Methodology to Estimate Volume-Capacity Ratios at Traffic Signals Based on Upstream-Link Travel Times

So, Jaehyun (Jason),Stevanovic, Aleksandar,Ostojic, Marija American Society of Civil Engineers 2017 Journal of transportation engineering.Part A.Syste Vol.143 No.4

<P>This study utilizes travel time data from a well-equipped Intelligent Transportation System corridor to integrate travel time and traffic signal data with the goal of developing a volume-delay relationship between a signal's volume-capacity ratio and travel time. Specifically, the traffic signal timings were retrieved from an advanced transportation management system, individual travel time data were extracted from a WiFi-based travel time measurement system, and traffic volumes and queues were obtained by observing closed-circuit television video recordings. The collected data were then integrated on a cycle-by-cycle basis by using a C#-automated data postprocessing interface. Several traditional volume-delay functions were calibrated to fit the field data. Also, a new volume-delay function, named So-Stevanovic Volume-Delay Function, was developed to account for exponential behavior of travel time near and beyond the traffic saturation point. The So-Stevanovic Volume-Delay Function satisfied the seven Spiess's requirements for a well-behaved congestion function and produced slightly better results than the best traditional volume-delay function. All of the functions were then tested again on a different road segment in order to validate the results. These tests confirmed the previous findings that the So-Stevanovic Volume-Delay Function was the best predictor of relationship between volume-capacity ratio and link travel time. Further research should be conducted to validate this function in a variety of field traffic conditions. (C) 2017 American Society of Civil Engineers.</P>

데이터 분석기법이 ITS 효과평가 결과(사전사후분석)에 미치는 영향에 대한 연구

소재현,Aleksandar Stevanovic,Kameron Kergaye,위정란 한국ITS학회 2018 한국ITS학회 학술대회 Vol.2018 No.04

Pumped-Hydro Storages are Balancing Electric Energy Production of Wind and Solar Reducing Average Costs and Pollution

Aleksandar Gajic,Vladimir Stevanovic,Stan Pejovic 한국유체기계학회 2019 International journal of fluid machinery and syste Vol.12 No.1

The new world energy policy is influenced by climate changes, narrow range of operation of Thermal Power Plants, potential risks of Nuclear Power Plants and limited resources of oil, gas and coal. Taking into account that renewable energy, solar and wind power particularly are very dependent on the climate, Hydro Power takes a new role in energy systems. Electricity conversion and storage in periods of lower consumption and electricity production from the stored energy in periods of higher demand or reduced production, are crucial for the maintenance of stable and efficient electrical system. This requirement has especially strengthened nowadays due to the expansion of integration of new wind and solar plants. These renewable sources are characterized with inherent intermittent production both in daily periods and periods of several days, weeks or even months. A number of technologies might be considered for the electricity conversion and storage, but the only nature and high capacity available technology is based on the pumped storage plants. This article studies the potential of the pumped storage plants as the effective and economically competitive technology for the storage of wind, solar, run-of-river and other environmentally friendly energies. Nuclear and coal fired plants can change power output to achieve demand but only at the price of extremely high maintenance cost. In addition, natural gas generators contribute to climate change and pollution only slightly less than coal. The pumped storage method is the most common storage system in the electricity sector. It is traditionally dependent on natural conditions, usually making use of rivers or lakes. However, some innovative methods such as the use of the sea as the lower reservoir, or a proposal to use a surface reservoir as the upper reservoir and an underground reservoir as the lower have emerged. Analyses indicate that there is a strong economic incentive for further investment in pumped-storage installations when other hydro storages and sites are not available.

Agmatine protection against chlorpromazine-induced forebrain cortex injury in rats

Bratislav Dejanovic,Ivana Stevanovic,Milica Ninkovic,Ivana Stojanovic,Irena Lavrnja,Tatjana Radicevic,Milos Pavlovic 대한수의학회 2016 Journal of Veterinary Science Vol.17 No.1

This study was conducted to investigate whether agmatine (AGM) provides protection against oxidative stress induced by treatment with chlorpromazine (CPZ) in Wistar rats. In addition, the role of reactive oxygen species and efficiency of antioxidant protection in the brain homogenates of forebrain cortexes prepared 48 h after treatment were investigated. Chlorpromazine was applied intraperitoneally (i.p.) in single dose of 38.7 mg/kg body weight (BW) The second group was treated with both CPZ and AGM (75 mg/kg BW). The control group was treated with 0.9% saline solution in the same manner. All tested compounds were administered i.p. in a single dose. Rats were sacrificed by decapitation 48 h after treatment Treatment with AGM significantly attenuated the oxidative stress parameters and restored antioxidant capacity in the forebrain cortex. The data indicated that i.p. administered AGM exerted antioxidant action in CPZ-treated animals. Moreover, reactive astrocytes and microglia may contribute to secondary nerve-cell damage and participate in the balance of destructive vs. protective actions involved in the pathogenesis after poisoning.

