kinds of filling, the reasonable method is put forward in this paper. By comparing mechanical characteristic of flashboard in channel goaf before and after strengthening, we confirmed the foundation stability of channel goaf and the security of the ground building which can satisfy the long term usage requirements.

scholarly journals Performance of three iGrav superconducting gravity meters before and after transport to remote monitoring sites

2020 ◽  
Vol 223 (2) ◽  
pp. 959-972
Author(s):  
Florian Schäfer ◽  
Philippe Jousset ◽  
Andreas Güntner ◽  
Kemal Erbas ◽  
Jacques Hinderer ◽  
...  
Keyword(s):  
Geothermal Field ◽  
Absolute Gravity ◽  
Absolute Calibration ◽  
Noise Levels ◽  
Before And After ◽  
Gravity Measurements ◽  
Superconducting Gravity ◽  
The Stability ◽  
Comparison Measurements

SUMMARY High spatial and temporal resolution of gravity observations allows quantifying and understanding mass changes in volcanoes, geothermal or other complex geosystems. For this purpose, accurate gravity meters are required. However, transport of the gravity meters to remote study areas may affect the instrument's performance. In this work, we analyse the continuous measurements of three iGrav superconducting gravity meters (iGrav006, iGrav015 and iGrav032), before and after transport between different monitoring sites. For 4 months, we performed comparison measurements in a gravimetric observatory (J9, Strasbourg) where the three iGravs were subjected to the same environmental conditions. Subsequently, we transported them to Þeistareykir, a remote geothermal field in North Iceland. We examine the stability of three instrumental parameters: the calibration factors, noise levels and drift behaviour. For determining the calibration factor of each instrument, we used three methods: First, we performed relative calibration using side-by-side measurements with an observatory gravity meter (iOSG023) at J9. Secondly, we performed absolute calibration by comparing iGrav data and absolute gravity measurements (FG5#206) at J9 and Þeistareykir. Thirdly, we also developed an alternative method, based on intercomparison between pairs of iGravs to check the stability of relative calibration before and after transport to Iceland. The results show that observed changes of the relative calibration factors by transport were less than or equal to 0.01 per cent. Instrumental noise levels were similar before and after transport, whereas periods of high environmental noise at the Icelandic site limited the stability of the absolute calibration measurements, with uncertainties above 0.64 per cent (6 nm s–2 V–1). The initial transient drift of the iGravs was monotonically decreasing and seemed to be unaffected by transport when the 4K operating temperatures were maintained. However, it turned out that this cold transport (at 4 K) or sensor preparation procedures before transport may cause a change in the long-term quasi-linear drift rates (e.g. iGrav015 and iGrav032) and they had to be determined again after transport by absolute gravity measurements.

The Effect of VikaneTm on the Stability of Cellulosic and Ligneous Materials -- Measurement of Deterioration by Chemical and Physical Methods

1990 ◽  
Vol 185 ◽  
Author(s):  
Helen D. Burgess ◽  
Nancy E. Binnie
Keyword(s):  
Hydrolytic Degradation ◽  
Degree Of Polymerization ◽  
Accelerated Ageing ◽  
Total Acid ◽  
Long Term Stability ◽  
Before And After ◽  
Pulp Fibres ◽  
General Scientific ◽  
The Stability

AbstractVikaneTM (sulphuryl fluoride) is a commercial fumigant[1] which is used for the control of pests in museum collections. This paper summarizes the results obtained through an investigation of the effect of VikaneTM on twenty-five paper and textile samples. Samples chosen were representative of artifacts present in North American collections (cotton, linen, jute, and wood pulp fibres, from 1622 to present).The effect of the fumigation treatment has been evaluated by chemical and physical analyses: (1) Acidity -- surface pH, cold extracted pH, total acid (iodometric titration), (2) Oxidative and Hydrolytic Degradation - viscometric average degree of polymerization, carbonyl content (hydrazone derivatization), (3) and Fumigant Residues (specific ion electrode). Analysis of unfumigated and fumigated samples was carried out before and after accelerated ageing (70°C and 50% relative humidity) in order to estimate the long term stability of fumigated samples.The data obtained show that commercial grade VikaneTM degrades cellulosic and ligneous fibres. A second set of experiments on two fibre types using a new experimental grade of VikaneTM gave significantly less degradation. The presentation of this work will concentrate upon a general scientific interpretation of results.It is anticipated that the conclusions will be applicable to a broad range of artifacts.

