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This paper aims to examine how the number of short videos posted and the number of influencers employed, two important strategies in short video marketing, affect consumer behavior and how price discounts moderate the effects of influencer endorsement on consumer browsing and purchasing behavior.

Drawing on the literature on influencer endorsement, this study used an ordinary least square model to empirically examine the two effects of endorsement strategies in increasing product traffic and sales for consumers at a short video app, Douyin (TikTok).

The results show that the number of short video ads produces the classic inverted U-shape for traffic and sales, and both effects were strengthened under a high discount condition. Whereas the number of influencers has a positive effect on traffic but produces an inverted U-shape for sales, both effects were undermined under a high discount condition.

This study is the first to explore the two distinct effects (repetition effect and diffusion effect) of influencer endorsement on browsing and purchasing behavior and theorize about the moderate effects of discounts on these effects.

There are two major strategies for short video advertising which are KOL (key opinion leader) endorsement and in-feed advertising. The authors aim to research the effectiveness of these two strategies for heterogeneous sellers.

The study employed a data set of users from Douyin. Using an endogenous treatment model, the study empirically examines the two strategies' effectiveness in attracting product traffic for online retailors at a short video app Douyin (TikTok).

The results show that the performance of in-feed advertising is higher when the seller's product is of lower price and when the seller has smaller cumulative video exposure. In addition, KOL endorsement is effective regardless of the product price, but performs better when the seller has larger cumulative video exposure.

To the best of the authors’ knowledge, this study is one of the first to explore the interaction effects of two major advertising strategies, KOL endorsement and in-feed advertising on short video platforms. The findings provide important theoretical contributions and practical implications.

Condition assessment on reinforced concrete (RC) structures is one of the critical issues as a result of structure degradation due to aging in many developed countries. The purpose of this paper is to examine the sensitivity and reliability of the conventional dynamic response approaches, which are currently applied in the RC structures. The key indicators include: natural frequency and damping ratio. To deal with the non-linear characteristics of RC, the concept of random decrement is applied to analyze time domain data and a non-linear damping curve could be constructed to reflect the condition of RC structure.

A full-scale RC structure was tested under ambient vibration and the impact from a rubber hammer. Time history data were collected to analyze dynamics parameters such as natural frequency and damping ratio.

The research demonstrated that the measured natural frequency is not a good indicator for integrity assessment. Similarly, it was revealed that the traditional theory of viscous damping performed poorly for the RC with non-linear characteristics. To address this problem, a non-linear curve is constructed using random decrement and it can be used to retrieve the condition of the RC structure in a scientific manner.

The time domain analysis using random decrement can be used to construct a non-linear damping curve. The results from this study revealed that the damage of structure can be reflected from the changes in the damping curves. The non-linear damping curve is a powerful tool for assessing the health condition of RC structures in terms of sensitivity and reliability.

The purpose of this paper is to investigate the influence of praseodymium (Pr) additions (0, 0.05 and 0.5 wt%) on the mechanical properties and microstructure of SnAgCu solder joint during aging process. Moreover, the authors aim to indicate that the decreased soldification undercooling of Sn3.8Ag0.7Cu solder can suppress the formation of Ag3Sn plate to some extent.

The shear strength evolution of SAC, SAC‐0.05Pr and SAC‐0.5Pr solder joint were studied under 150°C aging process with STR‐1000. The effect of Pr additions on the solidification behavior of SnAgCu solder was also studied by differential scanning calorimetry. To study the microstructure evolution, the cross‐sections of all specimens were observed by means of scanning electron microscope (SEM) and energy dispersive spectroscopy (EDS). Meanwhile, the etchant, consisting of 20%HNO3+distilled water was used for deep etching to reveal the interfacial morphology.

The shear force reduction rate of SAC solder joint during aging was restrained by 0.05%Pr addition but promoted with 0.5% Pr addition. The growth of IMC layer of SnAgCu joint in the aging process was suppressed significantly by different amounts of Pr additions. However, the beneficial effect of Pr addition due to the suppression of IMC layer growth was weakened by the micro‐cracks formed in PrSn3 compounds in SnAgCu‐0.5Pr joint. Pr additions (0.05, 0.5 wt%) decrease the solidification undercooling of SnAgCu solder, which will suppress the formation of Ag3Sn plate to some extent.

Further studies are necessary for confirmation of the practical application, especially of the manufacturing technology of solder paste containing Pr.

The appropriate amount of Pr in Sn3.8Ag0.7Cu solder is about 0.05 wt%. It is found that SAC‐0.05Pr solder has an improvement in solder joint reliability in long aging processes. The results suggested the novel solder alloys can meet the requirements of high reliability application.

The paper demonstrates that: Pr additions promote the solidification of SAC solder; shear force reduction rate of SAC solder joint was reduced by 0.05%Pr addition; the IMC layer growth rate of SnAgCu solder joint was suppressed by Pr additions; and micro‐cracks were found in PrSn3 phases after aging.

