Dongmin Li, Guofang Ma and Jia Li
It is essential to level the drilling platform across which a drilling robot travels in a slant underground coal mine tunnel to ensure smooth operation of the drill rod. However…
Abstract
Purpose
It is essential to level the drilling platform across which a drilling robot travels in a slant underground coal mine tunnel to ensure smooth operation of the drill rod. However, existing leveling methods do not provide dynamic performance under the drilling conditions of the underground coal mine. A four-point dynamic leveling algorithm is presented in this paper based on the platform attitude and support rod displacement (DLAAD). An experimental drilling robot demonstrates its dynamic leveling capability and ability to ensure smooth drill rod operations.
Design/methodology/approach
The attitude coordinate of the drilling robot is established according to its structure. A six-axis combined sensor is adopted to detect the platform attitude, thus revealing the three-axis Euler angles. The support rod displacement values are continuously detected by laser displacement sensors to obtain the displacement increment of each support rod as needed. The drilling robot is leveled according to the current support rod displacement and three-dimensional (3 D) attitude detected by the six-axis combined sensor dynamically.
Findings
Experimental results indicate that the DLAAD algorithm is correct and effectively levels the drilling platform dynamically. It can thus provide essential support in resolving drill rod sticking problems during actual underground coal mine drilling operations.
Practical implications
The DLAAD algorithm supports smooth drill rod operations in underground coal mines, which greatly enhances safety, reduces power consumption, and minimizes cost. The approach proposed here thus represents considerable benefits in terms of coal mine production and shows notable potential for application in similar fields.
Originality/value
The novel DLAAD algorithm and leveling control method are the key contributions of this work, they provide dynamical 3 D leveling and help to resolve drill rod sticking problems.
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Andrea Flanagan-Bórquez and Kiyomi Sánchez-Suzuki Colegrove
In this chapter, we analyze and reflect on how our cultural identities and educational experiences as international students who pursued a doctoral degree in the United States…
Abstract
In this chapter, we analyze and reflect on how our cultural identities and educational experiences as international students who pursued a doctoral degree in the United States affected and influenced our teaching philosophy and praxis as professors and educators. In this sense, we examine how our cultural identities and experiences help us define and shape our teaching praxis in the contexts in which we teach. We both are professors of color – Latino and Latino-Japanese – who graduated from doctoral programs in the United States. Currently, we work and serve culturally and linguistically diverse students, including first-generation students, in public higher education settings in Chile and the United States. We used a collection of narratives to delve into the significance of these events in our praxis. As theoretical lenses, we analyze these narratives using cultural identity and the reflecting teacher to examine our practices and identities as educators. We both conclude that our reflections, experiences, and cultural identities have been instrumental in the process of developing a professional identity that guides our teaching praxis in ways that are critical and social justice oriented.
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Huseyin Unal, Salih Hakan Yetgin and Fehim Findik
– The purpose of the study was to find the best performance polymer material to be used in railway car bogies.
Abstract
Purpose
The purpose of the study was to find the best performance polymer material to be used in railway car bogies.
Design/methodology/approach
Wear tests and optical and scanning electron microscopy were used.
Findings
The friction coefficients of ultra-high-molecular-weight polyethylene (UHMWPE) and Nylon 6 polymers, as opposed to AISI 4140 steel, reduced with the increment of applied loads. With the increment of sliding speed, the friction coefficient increased in both UHMWPE and Nylon 6 polymers. The specific wear rate of the UHMWPE polymer was determined to be about 10-14 m2/N, whereas the rate of Nylon 6 was determined to be 10-13 m2/N.
Practical implications
The aim of the study was to find the best performance polymer material to be used in railway car bogies.
Originality/value
The friction and wear performance of UHMWPE and Nylon 6 engineering polymers were studied and compared to their AISI 4140 steel counterparts. It is an original work and it is not published in any media.
Rare earths are essential materials for many high-tech industries critical to both economic development and national defense. China, the world's dominant supplier of rare earths…
Abstract
Purpose
Rare earths are essential materials for many high-tech industries critical to both economic development and national defense. China, the world's dominant supplier of rare earths, has recently been imposing stricter controls over its production and export. The purpose of this paper is to examine the domestic roots of the changes in China's rare earth industry production and exports in its three-decade rise to the current global monopoly.
Design/methodology/approach
This paper adopts the historical institutionalism approach to analyze the trajectory of industry and trade development. The author analyzes data collected from government whitepapers and reputed scholarly and news sources.
Findings
This paper argues that the Chinese rare earth industry has gone through three periods of development, in which the state attempted to control the market and industry through reformulating rules and institutions to achieve state goals. Domestic state institutions, combined with macroeconomic environment and state governance strategy shaped the three-decade experience of rare earth industry and trade development in China.
