From theory to practice: toward a typology of project-managementstyles

Research literature on the management of projects has been quite slow in its conceptual development and still suffers from a scanty theoretical basis. One of the main impediments in the study of projects has been the absence of constructs and the little distinction that has been made between the project type and its managerial and organizational style. Based on the findings in a field study of 26 case projects, this research shows that there is a need to adopt a more project-specific contingency approach to project management in organizations. This study explores a two-dimensional theoretical model for the classification of technical (or engineering) projects. Projects are classified according to four levels of technological uncertainty at the time of project initiation and three levels of system scope, which is their location on a hierarchical ladder of systems and subsystems. Considerable differences were found in management style, project organization and operational practice when moving along each of the model's two axes. Differences also were observed in simultaneous change in both dimensions. The findings suggest a handful of practical and managerial implications. They are based on the premise that a proper project classification prior to project initiation and a carefully selected management style may lead to better implementation and to an increased chance of project success     

Donor/Acceptor‐Modified Electrodes for Photoelectrochemical and Photobioelectrochemical Applications

A 7‐pyrrolidino‐7‐benzylamino‐8,8‐dicyanoquinodimethane, PBEDQ, ( 1 ), donor–acceptor–modified electrode yields, in the presence of hydroquinone, ( 2 ), an anodic photocurrent with quantum efficiency of 1.5%. The PBEDQ‐functionalized electrode yields, in the presence of the electron acceptor diquat, ( 3 ), a cathodic photocurrent with a quantum efficiency corresponding to 2.1%. The electron transfer cascades leading to the anodic or cathodic photocurrents in the different systems are discussed. It is further demonstrated that the integration of 1,4‐dihydronicotinamide adenine dinucleotide, NADH, as electron donor, with the PBEDQ‐modified electrode leads to an anodic photocurrent. This allowed the assembly of a photobioelectrochemical integrated electrode composed of the photoactive PBEDQ donor–acceptor compound, NAD⁺ as cofactor, and the NAD⁺‐dependent glucose dehydrogenase, GDH. Irradiation of the integrated electrode in the presence of glucose results in the GDH–biocatalyzed oxidation of glucose to gluconic acid with the concomitant generation of NADH that acts as electron donor for the photoactive donor–acceptor PBEDQ units, leading to the generation of steady‐state anodic photocurrent. The photocurrent intensities are controlled by the concentrations of glucose. The integrated PBEDQ/NAD⁺/GDH electrodes introduces a functional photobioelectrochemical electrode for the detection of glucose, and demonstrates the assembly of a functional photo‐biofuel cell that uses light and a biomass product (glucose) for the generation of electric power.     

The effect of surface treatments on the adhesion of electrochemically deposited hydroxyapatite coating to titanium and on its interaction with cells and bacteria

The effect of different mechanical and chemical pre-treatments on the adhesion strength of hydroxyapatite (HAp) coating on a commercially pure titanium (CP-Ti) substrate was studied by means of a standard tensile test followed by microscopic and chemical analysis to determine the locus of fracture. In addition, the effects of either these pre-treatments or post-treatment by low-energy electron irradiation, which allowed tuning the wettability of the surface, on both osteoblast progenitor attachment and S. aureus bacteria attachment were investigated. A dedicated program was developed for unambiguous identification and count of stained cells. A single-phase HAp coating was formed by electrodeposition. A series of surface pre-treatments consisted of grinding down to P1000, etching in HNO₃/HF solution, grit blast, soaking in NaOH and subsequent heat treatment provided the highest adhesion strength to the HAp coating. Osteoblast progenitors derived from rats may be attached preferentially to a hydrophilic surface (post-treatment to θ = 30°), while the bacteria seemed to be less attached to hydrophobic surfaces (post-treatment to θ = 105°). However, the results were not statistically different. The bacteria seemed to be less attached to the smoother, uncoated surfaces.     

pH-metric determination of acid values in vegetable oils without titration

A new method for determining acid values in vegetable oils has been developed for a nontitration pH-metric technique with a reagent consisting of 0.20 M triethanolamine in a 1∶1 solution of water and isopropanol. The emulsive properties of this reagent provide rapid (within a minute) and quantitative extraction of free fatty acids from an oil into the solvent phase. Acid values were determined by measuring conditional pH of the emulsified reagent in a pH-meter with an aqueous reference electrode. Three different applications of this technique are discussed.     

Corrosion behavior of PIRAC nitrided Ti-6Al-4V surgical alloy

Hard titanium nitride (TiN) coatings were obtained on the surface of Ti-6Al-4V alloy using an original PIRAC nitriding method, based on annealing the samples under a low pressure of monatomic nitrogen created by selective diffusion of N from the atmosphere. PIRAC nitrided samples exhibited excellent corrosion resistance in Ringer's solution in both potentiodynamic and potentiostatic tests. The anodic current and metal ion release rate of PIRAC nitrided Ti-6Al-4V at the typical corrosion potential values were significantly lower than those of the untreated alloy. This, together with the excellent adhesion and high wear resistance of the TiN coatings, makes PIRAC nitriding an attractive surface treatment for Ti-6Al-4V alloy surgical implants.     

Hierarchical Structuring in Block Copolymer Nanocomposites through Two Phase‐Separation Processes Operating on Different Time Scales

Tailoring the size and surface chemistry of nanoparticles allows one to control their position in a block copolymer, but this is usually limited to one‐dimensional distribution across domains. Here, the hierarchical assembly of poly(ethylene oxide)‐stabilized gold nanoparticles (Au‐PEO) into hexagonally packed clusters inside mesostructured ultrathin films of polystyrene‐block‐poly(methyl methacrylate) (PS‐b‐PMMA) is described. A close examination of the structural evolution at different nanoparticle filling fractions and PEO ligand molecular weights suggests that the mechanism leading to this structure‐within‐structure is the existence of two phase separation processes operating on different time scales. The length of the PEO ligand is shown to influence not only the interparticle distances but also the phase separation processes. These conclusions are supported by novel mesoscopic simulations, which provide additional insight into the kinetic and thermodynamic factors that are responsible for this behavior.     

Electric‐Field‐Induced Alignment of Block Copolymer/Nanoparticle Blends

External electric fields readily align birefringent block‐copolymer mesophases. In this study the effect of gold nanoparticles on the electric‐field‐induced alignment of a lamellae‐forming polystyrene‐block‐poly(2‐vinylpyridine) copolymer is assessed. Nanoparticles are homogeneously dispersed in the styrenic phase and promote the quantitative alignment of lamellar domains by substantially lowering the critical field strength above which alignment proceeds. The results suggest that the electric‐field‐assisted alignment of nanostructured block copolymer/nanoparticle composites may offer a simple way to greatly mitigate structural and orientational defects of such films under benign experimental conditions.