The purpose of this paper is to investigate the effects of minor addition of the rare earth (RE) element cerium, Ce, on the microstructures and creep properties of Sn-Ag-Cu solder alloys.

The pure Sn, Sn-Cu alloy, Sn-Ag alloy and Cu-Ce alloy were used as raw materials. Sn-Ag-Cu alloys with different contents of RE Ce were chosen to compare with Sn-Ag-Cu. The raw materials of Sn, Sn-Cu alloy, Sn-Ag alloy, Cu-Ce alloy were melted in a ceramic crucible, and were melted at 550°C ± 1°C for 40 minutes. To homogenize the solder alloy, mechanical stirring was performed every ten minutes using a glass rod. During the melting, KC1 + LiCI (1.3:1), were used over the surface of liquid solder to prevent oxidation. The melted solder was chill cast into a rod.

It is found that the microstructure exhibits smaller grains and the Ag₃Sn/Cu₆Sn₅ intermetallic compound (IMC) phases are modified in matrix with the addition of Ce. In particular, the addition of 0.03 wt.% Ce to the Sn-Ag-Cu solder can refine the microstructures and decrease the thickness of the IMC layers of Sn-Ag-Cu solder alloys. Meanwhile, thermodynamic analysis showed that these phenomena could be attributed to the reduction of the driving force for Cu-Sn IMC formation due to the addition of Ce. Results calculated using the thermodynamic method are close to the above experimental data. Thus, the optimum content of Ce in Sn-Ag-Cu solder alloys should be about 0.030 percent. Additionally, the effect of Ce on the creep rupture life of Sn-Ag-Cu soldered joints was studied. It was found that the creep rupture life may be increased up to 7.5 times more than that of the original Sn-Ag-Cu alloy, when Ce accounts for 0.030 percent.

This paper usefully investigates the effects of the RE cerium (Ce), on the microstructures and creep properties of Sn-Ag-Cu solder alloys, optimizing the quantity of Ce in the Sn-Ag-Cu solder alloy through a thermodynamic method and by creep-rupture life testing.

The purpose of this paper is to explore the formation and growth mechanism of bulk Cu₆Sn₅ intermetallic compounds, selecting Sn‐Ag‐Cu‐Ce solders as specimens.

In order to further enhance the properties of SnAgCu solder, trace amount of rare earth Ce was selected as alloying addition into the alloy; in previous investigations, the enhancements include better wettability, physical properties, creep strength and tensile strength. In this paper, the microstructure of Sn‐Ag‐Cu‐Ce soldered joints and its interfacial intermetallic compounds were investigated. Moreover, different morphologies of Cu₆Sn₅ IMCs were enumerated and described, and Ostwald ripening theory was employed to interpret the formation mechanism of bulk Cu₆Sn₅ IMCs.

In addition, based on finite element simulation, it is found that the von Mises stress concentrate around the bulk Cu₆Sn₅ IMCs inside the Sn‐Ag‐Cu‐Ce soldered joints after three thermal cycling loading (−55‐125°C). From the stress distribution, the failure site was predicted to fracture near the bulk Cu₆Sn₅ IMCs interface. This coincides with the experimental findings significantly.

The results presented in this paper may provide a theory guide for developing novel lead‐free solders as well as reliability investigation of lead‐free soldered joints.

The research on lead-free solder alloys has increased in past decades due to awareness of the environmental impact of lead contents in soldering alloys. This has led to the introduction and development of different grades of lead-free solder alloys in the global market. Tin-silver-copper is a lead-free alloy which has been acknowledged by different consortia as a good alternative to conventional tin-lead alloy. The purpose of this paper is to provide comprehensive knowledge about the tin-silver-copper series.

The approach of this study reviews the microstructure and some other properties of tin-silver-copper series after the addition of indium, titanium, iron, zinc, zirconium, bismuth, nickel, antimony, gallium, aluminium, cerium, lanthanum, yttrium, erbium, praseodymium, neodymium, ytterbium, nanoparticles of nickel, cobalt, silicon carbide, aluminium oxide, zinc oxide, titanium dioxide, cerium oxide, zirconium oxide and titanium diboride, as well as carbon nanotubes, nickel-coated carbon nanotubes, single-walled carbon nanotubes and graphene-nano-sheets.

The current paper presents a comprehensive review of the tin-silver-copper solder series with possible solutions for improving their microstructure, melting point, mechanical properties and wettability through the addition of different elements/nanoparticles and other materials.

This paper summarises the useful findings of the tin-silver-copper series comprehensively. This information will assist in future work for the design and development of novel lead-free solder alloys.

The early detection of cracks, corrosion and structural failure in aging structures is one of the major challenges in the civil, mechanical and aircraft industries. Common inspection techniques are time consuming and hence can have strong economic implications due to downtime. The paper aims to discuss these issues.

As a result, during the past decade a number of methodologies have been proposed for detecting crack in structure based on variations in the structure's dynamic characteristics. This work showcases the efficacy of particle swarm optimization (PSO) and genetic algorithm (GA) in damage assessment of structures.

