Life time prediction of self-supporting flame-sprayed alumina-rich coatings

Main objective of the presented research is the life time prediction of self-supporting flame-sprayed Al₂O₃- and Al₂O₃ -ZrO₂ -TiO₂-materials under constant load. The characteristic life time and its scatter were derived from stable crack growth tests and Weibull-statistics including the four-point-bending and ball-on-three-balls method. The potential life time was estimated in order to assess room-temperature handling and long term storage of self-supporting flame-sprayed alumina components. In terms of flexural strength, energy release, and subcritical crack growth parameters, distinct differences between both materials were shown. In turn, the characteristic life times only barely deviated from each other. From that the conclusion was drawn that life time performance under constant load application is governed by the characteristic flame-spray microstructure. However, advantages in the flame-spray processing of Al₂O₃ - ZrO₂ -TiO₂ are still given, attributed to its lower melting temperature.     

Reservoir characterization and volumetric estimation of Orok Field,Niger Delta hydrocarbon province

Geophysical analysis was undertaken on the available suit of well logs, 3D seismic and checkshot data from the field in a view to carrying out reservoir characterization and volumetric estimation of Orok Field Niger Delta Province. Lithology delineation and Petrophysical evaluation including porosity, water saturation and net-to-gross were undertaken. Well to seismic tie, structural interpretation and horizon mapping were carried out. Time and depth maps were generated and volumetric estimation of the reservoirs were carried out. Four gas-bearing reservoir (A001, B001, C001 and D001) of variable thickness and depth from the subsurface were identified. Their effective porosity ranges from 19% for A001, 20% for B001, 20% for C002 and 18% for the basal D001 respectively. Water saturation estimated from the reservoir sands ranges from 23% for A001, B001 20%, C001 12% and 10% for D001. The hydrocarbon saturation of the reservoirs stood at 77%, 80%, 82%, 90% for A001, B001, C001 and D001 respectively. Only sand A001 and sand B001 had good seismic tie and were able to be mapped through the seismic. Three synthetic structural building listric faults were interpreted across the inlines intercepting the top of reservoir Sand A001 and B001. The volumetric estimation reveals that A001 and B001 have an area of 813.708 acres and 813.693 acres and volume of 151?billion cu.ft and 286?billion cu.ft of gas respectively. Three synthetic structural building listric faults (F1, F2 and F3) intercept the top of sandstones A001 and B001. The structural trapping mechanism in both sandstones resulted from synthetic fault assisting structures i.e rollover anticlines. The modeled faults trends approximately northwest to southeast direction and dip in the southwest direction.     

Optimization of photosynthetic hydrogen yield from platinized photosystem I complexes using response surface methodology

Light-dependent hydrogen production by platinized Photosystem I isolated from the cyanobacterium Thermosynechococcus elongatus BP-1 was optimized using response surface methodology (RSM). The process parameters studied included temperature, light intensity and wavelength, and platinum salt concentration. Application of RSM generated a model that agrees well with the data for H₂ yield (R² = 0.99 and p < 0.001). Significant effects on the total H₂ yield were seen when the platinum salt concentration and temperature were varied during platinization. However, light intensity during platinization had a minimal effect on the total H₂ yield within the region studied. The values of the parameters used during the platinization that optimized the production of H₂ were light intensity of 240 μE m⁻² s⁻¹, platinum salt concentration of 636 μM and temperature of 31 °C. A subsequent validation experiment at the predicted conditions for optimal process yield gave the maximum H₂ yield measured in the study, which was 8.02 μmol H₂ per mg chlorophyll.     

Synthesis and characterization of novel yttrium-incorporated copper selenide (CuSe:Y) thin materials for solar energy applications

Journal of Materials Science: Materials in Electronics - Undoped and Y-doped CuSe with different dopant concentration (0.01–0.04&nbsp;mol%) have been successfully synthesized using...     

The critical success factors of using social media for supply chain social sustainability in the freight logistics industry

This paper pioneers the investigation of the significant factors that influence corporate decisions on the use of social media for supply chain social sustainability, and it highlights a crucial research area that is currently understudied in supply chain management literature. A theoretical framework was developed in this study based upon the Technology–Organization–Environment (TOE) and Human–Organization–Technology (HOT) theories to obtain the significant critical success factors (CSFs) which influence the use of social media for supply chain social sustainability in freight logistics firms in Nigeria. The Best-Worst Method was applied to analyse and rank the CSFs using their determined relative importance level. The research findings indicate that customer satisfaction, sufficient security and privacy, affordability and competitive pressure are the highest ranked CSFs to achieve supply chain social sustainability using of social media. This research has important implications for policy makers and practitioners to gain perspectives on how to foster the use of social media in the freight logistics sector for supply chain social sustainability.