The synthesis of N-derivatives of 3-aminoperylene and their absorption and fluorescence properties

N-Acetyl and N-triazinyl 3-aminoperylenes were prepared. N-(4,6-Dichloro-1,3,5-triazin-2-yl)-3-aminoperylene was synthesized by the condensation of 3-aminoperylene with cyanuric chloride; other N-triazinyl derivatives were prepared by the successive substitution of chlorine atoms with methoxy or aniline groups. The structure and purity of the compounds were confirmed by elemental analysis, NMR spectroscopy and mass spectrometry. The UV/vis absorption, fluorescence and excitation spectra as well as the fluorescence quantum yields for the compounds were measured in dibutyl ether, 1,4-dioxane, ethyl acetate and acetonitrile; fluorescence lifetimes were measured in ethyl acetate and dimethyl sulfoxide. The influences of both the character of the N-substituent and the solvent polarity upon the spectra and quantum yields are discussed.     

Dependence of Strehl ratio on f-number of optical system

Formulas for a minimum of wave aberration variance and a maximum of the Strehl ratio in the optimal image point are derived using the third- and fifth-order aberration theory. Moreover, relations for the calculation of the optimal value of f-number of the optical system were derived, which enabled us to theoretically analyze real optical systems and their image quality. The optimal f-number corresponds to such a value of f-number when the image quality of a real optical system is comparable to an aberration-free optical system. This value may also serve as an auxiliary criterion of the image quality of the optical system, for example, in photography.     

An AHP-based decision-making tool for the solution of multiproduct batch plant design problem under imprecise demand

This paper addresses the problem of the optimal design of batch plants with imprecise demands in product amounts. The design of such plants necessarily involves the way that equipment may be utilized, which means that plant scheduling and production must form an integral part of the design problem. This work relies on a previous study, which proposed an alternative treatment of the imprecision (demands) by introducing fuzzy concepts, embedded in a multi-objective Genetic Algorithm (GA) that takes into account simultaneously maximization of the net present value (NPV) and two other performance criteria, i.e. the production delay/advance and a flexibility criterion. The results showed that an additional interpretation step might be necessary to help the managers choosing among the non-dominated solutions provided by the GA. The analytic hierarchy process (AHP) is a strategy commonly used in Operations Research for the solution of this kind of multicriteria decision problems, allowing the apprehension of manager subjective judgments. The major aim of this study is thus to propose a software integrating the AHP theory for the analysis of the GA Pareto-optimal solutions, as an alternative decision-support tool for the batch plant design problem solution.     

Zein-Based Films Containing Monolaurin/Eugenol or Essential Oils with Potential for Bioactive Packaging Application

Zein is renewable plant protein with valuable film-forming properties that can be used as a packaging material. It is known that the addition of natural cross-linkers can enhance a film’s tensile properties. In this study, we aimed to prepare antimicrobial zein-based films enriched with monolaurin, eugenol, oregano, and thyme essential oil. Films were prepared using the solvent casting technique from ethanol solution. Their physicochemical properties were investigated using structural, morphological, and thermal techniques. Polar and dispersive components were analyzed using two models to evaluate the effects on the surface free energy values. The antimicrobial activity was proven using a disk diffusion method and the suppression of bacterial growth was confirmed via a growth kinetics study with the Gompertz function. The films’ morphological characteristics led to systems with uniform distribution of essential oils or eugenol droplets combined with a flat-plated structure of monolaurin. A unique combination of polyphenolic eugenol and amphiphilic monoglyceride provided highly stretchable films with enhanced barrier properties and efficiency against Gram-positive and Gram-negative bacteria, yeasts, and molds. The prepared zein-based films with tunable surface properties represent an alternative to non-renewable resources with a potential application as active packaging materials.     

Compatibilized iPP/aPS blends: The effect of the viscosity ratio of the components on the blends morphology

More than 25 PP/PS/SEP blends, where PP is isotactic polypropylene, PS is atactic polystyrene, and SEP is poly(styrene‐block‐ethylene‐co‐propylene), were prepared. The main objective of this study was to investigate the influence of PP/PS viscosity ratio, λ_TM, on the blends' morphology. It was shown that λ_TM strongly influenced not only the overall morphology of the blends, but also the morphology of SEP, which exhibited as many as five different types of structure when blended with PP and/or PS. SEP was found an efficient compatibilizer of PP/PS blends as it decreased the average particle size in all studied systems. An interesting “by‐product” of this work was the discovery of a brand‐new type of polymer morphology, which was called morel structure. The characteristic feature of the morel structure was PS matrix compartmentalized by SEP. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 101: 2236–2249, 2006     

The synthesis of bi- and trichromophoric dyes bearing an s-triazinyl ring spacer

An alternative procedure has been described for the syntheses of several bi- and trichromophoric compounds consisting of 1-aminopyrene and 3-aminobenzanthrone chromophoric subsystems connected by an s-triazinyl ring spacer. The synthetic method used, which utilises an autoclave under autogenous pressure, is suitable for the nucleophilic substitution of both chlorine atoms within the triazinyl ring by weakly basic aromatic amines. The structures of the synthesized compounds were confirmed using elemental analysis, ¹H NMR, and mass spectra. UV/vis absorption and fluorescence spectra and fluorescence quantum yields were measured. The dependence of fluorescence intensity and fluorescence quantum yields on solvent polarity was investigated.     

Influence of total reflection on the imaging quality of optical systems

In the case of total reflection at a boundary surface between two different optical media, the ray reflected at the boundary is spatially shifted with respect to the point where the incident ray intersects the boundary. The light penetrates into the second medium, and the evanescent electromagnetic wave propagates along the boundary. The described effect is called the Goos-H?nchen effect. Our work describes the influence of the Goos-H?nchen effect on the imaging properties of planar optical systems, and a differential equation of a wave-front meridian that corresponds to a reflected bundle of rays is derived. It is shown that the wave front can be described by the d'Alambert differential equation. This equation makes it possible to determine the coordinates of individual points on the wave-front meridian. The influence of total reflection on the value of the Strehl definition of the reflected ray bundle, is also investigated.     

Electrical characterization of megabit DRAMs. 1. External testing

An approach to the electrical characterization of dynamic RAMs in which chip design and DRAM process technology are verified and optimized concurrently is reported. Both parametric and functional tests were performed. The authors describe an information and scheduling system for analysis and testing that handles the required electrical measuring data from the testers. It is shown how data analysis supports the interpretations by data correlations on a real statistical basis. The short learning cycle required by this approach was obtained by ensuring the smooth cooperation of all those involved in the overall analysis