Current-voltage characteristics of carbon nanotube FETS

U ovom radu ispitivane su karakteristike FETova izrađenih na bazi ugljeničnih nanotuba (CNT FETova). U prvom delu rada, predstavljene su neke osnovne osobine ugljeničnih nanotuba. Zatim je razvijen analitički model strujno-naponskih karakteristika CNT FETova koji dobro opisuje ponašanje ove savremene nanoelektronske naprave. Na bazi predloženog modela urađene su simulacije. Dobijeni rezultati su u saglasnosti sa prethodno publikovanim. .In this paper, one of the most actual devices - carbon nanotube field effect transistor (CNT FET) is investigated. At the beginning, the nanotube properties are presented. The main contribution of this paper is the new analytical model of CNT FET current-voltage characteristics. Developed model describes behavior of CNT FET in very good manner and, at the same time, the model is relatively simple. Using the developed model, simulations were performed. The results obtained by using proposed model are in very good agreement with already known and published ones.

Modelling of Continuous L-Malic Acid Production by Porcine Heart Fumarase and Fumarase in Yeast Cells

Continuous production of L-malic acid will be presented in this paper. The fumarase isolated from porcine heart, fumarase in the permeabilized non-growing cells of baker’s yeast and Saccharomyces bayanus (UVAFERM BC) were used as biocatalysts. In the production of L-malic acid with fumarase isolated from porcine hearts, there was no enzyme deactivation for a period of two days.At the average residence time of 4 hours, the conversion of about 80 % was achieved.Inactivation of the enzyme was observed using permeabilized cells.Thi s inactivation is described as a reversible process.C onversion of about 50 % was achieved with the remaining enzyme activity.A mathematical model that describes the production of L-malic acid, which contains the enzyme inactivation rate, was developed. Based on simulations, the used biocatalysts were compared. The results show that in the continuous production of L-malic acid, one milligram of purified enzyme corresponds to 68 g (wet weight) cells of Saccharomyces bayanus or 120 g (wet weight) cells of baker’s yeast

Current-voltage characteristics of carbon nanotube FETS

U ovom radu ispitivane su karakteristike FETova izrađenih na bazi ugljeničnih nanotuba (CNT FETova). U prvom delu rada, predstavljene su neke osnovne osobine ugljeničnih nanotuba. Zatim je razvijen analitički model strujno-naponskih karakteristika CNT FETova koji dobro opisuje ponašanje ove savremene nanoelektronske naprave. Na bazi predloženog modela urađene su simulacije. Dobijeni rezultati su u saglasnosti sa prethodno publikovanim. .In this paper, one of the most actual devices - carbon nanotube field effect transistor (CNT FET) is investigated. At the beginning, the nanotube properties are presented. The main contribution of this paper is the new analytical model of CNT FET current-voltage characteristics. Developed model describes behavior of CNT FET in very good manner and, at the same time, the model is relatively simple. Using the developed model, simulations were performed. The results obtained by using proposed model are in very good agreement with already known and published ones.

Retrobulbar chondrosarcoma in a dog

This paper presents a review of a dog, with a retrobulbar chondrosarcoma, which was admitted for surgery for visible changes in his eye during inspection. Orbital neoplasia in dogs may be primary and secondary. Sixty percent of orbital neoplasia in dogs are primary, ninety percent of which are malignant. Retrobulbar neoplasms are rare and in their early stage represent a diagnostic challenge. Chondrosarcoma of the skull is a slow-progressing malignant disease which occurs locally, aggressive with invasion into the surrounding tissues. Dogs with chondrosarcoma of the skull have life expectancy between 210 and 580 days - in our case it was 180 days - after the first alterations on the eye of the dog occurred

