Quantitative Test and Engineering Application of Wear Resistance of a Kind of Mine-Filled Composite Pipeline

Wear resistance is one of the most important performance indicators of filling pipelines, but there are few studies on its quantitative test and life prediction. In this paper, an experimental device and its application method for testing the wear resistance of the pipeline are proposed, and the device is used to test the wear resistance of the self-developed lining composite pipeline, the traditional 16 Mn steel pipeline and the ordinary carbon structural steel pipeline. The results show that the wear resistance of the composite lining material is 12.35 times of that of 16 Mn steel and 7.32 times of that of ordinary carbon structural steel. The wear resistance mechanism is analyzed from the perspective of the material composition of the composite liner, mainly because the composite liner material uses fused alumina grain sand, silicon carbide and other extremely wear-resistant materials with high hardness as aggregate, and the aggregates are spherical or nearly spherical particles, with smooth surface and small friction resistance. Finally, through a comparison engineering application of a certain iron ore concentrate transportation. Compared with the traditional 16 Mn steel pipeline, the composite lined pipeline has been used for more than 5 years without any problems, while the traditional 16 Mn steel pipeline is worn through within 1 year. Engineering application shows that the composite lined pipeline has good wear resistance, and it also confirms the reliability of the detection method proposed in this paper.

Effect of Polymer Liners in Different Via Shapes: Impact on Crosstalk Induced Delay

The performance of a through silicon via (TSV) based 3D integrated circuit technology is primarily dependent on the choice of an appropriate liner material. The most commonly used liner material SiO2 is undergoing considerable reliability challenges such as coefficient of thermal expansion (CTE) mismatch, scallop formation, and interfacial delamination related problems. Therefore, TSVs employed with a polymer liner have achieved significant attention in recent years due to their low dielectric constant and excellent step coverage along the via surface that can effectively reduce thermal stress and crosstalk induced delay. This paper presents a comprehensive and accurate RLGC model for different via shapes considering the impact of various liner materials on the crosstalk induced delay. Considering an accurate via geometry and material properties at 32 nm and 45 nm technology, the proposed equivalent RLGC parameters include the cumulative effects of TSV metal, liner, bump, and the silicon substrate. The aforementioned parameters are used to model a novel T-type equivalent electrical network of cylindrical, tapered, and coaxial TSVs considering a coupled driver-via-load (DVL) setup. The proposed equivalent models of different via shapes are used to demonstrate the worst-case crosstalk induced delay in TSVs under the influence of various liner materials. Considering a tapered TSV, a significant improvement in crosstalk induced delay at 32 nm w.r.t. 45 nm technology is observed as 53.5%, 33.76%, and 19.12% at aspect ratios of 2.4, 3, and 4, respectively for the BCB liner.

OPTIMIZATION OF TRIBOLOGICAL PROPERTIES OF AN EPOXY HYBRID POLYMER COMPOSITE REINFORCED WITH ZrB2 AND PTFE PARTICLES USING RESPONSE SURFACE METHODOLOGY FOR HIGH-TEMPERATURE TRIBOLOGICAL APPLICATIONS

Hybrid PTFE/epoxy composites are widely used as materials for self-lubricating spherical bearing which are used in a high-temperature environment. In the present work, zirconium diboride (ZrB2) particles are incorporated to enhance high-temperature tribological properties of PTFE/epoxy composites. Pin on disc experiment is conducted with the aid of design of experiments (DOE) using central composite-response surface methodology (RSM). Under a load of 40 N and 1.25 m/s sliding speed, the optimum content 5.95 vol% of PTFE and 5.05 vol% of ZrB2, yields an ultralow coefficient of friction (COF) in conjunction with a low wear rate of the composite. The addition of ultra-high-temperature ceramic ZrB2 particles and solid lubricant PTFE is found to enhance the thermal conductivity and improve the heat transfer thereby reducing contact temperature. The use of optimum composition of the composite is capable of reducing the wear rate and high local temperature due to friction, implying its potential use as a self-lubricating spherical bearing liner material.

Preliminary Study on the Remaining Life Estimation Method for Research Reactor Tank Liner

The reactor tank liner is one of the most crucial safety barriers in a research reactor as it retains the radioactive material released from the fuel during the accident condition. It also contains the primary coolant for fission heat removal. The integrity of the tank liner determines the service life of the research reactor. So far, the remaining life estimation of pressure vessels in nuclear power plants is more widely applied and established than that of the research reactor tank liner. Therefore, a study on the remaining life estimation method of the research reactor tank liner is needed to ensure the research reactor operation safety. This paper aims to preliminarily study several methods applied to estimate the remaining life of a research reactor tank liner. The preliminary study consists of a qualitative assessment and a quantitative assessment. The qualitative assessment aims to propose several techniques or methods applied in estimating the remaining life of the reactor tank liner. The quantitative assessment applies one of the remaining life estimation methods discussed in the previous assessment. Generally, the remaining life of the research reactor tank liner can be estimated using the theoretical method and the experimental method. The theoretical methods are applied by calculating the neutron fluence received by the tank liner or by analyzing the fracture mechanics using numerical modeling if the cracks or other defects exist. The calculation of atom displacement number (dpa), as a standard measure of the neutron-induced radiation damage of the materials, can support the neutron fluence calculation. The experimental method is conducted by measuring several parameters of the tank liner material, such as the corrosion rate or the mechanical properties. In the quantitative assessment, the remaining life estimation of the Kartini Reactor tank liner was performed by neutron fluence calculation method using MCNP6 computer code. The result shows that the maximum neutron fluence received by the tank wall is 2.950E+17 n/cm2 for 40 years operating period. By comparing the cumulative neutron fluence received for 40 years to the thermal neutron fluence limit value of 1.18E+23 n/cm2, the Kartini Reactor tank liner can still be used for the next 1.6E+07 operation years. The result of the quantitative assessment implicitly shows that the remaining life estimation of the tank liner needs to: 1) consider all defects experienced by the tank liner and all factors (e.g., thermal, radiation, chemical, cyclic loading) which affect the tank liner material condition, and 2) perform the combination of theoretical and experimental methods. For an open-pool type reactor, corrosion monitoring and corrosion rate measurement are essential to perform the remaining life assessment of the tank liner.

