Search results

Heroin has been a street drug along the East African coast for 25 years (Beckerleg, 1995) but it has only recently been recognised and documented (Kilonzo et al, 2001; Jones & Needle, 2005). Heroin use is risky and HIV transmission an increasing problem (McCurdy et al, 2005). Susan Beckerleg and colleagues uncover high rates of unprotected sex, excessive needle sharing and continued re‐use of old and dirty needles often kept in old tins, pockets, or as most do, hidden under rocks.

This paper reports on a questionnaire survey of 300 heroin users in Zanzibar town, in Tanzania. It was found that about 13% of respondents were current injectors of heroin, but that 38% of respondents reported have ‘ever injected’ heroin. Many injectors reported hiding their needles and syringes and almost half of them had shared their equipment during the past four weeks. Most of the respondents reported that they had not had sexual intercourse during the past four weeks. Of those who were sexually active most reported not having used a condom the last time they had intercourse. These findings highlight the need for a wider recognition of the extent of heroin use in East Africa as well as the urgent need to provide harm reduction and treatment services.

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.

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.

This paper aims to analyze the effect of cerium addition on the microstructure and the mechanical properties of Tin-Silver-Copper (SAC) alloy. The mechanical properties and refined microstructure of a solder joint are vital for the reliability and performance of electronics. SAC305 alloys are potential choices to use as lead-free solders because of their good properties as compared to the conventional Tin-Lead solder alloys. However, the presence of bulk intermetallic compounds (IMCs) in the microstructure of SAC305 alloys affects their overall performance. Therefore, addition of cerium restrains the growth of IMCs and refines the microstructure, hence improving the mechanical performance.

SAC305 alloy is doped with various composition of xCerium (x = 0.15, 0.35, 0.55, 0.75, 0.95) % by weight. Pure elements in powdered form were melted in the presence of argon with periodic stirring to ensure a uniform melted alloy. The molten alloy is then poured into a pre-heated die to obtain a tensile specimen. The yield strength and universal tensile strength were determined using a fixed strain rate of 10 mm per minute or 0.1667 mm s^(−1). The IMCs are identified using X-ray diffraction, whereas the elemental phase composition and microstructure evolution are, respectively, examined by using electron dispersive spectroscopy and scanning electron microscopy.

Improvement in the microstructure and mechanical properties is observed with 0.15% of cerium additions. The tensile test also showed that SAC305-0.15% cerium exhibits more stress-bearing capacity than other compositions. The 0.75% cerium doped alloy indicated some improvement because of a decrease in fracture dislocation regions, but microstructure refinement and the arrangement of IMCs are not those of 0.15% Ce. Different phases of Cu_6 Sn_5, Ag_3 Sn and CeSn_3 and ß-Sn are identified. Therefore, the addition of cerium in lower concentrations and presence of Ce-Sn IMCs improved the grain boundary structure and resulted refinement in the microstructure of the alloy, as well as an enhancement in the mechanical properties.

Characterization of microstructure and evaluation of mechanical properties are carried out to investigate the different composition of SAC305-xCerium alloys. Finally, an optimized cerium composition is selected for solder joint in electronics.

The relationship of outward foreign direct investment (OFDI) with home country's exports has significant implications for policymakers as well as business managers of MNEs. Since BRICS nations have emerged as important sources as well as destinations of FDI, this paper aims to study the impact of OFDI from these countries on home country exports by using panel data for BRICS for time period 1993–2015.

The author use panel unit root tests, panel cointegration, VECM and causality tests in the study.

The results reveal that OFDI has a negative and significant impact on home country exports indicating that outward FDI is a substitute for exports in these countries. It also indicates long-run causality from exports towards OFDI. There is no long-run causality running from OFDI to exports, suggesting that MNEs do not “connect” with home economies' firms through forward and backward linkages in value chain.

