Measuring changes in publication patterns in a context of performance-based research funding systems: the case of educational research in the University of Gothenburg (2005–2014)

Scientometrics - We present a novel way to frame a discussion of changes in publication patterns that occur in a context of performance-based research funding systems (PRFSs). Adopting an approach...     

Structural and optical properties of inorganic–organic hybrid material of acetanilide tetrachloromercurate(II)

The crystal growth of acetanilide tetrachloromercurate(II), an inorganic–organic hybrid derivative has been achieved by solution growth through slow cooling method. The X-ray diffraction structural analysis of the hybrid material results that the compound exist in orthorhombic space group P2₁2₁2₁ with lattice parameters; a?=?13.111(2) ?, b?=?11.311(2) ?, c?=?8.355(6) ?, α?=?β?=?γ?=?90° and unit cell volume?=?1436.24 ?³. The fourier transform infrared spectroscopy profile shows that the C–C and C–N stretching modes of acetanilide ring and the observed spectra falls in mid-infrared range υ(526–2850) cm^?1. The field emission scanning electron microscope image confirms that the hybrid material has a prismatic shape with an average granular size of ~25 nm. The energy dispersive X-ray spectroscopy analyzes the elemental proportions of the hybrid materials. Transmission electron microscopy image shows the narrow distribution of nano-spatial agglomeration of secondary interactions in inorganic–organic particles. The optical band gap (Eg?=?3.75 eV) as calculated by linear fit profile of Tauc plot for allowed transition predicts that the hybrid material has potential applications in solar cells, electronic and opto-electronic devices.     

Mapping the dynamics of research networks in ecology and evolution using co-citation analysis (1975–2014)

Scientometrics - In this paper we used a co-citation network analysis to quantify and illustrate the dynamic patterns of research in ecology and evolution over 40 years (1975–2014)....     

South–South research collaboration of countries in the Southern African Development Community (SADC)

This study investigates South–South collaboration in research, and specifically collaboration among the 15 countries of the Southern African Development Community (SADC) as well as between the SADC and the rest of Africa. It was found that only 3% of SADC papers during 2005–2008 were jointly authored by researchers from two or more SADC countries (intra-regional collaboration), and only 5% of SADC papers were jointly authored with researchers from African countries outside the SADC (continental collaboration). In contrast, 47% of SADC papers were co-authored with scientists from high-income countries. The few instances of intra-regional and continental collaboration in the SADC are largely the product of North–South collaboration. Authors from high-income countries are included in 60% of intra-regional co-authored papers and in 59% of continental co-authored papers. Moreover, between 2005 and 2008, South Africa produced 81% of all SADC papers and 78% of all intra-regional co-authored papers. This implies that there is a highly unbalanced and unequal partnership that can best be described as a variant of North–South collaboration with the scientific giant in the South taking on the role of the ‘political North’. As a consequence, guidelines for successful North–South collaborations should be extended to include South–South collaborations that comprise highly unequal partners, as is the case between South Africa and the other SADC countries.     

Electrochemical depositions of calcium phosphate film on commercial pure titanium and Ti–6Al–4V in two types of electrolyte at room temperature

Electrochemical depositions of calcium phosphate film on commercially pure titanium (cp-Ti) and Ti–6Al–4V in two types of electrolytes, mono-calcium phosphate monohydrate (MCPM) based aqueous solution and supersaturated calcium phosphate solution (SCPS), were carried out by the cathodic polarization. The calcium phosphate coating layer was successfully deposited on cp-Ti and Ti–6Al–4V under 3 mA/cm² current density for 45 min. The major phases that appeared in the film were DCPD (brushite) co-existed with octa-calcium phosphate (OCP). After soaking in revised simulated-body-fluid (r-SBF), the amorphous bone-like apatite became a single phase within a day for the specimen obtained from MCPM electrolyte. The specimens obtained from SCPS electrolyte took a week to complete the apatite precipitation in r-SBF. From the scratch test, the highest critical load of 87.2 N was obtained from the as-deposited rod-like DCPD on cp-Ti substrate. The critical load was decreasing almost 50% for all of the specimens after apatite precipitation in r-SBF. The decrease of critical load might result from loosening of the film structure during immersion of the specimens in r-SBF. The thickness of the films was 44–55 μm in average, which satisfied the qualification for using as an implant material.     

