Charging of Materials Non-Metallic Used in Underground Mines Endangered by Firedamp and/or Coal Dust

The expansion parts and components of non-metallic in devices have become a fait accompli. In the case parts, components of non-metallic are used in atmospheres explosive and may be a potential source of ignition [1]. Ignition hazards due to static electricity from the charged non-conductive non-metallic materials are well known [2]. The prevalence protection metal parts and components of anti-corrosion exist in any device equipped with a metal casing. Inherent risks associated services are caused by static electricity. Electrostatic phenomena arise in many situations, in a variety of environments and industries. The occurrence of charge static in many cases unexpected is unwanted and requires the use of expensive preventive measures. Brush discharge and propagating brush discharge (e.g. composite coating about non-conductive electrostatic properties of an isolated base conductive) create explosion hazard in underground endangered by firedamp and/or coal dust [3].

Toward high-sulfur-content,high-performance lithium-sulfur batteries:Review of materials and technologies

Lithium sulfur batteries(LSBs)are recognized as promising devices for developing next-generation energy storage systems.In addition,they are attractive rechargeable battery systems for replacing lithium-ion batteries(LIBs)for commercial use owing to their higher theoretical energy density and lower cost compared to those of LIBs.However,LSBs are still beset with some persistent issues that prevent them from being used industrially,such as the unavoidable dissolution of lithium polysulfide intermediates during electrochemical reactions and large volume expansion(up to 80%)upon the formation of Li_(2)S,resulting in serious battery life and safety limitations.In the process of solving these problems,it is necessary to maintain a high sulfur content in the cathode materials to ensure that the LSBs have high energy densities and excellent cycle performance.In this review,the novel preparation methods and cathode materials used for preparing LSBs in recent years are reviewed considering the sulfur content and cycle performance.In addition,the problems and difficulties in practically applying cathode materials are described,and the development trend is discussed.

Effect of zinc powder content on tribological behaviors of brake friction materials

Brake friction materials with different zinc powder contents(0,2,4,6,8 wt.%)were fabricated via powder metallurgy method.The results indicate that with the increasing zinc powder content,the density and thermal conductivity of the materials gradually increase,while the hardness decreases monotonously.With increasing zinc powder content,the curve of the nominal friction coefficient shows fluctuating trend but the lowest friction coefficient also shows an increase.However,the wear rate and braking noise of the friction material monotonously decrease with increasing zinc content.This effect may be attributed to the transformation of the tribological mechanism from adhesive wear and abrasive wear to adhesive wear.The brake friction material with 4 wt.%zinc powder exhibits both the best tribological and noise performance.

Opto-thermal Moisture Content and Moisture Depth Profile Measurements in Organic Materials

Opto-thermal transient emission radiometry(OTTER) is a infrared remote sensing technique, which has been successfully used in in vivoskin moisture content and skin moisture depth profiling measurements. In present paper, we extend this moisture content measurement capability to analyze the moisture content of fruit(tomato, grape, etc.) skins, and to study the relationship between fruits ripening process and their surface moisture and moisture depth profiles.

An experimental study of temperature and moisture content of wet porous materials under short-pulsed laser heating

The measurements of temperature and moisture content of a wet porous material were accomplished on the micro-seconds scale. The temperature wave was observed when the wet porous material was heated by short-pulsed laser with high power. It firstly revealed that the moisture content of wet porous material rapidly rises twice in one laser irradiation. The influences of laser parameters, the thickness and initial moisture content of the wet porous material on its temperature and moisture content were investigated.

REQUIREMENT OF FLUIDITY OFHIGH WATER CONTENT MATERIALS FOR THE GETWAY-SIDE BACKFILLING TECHNIQUE

Through analyzing the effects of water consumption, diameter of solid particle, and flow vefority on the fluidity of high water content material slurry, the relatinnship among the fluidity, the isotropy of the slurry, and the pumping facilities applied in getway-side backfilling has been found. And the requirment of fluidity of high water content material for the design of getway-side back filling technique is put forward in the paper.

Performance Analysis of Optimized Content Extraction for Cyrillic Mongolian Learning Text Materials in the Database

This paper had developed and tested optimized content extraction algorithm using NLP method, TFIDF method for word of weight, VSM for information search, cosine method for similar quality calculation from learning document at the distance learning system database. This test covered following things: 1) to parse word structure at the distance learning system database documents and Cyrillic Mongolian language documents at the section, to form new documents by algorithm for identifying word stem;2) to test optimized content extraction from text material based on e-test results (key word, correct answer, base form with affix and new form formed by word stem without affix) at distance learning system, also to search key word by automatically selecting using word extraction algorithm;3) to test Boolean and probabilistic retrieval method through extended vector space retrieval method. This chapter covers: to process document content extraction retrieval algorithm, to propose recommendations query through word stem, not depending on word position based on Cyrillic Mongolian language documents distinction.

