Enterprise system lifecycles in transition and less developed economies within the European Union

ABSTRACT

We analyze the lifecycle of enterprise systems (ES) in one transition (Poland) and two less developed economies (Greece and Portugal), all of them members of the European Union (EU). This study, involving practitioners with an accumulated experience of more than 280 projects, enables the comprehension of the approach to phases, activities, and the relevance of key players throughout the lifecycle. We found differences and similarities across these parameters that suggest that the traditional partition into “developed” and “transition” economies may be too simplistic, as the level of development of the economy should be taken into account. The main findings suggest that practitioners from less developed economies attach significant importance to technical issues, and adopters in transition economies strongly depend on external help. Although not directly transferrable, our results point to issues that should be taken into consideration when adopting or studying ES in countries with similar traits, such as Ukraine and Belarus in Central and Eastern Europe, or more recent EU member states, such as Croatia, Bulgaria, or Romania.     

Removal of Pb(II) from aqueous solutions by using clinoptilolite and bentonite as adsorbents

In the present study, the ability of natural zeolite clinoptilolite and bentonite (clay) to remove Pb(II) from aqueous solutions has been investigated in batch reactors with a maximum contact time of 120 min. Adsorption tests of Pb(II) were carried out using a solution concentration of 1,036 ppm at initial pH = 4, and solid to liquid ratio of 2 g/100 mL. The effects of agitation speed (0, 100, 200, 500 rpm), temperature (28°C, 45°C, 60°C) and particle size (2.5–5.0 mm, dust) of the minerals were examined. The effect of acidity of the aqueous solution was also examined. Bentonite was found to be more effective for the removal of Pb(II) than clinoptilolite, under the experimental conditions used. The removal of Pb(II) using bentonite reached 100% at ambient temperature and mild agitation (100 rpm), while it was approximately 90% at 60°C without agitation. On the other hand, the highest removal level reached by clinoptilolite was 55%. Clinoptilolite dust is found to be more efficient than granular clinoptilolite. Agitation and temperature affected the uptake of Pb(II), especially in the case of granular clinoptilolite (2.5–5.0 mm). Finally, it can be seen that acidity of the aqueous solution influences the removal of lead by the minerals. The adsorption of lead increases with an increase in pH of the solution from 1 to 4.     

Evaluating e-government: learning from the experiences of two UK local authorities

Abstract. Part of the remit of public sector management includes planning and reflecting on capital expenditure on new technology. With this in mind, the role that information systems play in supporting improvements in e-government service delivery to stakeholder groups continues to attract much attention. The authors of this paper seek to define the scope and role that information systems evaluation plays within the public sector. In particular, the authors assess whether public sector organizations might benefit from the use of established ex-ante evaluation techniques, when applied to analyse the impact of e-government information systems. Following a comprehensive review of the normative literature, an initial conceptual framework for public sector information systems evaluation is proposed, which is then empirically explored within two local government authorities. The conceptual framework is then revised by using the structured case approach, which is dependent on an iterative research cycle where triangulated data are elicited. This then supports the emergence of new concepts during each research cycle that leads to the view that information systems evaluation in the public sector is a process of experiential and subjective judgement, which is grounded in opinion and world views. This leads the authors to challenge the appropriateness of traditional modes of investment appraisal when applied in the public sector. The finalized framework embraces investment decisions, evaluation methods, culture and structure, as well as post hoc evaluation. It emphasizes the importance of situated, interpretive user assessments in evaluating e-government investments.     

The Athens–Corinth highway and railway crossing a tectonically active area in Greece

The paper discusses the appraisal, in terms of geological risk, of the new Athens–Corinth highway and railway projects in the area of Kakia Skala, which exhibits strong characteristics of neotectonic activity. After detailed mapping of the faults and the evaluation of their future behavior based on geological criteria, a seismic displacement of up to 0.5 m along the fault line was considered possible. Modifications were made to the initial alignment so that the engineering structures, particularly bridges, were located away from the main active fault. In places where such changes were not possible, for technical or economic reasons, the construction of over-bored tunnels was recommended.      

Aromatic Polyimides as Efficient Materials for Organic Electroluminescent Devices

Derivatives of newly synthesized aromatic polyimides containing sulphur atoms in the backbone were studied as electron–hole-transporting and light-emitting materials for use in combination with tris(8-hydroxyquinoline)-aluminium in multilayer organic electroluminescent devices. Efficient bipolar charge transport has been revealed in the polymers. Bright electroluminescence (15000cdm^-2 at 14V) was observed in the visible range. The possible role of intermolecular donor–acceptor interactions in the mechanism of electroluminescence is discussed. © of SCI.     

The Mechanism of Mitochondrial Injury in Alpha-1 Antitrypsin Deficiency Mediated Liver Disease

Alpha-1 antitrypsin deficiency (AATD) is caused by a single mutation in the SERPINA1 gene, which culminates in the accumulation of misfolded alpha-1 antitrypsin (ZAAT) within the endoplasmic reticulum (ER) of hepatocytes. AATD is associated with liver disease resulting from hepatocyte injury due to ZAAT-mediated toxic gain-of-function and ER stress. There is evidence of mitochondrial damage in AATD-mediated liver disease; however, the mechanism by which hepatocyte retention of aggregated ZAAT leads to mitochondrial injury is unknown. Previous studies have shown that ER stress is associated with both high concentrations of fatty acids and mitochondrial dysfunction in hepatocytes. Using a human AAT transgenic mouse model and hepatocyte cell lines, we show abnormal mitochondrial morphology and function, and dysregulated lipid metabolism, which are associated with hepatic expression and accumulation of ZAAT. We also describe a novel mechanism of ZAAT-mediated mitochondrial dysfunction. We provide evidence that misfolded ZAAT translocates to the mitochondria for degradation. Furthermore, inhibition of ZAAT expression restores the mitochondrial function in ZAAT-expressing hepatocytes. Altogether, our results show that ZAAT aggregation in hepatocytes leads to mitochondrial dysfunction. Our findings suggest a plausible model for AATD liver injury and the possibility of mechanism-based therapeutic interventions for AATD liver disease.     

