Compatibilization of polyethylene/aluminum hydroxide (PE/ATH) and polyethylene/magnesium hydroxide (PE/MH) composites with functionalized polyethylenes

Study was made of the compatibilization of polyethylene/aluminum hydroxide (PE/ATH) and polyethylene/magnesium hydroxide (PE/MH) composites with composition 60/40 wt%. Compatibilizers were hydroxyl or carboxylic acid functionalized copolymers prepared in our laboratory with metallocene catalysts and commercial butyl acrylate, maleic anhydride, epoxy, and acrylic acid functionalized polyethylenes. Comparison was made with stearic acid treatment of the composites. The effect of polymeric compatibilizers on the properties of the composites was studied by tensile and impact tests, dynamic mechanical analysis, differential scanning calorimetry, morphology studies, and flammability tests. Adhesion of the PE/ATH and PE/MH composites was significantly improved, as seen in morphology studies in the changed fracture mechanism. The improved adhesion was particularly reflected in the mechanical properties: an improvement in both stiffness and toughness was achieved with use of the functionalized copolymers prepared with metallocene catalysts. According to cone calorimetry, flame retardancy properties of the composites did not deteriorate upon addition of compatibilizers.     

Modification of phenol–formaldehyde resol resins by lignin,starch, and urea

Lignin‐based chemicals, starch, and urea were used as modifiers for phenol–formaldehyde resol resins. The effects of the addition stage of the modifiers used in the synthesis of the resins and the type of modification reagent on the structures of the resins and their molar masses and reactivities were investigated. The modifications with corn starch and lignin promoted condensation; this was verified by increased molar masses and high ratios of methylene bridges to the sum of free ortho and para aromatic groups with respect to the corresponding reference resin without a modification reagent. The later the modifier was added to the resin condensation mixture, the more methylene bridges were formed with respect to the amounts of free ortho and para aromatic groups. In addition, when urea or wheat starch was added in the later condensation stage, the final condensation also reached high stages. The modifications with lignosulfonate and starch, as well as the early addition of urea, enhanced p–p′ bridge structures. The lowest condensation stage and, therefore, the highest reactivity were found when wheat starch was added with the starting reagents. The curing heat of the wheat‐starch‐modified resins decreased according to the deferred addition point of starch. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 88: 582–588, 2003     

A representative and comprehensive review of the electrical and thermal properties of polymer composites with carbon nanotube and other nanoparticle fillers

In this review we present the results of our literature investigation into the electrical and thermal properties of carbon nanotube polymer composites. A short selection of data relating to conductive polymer composites with various fillers is provided for comparison. The effects of filler properties such as type and size, the use of hybrid fillers, fabrication methods for polymer composites and the importance of the modeling of the electronic and thermal transport mechanisms are discussed, as are more general factors influencing the properties of these composites. This review represents a comprehensive survey and constructive study and should serve as a useful reference tool for industrial and academic researchers working in this field. © 2017 Society of Chemical Industry     

A Novel Porous Tube Reactor for Nanoparticle Synthesis with Simultaneous Gas-Phase Reaction and Dilution

A novel porous tube reactor that combines simultaneous reactions and continuous dilution in a single-stage gas-phase process was designed for nanoparticle synthesis. The design is based on the atmospheric pressure chemical vapor synthesis (APCVS) method. In comparison to the conventional hot wall chemical vapor synthesis reactor, the APCVS method offers an effective process for the synthesis of ultrafine metal particles with controlled oxidation. In this study, magnetic iron and maghemite were synthesized using iron pentacarbonyl as a precursor. Morphology, size, and magnetic properties of the synthesized nanoparticles were determined. The X-ray diffraction results show that the porous tube reactor produced nearly pure iron or maghemite nanoparticles with crystallite sizes of 24 and 29 nm, respectively. According to the scanning mobility particle sizer data, the geometric number mean diameter was 110 nm for iron and 150 nm for the maghemite agglomerates. The saturation magnetization value of iron was 150 emu/g and that of maghemite was 12 emu/g, measured with superconducting quantum interference device (SQUID) magnetometry. A computational fluid dynamics (CFD) simulation was used to model the temperature and flow fields and the decomposition of the precursor as well as the mixing of the precursor vapor and the reaction gas in the reactor. An in-house CFD model was used to predict the extent of nucleation, coagulation, sintering, and agglomeration of the iron nanoparticles. CFD simulations predicted a primary particle size of 36 nm and an agglomerate size of 134 nm for the iron nanoparticles, which agreed well with the experimental data.

Copyright 2015 American Association for Aerosol Research     

Effects of Ospemifene on Drug Metabolism Mediated by Cytochrome P450 Enzymes in Humans in Vitro and in Vivo

The objective of these investigations was to determine the possible effects of the novel selective estrogen receptor modulator, ospemifene, on cytochrome P450 (CYP)-mediated drug metabolism. Ospemifene underwent testing for possible effects on CYP enzyme activity in human liver microsomes and in isolated human hepatocytes. Based on the results obtained in vitro, three Phase 1 crossover pharmacokinetic studies were conducted in healthy postmenopausal women to assess the in vivo effects of ospemifene on CYP-mediated drug metabolism. Ospemifene and its main metabolites 4-hydroxyospemifene and 4′-hydroxyospemifene weakly inhibited a number of CYPs (CYP2B6, CYP2C9, CYP2C19, CYP2C8, and CYP2D6) in vitro. However, only CYP2C9 activity was inhibited by 4-hydroxyospemifene at clinically relevant concentrations. Induction of CYPs by ospemifene in cultured human hepatocytes was 2.4-fold or less. The in vivo studies showed that ospemifene did not have significant effects on the areas under the plasma concentration-time curves of the tested CYP substrates warfarin (CYP2C9), bupropion (CYP2B6) and omeprazole (CYP2C19), demonstrating that pretreatment with ospemifene did not alter their metabolism. Therefore, the risk that ospemifene will affect the pharmacokinetics of drugs that are substrates for CYP enzymes is low.     