Chemical Analysis of Magnesia and Magnesia-Alumina Refractory Materials——Flame atomic absorption spectrometric method for determination of calcium oxide content

1 Scope This standard specifics the determination of calcium oxide coutent by flame atomic absorption spectrometric method.

Influence of Water Content on Conductivity and Piezoresistivity of Cement-based Material with both Carbon Fiber and Carbon Black

The influence of water content on the conductivity and piezoresistivity of cement-based material with carbon fiber （CF） and carbon black （CB） was investigated. The piezoresistivity of cement-based material with both CF and CB was compared with that of cement-based material with CF only, and the changes in electrical resistivity of cement-based material with both CF and CB under static and loading conditions in different drying and soaking time were studied. It is found that the piezoresistivity of cement-based material with both CF and CB has better repeatability and linearity than that of cement-based material with CF only. The conductivity and the sensitivity of piezoresistive cement-based material with both CF and CB are enhanced as the water content in piezoresistive cement-based material increases.

High Water Content Material Based on Ba-Bearing Sulphoaluminate Cement

A new type of high water content material which is made up of two pastes is prepared, one is refute from lime and gypsum, and another is based on Ba-bearing sulphoaluminate cement. It has excellent properties such as slow single paste solidifing ,fust double pustes solidifing ,fast coagulating and hardening, high early strength, good suspeasion property at high W/C ratio and low cost. Meanwhile, the properties and hydration mechanism of the material were analyzed by using XRD, DTA- TG and SEM. The hydrated products of new type of high water content material are Ba-bearing ettringite, BaSO4 , aluminum gel and C-S-H gel.

Research on toughening mechanisms of alumina matrix ceramic composite materials improved by rare earth additive

Mixed rare earth elements were incorporated into alumina ceramic materials. Hot-pressing was used to fabricate alumina matrix composites in nitrogen atmosphere protection. Microstructures and mechanical properties of the composites were tested. It was indicated that the bending strength and fracture toughness of alumina matrix ceramic composites sintered at 1550 ℃ and 28 MPa for 30 min were improved evidently. Besides mixed rare earth elements acting as a toughening phase, AlTiC master alloys were also added in as sintering assistants, which could prompt the formation of transient liquid phase, and thus nitrides of rare earth elements were produced. All of the above were beneficial for improving the mechanical properties of alumina matrix ceramic composites.

Determination of Moisture, Ash, Extract Content and TLC identification of Tibetan Medicinal Material Dracocephalum tanguticum Maxim.

[Objectives] The moisture, ash and extract content of Dracocephalum tanguticum Maxim. were measured.[Methods] The moisture, total ash, acid-insoluble ash and extract content of D. tanguticum Maxim collected from 16 producing areas were detected by using the methods in Chinese Pharmacopoeia (2015 edition, volume I), and D. tanguticum Maxim. was identified by thin layer chromatography in Chinese Pharmacopoeia (2015 edition, volume I).[Results] The moisture content of D. tanguticum Maxim collected from 16 producing areas ranged from 8.68% to 10.36%, averaging 9.28%. The content of total ash was between 7.21% and 11.60%, averaging 9.89%. The content of acid-insoluble ash was 0.21%-2.71%, averaging 1.51%. The extract content (water-soluble) was 26.67%-42.91%, averaging 32.65%. According to the results of TLC identification, the 16 samples and reference substance had the same characteristic spots at the corresponding positions.[Conclusions] It was recommended that the moisture, total ash and acid-insolue ash content of D. tanguticum Maxim were not be more than 11%, 12%, and 3% respectively, while the extract content was not less than 26%. It provides reference for filling the gaps in the quality standards of D. tanguticum Maxim.

A Novel Uniplanar Multi-Electrode Capacitive Sensor for In-Situ Weathering Damage Detection of Nonmetallic Materials

A uniplanar capacitive sensor with 5-electrodes on one plane substrate and a large reflector electrode,was designed to get the corresponding capacitance information for weathering damage detection of non-metallic materials exposed to a service environment.A 2-D finite-element method was employed to simulate the electric potential distribution and capacitance measurements for the sensor.2 marble slabs,one was healthy and the other was notched,were experimentally detected.Both the simulation and the preliminary experimental results show that the measured capacitances decrease after weathering damage occurs in nonmetallic material.The reflector can enlarge the sensitive depth.The weathering assessment of nonmetallic materials can be done by processing the measured capacitances.The proposed approach can effectively detect the weathering damage of nonmetallic material and can be practically used for in-situ weathering damage evaluation.

Study on Filling Cross-Roadway in Fully-Mechanized Coal Faces with High Water-Content Material

A new method using high water content material to mechanically fill cross roadways to form artificial bottom for coal faces was introduced. The reasonable determination of filling range, the optimization of the compounding ratio of high water content material, and the filling technique were discussed in detail. This new method has been spread after industrial testing in Baodian Colliery. Compared with the traditional method, the manual wooden chock method, the new one decreases about 40% of the filling range and cost in dealing every one set of cross roadway in the testing condition.