Performance measures and metrics in logistics and supply chain management: a review of recent literature (1995–2004) for research and applications

Performance measures and metrics are essential for effectively managing logistics operations, particularly in a competitive global economy. The global economy is featured with global operations, outsourcing and supply chain and e-commerce. The real challenge for managers of this new enterprise environment is to develop suitable performance measures and metrics to make right decisions that would contribute to an improved organizational competitiveness. Now the question is whether traditional performance measures can be used and out of them which ones should be given priority for measuring the performance in a new enterprise environment. Some of the traditional measures and metrics may not be suitable for the new environment wherein many activities are not easily identifiable. Measuring intangibles and nonfinancial performance measures pose the greater challenge in the so-called knowledge economy. Nevertheless, measuring them is so critical for the successful operations of companies in this environment. Considering the importance of nonfinancial measures and intangibles, an attempt has been made in this paper to determine the key performance measures and metrics in supply chain and logistics operations. This is based on a literature survey and some of the reported case experiences. Suggestions for future research directions are also indicated.     

A theoretical study of H absorption at a Fe(110)–Pd(100) interface and Fe–Pd alloys

The electronic structure and bonding at a Fe(110)–Pd(100) interface was theoretically analyzed in the framework of semi-empirical quantum chemical calculations. The Fe–Pd interface was modeled by a Fe₇₄Pd₇₄ cluster and a Fe–Pd six layer slab.The extended Hückel tight binding (EHTB) method and its modifications, including repulsive interactions, were used to calculate the interfacial adhesion and the H-absorption energy.The energetic minimum position for H is found at the Fe–Pd interface closer to the Pd layer.The interfacial Fe–Pd distance result to be 1.73 Å where Fe–Pd develops a strong bonding interaction. An important metal–metal adhesion was also found.The changes in the Density of States (DOS) and the Crystal Orbital Overlap Population (COOP) were compared in different structures: clusters, slab and two types of Fe–Pd alloys.The H as an impurity is responsible for a Fe–Fe and Pd–Pd bond weakening.However, the H effect is much less detrimental for the Fe–Pd bonds at the interface.When H is located at interstitial sites in bulk Fe–Pd alloys, the Pd–Pd overlap population shows a notorious decrease in the case of fcc structures while for fct structures the change is only 12%. The intermetallic bonding was also weakened as compared with the pure alloys. The objective of this work is to bring a plausible explanation to the null permeability to hydrogen in Pd-coated Fe films.     

Reaction on the paper ‘Reliability and validity of findings in ergonomics research’ of Kanis (2013)

In this paper, a reaction on the proposed flowchart of Kanis is given by applying it to a new case. The flowchart seems valuable in starting the discussion on how to improve the reliability and validity in experimental human factors/ergonomics (HF/E) research. However, it is unsure whether it is the golden standard.     

Concentration of resources: The National Research Council's (Canada) grants in aid of research: 1964–1974

Concentration of resources continues to be an important issue in the formulation of policy for the support of university research. In this paper, techniques for quantitatively assessing two dimensions of this issue, ‘between’ and ‘within’ committee concentrations, are developed. These techniques are applied in an analysis of the peer-adjudicated grants of the National Research Council of Canada for the years 1964–1974 inclusive. Results indicate that although ‘between’ committee concentrations have responded to changing priorities for university research, ‘within’ committee concentrations have remained remarkably stable over this decade. This is seen as having important implications for recent attempts at re-orienting university research in Canada.     

Cyclic fatigue crack growth behaviour in β-(Si–Al–O–N) at ambient and elevated temperatures

Four-point bending fatigue tests on a hot-pressed sintered Sm–-(Si–Al–O–N) ceramic were conducted at room temperature, 900 °C and 1000 °C in air under different load ratios and cyclic frequencies. The growth of indentation cracks was measured during the fatigue tests. The results indicate that the cyclic fatigue crack growth threshold is lower and crack growth rates are higher, for given values of K_max, at 1000 °C than those at room temperature. The cyclic fatigue crack growth behaviour at 900 °C is similar to that at room temperature. It was found that the crack growth retardation due to cyclic fatigue loading is much more pronounced at higher frequencies. An increase in cyclic frequency from 1 to 10 Hz cause a reduction of up to two orders of magnitude in crack propagation rates. High-temperature cyclic fatigue crack growth rates increased and threshold stress intensity factor ranges decreased with increasing load ratio. Possible mechanisms for cyclic crack growth are discussed.     

Expression of heat shock protein 70 (HSP70) at the interface of polymer–implants in vivo

