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Multi-objective Optimization Design for Cutting Head of Roadheader Xin Zhang1, 2, a, Xiaozhe Liu2, b, Jianwu Zhang1, c and Qingliang Zeng2, d 1 School of Mechanical Engineering, Shanghai Jiaotong University, Shanghai 200240, China 2 College of Mechanical and Electronic Engineering, Shandong University of Science and Technology, Qingdao 266510, China a zhangxinmt@163.com, b c6410@126.com, cjwuzhang@sjtu.edu.cn, d qlzeng@163.com Keywords: roadheader; cutting head; optimization; load fluctuation; specific energy consumption Abstract.
The power consumption of cutting head accounts for over 60﹪ of the whole roadheader power consumption, so the design of cutting head directly affects the overall performance and energy consumption of roadheader.
The load fluctuation and energy consumption are not only decided by the physical properties of coal, but also associated with various parameters of cutting head.
(3) Where 1k is proportional factor, and 0t is equal to the cutting spacing value of the last pick in cone segment.
Dun: The Coal Broken Theory of Shearer (China Coal Industry Publishing House, China 1992) [5] Xin Zhang, Xinping Li: Colliery Mechanical & Electrical Technology.

In high-strength steels, final microstructure and mechanical properties upon heat treatment are dictated mainly by their alloying concept.
In order to find whether molybdenum affects mechanical properties and transformation temperatures, its content in the AHSS-2 steel was set to 0.16 %.
Volume fractions of retained austenite were determined using X-ray diffraction in specimens with the best mechanical properties.
Very good mechanical properties were obtained mainly in AHSS-2 steel which contained higher amounts of chromium and molybdenum.
The best mechanical properties were achieved in AHSS-2 steel which had higher levels of chromium and molybdenum.

We report on the die bonding processes and how the surface roughness and metallization schemes affect the processes of die bonding in 4H-SiC device fabrication using a soldering test and die shear test (DST) with differently prepared 4H-SiC samples.
Introduction Silicon carbide (SiC) is a promising material for device operation at high power, high temperature, and high frequency because it has prominent properties, such as high-breakdown electrical field, wide-energy bandgap, and high electron saturation drift velocity.
Conclusion We investigated the die bonding processes regarding how the surface roughness and metallization schemes affect the process of die bonding in SiC device fabrication with differently prepared 4H SiC samples.
Our results indicated that the surface roughness is also one of the most important factors to improve the die attaching to electroplated Cu plates for final packaging the devices.
In addition, in order to apply SiC devices for high temperature environments, further research such as reliable thermal-mechanical modeling, mechanics of material behaviors at elevated temperature (up to 600 �), and new classes of composite materials offering thermal conductivity up to 2400 W/cm 2 could be required.

This could be one of the biggest factors which governs the stability and accuracy of the process.
The mechanical properties of the Inconel-718 workpiece are summarized in Table 1.
Mechanical Properties of Inconel-718 Workpiece Yield Strength, 0.2% Tensile Strength Hardness Elongation Red. of Area 995Mpa 1231MPa 38-40HRc 29.7% 45.9% The holes were drilled progressively with a new set of gun drills with K15 cemented carbide drill tips, with uniform geometries and bearing pads configuration in three different lengths of 1100mm, 1600mm and 2100mm.
Deviation A Outer approach angle [°] 30.06 31.12 28.94 2.18 B Inner approach angle [°] 20.09 20.54 19.07 1.47 C Outer cutting land [µm] 2285.30 2208.43 2125.54 159.76 D Inner cutting land [µm] 2317.58 2342.64 2279.65 62.99 E Drill apex offset [µm] 1993.17 2004.40 1835.23 169.17 Summary The stability and accuracy of high aspect ratio gundrilling are greatly affected by the consistency of the critical drill geometries.
Random human errors are inevitable in the exhaustive course of drilling and thus the hole straightness accuracy produced will be adversely affected.

Evaluation of corrosion behaviour for aluminium alloy 7075 in 5% NaCl solution under slightly varying temperature D.S.Manoj Abraham1, a H.Kanagasabapathy2,b Richu John3,c Muthu Yasar4,c Shobin Paul5,c 1Mechanical Engineering Department, Ponjesly College of Engineering, Nagercoil,Tamilnadu,India,Pin:629003,Tel:+91-9944356354 2Mechanical Engineering Department,National Engineering College, Kovilpatti, Tamilnadu, India, Pin: 628503, Tel:+91-9442535810 3 Mechanical Engineering, Ponjesly College of Engineering,Nagercoil, Tamilnadu, India, Pin: 629003, Tel:+91-9809914687 4Mechanical Engineering, Ponjesly College of Engineering, Nagercoil, Tamilnadu, India, Pin: 629003, Tel:+91-9578517476 5Mechanical Enineering, Ponjesly College of Engineering, Nagercoil, Tamilnadu, India, Pin: 629003, Tel:+91-8547829660 amanoth_333@rediffmail.com, bhariram64@yahoo.co.in, cricjonu@gmail.com Key words: Al7075 T6, salt mist test, penetration rate Abstract The main focus
Most structural alloys corrode simply from exposure to atmospheric moisture, but the process can be greatly affected by exposure to certain other substances.
The factors that affect the stability of the aluminium oxide and thereby cause corrosion concists, the oxide is not stable in alkaline (pH > 9) or acidic (pH < 4) environments.
Weilage.B, Wank.A, Pokhmurska, H.Podlesak, Corrosion properties of SIC reinforced surface layers of aluminium alloy by laser beam melt injection, Corrosion 2005 Warsaw [7].
Bodunrin,Mechanical Properties and Corrosion Behaviour of Aluminium Hybrid Composites Reinforced with Silicon Carbideand Bamboo Leaf Ash, Tribology in Industry, Vol. 35, No.1(2013) 25‐35 [9]. http://www.hsctut.materials.unsw.edu.au [10]. www.npl.co.uk

