Search results

The influence of different factors on the sorption, such as pH, amount of hemp powder applied as well as initial concentration, were studied, respectively.
The hemp fibres can be easily converted into small powders under the mechanical action.
This can be explained by the fact that the medium pH affected the solubility of Zn2+ ions and the ionization state of the functional groups of the hemp powders [8].
Effect of initial concentration on sorption amount of Zn2+ ions It is very difficult to compare data from different literature sources, because sorption capacity for zinc ions is dependent on many factors such as initial concentration of zinc ions, contact time and identical researchers selected.
However, hemp powders were proved good sorption property for zinc ions, resulting in low adsorbing rate.

These factors make them ideal for various applications in geopolymer technology [6].
Chen et al., [8] investigated the mechanical properties of reinforcement fly-ash based geopolymer with alkali-pre-treated sweet sorghum fibre.
Alomayri et al., [9] studied the characterization of cotton fibre-reinforced geopolymer composites and found that the appropriate addition of cotton fibres can improve the mechanical properties of geopolymer composites.
Duxson et al., [11] mentioned that if the alkaline content is too great in a geopolymer formulation, then the mechanical properties of the geopolymer will deteriorate.
Silsbee, Wood fiber surface treatment level effects on selected mechanical properties of wood fiber–cement composites, Cement and Concrete Research.

Coarse and fine aggregate retrieved in such a way is very similar to original one in terms of its physical and mechanical properties.
Heterogeneity has been significantly reduced by : · elimination of coarse aggregate (replaced by sand of maximum 600µm), · enhancement of mechanical properties of concrete stone, · decrease of aggregate amount in relation to the suspension [4,5].
The study refutes the hypothesis of the lack of significant influence of any of the factors on the body density after 28 days.
Ultra - High Performance Concrete UHPC production, properties and possible applications ( in Deutsch).
Properties of steam cured concrete used with ground granulated blast – furnace slag, CAJ Proceedings of Cement and Concrete.

High-temperature hot deformation is linked with dynamic recovery and recrystallization which affect the alloy structure and properties.
When optimizing hot processing of austenitic alloys, such factors should be taken into account as [3]: grain size, intermetallic phases and carbides precipitation processes and strain parameters.
Two of the above-mentioned factors are considered most important: austenite grain size and the course of recrystallization during hot deformation.
This is particularly important in creep-resisting steels and austenitic alloys, where grain refining has an advantageous influence on their mechanical properties and creep characteristics [2, 4].
The alloy deformed in the temperature range 1000÷1050 °C exhibited the properties characteristic of dynamically recrystallized structures.

capacity and fatigue properties of military bridge, effectively reduces weight of bridge span structure, and reduces by above 23% compare with that of traditional steel bridge.
Material selection should consider not only the material properties, but it is more important to consider manufacturing methods, connection technology, cost performance and other factors of material.
Considering the ecological and environmental factors, material components that can be reused (such as basalt fiber and thermoplastic matrix) will be widely used in development of new lightweight material of crossing-river and military bridge equipment.
Any structural material must be able to withstand the mechanical load.
As various requirements must be satisfied, to evaluate material is necessary so as to determine priority of material properties.

Introduction In metal forming, the plastic flow between the die and tool is affected by the friction factor, the compression load, the tolerance due to die elasticity, the heat conduction between work temperature and room temperature.
It is because the compression test of cylinder is used for determining the friction factor and the mechanical strength of billet material.
Friction calibration curve of for various friction factors ( 0 ::6:3:2 iiddh= ).
Fig. 7 shows the friction calibration curve for various friction factors ( 0 ::6:3:2 iiddh= ).
E., Proceedings of the Institution of Mechanical Engineering, Part B: Journalof Engineering Manufacture, 215(6), 883(2001)

Causes of failure of NC machine tool is divided into system fault, artificial fault and gradual fault[1,2]：System fault refers to the fault caused by NC system design, structure and properties of such defects; artificial fault is caused by such as transportation, installation, impact and improper operation and other external factors, the operation skill and habit of operators used to play an important role; In addition to the system fault, the artificial fault, and most of the failure is due to the key components of wear, vibration, such as processing overload or external environmental changes caused by gradual fault[3,4].
For mechanical systems, due to various types of CNC machine tools adopts different mechanical structure, components, according to the characteristics of performance degradation, based on the machine's monitoring system, properly adding sensor, collecting the signal, obtain machining, the fault signal feature real-time data.
Due to special structure and distribution of CNC machine tools, sensors should be installed accurately in place, the wiring should not affect the machine movement.
Zero mean treatment is also called the centralized processing, the mean of vibration signals may produce offset due to the vibration or other factors, with zero mean treatment technology, in order to eliminate vibration interference; by elimination of vibration signal polynomial trend item method, which can eliminate the unfavorable trend signal analysis, to reduce the error of CNC machine fault diagnosis, trend corresponding signal in the frequency domain of the low frequency signal, eliminating the trend is equivalent to a high-pass filtering of signal.
The degradation model by historical vibration data collected for analysis and self-learning, monitoring and prediction on the state of mechanical components.

Tillage methods significantly affect GHG emissions in the farmland.
The two main factors referred above reduced the evaporation at soil surface.
CO2 emissions flux during the whole year under different tillage Results in this study were similar to previous researches which reported that soil temperature and SMC were important affecting factors of respiration [7].
Results of this study give a good indication of the significance of tillage practices for mitigating GHG emissions during growing seasons, further research on the soil properties which are responsible for the emissions patterns has to be conducted.
Rey: Exchange of greenhouse gases between soil and atmosphere: interactions of soil physical factors and biological processes.

Based on the above thinkig, since the 1980s, Architectural Design Institute of Northeast China, Zhejiang University,etc have made some preliminary discussions of the physical and mechanical properties of AAC and the seismic behavior of the block wall and the block masonry structure[1~7].
Vertical pressing stress impact Many domestic and abroad researches have shown that vertical pressing stressσ0 is one of the important factors that influence masonry shear strength.
The vertical pressing stress decides the masonry shear failure feature and also directly affects the masonry shear strength..
(3)The vertical pressing stress decided the masonry shear failure form and also directly affected the masonry shear strength.

The emergence of this phenomenon, in addition to the management, manufacturing quality products and promotions and other causes, one of the main reasons is that NC machine varieties, properties and structure of production in our country is not advanced, new product development cycle is long, which can not be timely according to the needs of users to provide satisfactory products.
But the overall scheme of machine tool in the traditional design often depends on the " wisdom ", randomness, become the key factors affecting the quality of the products, along with the development of CAD technology, computing technology and design methodology, and the need of market competition, must develop both based on knowledge, overall scheme and scientific analysis and prediction virtual design software
Structure design is in the overall layout of the program to determine the basic design, the main shape and size on the mechanical structure, the same analogy and generative design two.