Science-based Firms Going Public: The Role of Patent Indicators and Top Management Teams

This paper examines how specific dimensions related to innovative capabilities influence the economic value of science-based firms when they go public. To test a set of hypotheses, we conduct an empirical research of a sample of dedicated biotechnology firms that completed an initial public offering (IPO) in the USA during 1983–2009. The results indicate that technological diversity, the patent stock’s value and dominant functional diversity in top management teams (TMTs) are positively associated with raising funds through an IPO. However, intrapersonal functional diversity in the TMT does not have a significant effect.     

Research evolution in science parks and incubators: foundations and new trends

In this paper we undertake a quantitative review of the existing literature on parks and incubators to identify their foundations from a longitudinal perspective. To do so, we searched records in the SSCI database from 1990 to 2015 and identified 318 citing documents, which we split into four periods of 5 years each, to identify the interactions and path dependence that exist between different foundations of research. We evaluate the evolution of the theoretical foundations of this research line taking into account changes in citations over time. We also identify areas of future research closely connected with the theoretical foundations already identified. For this purpose, we used two bibliometric techniques—co-citation analysis and bibliographic coupling—that enable us to assess the thematic similarity between scientific publications based on overlaps in their referencing patterns.     

Assessing gender balance among journal authors and editorial board members

The study of journal authorship and editorial board membership from a gender perspective is addressed in this paper following international recommendations about the need to obtain science and technology indicators by gender. Authorship informs us about active scientists who contribute to the production and dissemination of new knowledge through journal articles, while editorial board membership tells us about leading scientists who have obtained scientific recognition within the scientific community. This study analyses by gender the composition of the editorial boards of 131 high-quality Spanish journals in all fields of science, the presence of men and women as authors in a selection of 36 journals, and the evolution of these aspects from 1998 to 2009. Female presence is lower than male presence in authorship, editorial board membership and editorship. The presence of female authors is slightly lower than the presence of women in the Spanish Higher Education sector and doubles female presence in editorial boards, which mirrors female presence in the highest academic rank. The gender gap tends to diminish over the years in most areas, especially in authorship and very slightly in editorial board membership. Large editorial boards and having a female editor-in-chief are positively correlated with women presence in editorial boards. The situation of women in Spanish science is further assessed in an international context analysing a selection of international reference journals. The usefulness of journal-based indicators to monitor the situation of men and women in science and to assess the success of policies oriented to enhance gender equality in science is finally discussed.     

Practicing what We Preach

• With the increasing globalisation of knowledge and management education, it is important that we build on our scanty understanding of trends and levels of geographic diversification in editorial board membership of management journals.
• Our study examines geographic diversity in editorial boards in Management over a 20-year period. It uses secondary data from 57 journals covering approximately 16,000 editorial board members.
• We found that the geographic diversity of editorial boards (EBs) has increased in the last 20 years, but it is still low for most management journals. Further, two factors partly predict the geographic diversity of EBs of management journals: the editor’s country of residence and the field of research.
• Continued active management by editors, professional associations and individual academics alike is necessary to ensure that our editorial boards properly reflect the diverse management community.

     

The rheological behaviour of concentrated dispersions of graphene oxide

The rheological behaviour of concentrated aqueous dispersions of graphene oxide (GO) was studied as a model system and then compared to those of GO in poly(methyl methacrylate) (PMMA). Dynamic and steady shear tests were conducted using a parallel plate rheometer. The aqueous system behaved as a reversibly flocculated dispersion with linear viscoelastic regions (LVR) extending up to strains of 10 %. Dynamic frequency sweeps conducted within the LVR showed a classic strong-gel spectrum for high concentrations. Under steady shear, the dispersions shear-thinned up to a Peclet number (Pe) <1, followed by a power law at higher Pe. The dispersions were thixotropic and recovered their structure after 60 min rest. The change in rheological properties of the PMMA upon the addition of the GO was less pronounced possibly due to the absence of hydrogen bonding; a relatively small increase in viscosity was found, which is encouraging for the melt processing of graphene composites.     

