Structural Characteristics Predict the Stability of HIV

2011 ◽  
pp. 305-325
Author(s):  
Zohar Biron-Sorek ◽  
Yide Sun ◽  
Elaine Kan ◽  
Jeanne Flandez ◽  
Michael Franti ◽  
...  
Keyword(s):  
Structural Characteristics ◽  
The Stability

scholarly journals Farms as a resilience factors to land degradation in peri-urban areas

2013 ◽  
Vol 44 (2s) ◽  
Author(s):  
Paolo Zappavigna ◽  
Andrea Brugnoli
Keyword(s):  
Urban Areas ◽  
Structural Characteristics ◽  
Labour Force ◽  
Social Characteristics ◽  
The Family ◽  
External Conditions ◽  
Resilience Factors ◽  
The Stability ◽  
Economic Size

The purpose of this study was the analysis of the effects induced by urban pressures on the socio-economic and territorial characteristics of the rural peri-urban areas in order to identify planning and intervention strategies aimed at enhancing the quality of agriculture and landscape. A survey was conducted in the surroundings of Parma on farms located in the vicinity of urban areas. The structural, productive and social characteristics of the family-farm units were analyzed. The survey updated an identical survey, carried out in 1986, in which it was examined a sample of 208 farms. The units surveyed were evaluated in two aspects: the “vitality”, which takes into account the structural characteristics (size, production, labour force, etc.), and the “stability”, in which a crucial role is played by the age of the conductor and the presence of a successor. It was found that only 28% of the original farm sample is still alive, one third has disappeared, 30% was absorbed by existing farms, 8% has been abandoned. The factors most favourable to the survival resulted those referred to the vitality, especially the physical and economic size of the farm, the presence of cattle, the percentage of land in property, the presence of young labour. Among the factors that predispose to the abandonment, the urbanization processes were found to be determinants, in terms of expansion of both the built-up area and of that planned as urbanisable. The research has highlighted the importance of the vitality of the farms together with a context that has maintained its original rural features. These combined aspects can better define what we call the resiliency of the landfarms system i.e. the capability of positively reacting to the variable modifications of the internal and external conditions.

scholarly journals Synthesis and characterization of one-dimensional titanate structure

2008 ◽  
Vol 2 (2) ◽  
pp. 109-114 ◽  
Author(s):  
Ljubica Nikolic ◽  
Marija Maletin ◽  
Paula Ferreira ◽  
Paula Vilarinho
Keyword(s):  
Heat Treatment ◽  
Structural Characteristics ◽  
Hydrothermal Process ◽  
Synthesis And Characterization ◽  
One Dimensional ◽  
Treatment Conditions ◽  
Alkaline Conditions ◽  
The Stability ◽  
Simple Hydrothermal Process

One-dimensional titania structures were synthesized trough a simple hydrothermal process in a highly alkaline conditions. The aim of this work was to elucidate the effect of time on the formation of 1D titanates as well on its structural characteristics (morphology, phase composition, surface area). Apart from that, the effect of heat treatment conditions on the stability of titanate based 1D samples has been investigated. The results have revealed that it is possible to form one-dimensional titanates already after 1 hour of hydrothermal synthesis. Although the composition of titanates is still under debate, the results probably correspond to the layered sodium titanates. The 1D prepared structures show a remarkable stability during heating, remaining the basic morphology and composition even up to 700?C.

scholarly journals Water Softening Mechanism and Strength Model for Saturated Carbonaceous Mudstone in Panzhihua Airport, China

2020 ◽  
Vol 2020 ◽  
pp. 1-12
Author(s):  
Ziwen Wang ◽  
Jifang Du ◽  
Shuaifeng Wu ◽  
Yingqi Wei ◽  
Jianzhang Xiao ◽  
...  
Keyword(s):  
Shear Strength ◽  
Water Saturation ◽  
Structural Characteristics ◽  
Water Immersion ◽  
Analytical Techniques ◽  
Friction Angle ◽  
Mechanical Tests ◽  
Water Softening ◽  
Softening Mechanism ◽  
The Stability

