Optic-Fiber Temperature Sensor

As an important parameter in industry, agriculture, biomedical, and aerospace, temperature possesses a significant position for the development of our society. Thus, it has become a hot point to develop novel sensors for temperature monitoring. Compared with traditional electronic sensors, optical fiber sensors break out for the compact structure, corrosion resistance, multiplex and remote sensing capability, cheap prices, and large transmission capacity. Especially the phase modulation type optical fiber sensors attract much attention for the fast and accurate measurement of the external parameters in a large dynamic measurement range. In this work, we review the optical fiber Mach-Zehnder interferometer (MZI) for temperature sensing which is widely used these years. The fundamental principles of MZI fiber sensors are proposed and discussed to further understand MZI. Different kind of structures for temperature sensing of recent years are summarized as several typical MZI categories and their advantages and disadvantages are indicated separately. Finally, we make a conclusion of the MZI temperature sensing and several methods typically to realize the MZI in practical application for the readers

Dynamic Analysis of Deep Mining Disaster Control in China and its Application in the Ivory Coast’s Mining Activities

With the increasing depth of mining, rock burst is on the rise. China’s deep mining industry faces such a threat. A major problem of deep mining is high ground stress, which is the major factor of rock burst. Due to the complexity of the rock burst mechanisms, complexity of induced factors as well as suddenness and randomness of rock burst occurrences, studies of rock burst prediction and control for safe mine exploitation is far from satisfying. The purpose of this paper is to examine of rock burst phenomenon in order to understand both stability in rock mechanics and the prediction of instability disasters in rock mechanics for application in the Ivory Coast mining sector with reference to the current Chinese mining industry

Market Stakeholder Analysis of the Practical Implementation of Carbonation Curing on Steel Slag for Urban Sustainable Governance

Carbonation curing on steel slag is one of the most promising technologies for the iron and steel industry to manage its solid waste and carbon emissions. However, the technology is still in its demonstration stage. This paper investigates the market stakeholders of carbonation curing on steel slag for construction materials for its effective application by taking China as a case study. A holistic analysis of the competition, market size, and stakeholders of carbonation curing on steel slag was carried out through a literature review, a survey, a questionnaire, and interviews. The results showed that carbonation curing on steel slag had the advantages of high quality, high efficiency, low cost, and carbon reduction compared with other technologies. Shandong province was the most suitable province for the large-scale primary application of the technology. Stakeholder involvement to establish information platforms, enhance economic incentives, and promote adequate R&D activities would promote carbonation curing of steel slag into practice. This paper provides a reference for the commercialization of carbonation curing on similar calcium- and magnesium-based solid waste materials

Carbonation Curing on Magnetically Separated Steel Slag for the Preparation of Artificial Reefs

Magnetic separation is an effective method to recover iron from steel slag. However, the ultra-fine tailings generated from steel slag become a new issue for utilization. The dry separation processes generates steel slag powder, which has hydration activity and can be used as cement filler. However, wet separation processes produce steel slag mud, which has lost its hydration activity and is no longer suitable to be used as a cement filler. This study investigates the potential of magnetically separated steel slag for carbonation curing and the potential use of the carbonated products as an artificial reef. Steel slag powder and steel slag mud were moulded, carbonation-cured and seawater-cured. Various testing methods were used to characterize the macro and micro properties of the materials. The results obtained show that carbonation and hydration collaborated during the carbonation curing process of steel slag powder, while only carbonation happened during the carbonation curing process of steel slag mud. The seawater-curing process of carbonated steel slag powder compact had three stages: C-S-H gel formation, C-S-H gel decomposition and equilibrium, which were in correspondence to the compressive strength of compact increasing, decreasing and unchanged. However, the seawater-curing process of carbonated steel slag mud compact suffered three stages: C-S-H gel decomposition, calcite transfer to vaterite and equilibrium, which made the compressive strength of compact decreased, increased and unchanged. Carbonated steel slags tailings after magnetic separation underwent their lowest compressive strength when seawater-cured for 7 days. The amount of CaO in the carbonation active minerals in the steel slag determined the carbonation consolidation ability of steel slag and durability of the carbonated steel slag compacts. This paper provides a reference for preparation of artificial reefs and marine coagulation materials by the carbonation curing of steel slag

Basic Research on Rockburst Control Technology for Deep Well Filling of Municipal Solid Waste