Synthetic polymer meshes are widely applied in the modern surgical approach for repairing abdominal wall defects. The implanted material is often observed leading to post-operative complications such as deficient abdominal wall mobility and adhesion formation with the abdominal cavity and/or abdominal organs. However, the functioning of the implant is primarily affected by the wound healing process guided by inflammatory events occurring at the tissue–material interface. This could presumably be influenced by the physicochemical properties of the polymer. With regard to it, the cellular and molecular processes involved in the successful restoration of the abdominal wall function are poorly understood. The present in vivo study, therefore, exemplary investigated in a rat model, the commercially available polymer-meshes Prolene® (polypropylene, PP), Mersilene® (polyester, PE) and Vicryl® (polyglactin 910), as well as new mesh variants consisting either of PP (EB) or a combination of PP and polyglactin 910 (A plus or Vypro®). The implanted material was evaluated by light and electron microscopy, immunohistochemistry as well as morphometry over an implantation period of 90 days. The data show that polymers induce heat shock protein (HSP)70, and its expression at the interface correlates inversely with the activity of the inflammatory reaction in vivo. Further, an ascent in HSP70 expression parallels the increasing implantation period and evolving foreign-body granulomas. Accordingly, a major role for HSP70 in modulating the local acceptance of polymers and as an additional marker for in vivo testing of polymers is suggestive. ©©2000 Kluwer Academic Publishers     

Enhanced visible-light-driven photocatalytic and dielectric properties of inorganic–organic hybrid (NiO-g-C3N4) nanocomposite for degradation of rhodamine blue

In this work, NiO NP’s was synthesized by the hydrothermal method and g-C₃N₄ nanosheets prepared via thermal treatment method, then NiO/g-C₃N₄ (80:20 wt%) was successfully achieved by a simple mixing method. The optimized NiO/g-C₃N₄ hybrid nanocomposite was acting as an efficient photocatalyst for degradation of rhodamine blue (RhB) under visible light irradiation. As prepared pristine (NiO and g-C₃N₄) and inorganic–organic hybrid nanocomposite (NiO/g-C₃N₄) materials were characterized by various spectral techniques. From XRD and TEM results, the NiO nanoparticles before and after loading on g-C₃N₄ surface retained the crystalline phase(fcc) and spherical structure, indicating the synthesis strategy is promising which does not alter its composition and morphology. The adsorption edge of NiO/g-C₃N₄ was shifted towards lower energy region when compared with pure NiO and g-C₃N₄ alone reflects that the resulting nanocomposite has larger adsorption efficiency under visible light and thus increases the charge separation efficiency during degradation process. The percentage of degration of RhB for NiO, g-C₃N₄ and NiO/g-C₃N₄ hybrid is calculated to be 81, 89 and 94% indicates the effective degradation illuminated under visible light. The enhanced photocatalytic activity of NiO/g-C₃N₄ photocatalyst probably recognized for the successful interfacial charge separation between NiO and g-C₃N₄ thus avoids recombination of photoexcited electron–hole pair.

     

Development of high strength in Ni–42Cr–7·7Al (at.-%) alloy

Abstract

An investigation has been made of the aging of supersaturated nickel based solid solution in a Ni–42Cr–7·7 Al (at.-%) alloy. Solution treatment of the alloy in the range 1150–1300°Cfollowed by quenching and aging at ~550–750°C produces high values of hardness and strength, e.g. 835 HV on aging at 600°C. This hardening results from a discontinuous precipitation reaction producing a fine scale lamellar structure consisting of nickel based and chromium based solid solutions; interlamellar spacings of ~60 nm were obtained. The rate of precipitation is substantially greater than that in a binary Ni–42 at.-%Cr alloy.

MST/736     

Network closure, brokerage, and structural influence of journals: a longitudinal study of journal citation network in Internet research (2000–2010)

The study aims to assess journals’ structural influence in Internet research and uncover the impacts of network structures on journals’ structural influence drawing on theories of network closure and structural holes. The data of the study are the citation exchanges among 1,210 journals in Communication and other seven social scientific fields (i.e., Business, Economics/Finance, Education, Information Science, Political Science, Psychology, and Sociology) in Internet research. The top two most influential journals in Internet research are American Economic Review and Journal of Personality and Social Psychology. Journals in “Communication” field emerge to be an important source of influence in Internet research, whose mean structural influence ranks third among the eight fields, below “Business” and “Economics/Finance”, but above other five fields. Journals’ structural influences are found to grow over time and the growth rates vary across journals. Network brokerage is found to exert a significant impact on journals’ structural influence, while the impact of network closure on journals’ structural influences is not significant. The impact of network brokerage on journals’ structural influence will increase over time.     

Infrared spectroscopy of graphene nanoribbons and aromatic compounds with sp3C–H (methyl or methylene groups)

Journal of Materials Science - Graphene nanoribbon (GNR) has attracted attention because of the adjustable band gap, depending on the width and functional groups. The introduction of sp3C–H...     

