Stochastic Fuzzy Algorithms for Impairment of Assets Management

The present paper aims to analyze the impairment of tangible assets with the help of artificial intelligence. Stochastic fuzzy numbers have been introduced with a dual purpose: on one hand to estimate the cash flows generated by tangible assets exploitation and, on the other hand, to ensure the value ranges stratifications that define these cash flows. Estimation of cash flows using stochastic fuzzy numbers was based on cash flows generated by tangible assets in previous periods of operation. Also, based on the Lagrange multipliers, were introduced: the objective function of minimizing the standard deviations from the recorded value of the cash flows generated by the tangible assets, as well as the constraints caused by the impairment of tangible assets identification according to which the cash flows values must be equal to the annual value of the invested capital. Within the determination of the impairment value and stratification of the value ranges determined by the cash flows using stochastic fuzzy numbers, the impairment of assets risk was identified. Information provided by impairment of assets but also the impairment risks, is the basis of the decision-making measures taken to mitigate the impact of accumulated impairment losses on company’s financial performance

Correlation of Geometrical Specifications for Flexible Quality Control in the Manufacturing of Plastic Products

This article presents an analysis to meet the demand for process-optimized applications in industrial plastic production. Since in an injection molding process primarily plastic products are created, which underlie a strict quality control, machine technicians thereby carry out worker operator control in order to ensure even production drawing quality. Thereby injection molding products are qualified among others via component dimensions. Due to the complex accessibility of molded part geometry, these controls underlie high and varying sensor influence. Due to technology advancement and increasingly accurate quality requirements, the demand for process-optimized quality controls is continuously growing. First, the complexity of geometrical quality control from workpieces is presented. Practical and simulative tests to determine the correlation of geometric specifications are examined by means of a variable injection molding process. Finally, the new control dimensions\u27 relevance shall be implemented via appropriate correlation evidence

Influence of Variation of Cutting Speed on Wear, Cutting Forces and Tool Temperature during Performance Drilling

The paper presents the results and the influence a single factor has in the drilling process. The research is focused on how modifying the cutting speed influences parameters like cutting forces, cutting temperature, tool life, wear mechanism, and chip formation. For this experiment three different cutting speeds have been tested on high-speed adapted twisted drill geometry, each of them corresponding to a certain cutting domain: 200 m/min, 165 m/min and 110 m/min. The temperature, predicted with finite element simulation (FEM), forces, wear evolution and the shape of chips have been analysed in order to prove if high speed adapted drill geometry can be used instead of an ordinary drill while performing at lower speeds. The tests certified the ability of a drill designed for high speed to process in conditions associated with lower cutting speeds, behaving similarly in all the cases

Catalase Immobilized on Poly(Acrylic Acid-co-Vinyl Alcohol)

The paper studies the reaction of catalase’s immobilization on a synthetic polymer (copolymer of the acrylic acid with vinyl alcohol), through amidation of enzyme’s terminal amine groups with the lateral carboxylic group of the macromolecular support, as activated by dicycloxexyl carbodiimide. The support, possessing the properties of a hydrogel, has been synthesized through copolymerization of the acrylic acid with vinyl acetate, followed by hydrolysis of the acetate groups to the hydroxylic groups. The influence of some reaction parameters (such as the activator/support and enzyme/support ratios, duration) on the efficiency of the enzyme’s coupling was studied. The coupling reactions were realized conformely to a centered, rotator, composed, second order experimental program, which permitted the establishment of the conditions necessary for obtaining a coupling product containing the highest amount of immobilized enzyme. Kinetic study of the reaction catalyzed by the coupling products has indirectly evidenced enzyme’s immobilization to the macromolecular support, and also, a sufficiently high catalytic activity of the enzymatic preparation obtained

Application of abrasive sand blasting process in micro geometrical cutting edge optimization

Cilj je ovoga članka odrediti parametre optimizacije i geometrijskih poboljšanja u mikro geometriji svrdla od tvrdog karbida primjenom postupka pjeskarenja. Treba uzeti u obzir učinke pjeskarenja na oštricu i na mikro geometriju tijela alata. Taj postupak je jedan od najuobičajenijih postupaka u izradi alata od tvrdog karbida koji se primjenjuje na različite načine, ne uvijek s najboljim rezultatima. Mikro geometrijska optimizacija oštrice usmjerena je na dva važna parametra, polumjer oštrice i K-faktora centriranja, koji su od odlučujuće važnosti za vijek trajanja alata i parametre rezanja. Ovaj se postupak optimizacije može poboljšati i kombiniranjem s drugim poznatim postupcima čiji je cilj postizanje istog rezultata.This paper aims to establish the parameters of optimization and geometrical improvements for the micro-geometry of solid carbide drills through the application of sand blasting process. The effects of sand blasting over the cutting edge and also upon the micro geometry of the tool body are to be taken into consideration. This process is one of the most common ones used in the solid carbide tool fabrication, being implemented in various ways, not always achieving the best results. The micro geometrical optimization of the cutting edge is concentrated on two important parameters, edge radius and K-factor alignment, both of these having a critical role in the tool life and over the cutting parameters. The improvement of this optimization process can also be achieved by combining it with other known processes aiming at the same result

Furazolidone Immobilized in a Hydrogel Based on Crosslinked Carboxymethyl Cellulose