AbstractGiven the scarcity of raw materials for rockburst prevention in filling mining and the lack of space for disposal of large amount of municipal waste, the feasibility of preparing filling materials for rockburst mines from stale waste was investigated by laboratory tests and theoretical analysis. On this basis, the process of preparing filling materials from stale garbage was proposed, and corresponding equipment were developed to prepare stale garbage filling mass. According to the characteristics and uses of the stale waste filling materials, two processes of volume filling and strength filling are proposed, and the key technology of stale garbage filling to control rockburst was designed. The following conclusions were drawn: stale garbage can be made into mine filling material because of its composition, strength, and shape. The process of preparing mine filling materials from obsolete waste includes crushing, screening, compression, and packaging. The equipment suitable for the process includes crushing-screening, compression-forming, and sealing-packaging integrated equipment. The equipment has realized effective screening, compression, and bulk packaging of stale garbage, so that the stale garbage filling mass can meet the requirements of environmental protection and strength. Strength filling is a filling method that uses the strength of stale garbage filling mass to protect the overlying strata from or less damage, thereby reducing the stress concentration in the coal face and reducing the risk of rockburst occurring. Volume filling mainly depends on the volume of the filling mass, with the main purpose of reducing the stress concentration in the roadway surrounding rock. The rockburst mine filling technology of stale garbage is support track filling technology and bag filling technology, and the deep well sealing of stale garbage is block stacking technology. The deep well filling mining key technologies provide a new approach to against rockburst and treat large amounts of municipal waste

Modeling Rett Syndrome Using TALEN-Edited MECP2 Mutant Cynomolgus Monkeys

Gene-editing technologies have made it feasible to create nonhuman primate models for human genetic disorders. Here, we report detailed genotypes and phenotypes of TALEN-edited MECP2 mutant cynomolgus monkeys serving as a model for a neurodevelopmental disorder, Rett syndrome (RTT), which is caused by loss-of-function mutations in the human MECP2 gene. Male mutant monkeys were embryonic lethal, reiterating that RTT is a disease of females. Through a battery of behavioral analyses, including primate-unique eye-tracking tests, in combination with brain imaging via MRI, we found a series of physiological, behavioral, and structural abnormalities resembling clinical manifestations of RTT. Moreover, blood transcriptome profiling revealed that mutant monkeys resembled RTT patients in immune gene dysregulation. Taken together, the stark similarity in phenotype and/or endophenotype between monkeys and patients suggested that gene-edited RTT founder monkeys would be of value for disease mechanistic studies as well as development of potential therapeutic interventions for RTT

Width design for gobs and isolated coal pillars based on overall burst-instability prevention in coal mines

An investigation was conducted on the overall burst-instability of isolated coal pillars by means of the possibility index diagnosis method (PIDM). First, the abutment pressure calculation model of the gob in side direction was established to derive the abutment pressure distribution curve of the isolated coal pillar. Second, the overall burst-instability ratio of the isolated coal pillars was defined. Finally, the PIDM was utilized to judge the possibility of overall burst-instability and recoverability of isolated coal pillars. The results show that an overall burst-instability may occur due to a large gob width or a small pillar width. If the width of the isolated coal pillar is not large enough, the shallow coal seam will be damaged at first, and then the high abutment pressure will be transferred to the deep coal seam, which may cause an overall burst-instability accident. This approach can be adopted to design widths of gobs and isolated coal pillars and to evaluate whether an existing isolated coal pillar is recoverable in skip-mining mines

Analysis of Coal Floor Fault Activation Inducing Water Inrush Using Microseismic Monitoring—A Case Study in Zhaogu No. 1 Coal Mine of Henan Province, China

Previously conducted studies have established that mining activities can activate faults, which will cause floor water inrush disasters and cause loss of personnel and property. In order to reduce the possibility of water inrush disasters in mining, it is particularly important to study the dynamic characteristics and rules of floor fault activation under the influence of mining. In this work, firstly, a microseismic monitoring system was established in the working face to analyze the changes of microseismic indexes before and after grouting. It was found that grouting can enhance the strength of a rock mass and play a role in sealing the water channel. Secondly, the quadratic kernel function of microseismic event energy was established. It was found that the accumulation degree of microseismic events and the region of high energy kernel density increased with the decrease of the distance between the working face and the left boundary of the “analysis region”. Combined with a microseismic event index and water inflow, the activation process of the floor fault was divided into five stages. Finally, the plastic failure region of surrounding rock under different excavation steps was analyzed by numerical simulation, and the characteristics of fault activation were further explained. A method of taking measures to prevent water inrush in the “sign stage of fault activation” was proposed