Synthesis and crystallization of lead–zirconium–titanate (PZT) nanotubes at the low temperature using carbon nanotubes (CNTs) as sacrificial templates

Pb(Zr_0.52Ti_0.48)O₃ (PZT) nanotubes with diameters of 80–100 nm and a wall thickness of 15–20 nm were prepared by sol–gel template technique and using multi-walled carbon nanotubes (MWCNT) as sacrificial templates. The coating process of MWCNT with PZT precursor sol and removal of the carbon nanotubes by an interrupt heat treatment were discussed and studied by Raman spectroscopy. Simultaneous thermal analysis (STA) revealed that PZT nanotube crystallized at the low temperature of 410 °C by the significantly low activation energy of crystallization of 103.7 kJ/mol. Moreover, based on the X-ray diffraction (XRD) pattern and selected area electron diffraction pattern the crystal structure of the PZT nanotube was determined as perovskite. High resolution transmission electron microscope (HRTEM) and field-emission scanning electron microscope (FE-SEM) images proved that the final PZT had a tubular structure.     

Experimental hydration of two synthetic glassy blast furnace slags in water and alkaline solutions (NaOH and KOH 0.1 N) at 40° C: structure,composition and origin of the hydrated layer

The hydration of blast furnace slags has been modelled using two synthetic (CaO, SiO₂, Al₂O₃, MgO) glasses with different Al₂O₃/MgO values. Experiments (duration: 16 h to 150 d) were performed at 40° C in deionized water (pH 6.5) and in NaOH and KOH (0.1 N) solutions (pH=12.9). The hydrated layer was characterized from a combination of several techniques at different scales: surface analysis by XPS and SEM; TEM of ultrathin diamond-cut sections including electron microdiffraction and EDS analysis; X-ray diffraction of scratched powders. In water, the hydrated zone is only about 0.5m thick after 150 d with a leached layer covered by a thin siliceous film on which are scattered rare amorphous lamellae. In alkali media, the hydrated zone is composed of three parts: an inner layer made of modified residual glass, calcium-depleted and richer in magnesium and aluminium than the initial glass; an intermediate lamellar of constant thickness (O.3m) after 15 d with magnesium and aluminium as major components (hydrotalcite type composition) and labelling the initial solid-solution interface, an outer layer with initially abundant C-S-H more or less carbonated after reaction with atmospheric CO₂. The hydrotalcite-type layer separates the inner domain dominated by the formation and evolution of a leached glass layer from an outer one, where the precipitation of C-S-H and other amorphous or crystalline compounds, followed by carbonation, are the major processes.     

Structure and dielectric properties of a new series of pyrochlores in the Ca–Sm–Ti–M–O (M = Nb and Ta) system

The present work investigates the dielectric properties of pyrochlore type oxides, Ca–Sm–Ti–M–O (M = Nb and Ta) in the low frequency region (100 Hz–1 MHz) over the temperature range 30–100 °C. The 1 MHz dielectric constants (K) of these oxides are in the range 23–108 and show low variation with frequency (1 kHz–1 MHz). The temperature coefficient of dielectric constant (TCK) over the temperature range varies from positive to negative values in the range 48 to −107 ppm/°C. Rietveld analysis of the X-ray diffraction data establishes a cubic pyrochlore-type phase in the space group Fd3 m (no. 227).The grain morphology observation by scanning electron microscope shows well sintered grains.     

Particle formation and aggregation–collapse behavior of poly(N-isopropylacrylamide) and poly(ethylene glycol) block copolymers in the presence of cross-linking agent

The effect of feed molar ratio of N-isopropylacrylamide (NIPAM) to poly(ethylene oxide) (PEO) on the particle formation of poly(N-isopropylacrylamide) (PNIPAM) and PEO block copolymers (PNIPAM-b-PEO) and their aggregation-collapse behavior have been studied in aqueous solutions. It is found that in the presence of cross-linking agent N,N'-methylenebisacryla-mide (BIS), different morphologies of PNIPAM-b-PEO copolymers can be obtained, including a grafting-like structure, a hemispherical core-shell structure and a well-defined core-shell nanoparticle, as the feed molar amount of NIPAM in the copolymerization is increased. The increase in temperature causes the self-aggregation of grafting-like copolymers and hemispherical particles due to the hydrophobic interaction between locally unshielded PNIPAM blocks prior to the conformational transition of PNIPAM. When the feed molar ratio of NIPAM to PEO exceeds a certain value, a well-defined core-shell nanoparticle can be produced during the copolymerization. At low concentrations, PNIPAM cores of single core-shell nanoparticles can undergo the conformational transition without aggregation. The increase in the concentration of the well-defined core-shell nanoparticles, however, results in a week aggregation at temperatures lower than the theta-temperature of pure PNIPAM due to the association of methyl groups at the periphery of PEO shells.     

Corrosion Resistance of Alloys of the Al–Cu–Fe–(Si,B) System in Mineralized Saline and Acid Solutions

Materials Science - We study the influence of alloying with 4–7 at.% Si and/or 1–3 at.% B on the corrosion behavior of Al– Cu–Fe quasicrystalline alloys in the solutions of...