scholarly journals A New Calculation Method of Cutterhead Torque Considering Shield Rolling Angle

2021 ◽  
Vol 12 (1) ◽  
pp. 396
Author(s):  
Xiang Shen ◽  
Dajun Yuan ◽  
Dalong Jin ◽  
Chengyong Cao

The existing cutterhead torque calculation method usually simplifies the characteristics of the shield, which ignores the rolling angle. In this paper, the cross-river shield project of Wuhan Metro Line 8 is taken as the research focus. Firstly, the measured data of the cutterhead torque (CT), the rolling angle and rotation direction were analyzed. Then on this basis, the penetrability, tunneling thrust, and rolling angle were taken as the influential factors to analyze CT sensitivity. Finally, based on the theoretical calculation model, a modified solution of CT was obtained considering the rolling angle. The results show that the rolling angle can be reduced to zero by changing the direction of the cutterhead rotation; the rolling angle has a greater impact on CT than the other two factors as shown through the analysis of the range difference and Statistical Product and Service Solutions (SPSS) method. As the absolute value of the rolling angle increases, CT also increases, and the relationship between them is linear. To a certain extent, the rolling angle of the shield can reflect the difficulty of tunneling and the running status. By monitoring the rolling angle of the shield, the prediction of CT can be more in line with the actual construction conditions.

Author(s):  
Jean Real Brunette ◽  
Gilles Lafond

SUMMARY:The time response of the Electroretinogram (ERG) is an essential part of the examination. Peak time of response increases with dark adaptation and decreases with the intensity of stimulation. When working with constant amplitude during dark adaptation sensitivity increases but the intensity of stimulation decreases. It is essential to clarify the relationship of these two factors for valid interpretation of results. The present work suggests that the state of adaptation or retinal sensitivity affects amplitude, while peak time of the response is modified by the absolute value of the stimulating source whatever the state of adaptation. This observation has been done on rod responses and is valid as long as pigments remain unbleached and able to respond.


2018 ◽  
Vol 15 (1) ◽  
pp. 73-83
Author(s):  
Siti Zulaika Zolkeplee ◽  
Abu Bakar Hamed ◽  
Ahamad Faosiy Ogunbado

The issue of unpayable educational loan that lead to student’s defaults has become a worrying trend all over the world. This research aims to examine the relationship of anxiety, parental influence, media awareness, and religiosity on student’s perception on educational loan repayment. A survey approach has been adopted to investigate student’s perception on educational loan repayment in Universiti Utara Malaysia. The data for this study were collected via structured questionnaires which were completed by 359 undergraduate Muslim’s students who acquire their financial loan from National Higher Education Fund Corporation (NHEFC). The data were then quantitatively analyzed using SPSS program. The findings of Pearson’s correlation showed a positive correlation between student’s perception towards educational loan repayment and religiosity, parental influence, media awareness, and anxiety. Further analysis using a multiple regression indicated that all independent variables explained 32.9 per cent of student’s perception on educational loan repayment. The result again indicated that religiosity and parent’s influence are most influential factors on student’s perception towards educational loan repayment. Whilst, media awareness slightly contributed to student’s perception towards educational loan repayment and anxiety gave no impact. The result implied that the Ministry of Education may design the syllabus in school and university curricular by adding the value of responsibility in loan repayment especially in religious and moral subjects. Besides, the Ministry Education of Malaysia are also urged to use media to disseminate the information regarding the importance for students to make loan repayment to parents as well as students. The collection of student loan then can be used for the next generation in financing their study which could result the prosperity of nation.


2013 ◽  
Vol 353-356 ◽  
pp. 2073-2078
Author(s):  
Tian Zhong Ma ◽  
Yan Peng Zhu ◽  
Chun Jing Lai ◽  
De Ju Meng

