Novel two‐stage phenol–formaldehyde resol resin synthesis

The synthesis of phenol–formaldehyde resol resins was carried out in two stages to facilitate the start of a conventional batch process. In the first stage, the starting material solution was preprocessed in a continuous‐flow stirred‐tank reactor with a 5‐min residence time. In the second stage, synthesis was continued in a batch reactor. Samples were analyzed by titrimetric methods, gas chromatography, nuclear magnetic resonance spectroscopy, and differential scanning calorimetry. Most of the starting materials were consumed in the preprocessing reactor, which allowed better control of the reactivity of the prepolymer solution in the second stage. The methylolation and condensation reactions proceeded steadily during the production process in the batch reactor. The results of the study indicated that dividing a conventional one‐stage batch process into two stages could facilitate the control of the initial stages of resol production. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 103:371–379, 2007     

IR spectroscopy as a quantitative and predictive analysis method of phenol–formaldehyde resol resins

A set of resin samples was characterized by IR and ¹³C-NMR spectroscopy. The suitability of IR spectroscopy for the quantitative analysis of resins was evaluated by statistical methods using the NMR reference data as calibration. The values of interesting properties, for example, the amount of free phenol and the formaldehyde-to-phenol (F/P) molar ratio, of the resins being similar to the calibration resins were predicted from the IR spectra. Also, the predicted results were compared with the ones observed by ¹³C-NMR spectroscopy. © 1998 John Wiley & Sons, Inc. J Appl Polym Sci 69: 2175–2185, 1998     

Combined application of Product Lifecycle and Software Configuration Management systems for ITER remote handling

The advantages of Product Lifecycle Management (PLM) systems are widely understood among the industry and hence a PLM system is already in use by International Thermonuclear Experimental Reactor (ITER) Organization (IO). However, with the increasing involvement of software in the development, the role of Software Configuration Management (SCM) systems have become equally important. The SCM systems can be useful to meet the higher demands on Safety Engineering (SE), Quality Assurance (QA), Validation and Verification (V&V) and Requirements Management (RM) of the developed software tools. In an experimental environment, such as ITER, the new remote handling requirements emerge frequently. This means the development of new tools or the modification of existing tools and the development of new remote handling procedures or the modification of existing remote handling procedures. PLM and SCM systems together can be of great advantage in the development and maintenance of such remote handling system. In this paper, we discuss how PLM and SCM systems can be integrated together and play their role during the development and maintenance of ITER remote handling system. We discuss the possibility to investigate such setup at DTP2 (Divertor Test Platform 2), which is the full scale mock-up facility to verify the ITER divertor remote handling and maintenance concepts.     

Effects of ethanol to water ratio in feed solution on the crystallinity of spray-dried lactose

In the present study, the effects of ethanol to water ratio in feed solution on the physical properties of spray-dried alpha-lactose monohydrate were evaluated. Crystallinity of the spray-dried lactose was determined by isothermal microcalorimetry (IMC) and by differential scanning calorimetry (DSC). Water content of the spray-dried lactose was determined by thermogravimetric analysis and the surface area was evaluated by Brunauer, Emmett, and Teller (BET) method. The crystallinity of spray-dried lactose varied from 0% to 100%, depending on the ratio of ethanol to water in the feed solution. Lactose spray dried from pure ethanol was 100% crystalline and contained hydrate water. Lactose spray dried from pure water was 100% amorphous. The feed solution substantially affected the ratio of surface water to hydrate water, as the content of surface water increased and hydrate water decreased, while the crystallinity of spray-dried lactose decreased. Surface area of the spray-dried lactose increased as a function of amorphous content.     

Use of Magnetic Separation in Production of Electromelted Refractories

It is demonstrated that magnetic separation of crushed bacor (virgin and recycled bacor waste) on the magnetic separator produced by ÉMKO Electromechanical company made it possible to improve the quality of the finished products.     

A Mutasynthesis Approach with a Penicillium chrysogenum ΔroqA Strain Yields New Roquefortine D Analogues

Penicillium chrysogenum, which lacks the roqA gene, processes synthetic, exogenously added histidyltryptophanyldiketopiperazine (HTD) to yield a set of roquefortine‐based secondary metabolites also produced by the wild‐type strain. Feeding a number of synthetic HTD analogues to the ΔroqA strain gives rise to the biosynthesis of a number of new roquefortine D derivatives, depending on the nature of the synthetic HTD added. Besides delivering semisynthetic roquefortine analogues, the mutasynthesis studies presented here also shed light on the substrate preferences and molecular mechanisms employed by the roquefortine C/D biosynthesis gene cluster, knowledge that may be tapped for the future development of more complex semisynthetic roquefortine‐based secondary metabolites.     

On the syntheses of triacylglycerols from branched saturated fatty acids

A number of triacylglycerols with branched acyl groups were prepared via 1,2-isopropylidene glycerol for the purpose of studying three different physical properties: gel point, refractive index, and density. The monoacid triacylglycerols were prepared either via the corresponding acids or the acyl chlorides.     

Membrane components of Treponema denticola trigger proteinase release from human polymorphonuclear leukocytes

Tissue destruction during periodontitis is believed to be primarily brought about by leukocyte proteinases. We postulate that oral spirochetes cause discharge of polymorphonuclear leukocyte (PMN) lysosomal enzymes. Effects of Treponema denticola 53-kDa outer membrane protein, lipopolysaccharide (LPS), and peptidoglycan on degranulation of matrix metalloproteinases (MMP)-8 (collagenase) and -9 (gelatinase), cathepsin G, and elastase by human peripheral blood PMNs were studied by specific enzyme assays and Western blot analysis. T. denticola 53-kDa kDa outer membrane protein was found to be a particularly efficient inducer of MMP-8 release. The induction was comparable with that of phorbol myristate acetate, a known inducer of PMN specific granule discharge. All of the treponemal substances, most notably the 53-kDa protein and LPS, induced release of MMP-9, a component of C-type granules. Both collagenase and gelatinase released from PMNs were mostly in active forms. Release of cathepsin G and elastase was also observed with the 53-kDa protein treatment. The other T. denticola substances did not induce release of these serine proteinases. Lactate dehydrogenase was not released from PMNs by the treatments, indicating that the degranulation was specific and not caused by toxic effects of the substances. This was confirmed by transmission electron microscopy of PMNs treated with the 53-kDa protein that showed rapid vacuole formation and cell shape changes but no disintegration of the cells. Thus, T. denticola may participate in the PMN-dependent extracellular matrix degradation during the course of periodontal inflammation by triggering the secretion and activation of matrix metalloproteinases.     

Robust decomposed system control for an electro-mechanical linear actuator mechanism under input constraints

This paper aims to develop a robust decomposed system control (RDSC) strategy under input constraints for an electro-mechanical linear actuator (EMLA) facing model uncertainty and external disturbances. At first, a state-space model of a complex multi-stage gearbox EMLA system, driven by a permanent magnet synchronous motor (PMSM), is developed, and the non-ideal characteristics of the ball screw are presented through the model. The result is a four-order nonlinear strict-feedback form (NSFF) system decomposed into three subsystems. As the paper's main result, a novel RDSC strategy with uniform exponential stability for controlling subsystem states is presented. This developed controller avoids the "explosion of complexity" problem associated with backstepping by treating the time derivative of the virtual control input as an uncertain system term. The proposed method, despite assuming load disturbances and input constraints with arbitrary bounds, offers a straightforward control approach for a broader range of applications. Further, the controller's performance is evaluated by simulating two distinct duty cycles, each representing different levels of demand on the actuator facing load disturbances near the rated motor performance.