Water hydraulic manipulator for fail safe and fault tolerant remote handling operations at ITER

Department of Intelligent Hydraulics and Automation (IHA) of Tampere University of Technology has been involved in the European Fusion program since 1994 within the ITER reactor maintenance activities. In this paper we discuss the design and development of a six degrees of freedom water hydraulic manipulator with a force feedback for teleoperation tasks. The manipulator is planned to be delivered to Divertor Test Platform 2 (DTP2) during year 2008. The paper also discusses the possibility to improve the fail safe and redundant operation of the manipulator. During the design of the water hydraulic manipulator, special provisions have been made in order to meet the safety requirements such as servo valve block for redundant operation and safety vane brakes for fail safe operation.     

The safety climate and its relationship to safety practices, safety of the work environment and occupational accidents in eight wood-processing companies

Employees continuously observe their work environment and the actions of their fellow workers and superiors, and they use such observations as a basis for the creation of cognitive models associated with safety. These models regulate their actions in the workplace and thus have an influence on safety. This study attempts to define the structure of the safety climate as perceived by workers and the correlations between the safety climate, on the one hand, and the safety practices of the company, the safety level of the work environment and occupational accidents on the other. The variables used in this study were the same as those employed in two previous Finnish safety climate studies carried out in the plywood industry, shipyards, the forestry industry, building construction and stevedoring. The safety climate was measured by means of a questionnaire. Workers from four sawmills, two plywood factories and two parquet plants participated. The total number of participants was 508 in 1990 and 548 in 1993. The variables formed four factors, whose contents and reliabilities closely resembled the results obtained in the earlier studies. These results indicate that the structure of the safety climate among Finnish workers is quite stable. The safety climate correlated both with the safety level of the work environment and with the safety practices of the company, but the correlation between the safety climate and the safety of the work environment was stronger. This result differs from those of the previous studies, in which the safety climate was defined specifically in terms of an individual’s perceptions of the safety practices of the company and of the behavior of other employees. The two safety climate factors that described a company’s attitudes to safety and its safety precautions correlated with the accident rates. The better the safety climate of the company was, the lower was the accident rate. Four companies with an accident rate below the average for the wood-processing industry had a better safety climate than four similar companies with an accident rate above the average.     

“Plug-up”–a new concept for fabricating SOI MEMS devices

This paper reports a novel process sequence for fabricating micromechanical devices on silicon-on-insulator (SOI) wafers. Among the merits of the described process are its improved immunity to stiction and elimination of conductor metal endurance problems during sacrificial etching in hydrofluoric acid. With this novel process one can controllably embed vacuum cavities within SOI substrates. Further processing of such cavity wafers enables realization of a wide variety of micromechanical devices based on single crystalline silicon or even integrated read-out circuitry.K. Järvi and T. Häkkinen are gratefully acknowledged for the device fabrication. The Finnish National Technology Agency, Okmetic, VTI Technologies, and Micro Analog Systems participated in funding this work. The ultrasonic devices were fabricated in collaboration with Autotank, Oras, Suunto, Vaisala, and Enermet.     

Development of LC/MS/MS methods for cocktail dosed Caco-2 samples using atmospheric pressure photoionization and electrospray ionization

Good reliability of Caco-2 permeability studies requires competent sampling and analytical methods to ensure the comparability of day-to-day experiments. In this work, two n-in-one LC/MS/MS methods based on two different ionization techniques were developed and validated for a group of reference compounds; eight of them are recommended by the Food and Drug Administration (FDA) for the evaluation of oral drug permeability. The performance of a new ionization technique, atmospheric pressure photoionization (APPI), as an interface for quantitative LC/MS analysis was evaluated in comparison to the electrospray ionization (ESI). Generally, the validation parameters, including sensitivity, accuracy, and repeatability, were comparable for the APPI and ESI methods. The main difference was that the linear quantitative range of APPI was 3-4 orders of magnitude (r(2) >/= 0.998) whereas in ESI it was typically 2-3 orders of magnitude (r(2) >/= 0.990). By the APPI and ESI methods, the simultaneous analysis of nine highly heterogeneous compounds was achieved within 5.5-7 min, which leads to significant savings in time and cost of the analyses. The successful validation data indicate the usefulness of both the methods for the rapid and sensitive (LOD values typically 相似文献   

AUTOMATED OBJECT LOCATOR IN A FOREST FORWARDER

A double approach method for versatile detection of similar objects from the real environment is introduced. By searching both the shape and textural data from the video image, it is possible to solve a generalized location problem without a loss in overall reliability in near–real time. A forest forwarder is used as a proof-of-concept application for the technique.