Slope anchorage structure of soil nail is a kind of economic and effective flexible slope supporting structure. This structure at present is widely used in China. The supporting structure belong to permanent slope anchorage structure, so the design must consider earthquake action. Its methods of dynamical analysis and seismic design can not be found for the time being. The seismic design theory and method of traditional rigidity retaining wall have not competent for this new type of flexible supporting structure analysis and design. Because the acceleration along the slope height has amplification effect under horizontal earthquake action, errors should be induced in calculating earthquake earth pressure using the constant acceleration along the slope height. Considering the linear change of the acceleration along the slope height and unstable soil with the fortification intensity the influence of the peak acceleration, the earthquake earth pressure calculation formula is deduced. The soil nailing slope anchorage structure seismic dynamic calculation model is established and the analytical solutions are obtained. The seismic design and calculation method are given. Finally this method is applied to a case record for illustration of its capability. The results show that soil nailing slope anchorage structure has good aseismic performance, the calculation method of soil nailing slope anchorage structure seismic design is simple, practical, effective. The calculation model provides theory basis for the soil nailing slope anchorage structure of seismic design. Key words: soil nailing; slope; earthquake action; seismic design;


2021 ◽  
Vol 11 (9) ◽  
pp. 3827
Author(s):  
Blazej Nycz ◽  
Lukasz Malinski ◽  
Roman Przylucki

The article presents the results of multivariate calculations for the levitation metal melting system. The research had two main goals. The first goal of the multivariate calculations was to find the relationship between the basic electrical and geometric parameters of the selected calculation model and the maximum electromagnetic buoyancy force and the maximum power dissipated in the charge. The second goal was to find quasi-optimal conditions for levitation. The choice of the model with the highest melting efficiency is very important because electromagnetic levitation is essentially a low-efficiency process. Despite the low efficiency of this method, it is worth dealing with it because is one of the few methods that allow melting and obtaining alloys of refractory reactive metals. The research was limited to the analysis of the electromagnetic field modeled three-dimensionally. From among of 245 variants considered in the article, the most promising one was selected characterized by the highest efficiency. This variant will be a starting point for further work with the use of optimization methods.


Author(s):  
Yali Deng ◽  
Xuemeng Li ◽  
Liu Liu ◽  
Wing Hong Chui

Suicidal behavior is a severe problem among drug users. This study examines influential factors related to suicide attempts and analyzes possible mediators of the relationship between perceived social support and suicide attempts amongst Chinese drug users under compulsory institutional drug treatment. Taking perceived social support as the independent variable, we found that the relationship between suicide attempts and perceived social support is mediated by self-esteem as a protective factor and depression as a risk factor. Path analysis shows that self-esteem contributes relatively more to the indirect effects than depression does, accounting for 31.1% and 24.2% of the total effect, respectively. Generally speaking, the findings of this study point to an urgent need for addressing suicide attempts among Chinese drug users while treating self-esteem as the protective factor that deserves as substantial attention as depression receives.


2021 ◽  
pp. 1356336X2098588
Author(s):  
Jonas Wibowo ◽  
Ben Dyson

In this article, we focus on the contingency between learning and instruction in physical education (PE). We argue that the complex interconnectedness of teachers’ instruction and students’ learning processes should be studied using a unit of analysis that expresses the relationship between the two factors. A contingency perspective foregrounds the individual differences between different learners and how a teacher regards these differences. Furthermore, it has the potential to provide a precise lens for empirical research on how the students’ situations shape the evolution of the teaching--learning process. Based on scaffolding research and adaptive teaching research, which draws on socio-constructivist foundations, we call this unit of analysis ‘contingency’. We outline a framework of research that suggests depicting contingency dimensions, respective instructional continua, and contingency rules when investigating contingency in PE. Furthermore, autonomy as a core contingency dimension for PE and methodological issues will be discussed.


2011 ◽  
Vol 56 (No. 5) ◽  
pp. 242-249 ◽  
Author(s):  
Z. Ledvinka ◽  
L. Zita ◽  
M. Hubený ◽  
E. Tůmová ◽  
M. Tyller ◽  
...  

