Cylindrical Fibre Orientation Analysis by Light Scattering. Part 2: Experimental Aspects

An experimental set-up has been designed to record maps of intensity distribution for two orthogonal polarizations allowing the retrieval of average information along the optical path. A wide variety of the signatures of different samples is given to characterize the spatial orientation of a cloud of infinite cylinders by using a light scattering method. The information contained in the images is discussed and compared with numerical predictions.     

Deactivation of the S2 and Two Lowest Triplet States of 4H-1-Benzopyran-4-thione and Its Alkyl Derivatives in Methanol Solution

Spectral and photochemical properties of three aromatic thioketones, 4H-1-benzopyran-4-thione and its two alkyl derivatives, in their second excited singlet and two lowest triplet states have been a subject of stationary and time-resolved studies. Quantum yields of emissions from the above-mentioned states as well as lifetimes of these states have been measured. The results indicate an important role of intermolecular solvent-induced processes in deactivation of the excited states of the thioketones studied. The possible mechanism of these processes involves hydrogen atom abstraction and/or formation of exciplex. For relatively high thione concentrations, the contribution of self-quenching in deactivation of the triplet states becomes significant. The effect of the alkyl chain in a thione molecule on deactivation parameters is discussed.     

On the rate allocation problem under co-existence of uncertain utility function parameters and uncertain link capacities

The allocation problem is considered for a computer communication network with network links being shared among multiple transmissions running at the same time. Typically, each transmission brings benefit to a network owner proportional to the transmission rate allowed. Since the link capacities are limited and the minimal rates defined by Quality of Service (QoS) requirements have to be preserved, the rate allocation problem is defined here as a problem of maximizing the overall benefit (utility) under capacity and QoS constraints. In this paper, we consider the uncertain version of the problem, in which unknown utility function parameters and unknown link capacities are treated as uncertain variables characterized by certainty distributions. We present a method for solving the problem in a unified way, with both uncertainties combined in a single certainty index.     

On Generalized Carathéodory's Conditions in Ordinary Differential Equations

In this paper we prove that generalized Carathéodory's conditions (so called (G) conditions) imply well - known general conditions which guarantee existence and some properties of solutions of the Cauchy problem, in the Carathéodory sense, as e.g. continuous dependence on initial conditions.     

D-optimal design of a monitoring network for parameter estimation of distributed systems

This paper addresses the design of a network of observation locations in a spatial domain that will be used to estimate unknown parameters of a distributed parameter system. We consider a setting where we are given a finite number of possible sites at which to locate a sensor, but cost constraints allow only some proper subset of them to be selected. We formulate this problem as the selection of the gauged sites so as to maximize the log-determinant of the Fisher information matrix associated with the estimated parameters. The search for the optimal solution is performed using the branch-and-bound method in which an extremely simple and efficient technique is employed to produce an upper bound to the maximum objective function. Its idea consists in solving a relaxed problem through the application of a simplicial decomposition algorithm in which the restricted master problem is solved using a multiplicative algorithm for optimal design. The use of the proposed approach is illustrated by a numerical example involving sensor selection for a two-dimensional convective diffusion process.     

Effect of the Addition of Dried Dandelion Roots (Taraxacum officinale F. H. Wigg.) on Wheat Dough and Bread Properties

Dried and crushed dandelion roots (Taraxacum officinale F. H. Wigg.) (TO) were used as a formulation additive (at the amount of 0, 1, 3, 4, 5, and 6 g 100 g⁻¹ flour) to wheat bread. The farinographic properties of the dough and the physical and chemical properties of the bread were evaluated. It was found that the addition of dried flour caused a significant decrease in water absorption by the flour (1% and higher TO level), an increase in the development time (from 2% to 5% TO addition) and dough stability (3% and 4% TO level), and an increase in dough softening (4% and higher TO level). As the substitution of TO for wheat flour increased, there was a gradual decrease in loaf volume, an increase in specific weight and crumb hardness, and a darkening of the crumb color. The total polyphenol content increased linearly with the percentage increase of dried root additions TO from 0.290 to 0.394 mg GAE g⁻¹ d.m_., which translated into an increase in the antioxidant activity of the bread. It was found that dried crushed roots of Taraxacum officinale can be a recipe additive for wheat bread; however, due to their specific smell and bitter aftertaste, the level of this additive should not exceed 3 g 100 g⁻¹ flour.     

Novel Silsesquioxane-Derived Boronate Esters—Synthesis and Thermal Properties

The functionalization of mono- and octahydrospherosilicate with vinylboranes and allylboranes via hydrosilylation reaction in the presence of a Karstedt’s platinum (0) catalyst is presented. This is the catalytic route to obtain a new class of silsesquioxanes containing boron atoms in their structure in high yields (>90%) and with satisfactory selectivity. The obtained compounds were fully characterized by spectroscopic (¹H, ¹³C, ²⁹Si NMR) and spectrometric methods (MALDI-TOF-MS), as well as thermal analysis (TGA). The obtained compounds were subjected to thermal tests, characterizing the processes of melting, thermal evaporation, sublimation and thermal decomposition.