Synthesis,characterization, photocatalytic evaluation,and toxicity studies of TiO2–Fe3+ nanocatalyst

Based on our previous work on the green preparation of Ag–TiO₂ photocatalyst with bactericidal activity under visible light, we extended our studies to the synthesis of TiO₂–Fe³⁺ materials with enhanced photocatalytic activity for the degradation of recalcitrant organic pollutants in water. TiO₂–Fe³⁺ nanopowders were synthesized using a robust, environmentally friendly procedure. Established amounts of Fe(NO₃)₃·9H₂O and titanium tetraisopropoxide (TTIP) were mixed using glacial acetic acid as solvent. Hydrolysis of TTIP–Fe³⁺ was accomplished using a 30 % (W/V) Arabic gum aqueous solution. TiO₂–Fe³⁺ nanopowders were obtained by thermal treatment at 400 °C. In order to elucidate the structure of these photocatalysts, microscopic and spectroscopic characterization techniques were applied. The high resolution transmission electron microscopy (HRTEM) analysis indicated the presence of uniformly distributed particles with average particle size of about 9 nm. According to the HRTEM lattice fringes, ring pattern, and selected area electron diffraction pattern, the crystalline part of the samples consists of anatase (PDF 01-086-1157 with the lattice constant of 3.7852, 9.5139 Å and 90°) as dominant phase. X-ray photoelectron spectroscopy (XPS) was applied to determine the oxidation state of iron. The XPS provides evidence for Fe³⁺ surface species in the TiO₂–Fe³⁺ composite. Complete degradation of aqueous solutions (20 ppm) of methylene blue and/or methyl orange was accomplished after 4 h of treatment using 150 mg of TiO₂–Fe³⁺/150 mL of dye solution. The in vitro toxicity of the materials was tested. The materials showed no toxicity against human red blood cells.     

Assessing the effectiveness of supply flexibility sources: an empirical research

This paper focuses on supply flexibility, i.e., the ability of the purchasing function to respond in a timely and cost effective manner to changing requirements of purchased components, in terms of volume, mix and delivery date. It is argued that managerial actions may have different effects on different dimensions of supply flexibility. More specifically, we aim to answer the following research questions: what is the effectiveness of the different supply flexibility sources? Are there any variables that could moderate the relationship between supply flexibility sources and supply flexibility? We perform a regression analysis of the effectiveness of the different supply flexibility sources. In particular, we conduct a stepwise regression, setting the supply flexibility sources as independent variables, and the three dimensions of supply flexibility (identified in the factor analysis) as dependent variables. In order to refine the models and increase the generalisability of the study, some control variables (i.e., firm revenue and flexibility focus) are also included in the regression analysis. Results suggest that each dimension of supply flexibility is associated with a particular group of sources, i.e., the sources used to increase a certain dimension of supply flexibility (e.g., supplier responsiveness) may be ineffective for another dimension (e.g., adaptability).     

Solid lubricant behavior of MoS2 and WSe2-based nanocomposite coatings

Abstract

Tribological coatings made of MoS₂ and WSe₂ phases and their corresponding combinations with tungsten carbide (WC) were prepared by non-reactive magnetron sputtering of individual targets of similar composition. A comparative tribological analysis of these multiphase coatings was done in both ambient air (30–40% relative humidity, RH) and dry nitrogen (RH<7%) environments using the same tribometer and testing conditions. A nanostructural study using advanced transmission electron microscopy of the initial coatings and examination of the counterfaces after the friction test using different analytical tools helped to elucidate what governs the tribological behavior for each type of environment. This allowed conclusions to be made about the influence of the coating microstructure and composition on the tribological response. The best performance obtained with a WSe_x film (specific wear rate of 2 × 10^?8 mm³ N^–1m^–1 and a friction coefficient of 0.03–0.05) was compared with that of the well-established MoS₂ lubricant material.