Preparation and Characterization of Activated Carbon from Microwave and Conventional Heated Almond Shells Using Phosphoric Acid Activation

Activated carbon production from almond shells using phosphoric acid activation agent was achieved by applying both conventional heating and microwave heating in succession. The morphology and surface properties of activated carbon were studied using thermogravimetric and differential gravimetric analysis, Fourier-transform infrared spectroscopy, scanning electron microscopy, and Brunauer–Emmett–Teller analysis. A surface area of 1128 m²/g was achieved by optimizing the microwave power (500?W), microwave application time (15?minutes), conventional heating time (45?minutes), conventional heating temperature (500?°C), and the phosphoric acid:sample ratio (0.7:1). An adsorption capacity of methylene blue of 148?mg/g and an iodine value of 791?mg/g was obtained for the prepared activated carbon.     

ω-meson photoproduction on nucleons in the near-threshold region

The European Physical Journal A - The ω-meson photoproduction, γ + p→p + ω, is studied in the framework of a model, containing π-meson exchange in t-channel and...     

Existence of positive solutions for nonlinear three-point problems on time scales

In this paper, by using fixed point theorems in cones, we study the existence of at least one, two and three positive solutions of a nonlinear second-order three-point boundary value problem for dynamic equations on time scales. As an application, we also give some examples to demonstrate our results.     

Crystallographic report: Bis{µ‐[O‐cyclopentyl(4‐methoxyphenyl)dithiophosphonato]1κ:S,2κ:S‐[O‐cyclopentyl(4‐methoxyphenyl)dithiophosphonato]‐1κ2S,S′}dicadmium(II)

The centrosymmetric title compound, [Cd₂{CH₃OC₆H₄P(OC₅H₉)S₂}₄], features an eight‐membered [? Cd? S? P? S? ]₂ ring owing to the presence of bridging dithiolate ligands. Tetrahedral coordination geometries for cadmium are completed by chelating ligands. Copyright © 2004 John Wiley & Sons, Ltd.     

Distribution of 131I-labeled recombinant human erythropoietin in maternal and fetal organs following intravenous administration in pregnant rats

The aim of the present study was to demonstrate the possible transplacental transmission of ¹³¹I labeled recombinant human erythropoietin (¹³¹I-rh-EPO) in pregnant rats and its distribution through maternal and fetal organs. Six Wistar Albino Rats in their pregnancy of 18 days were used ¹³¹I labeled recombinant human erythropoietin (specific activity = 2.4 μCi/IU) was injected into the tail vein of rats. After 30 minutes labeled erythropoietin infusion maternal stomach, kidney, lung, liver, brain and heart as well as fetus were removed. Then, the same organs were removed from each fetus. Measuring weight of maternal and fetal organs as well as placenta were followed by radioactivity count via Cd(Te) detector. ¹³¹I labeled recombinant human erythropoietin was found to be able to pass rat placenta and its distribution order in fetal organs was similar to those of maternal organs. Besides, as measurements were performed closer to cornu uteri, uptakes were decreasing in every fetus and its corresponding placenta.     

Validation and verification of social processes within agent-based computational organization models

The use of simulation modeling in computational analysis of organizations is becoming a prominent approach in social science research. However, relying on simulations to gain intuition about social phenomena has significant implications. While simulations may give rise to interesting macro-level phenomena, and sometimes even mimic empirical data, the underlying micro and macro level processes may be far from realistic. Yet, this realism may be important to infer results that are relevant to existing theories of social systems and to policy making. Therefore, it is important to assess not only predictive capability but also explanation accuracy of formal models in terms of the degree of realism reflected by the embedded processes. This paper presents a process-centric perspective for the validation and verification (V&V) of agent-based computational organization models. Following an overview of the role of V&V within the life cycle of a simulation study, emergent issues in agent-based organization model V&V are outlined. The notion of social contract that facilitates capturing micro level processes among agents is introduced to enable reasoning about the integrity and consistency of agent-based organization designs. Social contracts are shown to enable modular compositional verification of interaction dynamics among peer agents. Two types of consistency are introduced: horizontal and vertical consistency. It is argued that such local consistency analysis is necessary, but insufficient to validate emergent macro processes within multi-agent organizations. As such, new formal validation metrics are introduced to substantiate the operational validity of emergent macro-level behavior. Levent Yilmaz is Assistant Professor of Computer Science and Engineering in the College of Engineering at Auburn University and co-founder of the Auburn Modeling and Simulation Laboratory of the M&SNet. Dr. Yilmaz received his Ph.D. and M.S. degrees from Virginia Polytechnic Institute and State University (Virginia Tech). His research interests are on advancing the theory and methodology of simulation modeling, agent-directed simulation (to explore dynamics of socio-technical systems, organizations, and human/team behavior), and education in simulation modeling. Dr. Yilmaz is a member of ACM, IEEE Computer Society, Society for Computer Simulation International, and Upsilon Pi Epsilon. URL: http://www.eng.auburn.edu/~yilmaz     

Effect of operating parameters on selective separation of heavy metals from binary mixtures via polymer enhanced ultrafiltration

Performance of continuous polymer enhanced ultrafiltration (PEUF) method was investigated for removal of mercury and cadmium from binary mixtures. This method includes the addition of polyethyleneimine (PEI) as a water soluble polymer to bind the metals, which was followed by ultrafiltration operation performed on both laboratory and pilot scale systems. The influence of various operating parameters such as temperature, metal/polymer ratio, presence of calcium ions and pH on retention of metals and permeate flux was investigated. To investigate the possibility of selective separation of mercury and cadmium, experiments were conducted for binary solutions at different pH and loading ratios. It was seen that the retention of mercury decreased and permeate flux increased when the temperature increased. The increased pH and decreased metal/polymer ratio, loading (L), resulted in higher retention of both metals. Shapes of retention vs. pH or L curves were very similar for both metals. Retentions stay almost constant at a value very close to unity until a critical L or pH value was reached, then, R decreases almost linearly with L or pH. However, retention of cadmium was affected more than that of mercury as the pH decreased and L increased. This leads to the selective separation of mercury and cadmium. At low pH values (about 5) and at high L values (about 0.3), mercury was removed by ultrafiltration operation while almost all cadmium passed through the membrane. At pH 5.5 and cadmium/polymer ratio about 0.35 and mercury/polymer ratio about 0.39, the highest separation factor was obtained as 49.     

Chiral recognition and separation of beta2-amino acids using non-covalently molecularly imprinted polymers

Non-covalently molecularly imprinted polymers (MIPs) for beta2-amino acids were prepared for the first time. N-(2-chlorobenzyloxycarbonyl)-(R)-beta2-homophenylalanine (N-2-ClZ-(R)-beta2-HPhe) was imprinted with methacrylic acid (MAA) and/or 4-vinylpyridine (4-VPy) as the functional monomers, with ethylene glycol dimethacrylate (EDMA) as the cross-linker. The MIPs made with different ratios of MAA:4-VPy were studied in HPLC mode. The results show that MIPs made with 4-VPy yielded the best chiral separation factor (alpha= 1.86) for the template molecule. The importance for an efficient separation of pi-stacking interactions between the MIPs and the template molecule is demonstrated. Racemates of Z-alpha-amino acids and beta-amino acid analogues of the template were either not or poorly resolved by the MIPs, thus demonstrating the close three-dimensional complementarity of the MIPs' recognition sites with the template.