Bone Regeneration Guided by a Magnetized Scaffold in an Ovine Defect Model

The reconstruction of large segmental defects still represents a critical issue in the orthopedic field. The use of functionalized scaffolds able to create a magnetic environment is a fascinating option to guide the onset of regenerative processes. In the present study, a porous hydroxyapatite scaffold, incorporating superparamagnetic Fe₃O₄ nanoparticles (MNPs), was implanted in a critical bone defect realized in sheep metatarsus. Superparamagnetic nanoparticles functionalized with hyperbranched poly(epsilon-Lysine) peptides and physically complexed with vascular endothelial growth factor (VEGF) where injected in situ to penetrate the magnetic scaffold. The scaffold was fixed with cylindrical permanent NdFeB magnets implanted proximally, and the magnetic forces generated by the magnets enabled the capture of the injected nanoparticles forming a VEGF gradient in its porosity. After 16 weeks, histomorphometric measurements were performed to quantify bone growth and bone-to-implant contact, while the mechanical properties of regenerated bone via an atomic force microscopy (AFM) analysis were investigated. The results showed increased bone regeneration at the magnetized interface; this regeneration was higher in the VEGF-MNP-treated group, while the nanomechanical behavior of the tissue was similar to the pattern of the magnetic field distribution. This new approach provides insights into the ability of magnetic technologies to stimulate bone formation, improving bone/scaffold interaction.     

Determining the principles of tunnel support based on the engineering geological behaviour types: example of a tunnel in tectonically disturbed heterogeneous rock in Serbia

A methodology for designing a tunnel support system according to the actual ground conditions and the critical behaviour types is analysed in this paper. The methodology is justified with the principles of the New Austrian Tunnelling Method that incorporates the top heading and bench method. The role of the geological material and its implication in tunnel design, reinforced with advances in site investigation methods, cannot be based solely on the development of the geotechnical classification systems and the consequent quantification of the rock masses. Support requirements for rock masses with equal classification ratings can be different. The procedure presented in this study cannot bypass the geological and/or in situ characteristics dictating or influencing the tunnel behaviour compared with a standardised classification that could miss the specifics and particularities of and around a tunnel section. The step-by-step procedure is applied in a tunnel excavated in tectonically disturbed heterogeneous flysch sediments in Serbia. The complex structure of these materials, resulting from their depositional and tectonic history that includes severe faulting and folding, presents a challenge to geologists and engineers. The possible ground types are evaluated, and then, combined with the factors of the tunnel geometry, the primary stress condition, and the water conditions, several behaviour types are considered. These classified behaviour types, followed by the suitable mechanical properties that are required for effective tunnel engineering design, are the basis for the numerical design of the appropriate primary support measures to achieve stable tunnel conditions. The twin-tube, two-lane highway tunnel was successfully constructed without significant problems.

     

Assessment of ground conditions with respect to mechanised tunnelling for the construction of the extension of the Athens Metro to the city of Piraeus

This paper refers to the proposed western extension of the Athens Metro to Piraeus city. The railway consists of a 9.45 m diameter, 8.2 km long tunnel and seven stations. Tunnelling works are expected to be undertaken within a variety of lithological formations ranging from very strong alpine limestones to recent soft littoral deposits. The tunnel alignment was divided into 12 areas with respect to the geological and geotechnical conditions that may be encountered during construction. In many of these zones, the geotechnical conditions together with the presence of sensitive surface and/or subsurface structures led to the selection of a closed-face TBM (Earth Pressure Balance Machine or Slurry Tunnel Boring Machine) as the appropriate tunnelling technique. The Piraeus extension is a project where in places both types of commonly used closed-face tunnelling machines will encounter ‘text book’ application areas, but not always. The applicability of each type of TBM is discussed using the available data obtained from an extensive site investigation.      

Geometrical characterization of stall cells on rectangular wings

The onset of stall cells (SCs) is experimentally investigated on a flattop loaded 18% thick airfoil optimized for use on wind turbine blades, exhibiting trailing edge separation. SCs are dynamic coherent vortical structures that appear on wings under separated flow conditions. Although SCs have been known for long, neither are their characteristics completely documented nor their generating mechanisms fully understood. The present investigation aims at providing additional information on the geometric characteristics in terms of width, length and occupied area. The relevant data are presented as functions of Reynolds (Re) number, angle of attack and aspect ratio (AR) of the model. In the tests reported, the dynamic character of SCs is suppressed by imposing a localized flow disturbance. For the specific airfoil and for the Re and AR range tested, it is found that: the angle of attack at which SCs are initially formed decreases linearly with Re number and independently of the AR; unlike two‐dimensional separation, their chordwise length increases with Re; the SC area relative to the wing planform area (defined as the relative SC area) grows asymptotically with angle of attack and Re number reaching an upper bound, which is independent of the AR; at intermediate angles of attack, the SC relative area is higher for the lower AR wing; for a fixed increment in Re number, the growth of the SC relative area is independent of the initial Re number; at lower angles of attack, the actual SC area is independent of the wing span. Copyright © 2013 John Wiley & Sons, Ltd.