From sustainability to sustainizability

Following the recent introduction of the Sustainability over Sets (SOS) concept as a sustainability analysis tool with broad flexibility in incorporating human input, in this work, the concepts of Sustainizability (SIZ) and Sustainizability over Sets (SIZOS) are introduced, as novel frameworks for sustainable system synthesis. Springing off the conceptual foundation of sustainability, SIZ (and SIZOS) refers to the existence of allowable external actions, and/or design changes that can render sustainable (sustainable over a set) an unsustainable (unsustainable over a set) system. Utilizing earlier mathematical results for SOS, rigorous necessary and sufficient conditions for SIZOS are presented. Two case studies, on a two-dimensional biological waste treatment system, and a three-dimensional food chain system, are then presented to illustrate the developed necessary and sufficient conditions for SIZOS.     

A comparative study of ZrO2, Y2O3 and Sm2O3 promoted Ni/SBA-15 catalysts for evaluation of CO2/methane reforming performance

Ni-based/SBA-15 catalysts, were promoted by 3wt % of samaria (Sm₂O₃), Yttria (Y₂O₃) and Zirconia (ZrO₂), by two-solvent impregnation method. The catalysts characterization was performed by N2 adsorption–desorption, X-ray Diffraction (XRD), X-ray Fluorescence (XRF), High Resolution Transmission Electron Microscopy (HRTEM), Field Emission Electron Scanning Microscopy (FESEM), Temperature Programmed Oxidation/Reduction (TPO/TPR) and NH₃-Temperature Programmed Desorption (NH₃-TPD) techniques. Then, evaluated by CO₂/methane reforming.The CO₂/methane reforming outcomes revealed that samaria-promoted catalyst showed excellent activity, stability and cock resistance, while yttria-promoted catalyst just illustrated good activity at high temperature and zirconia-promoted catalyst didn't show any modification in catalytic performance in comparison to Ni-based catalyst with no promoter. Samaria-promoted TEM and TPR analysis, indicated adding samaria improved the NiO particles interaction with SBA-15 support pores wall and NiO dispersion. The TPO analysis displayed that coke deposition in samaria-promoted sample after 12 h reaction is less than yttria-promoted during stream of 5 h. Also, it is suggested that for samaria containing catalyst, cock deposition occurred on the support. Therefore, nickel active sites were preserved for time on stream of 12 h, which is the main reason for samaria-promoted catalyst superior stability than other's.     

The Effects of One and Double Heat Treatment Cycles on the Microstructure and Mechanical Properties of a Ferritic–Bainitic Dual Phase Steel

Metallurgical and Materials Transactions A - In this study, samples with ferritic–bainitic dual phase structures consisting of 62 pct bainite were obtained from the AISI 4140 steel...     

Application of statistical methodology for the evaluation of mechanically activated phase transformation in nanocrystalline TiO2

Response surface methodology was employed to study the effect of three factors, namely as milling time, milling speed and ball to powder weight ratio, on the mechanical activation of polymorphic phase transformation in nanocrystalline TiO₂ powder and identify the probable interactions between these factors. The response was the rutile percentage after annealing the samples. Based on the statistical analysis, ball to powder weight ratio was found as the most effective factor and just one statistically significant interaction was found between milling speed and ball to powder ratio. It was also shown that increasing the milling time has no significant effect on the phase transformation since the required activation energy for the phase transformation is unattainable under these conditions. The rutile percentage was calculated from X-ray diffraction patterns of the samples via Rietveld refinement method. Raman spectroscopy was employed to verify the phase composition analysis based on X-ray diffraction results.     

