Modelling of the blend ratio effect on the mechanical properties of the biofibres

This work investigates the effect of the blend ratios of three different environmental-friendly biopolymers on fibres’ properties made by water bath extrusion machine and multi-stage drawing frame. Tensile test, shrinkage test, differential scanning calorimetry and scanning electron microscopy are used to study the mechanical and thermal properties of composed fibres. In the modelling stage, stepwise regressions were used as faster and less prone technique to over fit the results by watching the order in which blend ratios are increased or decreased, that help to meet the requirements of specific applications. The statistical-based models control the biodegradable fibre properties beyond the selected range of the blend ratios more than that can be obtained from single polymer equivalents. The forecasting designed program simulates the relationship between the blend ratios and the biofibre’ properties to save both time and cost of the production process, this novel method steps could be applied on different polymers.     

Development of Emu oil-loaded PCL/collagen bioactive nanofibers for proliferation and stemness preservation of human adipose-derived stem cells: possible application in regenerative medicine

Adipose tissue-derived stem cells (ASCs) are promising candidate in stem cell therapies, and maintaining their stemness potential is vital to achieve effective treatment. Natural-based scaffolds have been recently attracted increasing attention in nanomedicine and drug delivery. In the present study, a polymeric nanofibrous scaffold was developed based on the polycaprolactone/Collagen (PCL/Coll) containing Emu oil as a bioactive material to induce the proliferation of ASCs, while simultaneously preserving the stemness property of those cells. Fabrication of the electrospun Emu oil-loaded PCL/Coll nanofibers was confirmed by using FE-SEM, FTIR, and tensile test. ASCs were seeded on two types of nanofibers (PCL/Coll and Emu oil-loaded PCL/Coll) and their proliferation, cell cycle progression, and stemness gene expressions were evaluated using MTT, propidium iodide staining, and qPCR during 14?days, respectively. The results indicated that ASCs displayed improved adhesion capacity with the higher rates of bioactivity and proliferation on the Emu oil-loaded nanofibers than the other groups. The proliferation capacity of ASCs on Emu oil-loaded PCL/Coll nanofibers was further confirmed by the cell cycle progression analysis. It was also found that Emu oil-loaded nanofibers significantly up-regulated the expression of stemness markers including sox-2, nanog, oct4, klf4, and c-Myc. The results demonstrated that the nanofibers containing Emu oil can reinforce the cell adhesion and enhance ASCs proliferation while preserving their stemness; therefore, using scaffolds containing natural products may have a great potential to enhance the in vitro expansion capacity of ASCs in the field of stem cell therapy and regenerative medicine.     

SOURCE ROCK CHARACTERIZATION BASED ON BIOLOGICAL MARKER DISTRIBUTIONS OF CRUDE OILS IN THE SOUTHERN GULF OF SUEZ, EGYPT

The depositional environment and maturity of source rocks in the southern Gulf of Suez were evaluated using biomarker and isotope data from crude oils derived from a variety of source rock types of different geological ages. Two oils families were identified and are referred to as types A and B. Type A oils are characterized by a predominance of oleanane and relatively low gammacerane concentrations, suggesting that they were derived from a terrigenous source rock with a significant input of angiosperm material inferred to occur within the marginally-mature syn-rift Lower Miocene Rudeis Shale. By contrast, type B oils are distinguished by a predominance of gammacerane and relatively low oleanane concentrations, suggesting that they were generated from mature marine carbonate source rocks inferred to occur within the Upper Cretaceous Brown Limestone and Middle Eocene Thebes Formation. Maturity parameters including the sterane isomerisation ratios C ₂₉αββ/(αββ+ααα), C₂₉ααα20S/(S+R) and TAS/(TAS+MAS), together with aromatic sulphur compound ratios (4-MDBT / I-MDBT; 4,6- / 1,4-DMDBT; 2,4–/ 1,4-DMDBT; and DBT / phenanthrenes), support the higher thermal maturity of type B oils relative to type A oils.
The biomarker variablility reflects the occurrence of two distinct source rocks in the southern Gulf of Suez and suggests that two independent petroleum systems are present here. These appear to be confined to the pre-rift (pre-Miocene) and syn-rift megasequences respectively.     

A Reference Benchmark Solution for Free Convection in A Square Cavity Filled with A Heterogeneous Porous Medium

The Fourier-Galerkin (FG) method is used to produce a highly accurate solution for free convection in a square cavity filled with heterogeneous porous medium. To this end, the governing equations are reformulated in terms of the temperature and the stream function. These unknowns are then expanded in infinite Fourier series truncated at given orders. The accuracy of the FG solution is investigated for different truncation orders and compared to the results of an advanced finite-element numerical model using fine-mesh discretization. The obtained results represent a set of high-quality data that can be used for benchmarking numerical models.     