Research of the parameters of acoustic emission signals during the destruction of the liner material and the power shell of a metal-composite high-pressure cylinder

To The article provides information on the results of studying the parameters of acoustic emission signals during the destruction of the liner material and micro-plastic of the power shell of a metal-composite high-pressure cylinder. B-200 within the framework of a complex of studies to create an acoustic-emission portrait of metal-composite high-pressure cylinders. It was found that the most informative parameter when carrying out technical diagnostics of a liner is the signal amplitude recorded in the private range of 60-80 kHz, and a sign of microplastic rupture is the emission of acoustic emission signals reaching 82 dB.

Numerical Canal Seepage Loss Evaluation for Different Lining and Crack Techniques in Arid and Semi-Arid Regions: A Case Study of the River Nile, Egypt

Owing to the potential negative impacts of climatic changes and the grand Ethiopian renaissance dam, water scarcity has become an urgent issue. Therefore, the Egyptian Ministry of Water Resources and Irrigation has started a national project of the lining and rehabilitation of canals, to reduce seepage losses and for efficient water resource management. This study presents a new approach for assessing three different lining and crack techniques for the Ismailia canal, the largest end of the river Nile, Egypt. A 2-D steady state seep/w numerical model was developed for the Ismailia canal section, in the stretch at 28.00–49.00 km. The amount of seepage was significantly dependent on the hydraulic characteristics of the liner material. The extraction from aquifers via wells also had a considerable impact on the seepage rate from the unlined canals; however, a lesser effect was present in the case of lined canals. The concrete liner revealed the highest efficiency, followed by the geomembrane liner, and then the bentonite liner; with almost 99%, 96%, and 54%, respectively, without extraction, and decreasing by 4% for bentonite and geomembrane liners during extraction; however, the concrete lining efficiency did not change considerably. Nevertheless, the efficiency dramatically decreased to 25%, regardless of the lining technique, in the case of deterioration of the liner material. The double effect of both deterioration of the liner material and extraction from the aquifer showed a 16% efficiency, irrespective of the utilized lining technique.

Methods for Candida albicans biofilm formation on temporary soft liner/ Métodos para a formação de biofilme de Candida albicans em reembasador macio temporário

This study evaluated methods for the contamination of a soft liner material (Softone™) with Candida albicans biofilm. Specimens were either submitted or not to pretreatment in artificial saliva in an orbital incubator, and then held suspended in different positions (horizontal or vertical) and different storage conditions (bacteriological incubator or orbital incubator) during biofilm formation. Eight conditions were tested. All specimens were immersed in C. albicans inoculum and stored in an orbital incubator at 75 rpm or in a bacteriological incubator, both at 37ºC for 90 min. Then, they were washed in PBS, and maintained in RPMI-1640 medium under the same conditions for 48 h. The degree of contamination was determined by the XTT assay. Data were submitted to ANOVA 1-factor/Tukey HSD test (α=0.05). Specimens held horizontally in an orbital incubator showed the highest cell viability, while the ones kept vertically in a bacteriological incubator had the lowest viability (p0.0001). The best condition for C. albicans biofilm formation was obtained when specimens were not submitted to pretreatment in saliva and were held horizontally in an orbital incubator.

Geotechnical Characterization of Water Treatment Sludge for Liner Material Production and Soft Soil Reinforcement

A water treatment sludge (WTS) was characterized in order to evaluate if its properties would be suitable for use as liner of earthworks or for strengthening a clay soil. A WTS and a clayey soil was characterized in terms of granulometry, cumulative volumes, specific surface, density, plastic limit, liquid limit, water content, hydraulic conductivity, and characteristics of compaction (optimal water content and dry density). This study aimed to exhibit and evaluate these investigated parameters of WTS, soft soil and mixed proportions between the materials for liners’ material production while evaluating soft soils’ reinforcement feasibility. The results have shown WTS’s contribution with its fine granulometry and compaction characteristics, indicating filling properties and possible feasibility as soft soils additions for liners’ material production while being applicable for soils‘ reinforcements, corroborating with existing literature on the subject. Thus, the currently developed investigation has exposed WTS as a potential addition for these applications while also attending society’s new demands towards a more sustainable future.