The effect of gold clusters on the autoxidation of poly(3-hydroxy 10-undecenoate-co-3-hydroxy octanoate) and tissue response evaluation

We describe the synthesis and characterization of gold clusters embedded into poly (3-hydroxy octanoate-co-3-hydroxy-10-undecenoate) (PHOU), and evaluated the tissue response of the material upon implantation onto muscle tissue (rat). For this aim, PHOU was obtained by Pseudomonas oleovorans from octanoic acid (OA) and 10-undecenoic acid (UA) with a weight ratio of 50:50. The unsaturated co-polyester film in which HAuCl₄ was dispersed was exposed to air at room temperature to produce gold clusters embedded into cross-linked PHOU. The cross-linking kinetics of the gold catalyzed PHOU autoxidation was followed by sol-gel analysis. In vivo tissue reactions of the cross-linked PHOU embedded gold clusters were evaluated by subcutaneous implantation in rats. The rats appeared to be healthy throughout the implantation period. No symptom such as necrosis, abscess or tumor genesis was observed in the vicinity of the implants. Retrieved materials varied in their physical appearance after 6 weeks of implantation. AFM and SEM micrographs of the PHOU containing gold clusters were also taken.     

Investigation of the Usage of Depolymerized Nylon 66 Intermediate in Phenolic Resin Modification

In this study, the potential usage of the Nylon 66 hydrolysis products (HP) for curing “high ortho” novolac resin (N) was investigated. According to FTIR, DSC and TGA results, it is concluded that HP can be as a curing agent for N without the need for another crosslinking agent and thermal degradation stability of cured N-HP blends increased significantly up to 15% HP content. Furthermore, according to performed surface coating tests, it is shown that all films prepared with HP up to 30-wt % have excellent water resistance, drying and adhesion properties as well as with high hardness values.     

Influence of the phase state of self‐assembling redox mediators on their electrochemical activity

Self‐assembling redox mediators have the potential to be broadly useful in a range of interfacial electrochemical contexts because the oxidation state and state of assembly of the mediator are closely coupled. In this article, we report an investigation of the self‐assembly of single‐ and double‐tailed ferrocenyl amphiphiles [(11‐ferrocenylundecyl)trimethylammonium bromide (FTMA) and bis(11‐ferrocenylundecyl)dimethylammonium bromide (BFDMA), respectively] at the surfaces of Pt electrodes and the impact of the dynamic assembled state of the amphiphiles on their rate of oxidation. We conclude that frozen aggregates of BFDMA adsorb to the surfaces of the Pt electrodes, and that slow dynamics of reorganization of BFDMA within these aggregates limits the rate of electrooxidation of BFDMA. In contrast, FTMA, while forming assemblies on the surfaces of Pt electrodes, is characterized by fast reorganization dynamics and a corresponding rate of oxidation that is an order of magnitude greater than BFDMA. © 2014 American Institute of Chemical Engineers AIChE J, 60: 1381–1392, 2014     

Chemoselective reduction of α,β-unsaturated aldehydes and ketones over mesoporous B(O i Pr)3–MCM-41 catalyst via MPV reduction process: preparation, characterization and catalytic application

Boron alkoxide-containing ordered mesoporous silica material (B(O ⁱ Pr)₃–MCM-41) was prepared by the grafting method. The obtained B(O ⁱ Pr)₃@MCM-41 composite materials were fully characterized in details by PXRD, FT-IR-, ¹¹B-NMR-, ²⁹Si-NMR-, ¹³C-NMR-spectroscopies, scanning electron microscopy, EDX, transmission electron microscopy techniques, N₂ adsorption–desorption isotherms and Inductively coupled plasma-optical emission spectroscopy analyses, demonstrating the successful homogenous distribution of the B(O ⁱ Pr)₃ catalyst in the MCM-41 support. The as-prepared new materials were successfully applied in the chemoselective Meerwein–Ponndorf–Verley reduction of α,β-unsaturated carbonyl compounds. In the reduction of α,β-unsaturated aldehydes and ketones, which can not be reduced by usual catalysts, a very high selectivity, especially for the reduction of allylic aldehydes and ketones could be obtained. In most cases no side product formation could be observed. The catalyst was found to be encouraging as a heterogeneous catalyst as the yield was almost unchanged after up to six cycles. No leaching of the grafted boron tri-isopropoxide into the reaction mixture could be detected.     

Synthetic fuel production from tea waste: Characterisation of bio-oil and bio-char

The pyrolysis of tea waste was studied for determining the main characteristics and quantities of liquid and solid products. Particular investigated process variables were temperature (673-973 K), heating rate (5-700 K min⁻¹) and nitrogen gas flow rate (200-800 cm³ min⁻¹). The maximum oil and char yields are 30.4 (773 K) and 43.3% (673 K), respectively. The liquid and its aliphatic sub-fraction were characterized by elemental analysis, FT-IR, ¹H NMR, and GC/MS. The char was characterized with elemental analysis, SEM, BET, and FT-IR techniques. The aliphatic sub-fraction of the obtained bio-oil contains predominantly n-alkanes and alkenes, and branched hydrocarbons. According to the experimental results the liquid products can be used as liquid fuels, whereas the solid product seems to be not suitable for adsorption purposes, due to having low surface areas.     