We assessed the influence of the particular genotype, age of layers, feather growth-rate gene, and their mutual interactions on selected indicators of eggshell quality in six groups of hens of the laying type Dominant. The following genotypes were examined in the experiment: Barred Plymouth Rock, Dominant BPR 951 (K) strain, slow-feathering; Barred Plymouth Rock, Dominant BPR 901 (k) strain, fast-feathering; Blue Plymouth Rock, Dominant BLPR 954 (K) strain, slow-feathering; Blue Plymouth Rock, Dominant BLPR 894 (k) strain, fast-feathering; crossbreds of the above strains in the F<sub>1</sub> generation Dominant D 107 blue (K), slow-feathering and Dominant D 107 blue (k), fast-feathering. The layers were fed a feed mixture NP1 (16.64 % CP) from the 20<sup>th</sup> week of age and a feed mixture NP2 (15.02% CP) from the 42<sup>nd</sup> week. Husbandry conditions met the regular requirements of laying hens. Egg production and live weight of hens were monitored for the duration of the experiment (12 months). Eggshell quality was examined at the layers' age of 27, 35 and 56 weeks. The average hen-day egg production for the duration of the experiment (12 months) was not significantly influenced by the particular genotype or the feather growth-rate gene. The varying representation of the feather growth-rate gene significantly (P &le; 0.001) influenced the live weight; similarly, the relationship between the genotype and the representation of K/k alleles was significant. The average egg weight was influenced statistically significantly (P &le; 0.001) by the age of hens, their genotype (P &le; 0.05), feather growth-rate gene (P &le; 0.001), and the relationship between the age and genotype (P &le; 0.001). The age of hens, genotype, and the interaction of these two factors affected the egg shape index, as did the incidence of the feather growth-rate gene within the population (with a statistical significance of P &le; 0.001). The age, genotype and the feather growth-rate gene incidence within the population also significantly affected the eggshell quality indicators. In the eggshell to egg ratio, eggshell thickness and strength, an interaction was determined between the age of hens and their particular genotype. The eggshell colour was also significantly (P &le; 0.001) affected by hens' age, genotype (P &le; 0.001), as well as by the feather growth-rate gene (P &le; 0.001). No significant interaction between the age and the genotype was found for this indicator.


2014 ◽  
Vol 14 (4) ◽  
pp. 1337-1403 ◽  
Author(s):  
Zoë Kuehn ◽  
Pedro Landeras

Abstract Students from more advantageous family backgrounds tend to perform better than those from less advantageous backgrounds. But it is not clear that these students exert more effort. We build a model of students, schools, and employers to study the interaction of family background and effort exerted by the student in the education process. Two factors turn out to be key in determining the relationship between effort and family background: (i) the student’s attitude toward risk and (ii) how the student’s marginal productivity of effort depends on her family background. We show that when the degree of risk aversion is relatively low (high) compared to the sensitivity of the marginal productivity of effort, students from more advantageous family backgrounds exert more (less) effort. Empirically, we find that if parental education was reduced from holding a university degree to incomplete compulsory education, primary and secondary school students would exert around 21–23% less effort (approximately equal to a reduction of 2 hours weekly in homework). For primary school students we also find that marginal productivities of effort are higher for those from less advantageous family backgrounds.


2012 ◽  
Vol 201-202 ◽  
pp. 975-978
Author(s):  
Hong Fei Wang

For the manufacturing task of manufacturing collaborative alliances, the relationship between manufacturing task programming and manufacturing resources deployment is analyzed and the model for the span of manufacturing task with time sequence constraint is constructed. The problem of span programming of manufacturing task with time sequence constraint is analyzed by integrating qualitative and quantitative methods from production period for the manufacturing task. The mathematical formulations of influential factors and task span are constructed, and the optimal values of task span are obtained. By analyzing the results of quasi-quantitative study, some meaningful results that benefit to programming for collaborative manufacturing task are achieved.


1998 ◽  
Vol 82 (1) ◽  
pp. 339-349 ◽  
Author(s):  
Thomas L. Morrison ◽  
Anthony J. Urquiza ◽  
Beth L. Goodlin-Jones

This study examined the associations between two factors of depressive experience (dependency and self-criticism) and satisfaction in adult romantic relationships. The Depressive Experiences Questionnaire, along with measures of attachment and relationship satisfaction, were administered to 107 men and 140 women attending local community colleges. Self-criticism was associated with global relationship distress and sexual dissatisfaction. In a combined regression equation, measures of self-criticism, attachment security, and attachment activation all contributed to predicting general relationship distress. Only scores on self-criticism predicted sexual dissatisfaction. The relationship dissatisfaction reported by those with high scores on self-criticism appears to be a relational aspect of the “destructiveness of perfectionism” described by Blatt.


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