Description: In order to explore the thermal kinetics of nano Al-micro MnO 2 thermite system, the Al/MnO 2 thermite sample was mixed by the ultrasonic dispersion method. On the basis of the study of thermal decomposition of MnO 2 powder, the thermal performance of the sample was study by simultaneous thermal analysis technique at the temperature range from room temperature to 1000°C, which could found the thermite reaction occurred in 650-660°C before the melting of Al, which belongs to solid state reactions with the 350 J/g heat releasing. Besides, the microstructure changes of the thermite during reaction were observed by field emission scanning electron microscope (FE-SEM). Based on the TG-DSC test with multiple heating rates and using of the activation energy calculated by Kissniger method, it could be proved the sample had good stability and safety performance.

Description: To explore the reaction characteristics and mechanism of Al/MnO 2 thermite, selecting the high purity micron grade Al and MnO 2 powder, the Al/MnO 2 thermite sample was mixed by the ultrasonic dispersion method. On the basis of the study of thermal decomposition of MnO 2 powder, the thermal performance of the sample was study by simultaneous thermal analysis technique at the temperature range from room temperature to 900°C, and the reaction products were analyzed by X-ray diffraction (XRD). The microstructure changes of the thermite during reaction were observed by field emission scanning electron microscope (FE-SEM). The results showed that the MnO 2 has two processes of thermal decomposition during the temperature rising, and the reaction products were Mn 2 O 3 and Mn 3 O 4 , and the onset temperature were 498.3°C and 781.5°C, the heat release were - 197.1J/g and -57.4 J/g, respectively. Al/...

Description: Water, Vol. 10, Pages 703: Adsorption of Reactive Brilliant Red X-3B in Aqueous Solutions on Clay–Biochar Composites from Bagasse and Natural Attapulgite Water doi: 10.3390/w10060703 Authors: Si Chen Min Zhou Han-Fei Wang Teng Wang Xiao-Shu Wang Hao-Bo Hou Bi-Yu Song The study aims to determine the adsorption mechanism of reactive brilliant red X-3B (RBR) on a novel low-cost clay–biochar composite with different proportions of bagasse and natural attapulgite (ATP). Pure bagasse, pure ATP, and two mixtures with weight ratios of 1:5 and 1:3 were pyrolyzed at 700 °C for 4 h in a muffle furnace. Biochar samples were characterized with an element analyzer and by scanning electron microscopy, X-ray diffraction, Fourier transform infrared, X-ray photoelectron spectroscopy, Brunauer–Emmett–Teller method, and zeta potential measurement. Results of the batch and leaching experiments showed that the adsorption capacities followed the order of 1:3 clay–biochar > 1:5 clay–biochar > bagasse biochar > pure ATP. Furthermore, ATP and bagasse exerted a synergistic effect on the adsorption of RBR. The adsorption data showed good correlation with the Langmuir isotherm, and the kinetic data were fitted to the pseudo-second-order model. The adsorption of RBR on clay-biochar involved electrostatic interaction, hydrogen bond, π–π interactions, and surface participation. The modification of biochar by ATP improved the adsorption capacity by increasing functional groups and creating adsorption sites. Therefore, ATP-modified clay–biochar composites could be effective adsorbents for the removal of RBR from wastewater.

Description: The parametric design macro programs of two basic types of single-layer hemi-ellipsoidal latticed shell are developed by using APDL (Ansys Parametric Design Language) parameterized design language. The parametric design of single-layer hemi-ellipsoidal latticed shell structures can be built under the condition of giving the macroscopic geometric parameters such as specifical parameter t, parameter k, span S1, span S2, rise f, valley number Kn, radial node number Nx etc. Ansys software is applied to study comparison of characteristics of the Kewitte type net shell structure of different vector height f, radial node number Nx and boundary constraints. The results show that modeling design of hemi-ellipsoidal latticed shell can be built conveniently and quickly by the application of parametric design of macro program. The three-way grid type is more reasonable force performance, and it’s mechanical performance is better when the span ratio is 1/2. Thus it is suggested to give prior...

Description: Water, Vol. 10, Pages 1211: Experimental Study of Influence of Karst Aquifer on the Law of Water Inrush in Tunnels Water doi: 10.3390/w10091211 Authors: Weimin Yang Zhongdong Fang Xin Yang Shaoshuai Shi Jing Wang Hao Wang Lin Bu Liping Li Zongqing Zhou Xueqing Li Water inrush is a geological hazard often encountered in tunnel construction. In order to overcome problems encountered when using the existing water-inrush simulation model test, such as single function, low repetition utilization rate, and poor visibility, we developed a multi-type water-inrush model test system. Our test system can be a precursor to large-scale studies, handle multiple types, and perform serialization and visualization. We conducted cavity water-inrush simulation testing using this device, and studied the failure model of aquifuge rock. We reveal the evolution laws of water inrush from the cavity, including the initiation of fracture in the aquifuge rock, the formation of water-inrush channels, and the rupture of the aquifuge rock. By analyzing the seepage pressure changes at the monitoring points of the aquifuge rock, we divided the water-inrush process of the cave into a rack generation stage, a holing-through of fracture and forming of water-inrush channel stage, and a water-inrush stage. Test results show that the system is stable and reliable, only requiring a short test period, and can be used to guide large water-inrush testing and related projects.

Description: Water, Vol. 10, Pages 326: Multi-Objective Assessment of the Ecological Flow Requirement in the Upper Yangtze National Nature Reserve in China Using PHABSIM Water doi: 10.3390/w10030326 Authors: Huan Wang Hao Wang Zhenchun Hao Xu Wang Meng Liu Yali Wang Many dams have been constructed or are planned all around China. These dams significantly change the hydrological regime and sand concentration downstream, and subsequently affect the river habitat and riverbed substances. Therefore, a good understanding of the river habitat is urgently required to undertake efficient measures for fish diversity conservation. A multi-objective assessment method based on the Physical Habitat Simulation system (PHABSIM) was utilized to calculate the ecological river flow demand using maximum weighted usable area (WUA) and minimum river discharge as the main objectives. The study employed this method to assess ecological water flow demand in the National Nature Reserve for Rare and Endemic Fish in the Upper Reaches of the Yangtze River in China. Multiple factors such as the degree of endangerment, fish value (ecological value, economic value and scientific research value), data acquisition difficulty, and species representativeness were taken into consideration during selection of indicator fish for coupled habitat analysis. Requirements for both growth and breeding during the study period were considered. Ten species of fishes were chosen as indicator fishes, including floating egg and sinking egg fishes. Additionally, we applied the principle of “minimization of habitat demand and maximization of ecological demand” to include the needs of all indicator fishes. Further, this method comprehensively considered requirements for ecological flow and economic development. The results highlighted that an optimal ecological river flow demand of 2395 m3/s was needed to satisfy the needs for habitat protection and 1890 m3/s was required to meet the needs of social and economic development. The methods used in this study and results obtained, provide a valuable reference for water resources planning and ecosystem protection in other rivers and lakes.