In the past few decades, The factors of  ions composition, flow field, operating temperature, material properties and structure of equipment, kind and magnitude of stresses have been researched a lot[1-5].
Temperature is an important factor for SCC susceptibility.
Alyousif and Rokuro Nishimura [6] found that temperature not only affected the stress corrosion susceptibility but also changed the cracking mechanism.
In order to study the impact of various factors on SCC susceptibility, researchers have analyzed the prominent properties of chlorineion concentration, temperature, pH and hydrogen sulfide concentration by using the gray relational theory, Yates's algorithm and orthogonal design [9-11].
But the prominent property of operating pressure was not involved in the analyses above.

Among them, the functional parameters of surface roughness, such as Sbi, Sci, and Svi, are used to evaluate bearing and fluid retention properties of surfaces.
A good surface roughness can improve tribological properties, corrosion resistance, fatigue strength, and esthetic appeal of the product [2].
Among them, functional parameters of surface roughness are effective in characterizing functional properties of surfaces, especially bearing property and fluid retention property [3].
The network structures, especially number of neurons and layers in the hidden layer, are very important factors that determine the functionality and generalization capability of the network [7].
And the following factors are used to efficiently train the networks: maximum number of epochs = 5000, learning rate (η) = 0.05, momentum constant = 0.95, performance goal = 0.001.

The results showed that soil structural properties in tea and eucalyptus plantations were similar.
It has been a unique soil ecosystem as root absorption properties and fertilization management of tea plantations.
There are closely relationship between the stability of soil aggregates and the processes of ecosystems, and the stability of soil aggregates is also one of important factors for restricting soil erosion [4-5].
The results showed the human farming activities had important effect on soil properties at the soil depths of 0-20 cm in tea plantation.
Wang, “Fractal dimension of red soil particle and relationship with environmental factors in Xingguo County, China,” Transactions of the CSAE, vol .23, no. 12, pp.76-79, 2007

The modern high-speed printing press has a higher requirement on mechanic properties and axial bounce.
In order to avoid interfering and guarantee the metering equipment complete and does not affect press' normal running, it’s necessary to select the non-contact type measurement mode.
As it is affected by the vibration of the sheet feed cylinder and the gear and so on, the value of the cylinder’s axial bounce of the first set is big.
Fig.5 The curve about the value of the transfer cylinder’s axial bounce change with the speed Conclusions 1) The value of the press cylinder’s axial bounce can be measured precisely for the dynamic states by the laser Doppler non-contact type vibration meter. 2) Cylinder's fit-up gap is the main factor that affects the value of the cylinder’s axial bounce.
[6] Wang Yiming, Zhao Jibin, Wu Shuqin: Proceedings of the International Conference on Mechanical Transmissions 2nd, Chongqing, China (2006), p.83-87.

Bond proposed a method of determining the blast ability of rock by means of the index of the work of crushing; Northeastern University in 1984 through the blasting funnel test and acoustic wave test using multiple regression analysis method to derive the rock burst ability index formula, with the rock burst ability index to comprehensively evaluate the rock burst ability[1], the method can reflect the intrinsic law affecting the burst ability of the rock between the various factors, but the workload of field measurements is large, the calculation is complex.
In the self-learning process of the rig, the rig produces different mechanical responses to different rock interfaces, stops drilling when it encounters a rock interface, and manually enters the rock type identification code based on the characteristics of the rock cuttings and the principles of rock type identification, and at the same time, records the drilling machine's mechanical response to the rock layer and the rock type identification code.
l After collecting self-learning data sets of a certain size, regression analyses were performed to derive a mathematical modelling of rock type deterministic codes and the rig mechanical response parameters.
Improvements in Lithological Identification The lithology identification method requires a large amount of data as the basis, and at the same time, it is more dependent on the operator's judgement of the lithology of the ore rock, with high human factors, and different regression equations are obtained in different mining areas, and the correlation coefficients are between 0.60 and 0.82, which also indicates that the convergence of this method is insufficient to support a large range of applications. we propose a KNN method based on machine learning for lithology identification with drilling. 1.1 KNN The k-Nearest Neighbors (KNN) algorithm is a machine learning classification algorithm[12-14].
The method is not limited by the perforation process, and the requirement for geological conditions is as long as the ore rock has some difference in mechanical properties.