Carboxymethylcellulose reinforced starch films and rapid detection of spoiled beverages

The integrity of the packaging of a liquid foodstuff makes it difficult to detect spoilage. Therefore, it is important to develop a sensitive, fast and real-time material for liquid food detection. CMC, as lignocellulose derivatives and starch are widely used in the food industry. In this study, starch films with pH-responsive properties are successfully prepared from full-component starch and corn amylopectin (CA) by adding CMC. The effects of CMC on the mechanical properties, morphology characteristics, physical and chemical structures, stability and pH responsiveness of the starch films are analyzed. The starch/CMC-1.0 g composite films display good electrical conductivity and reduce the resistance of the composite film by two orders of magnitude. The composite films have pH response ability; in the simulation of orange juice spoilage experiment, the CA/CMC composite film has a more sensitive current response and was more suitable for the application to liquid food quality detection. Additionally, the starch/CMC composite films have potential applications for rapid detection and real-time monitoring of the safety of liquid food

Application prospect analysis of new technologies of mine-used belt conveyor

Introduction and application prospect of new technologies were discussed such as centralized control and unattended intelligent control of conveyor belt, anti-tearing of conveyor belt, new technology of energy saving and reduction, rapid installation and withdrawal technology. The realization of unattended monitoring was described from three aspects of vision function, hearing function and touch function. A new longitudinal tearing recognition device for mine conveyor belt was introduced, it uses camera video recognition technology to identify and judge damage of conveyor belt real timely. It is analyzed that application of new rubber conveyor belt with aramid as the skeleton material, the intelligent technology of video recognition, and low-resistance stainless steel roller can effectively save energy and reduce consumption. A non-foundation fixing method for rapid installation and withdrawal of belt conveyor was introduced. The application of the new technologies of mine-used belt conveyor will gradually realize the functions of high intelligence centralized automatic control, quick and efficient installation and withdrawal of belt conveyor, and lay a solid foundation for safe, high yield and high efficiency of coal mine

Design and application of manual pressurization device for initial support force of hydraulic support

In view of safety problems such as premature separation of roof, advance of cutting line and rib fall of coal wall caused by being lack of initial support force of hydraulic support, a manual pressurization device for initial support force of hydraulic support was designed. The pressurization device is in parallel with hydraulic check valve of original support lifting hydraulic system, improves the initial support force through manual operation of pressurization under the premise that normal lift is not affected. AMESim modeling and simulation of the pressurization control circuit before and after applying the manual pressurization device were carried out. The simulation results show that the manual pressurization effect of the device is obvious. The field test result of pressurized situation for initial support force of ZY8500/21/45D type support on a coal mine working face shows that the manual pressurization device can significantly improve initial support force of the support and meet the coal mining demand

Facile and Eco-Friendly Synthesis of Finger-Like Co3O4 Nanorods for Electrochemical Energy Storage

Co3O4 nanorods were prepared by a facile hydrothermal method. Eco-friendly deionized water rather than organic solvent was used as the hydrothermal media. The as-prepared Co3O4 nanorods are composed of many nanoparticles of 30–50 nm in diameter, forming a finger-like morphology. The Co3O4 electrode shows a specific capacitance of 265 F g−1 at 2 mV s−1 in a supercapacitor and delivers an initial specific discharge capacity as high as 1171 mAh g−1 at a current density of 50 mA g−1 in a lithium ion battery. Excellent cycling stability and electrochemical reversibility of the Co3O4 electrode were also obtained

A New Technique of Lattice Beam Construction with Pre-Anchoring for Strengthening Cut Slope: A Numerical Analysis of Temporary Stability during Excavation

In consideration of the temporary stability of the cutting slope during construction and its permanent stability under long-term service, a new technique of lattice beam construction with anchors pre-set in the slope from the original ground surface before cutting was proposed, and its construction process was briefly introduced. Compared with the model without pre-set anchors, the effectiveness of pre-setting anchors to strengthen the cutting slope during multi-excavation was verified in the numerical software FLAC3D. Various factors such as the factor of safety (FOS) and the maximum shear strain increment (MSSI) as well as the displacement for different stages were discussed. The results show that the anchors pre-set in the slope provide reinforcement step-by-step with excavations which changes the mechanical responses of the cutting slope and increases the factor of safety with a variation of 15.9–44.1% compared to the case without setting anchors. In addition, with excavations, the axial forces of the anchors pre-set in the stratum increase gradually, and the positions of the maximum axial forces gradually transfer from the vicinity of the cutting surface to the depth of the design slope. Numerical simulations prove that this new technique is beneficial for ensuring the temporary stability of the slope during excavations and is especially suitable for the advance anchorage of the cutting slope, in which the inclined original ground surface is cut at an angle steeper than it can stand safely and is close to the design slope surface after cutting. After the completion of slope excavation, the cast-in-place concrete lattice beam is immediately set on the design slope surface and connected with the anchor heads exposed on the cut slope surface to ensure the permanent stability of the slope. Therefore, this new technology has important guiding significance for both the temporary stability of slopes during construction and the permanent stability of slopes in service

Design of high cutting chock type hydraulic support

In view of problems of poor support effect, slow support speed, high support cost and great labor intensity of advance support with advanced hydraulic support, single hydraulic prop or timber in return airway of fully-mechanized high cutting coal mining face of a coal mine in Yulin mining area, a high cutting chock type hydraulic support was designed. Finite element analysis of the support was conducted under three kinds of operating conditions namely top beam eccentric load and pedestal torsion, top beam torsion and pedestal concentrated load, top beam concentrated load and pedestal eccentric load. The stress nephogram and deformation nephogram show that the whole support is stressed uniformly without apparent stress concentration phenomenon and large deformation. The field test result show that the support can effectively guarantee safety of working face roadway with small deformation of surrounding rock of roadway

Synthesis of Li2FeSiO4/carbon nano-composites by impregnation method

International audienc

Optimal design of balance jack control loop of hydraulic support

Principles and shortcomings of balance jack control of hydraulic support by use of compensation valve, high pressure internal overflow valve, floating two-way lock and automatic balance valve respectively were analyzed, and an optimal design scheme of the balance jack control loop of hydraulic support was proposed according to pressure characteristics of the balance jack cavity. Automatic fluid replacement and unloading of the balance jack cavity are realized by reasonably disposing components such as hydraulic pressure controlled reversing valve and low pressure unloading valve, so as to solve problem of safety valve frequently opening under non-emergency situation. The simulation and test results verify effectiveness of the optimal design scheme