OPTIMAL SYNTHESIS OF A MANIPULATOR USING TWO COMPETITIVE METHODS

This paper defines a program realization for finding the optimal geometry of a planar Z-mechanism. The paper shows the mathematical procedure for defining the objective function, the constraint function and the search fields which are used for solving the optimization problem. Starting from the solutions in practice, a numerical example is given to determine an optimum design with four optimization parameters. All the optimization parameters are geometric on the mechanism for defining the bucket position. The problem is solved by two different numerical methods - the method of formal search of hyperspace (passive scanning method) and the approximate method of Sequential Quadratic Programming - SQP (applying the function fminmax of the Matlab optimization toolbox). The verification is performed with animation using software for geometric modeling. The results are graphically illustrated

Zeolites as possible biofortifiers in maitake cultivation

The levels of Ni, Cu and Mg in Grifola frondosa (also known as Maitake mushroom) fruit body produced on zeolite Minazel Plus (MG)-supplemented substrate were measured with inductively coupled plasma optical emission spectrometry (ICP-OES). Two different concentrations of MG were added to the substrate for mushroom cultivation. Levels of selected metals were measured in cultivated dry carpophores. The content of Ni increased in fruit bodies produced on supplemented substrate, while in case of Cu, a pronounced decrease was observed. When two different concentrations of MG were implemented, the Mg level showed both positive and negative trend, depending on the applied concentration of zeolite. MG in a concentration of 1% showed the strongest influence on the observed elements in the cultivated fruiting body of Maitake mushroom

Theoretical and experimental analysis of dynamic processes of pipe branch for supply water to the Pelton turbine

The paper presents the results of the analysis of pipe branch A6 to feed the Hydropower Plant ”Perućica” with integrated action Pelton turbines. The analysis was conducted experimentally (tensometric) and numerically. The basis of the experimental research is the numerical finite element analysis of pipe branch A6 in pipeline C3. Pipe branch research was conducted in order to set the experiment and to determine extreme stress states. The analysis was used to perform the determination of the stress state of a geometrically complex assembly. This was done in detail as it had never been done before, even in the design phase. The actual states of the body pipe branch were established, along with the possible occurrence of water hammer accompanied by the appearance of hydraulic oscillation. This provides better energetic efficiency of the turbine devices. [Projekat Ministarstva nauke Republike Srbije, br. TR35049 and br. TR 33040

POOR QUALITY OF PRODUCT DESIGN AS A CAUSE OF OCCUPATIONAL HEALTH HAZARDS: A CASE STUDY

Quality of product design, which is expected from manufacturers on world market these days, could be provided exclusively by integral approach to product design. Such approach aims to achievement of optimal design solution of product, which is in line with a number of requirements, conditions and limitations of functionality, technology, market and usage. Only those manufacturers who are able to provide such approach to product design have prospective on market. This paper deals with a case study of neglect of integral approach to product design and its consequencies, in order to spread awareness of necessity of its adoption. Scope of this case study is focused on bridge crane whose working vibrations are meant to be potential cause of occupational desease of spinal column of crane operator

Degradacija različitih koncentracija MTBE-a pomoću Mucor hiemalis

In the last twenty years there has been increased usage of metil tertiary butil eter (MTBE) which led to it's high presence in the environment. Environmental Protection Agency (EPA) has characterized MTBE as potentially cancerogenic substance and proposed the methods for it's removal from natural sources. Bioremediation represents the world trend in developing remediation technologies, and is a complex process which assumes using different microorganisms. The etheric bond in MTBE's molecule is persistent in the environment. Still, microorganisms are capable for using this organic compaund as carbon and energy source due to their various enzyme systems and transform it into non toxic products. The objective of this research is investigation of biodegradability of various concentrations of MTBE (76, 100 438 and 746 ppm) by Mucor hiemalis 139ž. This strain has been isolated from the soil of NIS Oil Raffinery Pančevo, contaminated with organic pollutants. The degradation process was observed during 8 days of incubation in aerobic conditions. The MTBE’s degradation was detected by gas chromatography with flame ionizing detector (GC/FID). After 12 hours of incubation the concentration of MTBE was reduced. The MTBE’s reduction ranging form 47 to 76% from the initial concentration was detected after 8 days. The degradation level depended on the starting concentration of MTBE. These results indicate the possibility for using the authentic strain Mucor hiemalis in the bioremediation processes of soils and waters, as ecologically, economically and energetically sustainable remediation methods.Poslednjih 20 godina intenzivna upotreba metil tercijarnog butil etra (MTBE) dovela je do povećanja njegovog prisustva u čovekovoj sredini. Agencija za zaštitu čovekove sredine (EPA) okarakterisala je MTBE kao potencijalno kancerogeno jedinjenje i predložila metode za njegovo uklanjanje iz prirodnih sredina. Bioremedijacija predstavlja svetski trend u razvoju tehnologija remedijacije i sastoji se od kompleksa procesa koji podrazumevaju korišćenje različitih vrsta mikroorganizama. Mikroorganizmi su, zahvaljujući svojim fermentnim sistemima, sposobni da koriste različita organska jedinjenja kao jedinstven izvor ugljenika i energije i transformišu ih do netoksičnih produkata. Cilj rada bio je ispitivanje degradacije različitih koncentracija MTBE-a (76, 100, 438 i 746 ppm) pomoću Mucor hiemalis 139ž. Ovaj izolat izolovan je iz zemljišta NIS Rafinerije nafte Pančevo, kontaminiranog organskim zagađivačima. Proces degradacije praćen je u toku 8 dana inkubacije pri aerobnim uslovima. Degradacija MTBE-a praćena je pomoću gasnog hromatografa sa plamen jonizujućim detektorom (GC/FID). Posle 12 sati inkubacije došlo je do smanjenja koncentracije MTBE-a. Stepen degradacije MTBE-a posle 8 dana se kretao u intervalu od 47-76% od početne koncentracije. Stepen degradacije zavisio je od početne koncentracije MTBE-a. Ovi rezultati ukazuju na mogućnost primene autohtonog izolata Mucor hiemalis 139ž u procesima bioremedijacije zemljišta i voda, kao ekološki, ekonomski i energetski prihvatljiv metod remedijacije