scholarly journals The Regulation of the Internal Sodium Concentration of Asellus Aquaticus in the Absence of Sodium Chloride in the Medium

1959 ◽  
Vol 36 (3) ◽  
pp. 556-561
Author(s):  
A. P. M. LOCKWOOD
Keyword(s):  
Steady State ◽  
Sodium Chloride ◽  
Sodium Concentration ◽  
Considerable Proportion ◽  
Asellus Aquaticus ◽  
Short Term ◽  
Long Period ◽  
Short Period ◽  
Total Sodium

1. The freshwater isopod Asellus aquaticus has been observed to survive in continuously flowing de-ionized water for up to 16 days. 2. The haemolymph osmotic pressure, and the concentrations of sodium and chloride fall rapidly to about 65 % of the normal value and then decrease very slowly until death. 3. Animals loaded to a steady state in 22Na and then washed with de-ionized water lose tracer at a rate which only decreases slightly between the beginning of washing out and the death of the animal. 4. It is suggested that a movement of water from haemolymph to cells as the haemolymph concentration falls may partially account for the maintenance of the haemolymph concentration despite the steady ion loss. 5. Animals loaded for only a short period in tracer before washing out lose about 50-60% of their 22Na after a few hours in de-ionized water and then show little further loss for a long period. 6. The differences in the tracer loss curves following long-term and short-term loading have been interpreted as indicating that a considerable proportion of the total sodium of Asellus is not in the haemolymph.

Model of a Frame of Dynamic Routing and Its Equilibrium

2018 ◽  
Vol 28 (01) ◽  
pp. 1850005
Author(s):  
Shu Zhang ◽  
Yuan Yuan ◽  
Jian Xu
Keyword(s):  
Steady State ◽  
Numerical Method ◽  
Shortest Path ◽  
Routing Algorithm ◽  
Dynamic Routing ◽  
Numerical Results ◽  
Queue Size ◽  
Careful Selection ◽  
The Stability ◽  
Selection Of

Dynamic routing algorithm based on the shortest path principle is criticized due to the oscillation induced by such routing scheme. In the present work, we propose the model of TCP/RED algorithm by a new frame of dynamic routing, based on the measurement of occupation ratio of router buffer for different links, which only requires the information of the queue size at the buffer of the router, to stabilize the system. We classify several types of equilibrium and employ the numerical method to study the stability of the steady state. Our numerical results show that the careful selection of the parameters characterizing the dynamic routing algorithm can stabilize the system in some cases.

scholarly journals The effect of Natura 2000 network on the Eurasian Eagle-owl (Bubo bubo) population in Southeast Bulgaria: implications for conservation

2021 ◽  
Vol 29 (1) ◽  
pp. 170-178
Author(s):  
Boyan Milchev ◽  
Valeri Georgiev
Keyword(s):  
Gap Analysis ◽  
Natura 2000 ◽  
Area Network ◽  
Bubo Bubo ◽  
Long Term Study ◽  
Before And After ◽  
Eagle Owl ◽  
The Stability ◽  
Special Protection Areas

Abstract The effectiveness and efficiency of the Natura 2000 network for the Eurasian Eagle-owl conservation in SE Bulgaria was assessed by comparing data collected during a long-term study on number of breeding pairs and fledglings before and after network establishment. The Natura 2000 network and non-protected areas showed similar values of the calculated indices according to the number of occupied localities. However, the pairs in Natura 2000 sites bred significantly less fledglings after the creation of the network than the pairs in non-protected ones. The Special Protection Areas (SPA) system created specifically for the preservation of birds has the lowest efficiency in respect to Eurasian Eagle-owl protection. Proposals were made after ‘gap analysis’ for real protection and optimization of the protected-area network to increase the stability of the Eurasian Eagle-owl population in the changing environment.

