Far-field fluid-structure interaction—Formulation and validation

This paper presents a method for studying the effects of fluid-structure interaction on submerged structures subjected to dynamic loading. The phenomena of reflections radiating from artificial boundaries is first explained. Then a procedure which simulates the effect of a non-reflecting boundary is described. Next, both exponential and step plane waves are employed to model shock loading. The developments are implemented in the general purpose finite element structural package ASAS-NL. The proposed formulation is validated by testing two-dimensional and axi-symmetric submerged fluid-structure interaction problems for which there are existing numerical and analytical solutions.     

An analysis of an implicit finite element algorithm for geometrically nonlinear problems of structural dynamics part 1. Stability

A series of implicit finite element algorithms for the geometrically nonlinear structural dynamics problem are proposed. The proposed algorithms require only the solution of a linear system at each time step. Thus, they are computationally efficient. In addition, the algorithms are discrete conservation laws. The conservative nature of the proposed schemes has a positive effect in providing a stable approximation. The stability of the algorithms is analyzed using energy methods. One of the proposed computational methods is shown to be unconditionally stable.     

Bamboo fiber polypropylene composites: Effect of fiber treatment and nano clay on mechanical and thermal properties

In the current study, bamboo fibers were modified with sodium meta‐periodate in order to improve the mechanical and thermal properties of the bamboo‐clay‐polypropylene (PP) composites. Both raw and treated bamboo fibers were used in the manufacturing of the composites. The mechanical and thermal properties of the composites from modified bamboo fibers were found to increase considerably compared with those of untreated fibers. Tensile strengths of (raw bamboo fiber)/PP, (raw bamboo fiber‐clay)/PP, and (treated bamboo fiber‐clay)/PP composites showed a decreasing trend with increasing fiber loadings. However, the values for the chemically modified (bamboo fiber)‐clay‐PP composite at all mixing ratios were found to be higher than that of the original PP. The scanning electron micrographs showed that interfacial bonding between the treated fiber‐clay and matrix has significantly improved. It was determined that better dispersion of the filler into matrix occurred on 5% clay addition and fiber treatment. J. VINYL ADDIT. TECHNOL., 21:253–258, 2015. © 2014 Society of Plastics Engineers     

Experimental investigation of local clays and clay schemes as liners for solar ponds

This paper investigates the potential of using local clays and locally available materials as lining materials for solar ponds. Results for the liquid limit, the plastic limit, the plasticity index and the permeability were obtained for clays obtained from five regions in Jordan, namely Amman, Irbid, the Dead Sea, Karak and Tafilah. The results indicate that Amman clays have the lowest permeability values, making them a potential candidate as lining materials for solar ponds in Jordan. This paper also looks at various lining schemes for solar ponds, made of local clays and the other materials. The schemes were tested using saline water from the Dead Sea. It was found that an effective cheap lining scheme may consist of combinations of compacted local clay and locally manufactured low density polyethylene film sandwiched between the clay.     

Effects of climatic conditions on the performance of carnallite solar ponds

This paper reports an experimental investigation on the effects of climatic conditions as well as the size of plastic rings on the performance and stability of two Carnallite solar ponds each of 5 m² surface area and 1 m in depth. Measurements of salinity and the temperature histories of the ponds are included. The ponds are tested under the climatic conditions of Jordan. It is found that the effectiveness of plastic rings as wind suppressors for Carnallite solar ponds is very much dependent on their size. The smaller the size the better the performance and stability of the pond. In general, it was found that the overall effect of rain in Jordan on Carnallite solar pond performance and stability is negligible.     

Quality control of coins mint using PIXE and RBS analysis

PIXE and RBS analysis is used to investigate the elemental content of modern Lebanese coins, in order to control their minting quality. The coins of interest were 100, 250 and 500 Lebanese Lira (LL), which are mainly bulky metals with or without coated layer. Using 3 MeV protons, proton induced X-ray emission PIXE identified and quantified elements while Rutherford backscattering spectrometry RBS checked the thickness of the coated layer. Indeed, the combination of PIXE and RBS provides a powerful tool to investigate the elemental composition of coins, either modern or ancient. In addition, the experimental protocol was checked by analyzing some other coins of known composition, such as 1-euro and 2-euro.     

Quinoline yellow dye stimulates whey protein fibrillation via electrostatic and hydrophobic interaction: A biophysical study

Amyloid fibril formation of proteins is associated with a number of neurodegenerative diseases. Several small molecules can accelerate the amyloid fibril formation in vitro and in vivo. However, the molecular mechanism of amyloid fibrillation is still unclear. In this study, we investigated how the food dye quinoline yellow (QY) induces amyloid fibrillation in α-lactalbumin (α-LA), a major whey protein, at pH 2.0. We used several spectroscopy techniques and a microscopy technique to explore how QY provokes amyloid fibrillation in α-LA. From turbidity and Rayleigh light scattering experiments, we found that QY promotes α-LA aggregation in a concentration-dependent manner; the optimal concentration for α-LA aggregation was 0.15 to 10.00 mM. Below 0.1 mM, no aggregation occurred. Quinoline yellow–induced aggregation was a rapid process that escaped the lag phase, but it depended on the concentrations of both α-LA and QY. We also demonstrated that aggregation switched the secondary structure of α-LA from α-helices to cross-β-sheets. We then confirmed the amyloid-like structure of aggregated α-LA by transmission electron microscopy measurements. Molecular docking and simulation confirmed the stability of the α-LA-QY complex due to the formation of 1 hydrogen bond with Lys99 and 2 electrostatic interactions with Arg70 and Lys99, along with hydrophobic interactions with Leu59 and Tyr103. This study will aid in our understanding of how small molecules induce aggregation of proteins inside the stomach (low pH) and affect the digestive process.     

Opinions and attitudes toward humanoid robots in the Middle East

Robotics is expected to boom in the near future, moving massively beyond traditional application areas, and extending to all parts of the globe. Thus, in order to enable effective international customization of robot designs, and in order to facilitate their smoother harmonious introduction to everyday life, it is important to study the opinions and attitudes toward robots in different regions of the world. Although there exists a small body of research covering the US, EU, and Asia, there is almost no research regarding attitudes toward robots in the Middle East, a region with its own marked cultural idiosyncrasies. Therefore, we brought Ibn Sina, an Arabic-language conversational android robot to Dubai’s Gitex, one of the most important exhibitions in the region, and performed a questionnaire-based empirical study with 355 subjects from 38 countries, which had seen the robot interacting, and most of which had also interacted directly with it. Many interesting findings are presented: First, a statistically significant ordering of preferred application areas for robots overall was found, as well as strong effects of the region of origin on the preferred applications. Furthermore, strong religion, age, and education effects were observed. Overall, the results together with a theoretical discussion of possible causes provide interesting insights on cultural acceptance of robots in this richly complex region, which potentially have strong implications to their wider deployment in the future in specific settings.