Adaptations for Wear Resistance and Damage Resilience: Micromechanics of Spider Cuticular “Tools”

In the absence of minerals as stiffening agents, insects and spiders often use metal‐ion cross‐linking of protein matrices in their fully organic load‐bearing “tools.” In this comparative study, the hierarchical fiber architecture, elemental distribution, and the micromechanical properties of the manganese‐ and calcium‐rich cuticle of the claws of the spider Cupiennius salei, and the Zn‐rich cuticle of the cheliceral fangs of the same animal are analyzed. By correlating experimental results to finite element analysis, functional microstructural and compositional adaptations are inferred leading to remarkable damage resilience and abrasion tolerance, respectively. The results further reveal that the incorporation of both zinc and manganese/calcium correlates well with increased biomaterial's stiffness and hardness. However, the abrasion‐resistance of the claw material cross‐linked by incorporation of Mn/Ca‐ions surpasses that of many other non‐mineralized biological counterparts and is comparable to that of the fang with more than triple Zn content. These biomaterial‐adaptation paradigms for enhanced wear‐resistance may serve as novel design principles for advanced, high‐performance, functional surfaces, and graded materials.     

Experimental and Numerical Simulation of Dry Pressure Drop in High‐Capacity Structured Packings

Experimental and numerical studies were conducted on the performance and capacity of structured packings for mixture separation with very low separation factor. Different formations and conditions of the innovative structured packing PACK‐2100 with high surface area were studied to evaluate the main characteristics such as dry pressure drop. In addition, numerical simulation was performed to describe the details of the flow structure in these modified structured packings. Three‐dimensional computational fluid dynamics modeling of PACK‐2100 allowed for comparing the pressure drop in both laminar and turbulent flow regime. The obtained experimental and numerical data demonstrate the potential contribution of the packing to high‐efficiency systems with low separation factor.     

Vacuum enhanced membrane distillation for trace contaminant removal of heavy metals from water by electrospun PVDF/TiO<Subscript>2</Subscript> hybrid membranes

Electrospun hybrid membranes were synthesized using electrospinning of Poly (vinylidenefluoride) - titanium tetraisopropoxide (PVDF-TTIP) sol. Asymmetric post-treatment of membrane conducted for deprotonation of titanate and making hydrophilic/hydrophobic dual characteristics. The membranes were characterized by various methods such as wettability, scanning electron microscopy, infrared spectroscopy, X-ray diffraction and liquid entry pressure tests. For evaluating the separation performance, these membranes were applied in the VMD process to treat water heavy metal contaminants. The effects of operating parameters such as flow rate, temperature and membrane properties as porosity, on contaminant removal and producing ultra-pure water have been studied.     

Enhanced Configurable DCT Cordic Loeffler Architectures for Optimal Power-PSNR Trade-Off

The Discrete Cosine Transform (DCT) is one of the most widely used techniques of transforms in digital signal processing. It is the main algorithm in image and video coding systems. In this paper, we propose an algorithm which generates enhanced Cordic based Loeffler DCT architectures for angle’s precision degrees ranging from 10^?1 to 10^?7. High level PSNR, area and power estimators have been proposed to make a trade-off between consumption and image quality. An optimal architecture has been retained for its low complexity, low power and high PSNR. The complexity of this architecture is the lowest among the conventional DCT architectures even the BinDCT which is a reference in terms of reduced complexity. The selected architecture has also the closest PSNR to the reference Loeffler-DCT architecture without a substancial loss of power.     

Birefringent approach for assessing the influence of the extrusion temperature profile on the overall orientation of as‐spun aliphatic‐aromatic co‐polyester fibers

Since the success of a production process depends on its good planning and having a clear plan from the raw materials until the final product, the focus of this research is in modeling of the extrusion temperature profile of as‐spun aliphatic‐aromatic co‐polyester fibers. The extrusion temperature profile affects the properties, productivity and product cost. In this work, as‐spun aliphatic‐aromatic co‐polyester fibers were spun under a fractional factorial design as a function of the extrusion temperature profile using appropriate statistical methods. The influence of the extrusion temperature profile on the optical birefringence of the as‐spun fibers was characterized. From the obtained results the overall orientation of the spun filaments has been modeled. For measuring the birefringence, an interferometric technique was employed and its microinterferograms were included for illustration. POLYM. ENG. SCI., 2009. © 2009 Society of Plastics Engineers