scholarly journals Enterococci Isolated from Japanese Quails Exposed to Microgravity Conditions and Stability of their Properties

2009 ◽  
Vol 78 (2) ◽  
pp. 253-258 ◽  
Author(s):  
Andrea Lauková ◽  
Gabriela Michlovičová
Keyword(s):  
Lactic Acid Production ◽  
Long Term Storage ◽  
Japanese Quails ◽  
Before And After ◽  
Long Time ◽  
Microgravity Conditions ◽  
The Stability ◽  
Enterocin A ◽  
Long Storage

Enterococci isolated from the crop and caecum of Japanese quails exposed to 7 day conditions of microgravity were re-vitalized after their dry-freezing long storage. Originally, the strains were isolated from Japanese quails after their landing from flight onboard the orbital station Mir during the experiment in August 1990. Because taxonomy as well as the studies concerning the bacteriocins, especially those produced by enterococci, have been continually developed for years, the aim of this study was to confirm species identification, stability of the properties of enterococci as well as to test new properties after their long storage. Genotyping allotted the strains to the species E. faecium. Lactic acid production was detected in similar amounts in the strains before and after their long-storage in dry-frozen form. The strains were vancomycinsensitive and kanamycin-resistant before as well as after their long-time storage. Variability in sensitivity to different antibiotics was found among the strains tested even before and after longtime storage. Each of the strains possessed at least one structural enterocin gene. The structural genes for enterocin A, P, B, L50B were detected in E. faecium EP7. E. faecium EP2, EEP4 have the genes for ent A, B, L50B. The gene for ent P was detected only in the strain EP7. The most often detected was ent A gene followed by ent genes B, L50B. All strains inhibited growth of at least 4 out of 15 indicators. The stability of the enterococcal properties determined before as well as after their dry-freezing was not influenced during their long-term storage; moreover, new properties were determined.

TEM Analysis of Long-Period Polytypes in SiC—S

1976 ◽  
Vol 34 ◽  
pp. 630-631
Author(s):  
S. Shinozaki ◽  
J. W. Sprys
Keyword(s):  
Electron Diffraction ◽  
Isothermal Annealing ◽  
Tem Analysis ◽  
Long Period ◽  
Transmission Electron ◽  
Average Grain Size ◽  
High Resolution Tem ◽  
Structural Lattice ◽  
The Stability ◽  
Continuous Curves

In reaction sintered SiC (∽ 5um average grain size), about 15% of the grains were found to have long-period structures, which were identifiable by transmission electron microscopy (TEM). In order to investigate the stability of the long-period polytypes at high temperature, crystal structures as well as microstructural changes in the long-period polytypes were analyzed as a function of time in isothermal annealing.Each polytype was analyzed by two methods: (1) Electron diffraction, and (2) Electron micrograph analysis. Fig. 1 shows microdensitometer traces of ED patterns (continuous curves) and calculated intensities (vertical lines) along 10.l row for 6H and 84R (Ramsdell notation). Intensity distributions were calculated based on the Zhdanov notation of (33) for 6H and [ (33)3 (32)2 ]3 for 84R. Because of the dynamical effect in electron diffraction, the observed intensities do not exactly coincide with those intensities obtained by structure factor calculations. Fig. 2 shows the high resolution TEM micrographs, where the striped patterns correspond to direct resolution of the structural lattice periodicities of 6H and 84R structures and the spacings shown in the figures are as expected for those structures.