From the point of view of policymakers, it implies a net outflow of capital as the outflow of foreign investment would not be matched by any incremental export earnings since exports are getting substituted by production abroad. For business managers, it is indicative of a growing foreign market that warrants large scale production and justifies the high cost and risk involved in FDI as a mode of entry compared to exports.

To the best of authors' knowledge, this is the first attempt to deal with the relationship between home country exports and OFDI, for an important group of emerging market economies, i.e. BRICS. The understanding of this relationship allow us to identify whether factors contributing to OFDI from emerging economies are “tied” to their home economies thereby making exports necessary or are rather based on firm specific competencies which are leveraged in different locations to cater to expanding markets.

This study aims to analyze the theoretical complexity that underlies purchase managers’ perceptions of their ability to take part in the implementation of a new back-office service strategy.

A survey of purchasing department managers in the Antalya (Turkey) region was conducted. The purchasing managers of Antalya’s five-star accommodation businesses comprise the research sample.

Within the scope of the study, 205 questionnaires were gathered. Factor analysis, correlation and regression analysis were applied to the obtained data. The learning organization (LO) consists of three factors (organization, group/team and individual), service innovation (SI) consists of two factors (employee innovation behavior and new service development) and technology acceptance (TA) consists of four factors (perceived usefulness, perceived ease of use, facilitating situations and social factors), according to the findings of the factor analysis. According to correlation analysis, LO, SI and TA all have positive and significant relationships. The LO has been observed to play an intermediary function in the relationship between TA and SI as a consequence of the analysis that determines the mediation effect.

This study which dealt with the dimensions of SI, TA and LO showed a proposed model which gives a better understanding of how the development of back-office system strategies is affected by LOs.

This paper aims to contribute to the field of social entrepreneurship by exploring the interrelationships among the antecedents of social entrepreneurial intention (SEI) through the lens of Mair Noboa model (MNM). In recent years, many researchers have applied the antecedents of MNM to determine SEI. However, interrelationship among these antecedents has not been a focus of enquiry despite the repeated scholarly calls.

Applying quantitative methodology, the data was collected from a Web-based survey distributed across Bangladesh (N = 412). Data analysis was carried out based on the covariance-based structural equation modelling technique to confirm the hypotheses. The final measurement and structural models met all the requirements for reliability, model fit, convergent validity and discriminant validity. The proposed hypotheses were tested based on direct relationships and mediating effects.

The findings suggested that interrelationships among these antecedents do increase individuals’ intentions to become social entrepreneurs.

This paper fills an important knowledge gap by exploring the interrelationships among moral obligation, empathy, perceived social support and social entrepreneurial self-efficacy. This paper stressed identifying whether the SEI enhances through the interrelationships among these antecedents or not. The study findings bring new theoretical and practical implications on the role of empathy, moral obligation, perceived social support and social entrepreneurial self-efficacy.

Addressing the urgent issue of climate change and its impact on society requires immediate attention and innovative solutions. This chapter explores research that examines previous studies about the strategies companies use in their human resources (HR) departments to lessen the impact of climate change and support good social results.

This section conducted a thorough search of academic literature to find relevant studies on the connection between HR strategies, addressing climate change, and social impact. The inclusion criteria for this research targeted empirical studies on the relationship between HR practices and environmental and social outcomes. It employed particular keywords such as well-known academic databases.

This review discusses the important influence of HR strategies in addressing climate change and promoting positive social effects in companies. It evaluates successful HR practices that specifically endorse environmental and social goals through a comprehensive analysis of academic studies. The results offer useful knowledge for HR professionals and business leaders looking to align their HR strategies with climate change.

The findings of this chapter can benefit a diverse audience such as scholars who deal with human resource management, knowledge management and organizational innovation, HR personnel, business stakeholders and the employees.

This review offers a novel viewpoint by exploring the less-studied area of HR's potential to drive positive environmental and social changes. While past research has acknowledged HR's significance, this review goes further by analysing the specific HR approaches that have been successful in tackling climate change and enhancing social welfare.