Constituents,Oxidant-Antioxidant Profile,and Antimicrobial Capacity of the Essential Oil Obtained from Ferulago Sandrasica Peşmen and Quézel

Chemical constituents, total phenolic content, total oxidant status, total antioxidant status, lipid hydroperoxides, total free –SH levels, and antimicrobial activity of essential oil obtained from the Ferulago sandrasica (Umbelliferae) were investigated. The essential oil was obtained by hydrodistillation using a Clevenger-type apparatus. The chemical constituents were analyzed by gas chromatography‐mass spectrometry. The main components of the essential oil were ocimene (30.5%), carene-δ-3 (27.4%), and α-pinene (17.8). The antimicrobial activity was tested by a disc diffusion method against E. coli MC 400, E. coli ATCC 25922, E. coli 0157 H7, E. colaecea ATCC 23355, E. feacalis ATCC 19433, P. aeruginosa NRRL B-2679, S. aureus ATCC 25923, B. nischenoformis NRRL B-1001, S. aureus ATCC 33862, B. cereus NRRL B-3711, B. subtilis NRRL B-209, M. luteus NRRL B-1013, L. monocytogenes ATCC 7644, B. subtulis ATCC 6633.     

Teacher beliefs and technology integration practices: A critical relationship

Early studies indicated that teachers’ enacted beliefs, particularly in terms of classroom technology practices, often did not align with their espoused beliefs. Researchers concluded this was due, at least in part, to a variety of external barriers that prevented teachers from using technology in ways that aligned more closely with their beliefs. However, many of these barriers (access, support, etc.) have since been eliminated in the majority of schools. This multiple case-study research was designed to revisit the question, “How do the pedagogical beliefs and classroom technology practices of teachers, recognized for their technology uses, align?”     

Elman's recurrent neural network applications to condition monitoring in nuclear power plant and rotating machinery

The purpose of this study is to show the capability of recurrent neural nets (RNN) for condition monitoring and diagnosis in nuclear power plant systems and rotating machinery. In the first application, the study addresses the use of RNN for detecting anomalies introduced from the simulated power operation of a high-temperature gas cooled nuclear reactor. In the second, it is used to detect the motor bearing damage using a coherence function approach, which is defined between the motor current and vibration signals, for induction motors. Hence, the high performance of Elman's RNN was shown by means of two different applications.     

In vitro release study of diltiazem hydrochloride from poly(vinyl pyrrolidone)/sodium alginate blend microspheres

Polymeric blend microspheres of poly(vinyl pyrrolidone) (PVP) with sodium alginate (NaAlg) were prepared by cross‐linking with calcium ions and used to deliver a calcium channel blocker drug, diltiazem hydrochloride (DT). The prepared microspheres were characterized by Fourier transform infrared spectroscopy and scanning electron microscopy. Scanning electron microscopy confirmed the spherical nature of the particles. Preparation conditions for the microspheres were optimized by considering the percentage entrapment efficiency, particle size, and swelling capacity. Effects of variables such as PVP/NaAlg ratio, molecular weight of PVP, cross‐linker concentration, and drug/polymer ratio on the release of DT were discussed at two different pH values (1.2, 6.8) at 37°C. It was observed that DT release from the microspheres decreased with increasing molecular weight of PVP and extent of cross‐linking. However, DT release increased with increasing PVP content and drug/polymer ratio (d/p) of the blend microspheres. The highest DT release percentage was obtained as 99% for PVP/NaAlg ratio of 1/2 with d/p ratio of 1/2 at the end of 4 h. It was also observed from release results that DT delivery from the microspheres through the external medium are much higher at low pH (1.2) value than that of high pH (6.8) value. The drug release from the microspheres mostly followed Fickian transport. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci, 2008     

Ceramic Top Coats of Plasma-Sprayed Thermal Barrier Coatings: Materials,Processes, and Properties

The ceramic top coat has a major influence on the performance of the thermal barrier coating systems (TBCs). Yttria-partially-stabilized zirconia (YSZ) is the top coat material frequently used, and the major deposition processes of the YSZ top coat are atmospheric plasma spraying and electron beam physical vapor deposition. Recently, also new thermal spray processes such as suspension plasma spraying or plasma spray-physical vapor deposition have been intensively investigated for TBC top coat deposition. These new processes and particularly the different coating microstructures that can be deposited with them will be reviewed in this article. Furthermore, the properties and the intrinsic–extrinsic degradation mechanisms of the YSZ will be discussed. Following the TBC deposition processes and standard YSZ material, alternative ceramic materials such as perovskites and hexaaluminates will be summarized, while properties of pyrochlores with regard to their crystal structure will be discussed more in detail. The merits of the pyrochlores such as good CMAS resistance as well as their weaknesses, e.g., low fracture toughness, processability issues, will be outlined.     

Catalyst incorporation at defects during nanowire growth

Scanning and transmission electron microscopy was used to correlate the structure of planar defects with the prevalence of Au catalyst atom incorporation in Si nanowires. Site-specific high-resolution imaging along orthogonal zone axes, enabled by advances in focused ion beam cross sectioning, reveals substantial incorporation of catalyst atoms at grain boundaries in <110> oriented nanowires. In contrast, (111) stacking faults that generate new polytypes in <112> oriented nanowires do not show preferential catalyst incorporation. Tomographic reconstruction of the catalyst-nanowire interface is used to suggest criteria for the stability of planar defects that trap impurity atoms in catalyst-mediated nanowires.