Synthesis of microbial elastomers based on soybean oil. Autoxidation kinetics,thermal and mechanical properties

Microbial bioelastomers prepared by the autoxidation of the unsaturated medium-long chain length co-poly-3-hydroxyalkanoate’s (mlcl-PHAs) based on soybean oily acids (Sy) have been reported. Pseudomonas oleovorans were grown on a series of the mixture of octanoic acid (OA) and Sy with the weight ratio of 20:80, 28:72 and 50:50 in order to obtain unsaturated mlcl-copolyesters coded PHO-Sy-2080, PHO-Sy-2872, and PHO-Sy-5050, respectively. The microorganism was also grown on the mixture of Sy and 10-undecenoic acid (UA) with the weight ratio of 50:50 to obtain unsaturated copolyester coded PHU-Sy-5050. The PHAs obtained were characterized by ¹H NMR and GC-MS techniques. Double bond contents of the unsaturated PHAs obtained were varying between 0.8 to 20 mol %. Autoxidation of the unsaturated copolyesters were carried out on exposure to air at room temperature in order to obtain new biomaterials whose mechanical strength was improved. Autoxidation kinetics, shelf life, mechanical and thermal properties of these biomaterials were evaluated.     

Room temperature deposition of XRD-amorphous TiO2 thin films: Investigation of device performance as a function of temperature

In this study, TiO₂ thin films were fabricated by radio frequency sputtering at room temperature in pure Ar atmosphere starting from a 6?in. TiO₂ target. The thickness of the films was controlled by deposition time and the effect of Ar sputtering pressure on the characteristics of TiO₂ thin films was evaluated. Surface morphology and optical properties of TiO₂ films were investigated using X-ray diffraction (XRD), Atomic Force Microscopy (AFM), Scanning Electron Microscopy (SEM) and UV–Vis spectrophotometry. Also, the refractive index and extinction coefficient of films were inferred by fitting spectrophotometric data. Schottky diode were fabricated by evaporation of Ni on TiO₂ films. Current-voltage (I-V) measurements of Ni/TiO₂ films showed that the rectifying properties of the device improves with the increasing of TiO₂ film density and thickness. Therefore, the best I-V characteristic of the device was investigated depending on the temperature. Also, Ni/n-TiO₂/p-Si/Al devices were fabricated to understand their transport mechanism.     

Empirical investigation of owner-occupiers’ reinvestments in housing: the case of Ankara,Turkey

In Turkey, reinvestments in the existing housing stock are entirely dependent on households’ decisions in the free market. There are no policies to consider reinvestment processes, and the body of knowledge on households’ reinvestment decisions is scant. Understanding how individual reinvestment decisions are determined is vital to devise policy measures to improve the condition of the existing housing stock and neighbourhoods. In this study, an attempt is made to identify the basic motivations and factors underpinning the owner-occupants’ performed and planned reinvestments in the apartment flats of Ankara. The results display that consumption considerations, particularly circumstances of necessity and urgency, are the basic motivation for undertaking reinvestment works among the surveyed owner-occupants. Higher household head age, shorter duration of occupancy, higher house value and maintained installations and infrastructure in common parts of the apartment blocks are displayed to increase the probability of having undertaken reinvestment works. Also, perception of the dwelling to be in disrepair and landscaped common outdoor space of the apartment are identified to increase the probability of having reinvestment plans for the future. The analysis suggests that policy measures are required both to trigger reinvestment capacities of households and to monitor the tendencies of reinvestments.     

Formalism for Applying Domain Constraints in Domain-Oriented Schema Matching

Exchanging data between different software systems is a critical requirement in the architecture, engineering, and construction industry, where task specific data models and public data exchange standards have been applied for data representation and exchange. Matching two data models effectively and efficiently is a challenging task, especially when performed manually, due to the large size and the complexity of today’s data schemas. Some existing computer-aided approaches have attempted to automate matching of different schemas. These approaches work and reduce human effort under specific conditions; however, they do not always result in an accurate matching of two schemas. Achieving schema matching result comparable in accuracy to manual matching requires leveraging domain specific knowledge. Yet utilization of domain knowledge for schema matching rarely has been incorporated in prior studies. In this paper, we present a semiautomated approach that leverages domain knowledge to improve the schema matching process. Compared to a generic schema matching approach, the approach discussed in this paper is able to generate more accurate results due to the incorporation of domain specific constraints, which are represented and reasoned with to create a match between data models. A prototype was developed to validate this approach through a number of real world test cases, including the matching of two publicly-available data exchange standards.