Effect of coumarin and xanthotoxin on mitochondrial structure,oxygen uptake,and succinate dehydrogenase activity in onion root cells

At concentrations in which they occur on the plant surface and retard mitosis, coumarin and xanthotoxin lowered uptake of oxygen (by 60 and 30%, respectively) by meristematic cells ofAllium cepa root tips. They caused changes in the structure of the mitochondrial matrix to become dense, and protrusions of mitochondrial membranes were visible parallelling their hypertrophy, indicating alteration in the structure and physiology of these organelles. Coumarin and, to a lesser extent, xanthotoxin increased succinate dehydrogenase production in mitochondria and also in the cytoplasm, indicating changes in membrane permeability. Changes in oxygen uptake and mitochondrial structure, in addition to the retardation of mitosis, may be the reason these compounds act as allelochemicals after they have been removed from the plant surface and reach the root meristem.     

Nickel-ion bombardment of annealed and cold-worked type 316 stainless steel

Bombardment with high doses of 5 MeV nickel ions has produced swellings as high as 90% and 60%, respectively, in annealed and 20% cold-rolled Type 316 steels. The steels contained 15 ppm of cyclotron-injected helium. Swellings were determined by both transmission electron microscopy and by a step-height method that measures the total swelling integrated along the ion path. The swelling in annealed Type 316 has a pronounced peak in the vicinity of 625°C, which is about 155°C higher than the peak swelling temperature in-reactor. The magnitudes of the swelling, void densities and void sizes produced in annealed Type 316 by nickel ions and in-reactor at the respective peak swelling temperatures are similar and it is concluded that the nickel ion bombardments provide an acceptable simulation of in-reactor behavior. Using the high dose ion results to guide extrapolation of presently available EBR-II data to higher fluences leads to the prediction that the swelling of annealed Type 316 steel at the peak swelling temperature will reach 40% at $\text{2 × 10}{}^{\mathrm{p23}}\text{n/cm}{}^2\text{(E > 0.1 MeV)}$ in EBR-II core, and 70% at $\text{3 × 10}{}^{23}\text{n/cm}{}^2$. These fluences in EBR-II correspond to 155 and 230 dpa respectively. Twenty percent reduction by cold-rolling reduces the ion produced swelling by 35% at 625°C and by 50% at 575°C.     

Der Einfluß der Silikatphase auf die Eigenschaften von Eisenerzsintern

Schrifttumsübersicht. Herstellung synthetischer Olivine. Ermittlung des kristallchemischen Aufbaues. Thermo-Differentialanalyse. Eigenschaften der synthetischen Kalziumolivine. Auftreten von Kalziumolivinen in Sintern. Einfluß der Silikatphase auf die Sintereigenschaften.     

Der Einfluß von Bariumoxid auf die Zähigkeit von Hochofenschlacken

Messung der Zähigkeit der Hochofenschlacken mit einem Massengehalt von 0 bis 14% BaO. Änderung der Aktivierungsenergie des viskosen Fließens mit steigendem Anteil an Bariumoxid. Veränderungen der Schlackenstruktur sowie Entmischungen und Abweichungen der chemischen Zusammensetzung in Mikrobereichen bei Erhöhung der Bariumoxidgehalte.     

Modelling and effective modification of smooth boundary geometry in boundary problems using B-spline curves

To create curves in computer graphics, we use, among others, B-splines since they make it possible to effectively produce curves in a continuous way using a small number of de Boor’s control points. The properties of these curves have also been used to define and create boundary geometry in boundary problems solving using parametric integral equations system (PIES). PIES was applied for resolution 2D boundary-value problems described by Laplace’s equation. In this PIES, boundary geometry is theoretically defined in its mathematical formalism, hence the numerical solution of the PIES requires no boundary discretization (such as in BEM) and is simply reduced to the approximation of boundary functions. To solve this PIES a pseudospectral method has been proposed and the results obtained were compared with both exact and numerical solutions.     

A self-organizing fuzzy logic based protective relay-an applicationto power transformer protection

In the paper the fuzzy logic based multi-criteria protective relay for a three-phase power transformer is presented. Twelve criteria used to stabilize the relay are introduced and integrated by means of multi-objective decision-making methods. The introduced protection scheme contains several internal functions and coefficients which are subject to off-line pre-installation self-setting. Three unique procedures are delivered for self-adjusting the relay, and thus, making it self-organized. The results of testing show significant gains in both sensitivity and selectivity of the self-organized relay compared with traditional approaches     

Safety aspects in modelling and operating of batch and semibatch stirred tank chemical reactors

Safety aspects in modelling of batch and semibatch stirred tank reactors as well as a model based safety analysis have been considered. Applicability of two basic types of models – i.e. the perfectly mixed reactor model and the CFD model, both formulated for laboratory scale as well as pilot plant scale reactors – has been discussed. A formulation of the appropriate reactor model, which is adequate to the considered case study has been demonstrated and tested experimentally. Particular attention has been devoted to the formulation of robust CFD models employed to simulate a performance of the stirred tank reactors. It has been found that models for perfectly mixed reactors may have quite wide range of application, while the CFD models should be definitely used in case of fast reactions, high viscosity of the reacting mixture as well as of failure leading to stopping of the impeller. The CFD models are able to predict a dynamic behaviour of reactors at any circumstances, so they can play a significant role in safety analysis carried out for industrial scale reactors, for which experimental safety tests are expensive and dangerous.     

Two new measuring algorithms for generator and transformer relaying

This paper presents new digital measuring algorithms for generator and transformer protection. Two methods are proposed to make the estimation of amplitudes of the fundamental frequency component and the higher harmonics immune to frequency deviations. The first method is based on the software re-sampling of the physical data window and on the simultaneous iterative estimation of the frequency. The second algorithm employs the amplitude estimator having unique frequency response in the entire frequency spectrum and enables direct compensation for the frequency deviations. Also a new Volts/Hertz inverse-time algorithm is proposed which does not call for the direct measure of frequency. It relies on the second method and uses the amplitude estimator having the gain close to the inverse of the frequency; therefore, it acts as a direct amplitude-to-frequency estimator. The proposed algorithms were analyzed analytically and tested using EMTP simulations     

Influence of technological parameters on the epoxidation of 1‐butene‐3‐ol over titanium silicalite TS‐2 catalyst

BACKGROUND: The influence of technological parameters on the epoxidation of 1‐butene‐3‐ol (1B3O) over titanium silicalite TS‐2 catalyst has been investigated. Epoxidations were carried out using 30%(w/w) hydrogen peroxide at atmospheric pressure. The major product from the epoxidation of B3O was 1,2‐epoxybutane‐3‐ol, with many potential applications. RESULTS: The influence of temperature (20–60 °C), 1B3O/H₂O₂ molar ratio (1:1–5:1), methanol concentration (5–90%(w/w)), TS‐2 catalyst concentration (0.1–6.0%(w/w)) and reaction time (0.5–5.0 h) have been studied. CONCLUSION: The epoxidation process is most effective if conducted at a temperature of 20 °C, 1B3O/H₂O₂ molar ratio 1:1, methanol concentration (used as the solvent) 80%(w/w), catalyst concentration 5%(w/w) and reaction time 5 h. Copyright © 2009 Society of Chemical Industry