The paper deals with the obtainment of a polymer-drug system with controlled release of the biological active principle, based on furazolidone included in a hydrogel obtained by crosslinking of carboxymethylcellulose with epichlorohydrine. The influence of temperature and duration of crosslinking reaction on the crosslinking degree of carboxymethylcellulose (indirectly appreciated by its swelling capacity in polar liquids as water and dimethylformamide/water mixtures) is studied. Kinetic data concerning the inclusion of furazolidone from solution, in the hydrogel of crosslinked carboxymethylcellulose, as well as the release of the drug from the obtained polymer-drug system, are performed. The obtained results evidence that the inclusion rate as well as the amount of furazolidone diffused into the support depend on the dymethylformamide/ water ratio utilized as solvent, and on the drug concentration in solution. The product obtained through the insertion of furazolidone from a DMF/water mixture = 5/1 (with a content of 8.9 mg drug/hydrogel) was studied as to the kinetics of the active principle’s release, in vitro, by using as an eluent a buffer solution, which simulates the gastric fluid (pH = 2.4). The experimental results prove the obtention of a polymerdrug system with controlled release of the biologically active principle, conform to a zero order kinetic, in the time interval ranging between 3 – 12 hours

Magnetite Nanoparticles for Composite Coatings with Patterned Roughness

Extended Abstract Wettability control on solid surfaces is currently intensely studied due to its importance in many fields, such as self-cleaning coatings for solar energy panels, satellite dishes, automobile windshields, icerepellant and anti-corrosion surface treatments for aircrafts, high performance materials for biomedical applications, to mention just a few. The strategies for engineering synthetic coatings with water/ice repellant properties have been inspired by naturally occurring superhydrophobic materials and involve an optimum combination of hierarchical surface roughness and low surface tension, as concluded in recent comprehensive reviews This study aims to develop a method to prepare iron oxide nanoparticles that are capable of mutual magnetic interaction during the curing stage of a polymeric support to create micro-scale surface protuberances in a controlled manner. Materials and Methods The Fe 3 O 4 particles were obtained by partial oxidation of ferrous ions in alkaline solution and were characterized by transmission electron microscopy (TEM), X-ray diffraction (XRD) and magnetization measurement. They were subsequently functionalized in aqueous suspension using either sodium oleate or mixtures of non-ionic surfactants (Span80 and Tween80) with various hydrophilic to lipophilic balance (HLB) values. Chitosan was used as a model film-forming polymeric support. Functionalized particles were suspended in acidic chitosan solution. The obtained nanoparticle-polymer dispersions were deposited by spraying on glass slides and subsequently cured by drying under a static magnetic field (strength range 3 to 6 mT) generated with the aid of an electromagnet, to yield composite films. Results The Fe 3 O 4 particles obtained by the optimum procedure had a mean size of 14 nm as estimated from the TEM micrographs, an XRD pattern that is characteristic to highly crystalline magnetite and a saturation magnetization of 88.3 emu/g that is close to the theoretical value. Magnetic field generated surface roughness was evidenced in the composite films by optical and scanning electron microscopy. The film morphology varies depending on the surfactant nature and the strength of the applied magnetic field. The rate of the particle movement in the curing stage and therefore their aggregation degree is a result of the equilibrium between the aligning effect of the magnetic field and the drag force acting upon them. The optimum texture was produced with the sodium oleate functionalized nanoparticles, assembled in chain-like structures, thus forming ordered protuberances within the polymeric film

Study of Immobilization by Esteric Bond of 2-(m-Nitrophenyl)-4-(ОІ- Carboxymethyl)-О”2-Oxazolinone-5 on Gellan

The paper studies the coupling reaction, through ester-type covalent bonds, of an oxazolone derived from the N-(m-nitrobenzoyl)-L-asparagic acid, on gellan (a polysaccharide of microbian synthesis), in conditions of activation with dicyclohexyl carbodiimide. Based on a centered, rotatory, composed, second order experimental program, the regression equation describing the dependence of the amount of active principle, chemically bounded to the support, on the reaction’s  parameters (support/active principle ratio, active principle/activator ratio, duration) is obtained. One may observe that the efficiency of the coupling reaction is maximum when employing the parameters’ highest values, over the variation domain established. The coupling product has been characterized through elemental analysis and IR spectroscopy. For the establishment  of the capacity of the active principle’s controlled release by the polymer-active principle system thus obtained, drug’s release kinetics from the polysaccharidic support is studied in conditions of basic hydrolysis. The oxazolone release from the coupling products, by basic hydrolysis proceeds conformely to a zero order kinetics, proving their retard activity

Indolizines and pyrrolo[1,2- c ]pyrimidines decorated with a pyrimidine and a pyridine unit respectively

The three possible structural isomers of 4-(pyridyl)pyrimidine were employed for the synthesis of new pyrrolo[1,2-c]pyrimidines and new indolizines, by 1,3-dipolar cycloaddition reaction of their corresponding N-ylides generated in situ from their corresponding cycloimmonium bromides. In the case of 4-(3-pyridyl)pyrimidine and 4-(4-pyridyl)pyrimidine the quaternization reactions occur as expected at the pyridine nitrogen atom leading to pyridinium bromides and consequently to new indolizines via the corresponding pyridinium N-ylides. However, in the case of 4-(2-pyridyl)pyrimidine the steric hindrance directs the reaction to the pyrimidinium N-ylides and, subsequently, to the formation of the pyrrolo[1,2-c]pyrimidines. The new pyrrolo[1,2-c]pyrimidines and the new indolizines were structurally characterized through NMR spectroscopy. The X-ray structures of two of the starting materials, 4-(2-pyridyl)pyrimidine and 4-(4-pyridyl)pyrimidine, are also reported