Search results

Laser soldering has attracted attention as an alternative soldering process for microsoldering due to its localized and noncontact heating, a rapid rise and fall in temperature, fluxless and easy automation compared to reflow soldering.

In this study, the metallurgical and mechanical properties of the Sn3.0Ag0.5Cu/Ni-P joints after laser and reflow soldering and isothermal aging were compared and analyzed.

In the as-soldered Sn3.0Ag0.5Cu/Ni-P joints, a small granular and loose (Cu,Ni)6Sn5 intermetallic compound (IMC) structure was formed by laser soldering regardless of the laser energy, and a long and needlelike (Cu,Ni)6Sn5 IMC structure was generated by reflow soldering. During aging at 150°C, the growth rate of the IMC layer was faster by laser soldering than by reflow soldering. The shear strength of as-soldered joints for reflow soldering was similar to that of laser soldering with 7.5 mJ, which sharply decreased from 0 to 100 h for both cases and then was maintained at a similar level with increasing aging time.

Laser soldering with certain energy is effective for reducing the thickness of IMCs, and ensuring the mechanical property of the joints was similar to reflow soldering.

Solder bumps for chip interconnections are downsizing from current approximately 100 µm to the expected 1 µm in future. As a result, the Cu-Ni cross-interaction in Cu/Solder/Ni solder joints will be more complicated and then strongly influence the growth of the intermetallic compounds (IMCs). Thus, it is critical to understand the fundamental aspects of interfacial reaction in micro solder joints. This paper aims to reveal the effect mechanism of reflow temperature and solder size on the interfacial reaction in Cu/Solder/Ni solder joints.

The Cu-Ni cross-interaction in the Cu/Sn/Ni micro solder joints with 50 and 100 µm solder sizes at 250°C and 300°C were observed, respectively. The line-type interconnects were soaked in silicone oil, and the temperature of the line-type interconnects was 250 ± 3°C and 300 ± 3°C, which were monitored by a fine K-type thermocouple, and followed by an isothermal aging process at various times. After aging, the specimens were removed from the silicone oil and cooled in the air to room temperature.

The major interfacial reaction product on both interfaces was (Cu,Ni)₆Sn₅, and the asymmetric growth of (Cu,Ni)₆Sn₅, evidenced by the thickness of (Cu,Ni)₆Sn₅ IMCs at the Sn/Ni interface was always larger than that at the Sn/Cu interface, resulted from the directional migration of Cu atoms toward the Sn/Ni interface under Cu concentration gradient. The morphology of (Cu,Ni)₆Sn₅ IMC at Sn/Cu interface was columnlike at 250°C, and which changed from columnlike to scallop with large aspect ratio at 300°C, while that at Sn/Ni interface gradually evolved from needlelike to the mixture of needlelike and layered at 250°C, and which evolved from needlelike to scallop with large aspect ratio at 300°C. The evolution of morphology of (Cu,Ni)₆Sn₅ is attributed to the content of Ni. Furthermore, the results indicate that the Cu-Ni cross-interaction was stronger with small solder size and relatively low temperature in the Cu/Sn/Ni micro solder joints.

The asymmetric growth of (Cu,Ni)₆Sn₅ in the Cu/Sn/Ni micro solder joints, evidenced by the thickness of (Cu,Ni)₆Sn₅ IMCs at the Sn/Ni interface, was always larger than that at the Sn/Cu interface. The morphology evolution of (Cu,Ni)₆Sn₅ IMC at both interfaces was attributed to the content of Ni. The Cu-Ni cross-interaction was stronger with small solder size and relatively low temperature in the Cu/Sn/Ni micro solder joints.

The 50th anniversary of Fox's Beyond Contract and Man Mismanagement coincides with another vital contribution to the sociology of work from 1974: Braverman's Labor and Monopoly Capital. This article analyses these two scholars' complementary approaches to job design and the extent to which Fox's ideas influenced subsequent labour process thought.

The article's methodological approach is a historiographical reading of Fox and Braverman's thought in the context of their times and later scholarship.

The article demonstrates that despite some noteworthy overlap with Braverman concerning scientific management, Fox's insights were marginal to later iterations of labour process analysis. It delves into the reasons for this relative neglect, providing an understanding of the dynamics at play.

This paper's value lies in its combined industrial relations and labour process historiography. It offers a fresh perspective on Alan Fox's relationship to the latter field of study.

This study aims to improve the maneuverability and stability of four-wheel chassis in a small paddy field; a front axle swing steering four-wheel chassis with optimal steering is designed.

When turning, the front inner wheel stops and the rear inner wheel is in the following state. The hydraulic drive system of the walking wheel adopts a driving mode in which two front-wheel motors are connected in series and two rear wheel motors in parallel. The chassis uses a combination of a gasoline engine with a water cooling system, a CVT continuously variable transmission and a hydraulic drive system to increase the control capability. The front axle rotary chassis adopts a step-less variable speed engine and a hydraulic control system to solve the hydraulic stability of the chassis in uphill and downhill conditions so as to effectively control the over-speed of the wheel-side drive motors. Through the quadratic orthogonal rotation combination design test, the mathematical models of uphill and downhill front-wheel pressures and test factors are established.

The results show that the chassis stability is optimal when the back pressure is 0.5 MPa, and the rotating slope is 4°. The uphill and downhill pressures of the front wheels are 2.38 MPa and 1.5 MPa, respectively.

The influence of external changes on the pressure of hydraulic motors is studied through experiments, which lays the foundation for further research.

