Sourcing from Africa: A Systematic Review and a Research Agenda

Finnish Foundation for Economic Educatio

Integration of African firms into global value chains

Ever since the emergence of the global sourcing and manufacturing phenomenon, numerous firms have expanded their sourcing and manufacturing efforts to low-cost countries to increase their competitive advantage. However, as costs are drastically rising in previously cost-efficient countries, firms in both low-cost and high-cost countries are experiencing continental shifts in global sourcing and manufacturing patterns. On the one hand, firms from developed economies are gradually leaving previously cost-efficient sourcing destinations, such as China, to search for suppliers in alternative low-cost locations, such as the African continent, or reshoring to their home countries. On the other hand, firms from relatively low-cost economies, such as China, are also increasingly starting to source from other destinations, such as the African continent, and offshore their manufacturing activities to high-cost environments.  To facilitate a scientific treatment of the continental shifts in global sourcing and manufacturing, this dissertation focuses on the topic from the perspectives of China and Africa. Specifically, this dissertation investigates the challenges faced by Chinese manufacturing suppliers, and their responses, in supplying to global buyers, and the factors motivating Chinese firms to offshore their manufacturing to high-cost environments. Additionally, this dissertation takes a deeper look into the gaps in extant literature on sourcing from Africa and suggests future research avenues. Finally, yet importantly, this dissertation identifies the roles of African suppliers in global value chains as well as the motives of firms from both developed and developing economies in sourcing from Africa and the common obstacles met.  The overall findings of this dissertation reveal that the roles of Chinese and African firms have changed in global value chains, with China moving up the value ladder and Africa becoming more integrated. The findings also indicate that there are no overarching "etic" theories (i.e. general theories which everyone can transpose and adapt for their specific conditions, as opposed to "emic" theories which are contextual and suitable only for specific situations (Revilla and Sáenz, 2014)) in the purchasing and supply management discipline that can be applied regardless of national and cultural contexts, as it has been found that extant knowledge of theories and frameworks on global sourcing and manufacturing cannot necessarily be applied in the Chinese and African contexts

Finite element modeling of multi-pass welding and shaped metal deposition processes

This paper describes the formulation adopted for the numerical simulation of the shaped metal deposition process (SMD) and the experimental work carried out at ITP Industry to calibrate and validate the proposed model. The SMD process is a novel manufacturing technology, similar to the multi-pass welding used for building features such as lugs and flanges on fabricated components (see Fig. 1a and b). A fully coupled thermo-mechanical solution is adopted including phase-change phenomena defined in terms of both latent heat release and shrinkage effects. Temperature evolution as well as residual stresses and distortions, due to the successive welding layers deposited, are accurately simulated coupling the heat transfer and the mechanical analysis. The material behavior is characterized by a thermo-elasto-viscoplastic constitutive model coupled with a metallurgical model. Nickel super-alloy 718 is the target material of this work. Both heat convection and heat radiation models are introduced to dissipate heat through the boundaries of the component. An in-house coupled FE software is used to deal with the numerical simulation and an ad-hoc activation methodology is formulated to simulate the deposition of the different layers of filler material. Difficulties and simplifying hypotheses are discussed. Thermo-mechanical results are presented in terms of both temperature evolution and distortions, and compared with the experimental data obtained at the SMD laboratory of ITP

Effect of toroidal field ripple on plasma rotation in JET

Dedicated experiments on TF ripple effects on the performance of tokamak plasmas have been carried out at JET. The TF ripple was found to have a profound effect on the plasma rotation. The central Mach number, M, defined as the ratio of the rotation velocity and the thermal velocity, was found to drop as a function of TF ripple amplitude (3) from an average value of M = 0.40-0.55 for operations at the standard JET ripple of 6 = 0.08% to M = 0.25-0.40 for 6 = 0.5% and M = 0.1-0.3 for delta = 1%. TF ripple effects should be considered when estimating the plasma rotation in ITER. With standard co-current injection of neutral beam injection (NBI), plasmas were found to rotate in the co-current direction. However, for higher TF ripple amplitudes (delta similar to 1%) an area of counter rotation developed at the edge of the plasma, while the core kept its co-rotation. The edge counter rotation was found to depend, besides on the TF ripple amplitude, on the edge temperature. The observed reduction of toroidal plasma rotation with increasing TF ripple could partly be explained by TF ripple induced losses of energetic ions, injected by NBI. However, the calculated torque due to these losses was insufficient to explain the observed counter rotation and its scaling with edge parameters. It is suggested that additional TF ripple induced losses of thermal ions contribute to this effect

Non-destructive controlled single-particle light scattering measurement

We present a set of light scattering data measured from a millimeter-sized extraterrestrial rock sample. The data were acquired by our novel scatterometer, which enables accurate multi-wavelength measure- ments of single-particle samples whose position and orientation are controlled by ultrasonic levitation. The measurements demonstrate a non-destructive approach to derive optical properties of small mineral samples. This enables research on valuable materials, such as those returned from space missions or rare meteorites.Peer reviewe

Cosmic Strings and Superstrings

Cosmic strings are predicted by many field-theory models, and may have been formed at a symmetry-breaking transition early in the history of the universe, such as that associated with grand unification. They could have important cosmological effects. Scenarios suggested by fundamental string theory or M-theory, in particular the popular idea of brane inflation, also strongly suggest the appearance of similar structures. Here we review the reasons for postulating the existence of cosmic strings or superstrings, the various possible ways in which they might be detected observationally, and the special features that might discriminate between ordinary cosmic strings and superstrings.Comment: Minor errors corrected and some references added, 34 pages, 6 figure

In vitro cytotoxicity and surface topography evaluation of additive manufacturing titanium implant materials

Custom-designed patient-specific implants and reconstruction plates are to date commonly manufactured using two different additive manufacturing (AM) technologies: direct metal laser sintering (DMLS) and electron beam melting (EBM). The purpose of this investigation was to characterize the surface structure and to assess the cytotoxicity of titanium alloys processed using DMLS and EBM technologies as the existing information on these issues is scarce. "Processed" and "polished" DMLS and EBM disks were assessed. Microscopic examination revealed titanium alloy particles and surface flaws on the processed materials. These surface flaws were subsequently removed by polishing. Surface roughness of EBM processed titanium was higher than that of DMLS processed. The cytotoxicity results of the DMLS and EBM discs were compared with a "gold standard" commercially available titanium mandible reconstruction plate. The mean cell viability for all discs was 82.6% (range, 77.4 to 89.7) and 83.3% for the control reconstruction plate. The DMLS and EBM manufactured titanium plates were non-cytotoxic both in "processed" and in "polished" forms.Peer reviewe

Studies of New Vector Resonances at the CLIC Multi-TeV e+e- Collider

Several models predict the existence of new vector resonances in the multi-TeV region, which can be produced in high energy e+e- collisions in the s-channel. In this paper we review the existing limits on the masses of these resonances from LEP/SLC and TEVATRON data and from atomic parity violation in some specific models. We study the potential of a multi-TeV e+e- collider, such as CLIC, for the determination of their properties and nature.Comment: 17 pages, 16 EPS figures, uses JHEP3.cl