Originality/value
This paper builds on existing findings about Chinese state regulations to provide a novel analytical framework to analyze the role of the state in industry and trade development in the rare earth industry. The focus on a single strategic industry seldom studied in the current literature also provides ample empirical value to further scholarly understanding about this industry.
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Nestor L. Osorio and Gabriel E. Osorio
Mechatronics is a very important area of research in industrial applications. The purpose of this study is to find some of the most important components of the literature on this…
Abstract
Purpose
Mechatronics is a very important area of research in industrial applications. The purpose of this study is to find some of the most important components of the literature on this subject.
Design/methodology/approach
The analysis is based on the use of the database Compendex; it was searched in the broadest way for documents related to mechatronics. In addition, subject guides from libraries of universities with mechatronics programs were studied to find resources available in those areas.
Findings
The literature of mechatronics is extensive and multidisciplinary. Based on the results from Compendex, the following data were found: most productive authors, list of leading journals and conference proceedings, publishers and grant organizations, authors’ affiliations and other minor details. Based on the analysis of subject guides, the following types of resources were found: research databases, reference books and ebook collections.
Research limitations/implications
Part of the analysis is based on a search performed in one technical database, Compendex; it was the database that generated the largest number of citations as compared to Inspec and the Web of Science. The results have a strong English language focus. It is possible that by using the results from multiple data bases, some additional sources could be obtained.
Practical implications
Mechatronics is a relatively new technological field comprising a number of scientific and engineering areas. The results obtained summarized a significant amount of bibliographic information.
Originality/value
The work is original; to the best of the authors’ knowledge, no other study has analyzed the literature on this subject.
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Arkadiusz Kawa and Wojciech Zdrenka
The purpose of this study is to identify the factors that create value for the customer in the area of e-commerce logistics and to verify whether these factors impact online…
Abstract
Purpose
The purpose of this study is to identify the factors that create value for the customer in the area of e-commerce logistics and to verify whether these factors impact online retailers' performance through customer satisfaction and customer loyalty in a business to customer (B2C) area.
Design/methodology/approach
For the purpose of the study, a model of logistics value in e-commerce was introduced. The model was proposed based on the literature review. A total of 592 correctly filled questionnaires from telephone and web interviews [computer-assisted telephone interview (CATI) and computer-assisted web interview (CAWI)] were studied. The exploratory factor analysis (EFA) and structural equation modeling (SEM) were conducted in the study.
Findings
It was confirmed that four of five defined logistics value dimensions have positive impact on customer satisfaction. These dimensions are communication of delivery status, convenience of receipt, reception experience and convenience of return. The influence of speed of delivery on customer satisfaction was not confirmed. It was also confirmed that customer satisfaction has a positive impact on customer loyalty and that customer loyalty positively impacts online retailers' performance.
Originality/value
The study contributes to the current understanding of the influence of logistics factors on online retailers' performance through customer satisfaction and customer loyalty. There have been few studies that concern logistics value in e-commerce, with particular emphasis on above-mentioned relations. It is especially an important issue due to the fact that logistics can potentially lead to gain a competitive advantage in e-commerce.
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Kindness A.M. Uyanga, Modestus Okechukwu Okwu, A.O. Adeoye and S.E. Ogbeide
The study aims to carry out the production of a bulk heterojunction organic solar cell in a laboratory scale using a blend of poly (3-hexylthiopene) (P3HT) and [6, 6]-phenyl (C61…
Abstract
Purpose
The study aims to carry out the production of a bulk heterojunction organic solar cell in a laboratory scale using a blend of poly (3-hexylthiopene) (P3HT) and [6, 6]-phenyl (C61) butyric acid methyl ether (PCBM).
Design/methodology/approach
Four inverted geometry organic solar cells were prepared based on 1:1 ratio of P3HT to PCBM and subjected to post annealing at different temperatures of 32, 120, 130 and 140°C. Solar cells were fabricated with structure glass/ITO/P3HT:PCBM/PEDOT:PSS/Au and characterized using Keithley 2400 series sourcemeter and a multimeter interfaced to a computer system with a LabVIEW software, which showed both dark and illumination current–voltage characteristic curves. Four reference cells were also fabricated with structure soda lime glass/P3HT:PCBM and annealed at different temperatures of 32, 120, 130 and 140°C.
Findings
The third organic solar cell prepared, Sample CITO, had the best performance with power conversion efficiency (PCE) of 2.0281 per cent, fill factor (FF) of 0.392, short circuit current of −0.0133 A and open circuit voltage of 0.389 V. Annealing of active layer was found to improve cell morphology, FF and PCE. Annealing of the active layer at 140°C resulted in a decrease of the PCE to 2.01 per cent.
Research limitations/implications
These findings are in good agreement with previous investigation in literature which reported that best annealing temperature for a 1:1 ratio blend of active material is 130°C. Ultraviolet–visible spectra on reference cells showed that sample CITO had wider absorption spectra with peak absorbance at a wavelength of 508 nm.
Originality/value
This research is purely original.