Traditional studies in the sociology of science have highlighted the self-organized character of the academic community. This article focuses on recent interrelated changes that alter that distinctive governance structure and its related patterns of competition and cooperation. The changes that we identify here are contractualization and large-scale cooperative research. We use different data sources to exemplify these new patterns and discuss the illustrative role of research clusters in German academia. Research clusters as funded by the German Research Foundation (DFG) are both a highly prestigious scarce good in the competition for reputation and resources and a means of fostering cooperation. Our analysis of this German example reveals that this new institutional configuration of universities as organizations, academic researchers, and the state has a profound effect on organizational practices. We discuss the implications of our empirical findings with regard to collegiality in academia. Ultimately, we anticipate a further weakening of collegial bonds, not only because universities and the state have become more active in shaping the nature of academic competition and cooperation but also because of the increasing strategic and individualistic orientation of academic researchers. In the final section, we summarize our findings and address the need for further research and an international comparative perspective.

The construction industry has been traditionally referred to as slow when it comes to technological transformation. This study aims to investigate and present a scorecard of the construction industry in the past decade, the paper adopted Bibliometrics. The study identified the various digital transformation (DT) aspects in the construction industry and future research directions are also identified.

To achieve the aim of this research, an inductive approach was adopted through a grounded theory strategy. Secondary data was retrieved from the Scopus database and analysed using Biblioshiny and VOSviewer. The data was retrieved through specific keywords related to the study focus.

The study also proposed a balanced flow model for DT discussion in the construction industry. DT in the construction industry disrupts every aspect of the industry, albeit at different rates due to the existing barriers; hence, the study identified areas that require further research. It, thus, provides a theoretical and practical basis for researchers and practitioners alike.

The study reviewed the DT research discuss in the construction industry. It is worthy of note that this is the first study that analyses the DT of the construction industry in the past decade.

Following a crucial COVID-19 pandemic lockdown, the coronavirus has affected every academic institution, particularly libraries and information centres. To address this unprecedented scenario, libraries’ staff has decided to provide their services via digital access while staying close to the users. To predict users’ intention to use digital libraries after COVID-19, the authors combined the technology acceptance model (TAM), the theory of planned behaviour (TPB) and perceived risk.

Data were collected via a paper-based questionnaire using a convenient sampling method which was distributed at two major libraries; Maulana Azad Library, Aligarh Muslim University and Dr Zakir Husain Library, Jamia Millia Islamia in India.

Empirical findings suggested that all the proposed hypotheses were supported, and the integrated model had strong explanation power as the proposed model explained a 74.5% variance in users’ intention to use digital libraries after COVID-19.

This study offers substantial information to librarians, digital libraries, universities, institutes and other stakeholders and sheds light on the potential for a developing nation to transition to an economy with a strong digital infrastructure. The scope of the study is constrained to the users in India only, hence, leading to the possibility that it may be challenging to generalize the findings.

According to the best of the authors’ knowledge, it is one of the few studies to predict users’ intentions for using digital libraries after COVID-19 by applying the integrated model of TPB and TAM in an emerging economy. It helped understand the users’ attitudes towards using the digital services and resources available at the respective libraries. It also contributed considerably to the argument that users have grown accustomed to harnessing digital libraries during the post-COVID-19 period.

The current and modern electrical distribution networks, named smart grids (SGs), use advanced technologies to accomplish all the technical and nontechnical challenges naturally demanded by energy applications. Energy metering collecting is one of these challenges ranging from the most basic (i.e., visual assessment) to the expensive advanced metering infrastructure (AMI) using intelligent meters networks. The AMIs’ data acquisition and system monitoring environment require enhancing some routine tasks. This paper aims to propose a methodology that uses a distributed and sustainable approach to manage wide-range metering networks, focused on using current public or private telecommunication infrastructure, optimizing the implementation and operation, increasing reliability and decreasing costs.

Inspired by blockchain technology, a collaborative metering system architecture is conceived, managing massive data sets collected from the grid. The use of cryptography handles data integrity and security issues.

A robust proof-of-concept simulation results are presented concerning the resilience and performance of the proposed distributed remote metering system.

The methodology proposed in this work is an innovative AMI solution related to SGs. Regardless of the implementation, operation and maintenance of AMIs, the proposed solution is unique, using legacy and new technologies together in a reliable way.

Although businesses continue to take up artificial intelligence (AI), concerns remain that companies are not realising the full value of their investments. The study aims to provide insights into how AI creates business value by investigating the mediating role of Business Process Management (BPM) capabilities.

The integrative model of IT Business Value was contextualised, and structural equation modelling was applied to validate the proposed serial multiple mediation model using a sample of 448 organisations based in the EU.

The results validate the proposed serial multiple mediation model according to which AI adoption increases organisational performance through decision-making and business process performance. Process automation, organisational learning and process innovation are significant complementary partial mediators, thereby shedding light on how AI creates business value.

In pursuing a complex nomological framework, multiple perspectives on realising business value from AI investments were incorporated. Several moderators presenting complementary organisational resources (e.g. culture, digital maturity, BPM maturity) could be included to identify behaviour in more complex relationships. The ethical and moral issues surrounding AI and its use could also be examined.

The provided insights can help guide organisations towards the most promising AI activities of process automation with AI-enabled decision-making, organisational learning and process innovation to yield business value.

While previous research assumed a moderated relationship, this study extends the growing literature on AI business value by empirically investigating a comprehensive nomological network that links AI adoption to organisational performance in a BPM setting.