The stability of dislocation networks under various oxygen-doping conditions in superconducting Bi2Sr2CaCu2Oy single crystals and their influence on the flux pinning properties

1994 ◽  
Vol 52 ◽  
pp. 802-803
Author(s):  
Y. Feng ◽  
X. Y. Cai ◽  
R. J. Kelley ◽  
D. C. Larbalestier
Keyword(s):  
Single Crystals ◽  
Oxygen Content ◽  
Basal Plane ◽  
Flux Pinning ◽  
Pinning Centers ◽  
Before And After ◽  
Anomalous Peak ◽  
Basal Plane Dislocation ◽  
The Stability ◽  
Further Development

The issue of strong flux pinning is crucial to the further development of high critical current density Bi-Sr-Ca-Cu-O (BSCCO) superconductors in conductor-like applications, yet the pinning mechanisms are still much debated. Anomalous peaks in the M-H (magnetization vs. magnetic field) loops are commonly observed in Bi2Sr2CaCu2Oy (Bi-2212) single crystals. Oxygen vacancies may be effective flux pinning centers in BSCCO, as has been found in YBCO. However, it has also been proposed that basal-plane dislocation networks also act as effective pinning centers. Yang et al. proposed that the characteristic scale of the basal-plane dislocation networksmay strongly depend on oxygen content and the anomalous peak in the M-H loop at ˜20-30K may be due tothe flux pinning of decoupled two-dimensional pancake vortices by the dislocation networks. In light of this, we have performed an insitu observation on the dislocation networks precisely at the same region before and after annealing in air, vacuumand oxygen, in order to verify whether the dislocation networks change with varying oxygen content Inall cases, we have not found any noticeable changes in dislocation structure, regardless of the drastic changes in Tc and the anomalous magnetization. Therefore, it does not appear that the anomalous peak in the M-H loops is controlled by the basal-plane dislocation networks.

Sorbitol enhances the physicochemical stability of B12 vitamers

2020 ◽  
Vol 90 (5-6) ◽  
pp. 439-447 ◽  
Author(s):  
Andrew Hadinata Lie ◽  
Maria V Chandra-Hioe ◽  
Jayashree Arcot
Keyword(s):  
Ascorbic Acid ◽  
Uv Light ◽  
Heat Exposure ◽  
Water Soluble ◽  
Uv Exposure ◽  
Physicochemical Stability ◽  
Before And After ◽  
The Stability

Abstract. The stability of B12 vitamers is affected by interaction with other water-soluble vitamins, UV light, heat, and pH. This study compared the degradation losses in cyanocobalamin, hydroxocobalamin and methylcobalamin due to the physicochemical exposure before and after the addition of sorbitol. The degradation losses of cyanocobalamin in the presence of increasing concentrations of thiamin and niacin ranged between 6%-13% and added sorbitol significantly prevented the loss of cyanocobalamin (p<0.05). Hydroxocobalamin and methylcobalamin exhibited degradation losses ranging from 24%–26% and 48%–76%, respectively; added sorbitol significantly minimised the loss to 10% and 20%, respectively (p < 0.05). Methylcobalamin was the most susceptible to degradation when co-existing with ascorbic acid, followed by hydroxocobalamin and cyanocobalamin. The presence of ascorbic acid caused the greatest degradation loss in methylcobalamin (70%-76%), which was minimised to 16% with added sorbitol (p < 0.05). Heat exposure (100 °C, 60 minutes) caused a greater loss of cyanocobalamin (38%) than UV exposure (4%). However, degradation losses in hydroxocobalamin and methylcobalamin due to UV and heat exposures were comparable (>30%). At pH 3, methylcobalamin was the most unstable showing 79% degradation loss, which was down to 12% after sorbitol was added (p < 0.05). The losses of cyanocobalamin at pH 3 and pH 9 (~15%) were prevented by adding sorbitol. Addition of sorbitol to hydroxocobalamin at pH 3 and pH 9 reduced the loss by only 6%. The results showed that cyanocobalamin was the most stable, followed by hydroxocobalamin and methylcobalamin. Added sorbitol was sufficient to significantly enhance the stability of cobalamins against degradative agents and conditions.

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