Difference in the inhibitive effect of some Schiff base compounds containing oxygen, nitrogen and sulfur donors

2-(2-Hydroxybenzylideneamino)-2-methylpropane-1,3-diol (BAMP), 2-((2-hydroxynaphthalen-1-yl)methyleneamino)-2-methylpropane-1,3-diol (NAMP), 2-((pyridin-2-ylimino)methyl)phenol (PMP) and N-(thiophen-2-ylmethylene)pyridin-2-amine (TMP) were investigated as corrosion inhibitors of mild steel in 2 M HCl solution using weight loss, polarization and electrochemical impedance spectroscopy techniques. All measurements show that all compounds under study exhibit inhibitor properties for mild steel. Although the effect of molecular size on inhibition efficiency is observed from the results obtained between BAMP and NAMP, the introduction of heteroatoms into the structure is seen to be more pronounced eventhough the molecular size is diminished. TMP is seen to show the highest inhibitor efficiency of 97%.     

The changes in the Mechanic Properties of a direct tableting agent Microcrystalline Cellulose by Precompression

In the manufacturing of tablets, direct tableting agents are not only used in direct compression, but are also used in wet granulation and slugging methods. These agents are effective only if their particle size and form is appropriate. However, the precompression, milling and grinding which are applied in the slugging method changes the particular properties of these agents.

In this study, microcrystalline cellulose tablets were prepared both by direct compression and slugging. The consolidation, compressibility and flow properties of the two mixed powders were compared. Finally, it was observed that the compressibility of the mixed powder was influenced negatively by the slugging method.     

Review on Advanced EB-PVD Ceramic Topcoats for TBC Applications

Development of electron beam physical vapor deposited (EB-PVD) thermal barrier coatings (TBC) aims at low conductivity, increased temperature capability, and longer life. Considerable progress has been achieved by comprehensive understanding of the evolvement of the porous microstructure in columnar ceramic topcoats and its application to tailoring optimized micro-structures. New ceramic compositions such as alternative stabilizers in zirconia, hafnia modified coatings, and pyrochlores are addressed. They have demonstrated their potential for future TBC applications. New results of both microstructure and chemistry are presented together with a summary of recent research results.     

An investigation of mechanical and metallurgical properties of explosive welded aluminum-dual phase steel

The aim of this paper is investigation of microstructure and property relationship in aluminum-HSLA steel and aluminum-dual phase steel bimetals fabricated by explosive welding technique. Dual phase steel was produced by intercritical annealing and water quenching from 1.45Mn-0.2Si-0.186C HSLA steel. Hardness, tensile shear strength, tensile strength, toughness and microstructure of explosively welded aluminum-HSLA steel and aluminum-dual phase steel were evaluated. Both bimetals have a straight bonding interface. It was also seen that plastic deformation of dual phase steel was higher than HSLA steel near interfaces of bimetals. The hardness was increased near the bond interface of bimetals. Tensile and tensile shear strength tests showed that aluminum-dual phase steel is superior than aluminum-HSLA steel. Also, impact toughness of aluminum-dual phase steel was found significantly higher than that of aluminum-HSLA steel.     

Modeling of a blending and marine transportation planning problem with fuzzy mixed-integer programming

Transportation management is an area that remains critical to overall logistics and supply chain success. The problem of multi-commodity, multi-period blending and marine transportation planning in a wheat supply chain is addressed in this paper. In real world problems, practical situations are often not well-defined and thus cannot be described precisely. Therefore fuzzy mathematical programming becomes a valuable extension of traditional crisp optimization models. This research resolves the blending and marine transportation planning problem using fuzzy mixed-integer programming (FMIP) method. Two types of fuzzy mathematical programming models are used. A real-life example is used to illustrate the potential savings which can be attained by using fuzzy models. Results obtained in this study clearly demonstrate that FMIP provides a better and more flexible way of representing the problem.     

Control of ball screw drives based on disturbance response optimization

This paper presents a new method for designing control laws for ball screw drives by directly optimizing the load side disturbance response against cutting forces. The design applies, concurrently, the principles of pole placement and loop shaping, and is easy to implement in practice. In addition to good low frequency disturbance rejection, the control law provides active vibration damping, which reduces the magnification of tracking errors near the drive's mechanical resonance. Effectiveness of the proposed strategy is demonstrated in machining and high speed tracking experiments, where its performance is compared to the industry standard P-PI cascade control law.     

Fabrication of calix[4]pyrrole nanofilms at the glassy carbon surface and their characterization by spectroscopic, optic and electrochemical methods

meso-Octamethylcalix[4]pyrrole (CP) and meso-heptaethylcalix[4]pyrrole-meso-4-aminophenyl (4APCP) modified glassy carbon (GC) electrodes were prepared by the electrochemical oxidation in acetonitrile solution. Binding of the calix[4]pyrroles with the glassy carbon surface was investigated that it is through the etheric linkage revealed from the reflection-absorption infrared spectroscopy (RAIRS). Surface films of CP and 4APCP were investigated by cyclic voltammetry (CV), ellipsometry, X-ray photoelectron spectroscopy, RAIRS and the contact angle measurements. The thicknesses of the films were determined by ellipsometry which confirmed that the film was multilayer and homogeneous over the surface. Ellipsometric measurements also provided that the CP and 4APCP film thicknesses were 2.49 nm and 4.58 nm for 6 CV cycle modification, corresponding to 66 μF/cm² and 106 μF/cm² capacitances obtained by CV. The wetting behavior was examined by contact angle measurements and found that the hydrophobicity of the GC-4APCP surface was higher than that of GC-CP, probably due to the aromatic meso substituent present in the former.     

Production and characterization of pyrolytic oils by pyrolysis of waste machinery oil

The main objective of this work is to propose an alternative method for evaluation of the waste machinery oil which is an environmental problem in Turkey. For this purpose, pyrolysis of waste machinery oil was conducted in a tubular reactor. Effect of the experimental conditions (various temperatures, catalyst type) on the formation of pyrolytic oil, gas, and char was investigated. Nickel supported on silica and zeolite (HZSM-5) were used as catalysts. Properties of the pyrolytic oils were characterized by gas chromatograph equipped with a mass selective detector (GC–MS), gas chromatography with flame ionization detector (GC–FID for boiling point range distribution), nuclear magnetic resonance (¹H NMR) spectroscopy, higher heating value measurement, and elemental analysis. The behavior of the metals in the waste machinery oil and the pyrolytic oil samples was also quantitatively detected by inductively coupled plasma (ICP) analysis. As, Cd and Cr contents of the all pyrolytic oils were found as <0.05 ppm, while Cu content of the pyrolytic oils varied between 0.3 ppm and 0.61 ppm. Only Vanadium contents of the pyrolytic oils obtained at 800 °C (0.342 ppm) and in the presence of HZSM5 (0.57 ppm) increased compared to that obtained by waste machinery oil (0.1 ppm). Lower metal contents of the pyrolytic oils reveal that pyrolysis of the waste machinery oils leads to the formation of environmental friendly pyrolytic oils with higher heating values.