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This paper aims to clarify the size and morphology of transition metal dichalcogenides has an impact on lubrication performance of Cu-based composites. This study is intended to show that Cu-based electrical contact materials containing Nb_0.91Ti0.09Se₂ have better electrical and tribological properties than those containing NbSe₂. The tribological properties of Cu-based with different Ti-dopped NbSe₂ content were also discussed.

The NbSe₂ and Nb_0.91Ti_0.09Se₂ particles were fabricated by thermal solid state reaction method. The powder metallurgy technique was used to fabricate composites with varying Nb_0.91Ti_0.09Se₂ mass fraction. The phase composition of Cu-based composites was identified by X-ray diffraction, and the morphology of NbSe₂/Nb_0.91Ti_0.09Se₂ and the worn surface of composites were characterized by scanning electron microscopy and transmission electron microscopy. In addition, the tribological properties of composites were appraised using a ball-on-disk multi-functional tribometer. The data of friction coefficient and resistivity were analyzed and the corresponding conclusion was drawn.

In comparison with the pure copper, Cu-based composites containing Nb_0.91Ti_0.09Se₂/NbSe₂ had a lower friction coefficient, illustrating the Nb_0.91Ti_0.09Se₂ with nano-size particles prepared in this work is a perfect choice for the fabrication of excellent electrical contact composites. Compared to composites with NbSe₂, composites containing Nb_0.91Ti_0.09Se₂ have better tribological and electrical properties.

Because of the use of thermal solid state reaction method, the size of NbSe₂ and Nb_0.91Ti_0.09Se₂ is relatively large. Therefore, the fabrication of finer particles of Nb_0.91Ti_0.09Se₂ is encouraged.

In this paper, the authors discuss the tribological and electrical properties of Cu-based composites, and the value of optimum obtained as Nb_0.91Ti_0.09Se₂ content is 15 Wt.%.

The purpose of this paper is to summarize the current applications of BIM, the integration of related technologies and the tendencies and challenges systematically.

Using quantitative and qualitative bibliometric statistical methods, the current mode of interaction between BIM and other related technologies is summarized.

This paper identified 24 different BIM applications in the life cycle. From two perspectives, the implementation status of BIM applications and integrated technologies are respectively studied. The future industry development framework is drawn comprehensively. We summarized the challenges of BIM applications from the perspectives of management, technology and promotion, and confirmed that most of the challenges come from the two driving factors of promotion and management.

The technical challenges reviewed in this paper are from the collected literature we have extracted, which is only a part of the practical challenges and not comprehensive enough.

We summarized the current mode of interactive use of BIM and sorted out the challenges faced by BIM applications to provide reference for the risks and challenges faced by the future industry.

There is little literature to integrate BIM applications and to establish BIM related challenges and risk frameworks. In this paper, we provide a review of the current implementation level of BIM and the risks and challenges of stakeholders through three aspects of management, technology and promotion.

Ghana has recently reviewed its renewable energy Act 835 with an objective of providing 10% of its energy from renewables by 2020 (Ackah and Asomani, 2015). Meanwhile, solar Photovoltaic (PV) accounts for less than 2% of the energy mix (Energy Commission, 2018). In combating environmental issues such as climate change and meeting these policy targets, there is the urgent need to increase investment into the renewable sector. Therefore, the purpose of this paper is to critically examine the impeding constraints to photovoltaic investment in Ghana.

The Literature evaluation was carried out of critical constraints surrounding PV investments. Questionnaire was developed and administered online using Google form. Descriptive statistics was used to describe the features of each constraint. In addition, inferential analysis using relative importance index was used to rank these indicators. Again, one sample t-test was used to test the significance of the indicator. Multiple indicators were used to measure the latent constructs. Finally, independent test of mean equity was used to test relationship between the working experiences of despondence who have worked with solar PV below five years and those who worked from five years to ten years.

The research has highlights high installation and maintenance costs, lack of access to long-term capital finance, access to affordable consumer finance and lack of support to research and development as the major investment obstacles to solar PV investment in Ghana.

It is recommended that the Government of Ghana should provide incentives such as tax waivers, which will encourage entrepreneurs, invest into PV. In addition, it is recommended that solar PV companies must collaborate with financial institutions to provide low interest and flexible consumer financing schemed that can enable home users to purchase the technology. Future research should complement this work by focusing on the impact of domestic currency volatility on PV investment. The scope of this study is constrained to the PV industry in Ghana.

This study will serve as a guide to the private sector business owners to help make critical PV investment decisions. It has also brought to the forefront the reason why solar PV account for a small fraction of Ghana’s energy mix.

This paper seeks to espouse the prevailing constraints to PV investment in Ghana and seeks to contribute to already existing literature that will make profound changes in state policy around PV investment. By understanding these difficulties, driving pointers can be recognized to encourage effective future venture inside the sustainable power source area. In this way, the research leads to a better understanding of the impeding factors that hinders PV investment in Ghana. Again, the paper has achieved new discovery with regards to variations between years of experience with PV use. The variation being less than five years with over five years of PV use. By understanding these difficulties, driving pointers can be recognized to invigorate effective future ventures.