Catalytic performance of Samaria-promoted Ni and Co/SBA-15 catalysts for dry reforming of methane

Methane reforming with CO₂ over Samaria-promoted Ni and Co/SBA-15 was comparatively investigated. The Co, Ni (10%wt) and Sm (0.5, 1 and 1.5%wt) ions were introduced by two-solvent impregnation method. The Ni and Co catalysts with/without promoter, were examined by N2 adsorption-desorption, x-ray diffraction (XRD), high resolution transmission electron microscopy (HRTEM), scanning electron microscopy (SEM), temperature programmed reduction (TPR) and thermogravimetric analysis (TGA) methods, and then evaluated in CO₂ reforming of methane. The XRD and TEM results indicated that Ni and Co/SBA-15 promoted by 1%wt of Samaria, had the smallest NiO and Co₃O₄ particles size and the highest dispersion; as a result, they would rather studying dry reforming of methane test. Catalytic results indicated that Samaria promoted Ni/SBA-15 had the highest conversion (CH₄ conversion～58% at 700 °C), while a remarkable decrease of catalytic activity was observed over Samaria-promoted Co/SBA-15 (CH₄ conversion～25% at 700 °C). The positive effect of Samaria on Ni/SBA-15 catalyst activity is probably due to smaller NiO particles, higher NiO dispersion and lower trend to carbon deposition. On the contrary, the negative effect of Samaria on Co/SBA-15 catalyst activity is maybe due to Co oxidation to inactive phase and sintering of Co particles in high temperatures.     

Formula to Get Desired Soil Density

Changing the soil characteristics is a main concern to all civil engineers. Highway and foundation engineers are particularly more concerned with the subject. There are several methods to improve the soil characteristics. One of these methods is to add fine material, which fills the voids between the grains of the soil, helping to make the soil denser, thus gaining high resistance to penetration. This study uses statistical parameters of the soil grains distribution to predict the soil maximum dry density, then uses the fine biasness coefficient to predict the new density of the soil after mixing any amount of fine particles with the original soil. A mathematical formula is developed to make such a prediction. Lab testing results were compared with the results of the prediction. They were found to be in total agreement, and the margin of error was found to be quite low.     

Oncogene rearrangement in non-Hodgkin's lymphoma with a 14q+ chromosome of unknown origin

Southern blot analysis was performed with a panel of DNA probes to detect rearrangements of c-myc, bcl-1, bcl-2 and bcl-3 in 14 cases of B-cell non-Hodgkin's lymphoma (NHL) with a clonal cytogenetic rearrangement involving the chromosome 14q32 locus and no known donor chromosome [t(14;?)(q32;?)]. In our experience, 21% of all chromosomal abnormalities involving the 14q32 locus in B-cell NHL are of this type. We found oncogene rearrangements in five of the 14 cases: bcl-1 rearrangement on one mantle zone lymphoma, bcl-2 rearrangements in two follicular lymphomas, and c-myc rearrangements in two small noncleaved cell lymphomas. We conclude that a 14q32+ abnormality of unknown origin is a relatively frequent karyotypic finding in B-cell NHL. In one third of the cases, known oncogenes that have been previously described in reciprocal translocations involving the immunoglobulin heavy chain locus were shown to be involved in the 14q32+ abnormality. The translocations in the other cases are likely to have involved one of the above oncogenes with breakpoints not revealed by the probes employed, other known oncogenes, or oncogenes that have not yet been identified.     

A Comparative Evaluation of Air-Jet Sieve for Particle Size Analysis of Pharmaceutical Powders

The performance of the air-jet sieve (AJS), for the particle size analysis of pharmaceutical powder, was evaluated and compared with the conventional sieve shaker (ESS). Two grades of acetaminophen (APAP) were used as test pharmaceutical powders. The particle size analysis by the AJS was simple, reproducible, efficient and accurate. The problematic powder, possessing excessive electrostatic charges and ranging in mean diameter from 17 nm to 800 nm (beyond the scope of ESS) could be evaluated accurately by AJS. The analysis time required by AJS was relatively less than that required by ESS. The accuracy of the determination by AJS was not affected by the sample size. Both the speed of rotation (vibrations and/or shaking) and the total time of sifting affected the results of the determination by ESS. The particle size value of APAP-special determined by ESS and AJS were 680.0 ± 0.14 nm and 40.0 ± 0.32 respectively, whereas the value assigned by the manufacturer was below 74 nm (-200 mesh). The precision of either method for particle size analysis of powder possessing excessive electrostatic charge was improved by the use of carbon black as an anti-static agent.