Measuring co-authors’ contribution to an article’s visibility

The visibility of an article depends to a large extent on its authors. We study the question how each co-author’s relative contribution to the visibility of the article can be determined and quantified using an indicator, referring to such an indicator as a CAV-indicator. A two-step procedure is elaborated, whereby one first chooses an indicator (e.g. total number of citations, h-index …) and subsequently one of two possible approaches. The case where the indicator is an h-type index is elaborated in a Lotkaian framework. Different examples illustrate the procedure and the choices involved in determining a CAV-indicator.     

Should I stay or should I go? Founder’s decision to leave an entrepreneurial venture during an industrial crisis

We investigate if while experiencing an intensely negative industry-specific shock, skilled entrepreneurs may decide to leave the firm they founded, whereas founders who are less endowed with human capital may decide to continue their activity. Developing a stylised theoretical framework of the issue intended to derive the necessary and sufficient conditions for the emergence of this phenomenon, this study explores its occurrence in Italy during the ICT industry crisis from early 2000–2003 by analysing the individual stay/leave decision of a sample of 201 founders of 79 start-ups operating in the ICT services market.     

How to motivate vendor’s RFID adoption beyond mandate? A retailer’s perspective

Wal-Mart’s mandate of vendors’ RFID adoption has speeded the implementation of RFID, creating an innovative way of managing products and ushering in a new era of supply chain efficiencies. However, Wal-Mart’s action is widely controversial and hits troubles due to vendors’ protests. This research analyses how a retailer firm can stimulate its vendor to adopt this emerging innovation of supply chain management by using an incentive contract rather than a mandate. Such a contract should motivate the vendor to make costly efforts to adopt RFID, truthfully report the information of adoption cost, and execute RFID’s adoption at the retailer’s preferred timing. Established on the framework of the principal–agent theory (In economics, the principal–agent problem refers to the dilemma of how one party (the ‘principal’) could motivate the other party (the ‘agent’) to act in the best interests of one party (the ‘principal’) when both parties have different interests and information) and the real options theory (A real option theory investigates how valuable the flexibility (the ‘real options’) such as to the timing of the contract is when there is uncertainty in the contract), this paper derives such an incentive contract, discusses the effects of agency concerns and sheds substantive light on RFID’s adoption in a retailer–vendor dyad.     

Access to universities’ public knowledge: who’s more nationalist?

Access to public knowledge is a prerequisite for the good functioning of developed economies. Universities strive and are also requested to contribute to this knowledge both locally and internationally. Traditional studies on the geography of knowledge flows have identified a localisation effect; however, these studies do not use the country as the unit of observation and hence do not explore national patterns. In this paper, we hypothesise that the localisation of university knowledge flows is directly related to share of firm expenditure on research and development. To test this hypothesis, we use references to universities in patent documents as indicators based on a data set of around 20,000 university references, for 37 countries in the period 1990–2007, resulting in panels of around 300–500 observations. We build indicators for the university knowledge flows both inside and outside the applicant country, which we explain as a function of some proxies for national size and research structure based on econometric estimations. We draw some conclusions as to the importance of national business scientific strength for fostering increased domestic university knowledge flows.     

Growing trend of China’s contribution to tissue engineering

This study examines China’s performance on tissue engineering using scientometrics measures such as China’s global publication share, rank, growth rate and citation impact, its publications in various sub-fields, top journals in terms of national share based on last 5 years (2008–2012) publications data obtained from ISI Science citation index expanded database. We have also determined Chinese share with international collaborative papers at the national level, as well as h-core papers and high-cited papers, etc.     

ESA’s Drop Tower Utilisation Activities 2000 to 2011

The European Space Research and Technology Center ESTEC, ESA’s premises in Noordwijk, The Netherlands, has a long lasting cooperation with the ZARM-FAB (Centre of Applied Space Technology and Microgravity—Drop Tower Operation and Service Company) in Bremen on the utilization of the Drop Tower for ground-based microgravity research and space hardware development studies. During the period January 2000 to December 2011 ESA will have procured in total some 840 drops addressing a variety of scientific and technological disciplines. The experiments are usually carried out in campaigns of 15 to 20 drops each, with an annual average of about 5 campaigns. The cooperation agreement between ESA and the ZARM-FAB includes experiment preparation advice by ZARM’s experts, the integration of the hardware into the drop capsule, dedicated safety reviews, the execution of the drop or catapult experiments, the post-flight payload de-integration as well as the handover of acquired data to the experimenters. The experiment hardware itself is provided by the scientists or has to be procured from sources outside of ESA’s drop tower utilization contract. ESA appreciates the cooperation of the ZARM-FAB in Bremen whose drop- and catapult facility provides excellent microgravity quality, is operated by a highly competent, flexible and extremely supportive expert team, allows campaign integration at relatively short notice throughout the entire year, offers real-time experiment operations and immediately after each drop delivers experiment results and provides on-site hardware modification possibilities.     

Territorial innovation models: to be or not to be,that’s the question

Scientometrics - In a recent paper, Hirsch (hα: an index to quantify an individual’s scientific leadership, 2019. https://doi.org/10.1007/s11192-018-2994-1 )  proposes to...     

Brittle to ductile transition – An engineer’s point of view

Knowledge of mechanisms and governing parameters of various modes of damage to structural materials is very important in numerous aspects of practical physical metallurgy–steel production, manufacture of welded joints with required properties, or identification of damage causes in industrial accidents. The apparently simple task of finding a literature source with clear physical–metallurgical interpretation of the reasons for BDT (brittle-to-ductile transition) in steel and other body-centered cubic metals was found to be quite an intricate problem, since an unequivocal and comprehensive theoretical concept of BDT is still missing. Based on the main results of a literature survey a phenomenological explanation of the existence of BDT is presented.     