Optimizacija i fotokatalitička primena nanostrukturnog TiO2

The aim of this doctoral dissertation is chemical synthesis of titania based catalyst in forms of thin film and powder. Catalysts in the form of a thin film were prepared by the dip coating technique using an evaporation-induced, self-assembly method (EISA), with the use of selected polymers as a template (Pluronic F127 and PSM02). Titania based catalysts in powder form were prepared by modified sol-gel method. Catalysts were then modified with a selected dopant (ZrO2). The effects of various process parameters during the synthesis process of the catalysts were studied such as: pH value, calcination temperature etc. In addition, a number of key parameters in the preparation of TiO2 in the form of thin film as well as the (gas) atmosphere for the activation of the catalyst were also considered. Q4.16.01 - Izdawe 1 A complete physico-chemical characterization of photocatalysts (investigation of textural, structural, morphological, thermal, surface properties of the catalysts) was performed. The catalysts were tested in the reactions of the photocatalytic degradation and/or conversion of selected dyes (methylene blue and crystal violet) and the degradation and/or conversion of the selected pesticide (2,4- dichlorophenoxyacetic acid). Various process parameters were investigated such as: the impact of the initial concentrations of pollutants, the number of repeated cycles of reaction, the catalyst amounts, the wavelength of radiation, duration of UV irradiation treatment, pH of the tested solution in order to optimize the process parameters. In addition, the antimicrobial activity, against selected bacterial species, of the synthesized TiO2-based materials in the form of powder and thin film was investigated. The obtained results were discussed in order to determine the optimum process parameters of the photocatalytic reactions, and to achieve a more favorable degradation effect or conversion of pollutants. Physico-chemical characteristics of the obtained catalyst materials have been associated (correlated) with photocatalytic efficiency/activity. Optimisation refers to the complete design and synthesis of (different) titania based catalysts, followed by physico-chemical properties of the catalysts and numerous process parameters of the photocatalytic process in the application of heterogeneous catalysts

Relokacija resursa u drumskom saobraćaju zasnovana na upotrebi podataka iz GPS baziranih sistema za praćenje pokretnih objekata

In this thesis it is shown that the data hidden in the history of the vehicles movement in the road traffic, which are recorded in a database as a part of a vehicles tracking system (based on the GPS-system), can be an excellent starting point in the process of location-based optimization problem solving. In addition to the overall system description and substantial theoretical considerations, the new practice is implemented and introduced into service according to the needs and demands of the Emergency medical service in Niš. In the comprehensive vehicles tracking system, a program module dedicated to the resolving of the classical problem of resource allocation and relocation in road traffic, is fitted in an innovative way. The optimization algorithm to solve the well-known p-median problem has been designed and several aspects of the practical implementation are analyzed. The influence of the different scale of input data and the impact of the use of different types of the distances between locations (Euclidian, routed or time distances) are considered. The performances of the proposed algorithm were compared with the performances of the algorithms described in similar projects

X-ray computed micro tomography as complementary method for the characterization of activated porous ceramic preforms

X-ray computed micro tomography (CT) is an alternative technique to the classical methods such as mercury intrusion (MIP) and gas pycnometry (HP) to obtain the porosity, pore-size distribution, and density of porous materials. Besides the advantage of being a nondestructive method, it gives not only bulk properties, but also spatially resolved information. In the present work, uniaxially pressed porous alumina performs activated by titanium were analyzed with both the classical techniques and CT. The benefits and disadvantages of the applied measurement techniques were pointed out and discussed. With the generated data, development was proposed for an infiltration model under ideal conditions for the production of metal matrix composites (MMC) by pressureless melt infiltration of porous ceramic preforms. Therefore, the reliability of the results, received from different investigation techniques, was proved statistically and stereologicall

Characterization and utilization of the permeate and retentate obtained after “dead-end” ultrafiltration

In the recent years, with the increase in bioethanol production, the increasing amounts of distillery wastewater are generated. Such wastewater (stillage) is one of the most polluted waste product of the food and beverage industries. The present study evaluates the treatment of distillery wastewater by ultrafiltration (UF), in order to reduce its pollution and evaluate the composition of the permeate and retentate. Polyethersulfone ultrafiltration membrane with molecular weight cut-off (MWCO) 30000 Da, was used for the experiments. The UF was carried out in dead-end mode. The results of the analyses of the permeate and retentate obtained after ultrafiltration were considered as well as different ways for their further utilization. The pollutant level in the permeate was decreased significantly in comparison to the raw stillage, and suspended solids were completely removed from the stillage. [Projekat Ministarstva nauke Republike Srbije, br. TR 31002