To identify the water softening mechanisms that caused landslides in Panzhihua Airport, China, property and saturation tests of the mudstones extracted from a representative landslide were proposed. In this paper, water saturation tests were carried out on samples of carbonaceous mudstone collected from the east side of the No. 12 landslide at the airport. A number of different analytical techniques and mechanical tests were used to determine changes in chemical composition, mineral assemblages, and mudstone structural characteristics, including shear strength, after the mudstone had been softened. Three kinds of changes caused by water and three mudstone softening stages are proposed. The results show that the water has a significant influence on the properties of the mudstone, so the stability of the mudstone in the watery period is a big threat to the upper structure. A model for water immersion mudstone strength softening is developed. The model incorporates a permeability coefficient, the hydraulic gradient, and time; the model can be used to determine the mudstone’s shear strength and internal friction angle. This study provides a reference for the study of rock softened by water immersion.

scholarly journals Displacement Solution of Salt Cavern with Shear Dilatation Behavior Based on Hoek-Brown Strength Criterion

2019 ◽  
Vol 2019 ◽  
pp. 1-16 ◽  
Author(s):  
Huabin Zhang ◽  
Qingqing Zhang ◽  
Laigui Wang
Keyword(s):  
Plastic Zone ◽  
Elastic Strain ◽  
Large Strain ◽  
Structural Characteristics ◽  
Strength Criterion ◽  
Surrounding Rock ◽  
Salt Formation ◽  
Salt Cavern ◽  
The Stability ◽  
Influence Degree

In this study, an analytical solution of stress, strain, and displacement, in the elastic and plastic zone is proposed. The solution is derived on the basis of ideal elastoplastic mechanical model of spherical salt cavern with shear dilatation behavior, by adopting Hoek-Brown (H-B) criterion. The solution obtains not only in small and large strain stage but also in creep stage. The proposed solution is validated, by comparison of the obtained results with numerical results in FLAC3D. The results indicate that the result obtained adopting the H-B criterion is closer to that one obtained adopting the Mohr-Coulomb (M-C). The H-B criterion is more applicable for the salt cavern construction as it considers the structural characteristics of the rock salt formation. The displacement difference obtained by two different methods decreases with the increase of GSI or running pressure, but it increases with the enlarged angle of dilation. The influence of different assumptions of elastic strain of plastic zone on displacements is more significant under large strain conditions. The influence of the angle of dilation on displacements is more obvious when the elastic strain of plastic zone is given to stationary values, and the influence degree increases with the enlarged angle of dilation. Under the same conditions, the creep displacement decreases with the increase of GSI, and both the creep displacement and the effect degree enhance with the enlarged dilation angle. The proposed solutions can be used in the stability analysis of surrounding rock in the construction and operation of salt cavern storage.

scholarly journals Use of liners made of concrete on quartz aggregates and polyurethane composition to reduce vibration, noise and improve the stability of tramway track

2018 ◽  
Vol 230 ◽  
pp. 03014 ◽  
Author(s):  
Olena Palant ◽  
Dmytro Plugin ◽  
Andrii Plugin ◽  
Alexey Lobiak ◽  
Oleksii Pluhin
Keyword(s):  
Thermal Expansion ◽  
Structural Characteristics ◽  
Linear Thermal Expansion ◽  
The Finite Element Method ◽  
Temperature Stresses ◽  
The Stability ◽  
Water Saturated ◽  
Quartz Aggregates ◽  
Optimal Strength ◽  
Polyurethane Composition

The theoretical basis of reduction of thermal deformations of the ballastless continuous welded track has been developed. The design of the track with integrated rails has been improved by using a special concrete liner of optimal composition with quartz fillers and aggregates and two-component polyurethane. The method of calculating the concrete composition with optimal strength and coefficient of linear thermal expansion together with optimal structural characteristics, To reduce the temperature stresses in the rails, liners should be made of concrete with quartz fillers and aggregates which provide a reduction of the coefficient of linear thermal expansion αL to 1.1×10-6 K-1. The analysis of the stressstrain state of the rails during heating, performed using the finite element method, has shown that the liners made of concrete with quartz aggregates decrease by 10-32% the temperature stresses in rails. The composition of concrete for liners with the compressive strength of above 60 MPa has been substantiated and the polyurethane composition has been selected for insulation of rails from the channel wall with adhesion to concrete of 0.7 MPa in a dry state, 0.43 MPa in a water-saturated state, and adhesion to steel of 1.2 MPa.

