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The purpose of this paper is to investigate the effect of Sb (0, 0.2 and 2 wt.%) on wetting performance of lead-free solder of near eutectic Sn-Cu micro-alloyed with Ni and Ge.

The melting characteristic of the lead-free alloys was studied using differential scanning calorimetry. Wettability was examined using wetting balance test for two liquid fluxes, water based and alcohol based in two temperatures 265°C and 277°C. Also, contact angle was measured using sessile drop test.

It is shown that 0.2 wt.% Sb reduces the melting temperature and pasty range. Moreover, the addition of 0.2 wt.% Sb improves wetting behavior for alcohol-based flux. It is also demonstrated that the effect of Sb on meniscus height in wetting balance test and contact angle in sessile drop test follows the trend of wetting performance.

It is found that adding 0.2 wt.% Sb improves the wettability of Ni-Ge micro-alloyed Sn-Cu solder; however, higher concentration of Sb does not benefit the alloy.

The purpose of this study is to discover the components of virtual leadership in universities and higher education institutions during Covid-19 pandemic.

This research uses the qualitative research design, and semi-structured interviews with senior leaders were conducted with non-random purposeful and snowball sampling methods. Also, grounded theory was used for analyzing, coding and classifying the data.

After analyzing data, five main components influencing virtual leadership including leader's personality traits, followers' characteristics, technological, environmental and organizational components were identified.

As leadership, particularly virtual leadership, highly depends on context such as the level of technology in that certain region, the results cannot be generalized to other sectors or countries.

The research advances leadership development theory by highlighting the main components of virtual leadership in educational sector as a comprehensive perspective and complement the other aspects of virtual leadership such as consequences and challenges investigated by other studies.