Identification of Effective Management Practices and Technologies for Lessons Learned Programs in the Construction Industry

Organizations in the construction industry cannot afford to make repetitive mistakes on major projects. Conversely, there are great benefits to repeating positive experiences from past projects. This need for institutional memory is amplified by the reality that in the course of normal turnover and retirement, people with years of experience leave their organizations. An effective lessons learned program is a critical element in the management of institutional knowledge; it will facilitate the continuous improvement of processes and procedures and provide a direct advantage in an even more competitive industry. This paper describes a research study that aimed to identify effective management practices and technologies for lessons learned programs in the construction industry. Data from 70 organizations that participated in this study are presented. Research found that even though more lessons learned programs are being initiated, the potential for savings and improvement has not been fully met. The study has also identified seven crucial characteristics of a successful program and verified that most organizations are stronger in some categories and weaker in others. The key to an effective program is to address all seven areas and guidance is provided for those wishing to implement lessons learned programs.     

Selective Synthesis of Perillyl Alcohol from β-Pinene Epoxide over Ti and Mo Supported Catalysts

Catalysis Letters - Isomerization of β-pinene epoxide to perillyl alcohol using several materials based on titanium and molybdenum is reported. The metals were incorporated on SBA-15, MCM-41...     

Tillandsia Aeranthos flower-like magnetic nanostructures confined into polyvinyl alcohol beads

Magnetic beads composed by polyvinyl alcohol and iron oxides were developed and fully characterized. The materials were not only cross-linked by a physical treatment but also the magnetic nanoparticles (MNPs) are acting as cross-linking dots. Interestingly, the analysis of scanning electron micrographs revealed that, in the case of hydrated samples, flower-like structures (average diameter 6–9 μm) being constituted by MNPs were present, whereas when the beads were dried the MNPs structure changed to porous spheres (average diameter 2–3 μm). Some of the prepared materials were tested to determine their capability to act as water remediation devices, and good removal results were obtained toward both methylene blue (average removal efficiency higher than 80%) and methyl orange (average removal efficiency lower than 30%) adsorption. The experiments performed confirmed that the adsorbent, once the treatment has ended, can be removed off through the simple employment of a permanent magnet.     

Improved dark fermentation of cane molasses in mesophilic and thermophilic anaerobic fluidized bed reactors by selecting operational conditions

Sugarcane molasses is a carbohydrate-rich carbon source with potential to develop the biorefinery model in the sugarcane industry. Two of the most well-known renewable products from the dark fermentation of cane molasses are succinic acid and biohydrogen, with both having valuable applications in different industries. However, the continuous dark fermentation of cane molasses is a process regulated by many operational conditions, like reactor temperature and hydraulic retention time. It is important to control these conditions to shift metabolic pathways in order to increase production rates and yields. Thus, this research evaluates the response of mesophilic and thermophilic dark fermentation of cane molasses by mixed culture on hydrogen and succinic acid generation in fluidized bed reactors by changing the hydraulic retention time (8, 6, 4, 2, and 1 hour). In the thermophilic reactor (55°C), higher hydraulic retention times (from 8 to 4 hours) favored the succinate production (molar fractions between 75.0% and 81.4%). Similarly, in the mesophilic reactor (30°C), the molar fractions of succinate were 45.5% at the hydraulic retention time of 8 hours and 74.7% at 6 hours. The reduction of the hydraulic retention time to 1 hour decreased the succinic acid concentration to undetectable values and increased the hydrogen yield in both reactors. The lower hydraulic retention time also enhanced the hydrogen productivity to 171.1 mL/L_bed·h in the mesophilic reactor and to 303.4 mL/L_bed·h in the thermophilic reactor. These values were coincident with the predominant production of butyric and acetic acids. All of these points to the fact that the hydraulic retention time is an efficient parameter to control and select the production of hydrogen or succinic acid by mixed cultures under different temperatures.     

Effect of strong mineral fluxes on sintering of porcelain stoneware tiles

Strong fluxes are needed to fire vitrified ceramics at temperatures significantly lower than those usually reached in industrial firing cycles. This work is aimed at understanding the role of strong fluxes in the microstructural evolution during sintering. Six fluxes (colemanite, ulexite, wollastonite, diopside, spodumene and phonolite) were individually added to a porcelain stoneware batch and processed in standard conditions. Compacts and fired bodies were characterized by optical dilatometry, XRD-Rietveld, SEM and measuring technological properties. Strong fluxes change the firing behaviour with a complex interplay of sintering kinetics, microstructural features, and phase composition. Every flux has its own repercussion on the properties of the liquid phase (chemical composition, degree of polymerization, viscosity and surface tension) which are key points to explain the observed microstructure, densification rates, and stability at high temperature. Batches with phonolite, wollastonite or diopside exhibit characteristics closer to standard porcelain stoneware, while spodumene and borates suffer from unsatisfactory microstructures and lower densification efficiency.