The Principle and Calibration of the Third Gear Flow-Meter

2013 ◽  
Vol 397-400 ◽  
pp. 1713-1717
Author(s):  
Jun Zhang ◽  
Meng Meng Niu ◽  
Hong Mei Tang ◽  
Xian Hua Li ◽  
Cun Ren Tang
Keyword(s):  
Measurement Accuracy ◽  
Structural Characteristics ◽  
Developed Countries ◽  
Flow Meter ◽  
Typical Structure ◽  
The Third ◽  
System Pressure ◽  
Working Principle ◽  
The Developed Countries ◽  
The Stability

At present, the domestic development of the gear flow-meter is far behind the developed countries, especially in the micro gear flow-meter. This paper proposes a typical structure named the third gear flow-meter. The structural characteristics and working principle of the third gear flow-meter was introduced in detail, the prototype of the third gear flow-meter was designed and processed, and the calibration tests and pressure experiments of the third gear flow-meter prototype was made at last. We can draw that the three gear flow-meter can be used in hydraulic system pressure range is less than 25Mpa, the flow rate was 0.15~0.2m3/h can meet the high requirements of the stability of measurement, and the measurement accuracy in the whole flow range is 0.2 class. This article provides a reliable experimental data for the design of the micro gear flow-meter.

scholarly journals Analysis of the In Situ Steering Motion Characteristics and Sensitivity of Disc-Type Underwater Gliders

2020 ◽  
Vol 8 (9) ◽  
pp. 663
Author(s):  
Han Zhou ◽  
Pengyao Yu ◽  
Xiang Jin ◽  
Tianlin Wang
Keyword(s):  
Sensitivity Analysis ◽  
Stability Analysis ◽  
Structural Characteristics ◽  
Small Bodies ◽  
Underwater Gliders ◽  
Motion Characteristics ◽  
The Stability ◽  
Bodies Of Water ◽  
Yaw Angle

A disc-type underwater glider (DTUG) has a highly symmetrical shape and is characterized by omnidirectional characteristics and high maneuverability in small bodies of water. To further explore the disc shape’s advantages and characteristics in steering motion, DTUG motion was simulated by Matlab/Simulink. Based on the structural characteristics of DTUG, the motion control equations were established. The simulation of DTUG’s steering motion is carried out and compared with a previous DTUG (LUNA). The sensitivity analysis and Lyapunov stability analysis were also conducted. The results showed that the in situ steering motion can be realized by controlling the position of the center of gravity (CG) of DTUG without moving vertically, which facilitates rapid adjustment of the yaw angle and flexible movement in small bodies of water. The in situ steering motion was significantly affected by the control parameters. The parameter that had the greatest effect on it can be obtained through sensitivity analysis, which can guide DTUG to better adjust the yaw angle under different conditions. The stability analysis showed that the DTUG can remain stable within the range of the control parameter.

scholarly journals Targeting G-quadruplex Forming Sequences with Cas9

2020 ◽  
Author(s):  
Hamza Balci ◽  
Viktorija Globyte ◽  
Chirlmin Joo
Keyword(s):  
Single Molecule ◽  
Dna Sequences ◽  
Structural Characteristics ◽  
Structural Heterogeneity ◽  
Loop Formation ◽  
Conformational States ◽  
Single Molecule Fret ◽  
G Quadruplex ◽  
The Stability ◽  
The Impact