Axial-thrust responses due to a gas turbine’s rotor blade distortions

The axial thrust imposed on the shaft of a gas turbine depends upon its rotor blade inlet inclination to the turbine’s axial direction: this inclination can change due to the distortions resulting from fouling, aging, tip rubbing, erosion, thermal-fatigue cracks, and corrosion. Relevant influential parameters for an operational gas turbine were measured. Theoretical predictions for the behavior of the same turbine were obtained from computer simulations. The results of both measurements and theoretical predictions were compared and showed qualitative correspondence. The rotor blade profile distortions result in significant increases in the axial thrust on the compressor, which adversely affects the gas turbine’s thermodynamic performance, reliability, and operational life.     

Nonlinear correction to Darcy’s law for channels with wavy walls

For low Reynolds numbers ${\mathcal{R}}$ , the flow of a viscous fluid through a channel is described by the well-known Darcy’s law which corresponds to a linear relation between the pressure gradient ${\overline{\nabla p}}$ and the average velocity ${\overline{u}}$ . When the channel is not straight and when the Reynolds number is not negligible, additional terms appear in this relation. Some previous authors investigated the first three coefficients in the expansion of ${|\overline{\nabla p}|}$ in the powers of ${\overline{u}}$ and they showed that the coefficient of ${\overline{u}^2}$ vanishes for moderate ${\mathcal{R}}$ . Other authors demonstrated that this coefficient can be non-zero. This question is addressed and solved. It is demonstrated that both cases occur; Forchheimer’s law has a cubic correction for small ${\mathcal{R}}$ and a quadratic one for large ${\mathcal{R}}$ . Two analytical–numerical algorithms are constructed to prove this property. These algorithms are applied to the Navier–Stokes equations in three-dimensional channels enclosed by two wavy walls whose amplitude is proportional to ${b{\varepsilon}}$ , where 2b is the mean clearance of the channels and ${\varepsilon}$ is a small dimensionless parameter. The first algorithm is applied for small ${\mathcal{R}}$ by representing the velocity and the pressure in terms of a double Taylor series in ${\mathcal{R}}$ and ${\varepsilon}$ . The accuracy ${O(\mathcal{R}^2)}$ and ${O(\varepsilon^6)}$ following Padé approximations yield analytical approximate formulae for Forchheimer’s law. The first algorithm is applied to symmetric channels on the theoretical level (all terms on ${\mathcal{R}}$ and ${\varepsilon}$ are taken into account) to show that ${|\overline{\nabla p}|}$ is an odd function of ${\overline{u}}$ . This observation yields, in particular, a cubic correction to Darcy’s law. Numerical examples for non-symmetrical channels yield the same cubic correction. The second algorithm is based on the analytical–numerical solution to the Navier–Stokes equations for arbitrary ${\mathcal{R}}$ up to ${O(\varepsilon^{3})}$ . This algorithm yields, in particular, a quadratic correction to Darcy’s law for higher ${\mathcal{R}}$ .     

Determinant factors of individuals’ decision to emigrate in rural Spain: The role of ICT-based public policies

Depopulation is a dramatic problem in rural inland Spain. The present study draws on a survey administered to inhabitants of rural areas to analyse the factors influencing the decision to emigrate to larger centres of population, with a special focus on the impact of ICT-based public policies. The findings show that size of municipality, age and education affect the intention to emigrate. It is found that the digital divide in terms of quality of ICT access has not, in many cases, been overcome, having an effect on citizen satisfaction. To guide public actions, we identify population profiles depending on both level of satisfaction with ICT development and preference towards specific ICT-related public policy measures intended to combat depopulation. We also find that most individuals continue to think that improving investment in ICT infrastructures should be a priority of public policy, compared to more advanced measures such as bolstering e-government.     

A new approach based on embedding Green’s functions into fixed-point iterations for highly accurate solution to Troesch’s problem

In this paper, a novel approach is introduced for the solution of the non-linear Troesch’s boundary value problem. The underlying strategy is based on Green’s functions and fixed-point iterations, including Picard’s and Krasnoselskii–Mann’s schemes. The resulting numerical solutions are compared with both the analytical solutions and numerical solutions that exist in the literature. Convergence of the iterative schemes is proved via manipulation of the contraction principle. It is observed that the method handles the boundary layer very efficiently, reduces lengthy calculations, provides rapid convergence, and yields accurate results particularly for large eigenvalues. Indeed, to our knowledge, this is the first time that this problem is solved successfully for very large eigenvalues, actually the rate of convergence increases as the magnitude of the eigenvalues increases.     

Ghana’s nuclear power and its potential to curtail carbon dioxide emission

Clean Technologies and Environmental Policy - The Ghana Nuclear Power Agenda is a program laid out by the Ghana Atomic Energy Commission in collaboration with the government of Ghana to guide and...     

From the Green’s Function in Tight-Binding Representation to Interatomic Many-body Potentials

1.IntroductionCentralpairf0rcemodelsf0rtheinteratomicpo-tentialshavebeenusedextensively,butthestructure-dependenceandthetransferabilityofthesemod-elsaren0tclearbecausethemany-bodyeffectsarenotincludedinthesem0dels.T0overc0metheselimitations,manyinteratomicpotentialmodelshavebeenproposed['~'].F0rexamp1e,theembedded-at0mm0del(EAM)[']hasbeendesignedbased0nthedensity-functi0nal-the0ryandhasbeensuccessfullyappliedtocalculateextensivephysicalpr0pertiesofmaterials,butlitt1efirst-principleguidanceexi…