Efficiency of these tools has been tested on structures like beam, plane and space truss. The results show the effectiveness of PSO in crack identification and the possibility of implementing it in a real-time structural health monitoring system for aircraft and civil structures.

The methodology presented establishes the PSO as robust and competent tool over GA for crack identification using changes in natural frequencies.

Lesotho is one of the most vulnerable countries to effects of climate change with resultant recurrent drought. Drought and dry spells have become a common feature that causes crop failure which subsequently causes food insecurity for agrarian communities. While drought-related research has explored the association between rainfall and crop production, there is a gap in understanding people’s experiences of drought impacts and their opinion about what actions could be taken to avoid such impacts in the future. This study aims to ask: what are people’s experiences of drought and potential early actions that could save livelihoods and reduce human suffering?

A qualitative research approach was adopted where this paper carried out consultations in three agroecological zones, i.e. Southern Lowlands, Northern Lowlands and Mountains of Lesotho. Overall, this paper conducted 48 community consultations where genderized focus group discussions (mixed elderly, mixed youth, middled aged men and women) and nine key informants (local authorities, schoolteachers, wisemen and women in the community) interviews were conducted. Furthermore, interviews with stakeholders at the district level (sectoral leaders in disaster risk reduction sub-sectors) were conducted.

This study finds that there are interlinked socio-economic, productive and environmental impacts. Drought-related impacts reported were: cost of food, prevalence of diarrhoea in children under five years of age, conflicts over resources, animal diseases and mortality, aridity and crop failure. Informants also perceived the following actions could be taken before a drought is manifested: clear agro-climatological early warning messages, tailor-made drought-relevant advisories, water harvesting and availability of drought-tolerant seeds. It is thus imperative to streamline policy interventions regarding dissemination of early warning messages and anticipatory actions to reduce the negative impacts of drought on livelihoods.

In any qualitative study, the researchers need to reflect on their positionality and how that may influence the research process, outcomes and the general limitations of the research methods (Quandt, 2021). Given that the research team has worked with humanitarian organisations in the study area after which development interventions were implemented, this might have led to interviewees exaggerating the negative impacts of drought hoping the team to bring assistance into the community. In contrast, others may have downplayed the impact and anticipatory actions they deem necessary because of concern that people from different institutions come to ask questions without feedback.

This study provides much-needed evidence on how communities affected by drought conceptualise it and how it affects their livelihoods. It delivers an understanding of the nature of the impacts of drought and the nature of anticipatory actions perceived as essential in reducing these impacts and, in so doing, seeks to inform policymakers on designing interventions informed by evidence on lived experience. Future humanitarian and policy interventions to prepare for droughts can use this evidence to identify the type of support that would be the most well-received by community members who are preparing for long-term drying trends in their region.

The study presents an understanding of people’s opinions of the nature and state of drought impacts, which are key to any effort towards developing and implementing relevant anticipatory action interventions to minimise the impacts of drought.

Tin-Silver-Copper is widely accepted as the best alternative to replace Tin-Lead solders in microelectronics packaging due to their acceptable properties. However, to overcome some of the shortcomings related to its microstructure and in turn, its mechanical properties at high temperature, the addition of different elements into Tin-Silver-Copper is important for investigations. The purpose of this paper is to analyse the effect of lanthanum doping on the microstructure, microhardness and tensile properties of Tin-Silver-Copper as a function of thermal aging time for 60, 120 and 180 h at a high temperature of 150°C and at high strain rates of 25, 35 and 45/s.

The microstructure of un-doped and Lanthanum-doped Tin-Silver-Copper after different thermal aging time is examined using scanning electron microscopy followed by digital image analyses using ImageJ. Brinell hardness is used to find out the microhardness properties. The tensile tests are performed using the universal testing machine. All the investigations are done after the above selected thermal aging time at high temperature. The tensile tests of the thermally aged specimens are further investigated at high strain rates of 25, 35 and 45/s.

According to the microstructural examination, Tin-Silver-Copper with 0.4 Wt.% Lanthanum is found to be more sensitive at high temperature as the aging time increases which resulted in coarse microstructure due to the non-uniform distribution of intermetallic compounds. Similarly, lower values of microhardness, yield strength and ultimate tensile strength come in favours of 0.4 Wt.% Lanthanum added Tin-Silver-Copper. Furthermore, when the thermally aged tensile specimen is tested at high strains, two trends in tensile curves of both the solder alloys are noted. The trends showed that yield strength and ultimate tensile strength increase as the strain rate increase and decrease when there is an increase in thermal aging.

The addition of higher supplement (0.4 Wt.%) of Lanthanum into Tin-Silver-Copper showed a lower hardness value, yield strength, ultimate tensile strength, ductility, toughness and fatigue in comparison to un-doped Tin-Silver-Copper at high temperature and at high strain rates. Finally, simplified material property models with minimum error are developed which will help when the actual test data are not available.