ABSTRACTClustered Regularly Interspaced Palindromic Repeats (CRISPR) and CRISPR-associated (Cas) proteins, particularly Cas9, have provided unprecedented control on targeting and editing specific DNA sequences. If the target sequences are prone to folding into non-canonical secondary structures, such as G-quadruplex (GQ), the conformational states and activity of CRISPR-Cas9 complex would be influenced, but the impact has not been assessed. Using single molecule FRET, we investigated structural characteristics of the complex formed by CRISPR-Cas9 and target DNA, which contains a potentially GQ forming sequence (PQS) in either the target or the non-target strand (TS or NTS). We observed different conformational states and dynamics depending on the stability of the GQ and the position of PQS. When PQS was in NTS, we observed evidence for GQ formation for both weak and stable GQs. This is consistent with R-loop formation between TS and crRNA releasing NTS from Watson-Crick pairing and facilitating secondary structure formation in it. When PQS was in TS, R-loop formation was adequate to maintain a weak GQ in the unfolded state but not a GQ with moderate or high stability. The observed structural heterogeneity within the target dsDNA and the R-loop strongly depended on whether the PQS was in TS or NTS. We propose these variations in the complex structures to have functional implications for Cas9 activity.

Novel Copper Nanoparticles Intercalated Polyurethane Heparin/Poly-L-Lysine Chelates Coated Stents: Viability Study for Coronary Vascular Cells and Aneurysms Treatments

2021 ◽  
Vol 17 (2) ◽  
pp. 216-229
Author(s):  
Ji Ma ◽  
Teng-Fei Li ◽  
Hui-Feng Yuan
Keyword(s):  
Cell Proliferation ◽  
Functional Group ◽  
Structural Characteristics ◽  
Cell Behavior ◽  
Vascular Cell ◽  
Coronary Artery Stent ◽  
Viability Study ◽  
The Stability ◽  
Cardiovascular Implants ◽  
Surface Geomorphology

Continuous delayed endothelium regeneration and continues thrombosis development designate a task for coronary artery stent rehabilitation. To progress the direct vascular cell behavior, aneurysms treatments and compatibility of cardiovascular implants novel copper intercalated polyurethane heparin/poly-L-lysine chelates treated stent has established in this report. The functional group modifications, structural characteristics, and stability of the chelates have investigated for polyurethane heparin: poly-L-lysine, copper intercalated polyurethane heparin/poly-L-lysine coated stents. The FTIR results showed the copper intercalation at 446 cmr and the Cu 2s peak at 932 eV from XPS also indicated that the successful coating of copper, polyurethane heparin, poly-L-lysine. The relative surface geomorphology of the chelates displayed the uniform Cu coating consisting of multilayer poly-L-lysine on the substrate. The stability and biocompatibility studies indicated the significantly enhanced performance with clot the APTT and TT periods as clotting and cell proliferation assessments. This type of composite proposes a stage on a stent external area for discerning track of vascular cell performance and aneurysms treatments with low side effects.

Study on the Mechanism of the Landslide of Heda Expressway K377

2011 ◽  
Vol 255-260 ◽  
pp. 3437-3443 ◽  
Author(s):  
Lei Nie ◽  
Min Zhang ◽  
He Qing Jian
Keyword(s):  
Shear Strength ◽  
Stability Analysis ◽  
Structural Characteristics ◽  
Initial Slope ◽  
Economic Losses ◽  
Cut Slope ◽  
Sliding Surface ◽  
Slope Excavation ◽  
Geological Conditions ◽  
The Stability

During the construction of Heda expressway, the Ermi landslide, which occurred on section K377, has interrupted the construction of the expressway. Additional engineering geological investigation became necessary. The direct economic losses are over 3 million US dollars. This paper analyzed the Ermi landslide from the aspects of formation process, engineering geological conditions, the structural characteristics and stability analysis of the landslide. The results show that the formation of the Ermi landslide is mainly due to geological conditions in project area. Because the structure of the sliding body is loose and some weak interlayer exists in the slope, the shear strength of the sliding surface and sliding body is low. As cut-slope excavating, the resistant of the slope body reduced. Eventually the slope lost its stability and a landslide formed. In the stability analysis of the slope, the shear strength parameters of the sliding surface was determined by anti-analysis. Therefore, the result of the evaluation is closer to the actual conditions. Analyzing the stability of the three sliding surfaces respectively, the stability factors for initial slope are between 1.211 and 1.468, and the stability factors for current slope are between 0.958 and 1.076. Hence, the cut-slope excavation is the direct cause of the landslide.

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