Early growth response protein 1 acts as an activator of SOX18 promoter

Isidora Petrovic,Natasa Kovacevic-Grujicic,Milena Stevanovic 생화학분자생물학회 2010 Experimental and molecular medicine Vol.42 No.2

Sex-determining region Y box 18 (Sox18/SOX18) gene is an important regulator of vascular development playing a role in endothelial cell specification or differentiation,angiogenesis and atherogenesis. The aim of this study was to perform comprehensive functional characterization of the human SOX18 promoter, including determination of transcription start point (tsp)and identification of control elements involved in the regulation of SOX18 gene expression, with an emphasis on angiogenesis-related transcription factors. Analyses were performed in HeLa cells, representing a tumor cell line, and in EA.hy926 cells used as an endothelial model system. We have determined unique tsp of SOX18 gene, located 172 nucleotides upstream from ATG codon. Further, we have shown that SOX18 promoter region, -726 to -89 bp relative to tsp, contains positive cis-regulatory element(s) that stimulates SOX18 promoter activity, while region -89 to + 166 represents the minimal promoter. Within this region we have recognized the presence of essential element(s),positioned from -89 to +29, which harbors cluster of three putative early growth response 1 (EGR1) binding sites. By in vitro binding assays and functional analyses we have shown that these three putative binding sites are functionally relevant and sufficient for EGR1-induced SOX18 transcription. Mutations of these binding sites significantly impaired activity of the SOX18 promoter, particularly in EA.hy926 cells, indicating the importance of these regulatory elements for SOX18 promoter activity in endothelial setting. By data presented in this study, we have established SOX18 as a novel target gene regulated by EGR1 transcription factor, thus providing the first functional link between two transcription factors previously shown to be involved in the control of angiogenesis.

Influence of a Low Content of PEO Segment on the Thermal, Surface and Morphological Properties of Triblock and Diblock PCL Copolymers

Marijana Ponjavic,Marija S. Nikolic,Sanja Jevtic,Jelena Rogan,Sanja Stevanovic,Jasna Djonlagic 한국고분자학회 2016 Macromolecular Research Vol.24 No.4

Two series, one of triblock (PCL/PEO/PCL) and the other of diblock (PCL/PEO) copolymers were prepared by ring-opening polymerization of ε-caprolactone catalized with tin(II) octoate and by using dihydroxy or monohydroxy poly(ethylene oxide) as the macroinitiator. The PEO block length was fixed (Mn 1,000 g/mol) and the PCL block lengths (Mn 10,000-40,000 g/mol) were tailored by changing weight ratio of ε-CL/PEO. The copolymers’ structure was confirmed by 1H and quantitative 13C NMR spectroscopy while their molecular weights were determined by GPC analysis. The thermal properties and the degree of crystallinity of the copolymers were investigated and compared by using DSC and WAXS. Both types of copolymers were semicrystalline with the orthorhombic PCL crystal lattice. The surface morphology of the copolymer films was investigated by using optical microscopy and AFM analysis, which confirmed the spherulitic lamellar structure with spherulites of different diameters. Data indicated that a low content of PEO segment had an influence on thermal degradation behavior, crystallinity and morphology of copolymers. Roughness of copolymer films was affected by the content of PEO and correlated with the spherulites’ diameter. The small changes in water and moisture absorption properties of copolymers compared to homopolymer PCL were observed.

BMB Reports : Cyclic AMP response element binding (CREB) protein acts as a positive regulator of SOX3 gene expression in NT2/D1 cells

( Natasa Kovacevic Grujicic ),( Marija Mojsin ),( Jelena Popovic ),( Isidora Petrovic ),( Vladanka Topalovic ),( Milena Stevanovic ) 생화학분자생물학회(구 한국생화학분자생물학회) 2014 BMB Reports Vol.47 No.4

SOX3 is one of the earliest neural markers in vertebrates, playing the role in specifying neuronal fate. In this study we have established first functional link between CREB and human SOX3 gene which both have important roles in the nervous system throughout development and in the adulthood. Here we demonstrate both in vitro and in vivo that CREB binds to CRE half-site located -195 to -191 within the human SOX3 promoter. Overexpression studies with CREB or its dominant-negative inhibitor A-CREB indicate that this transcription factor acts as a positive regulator of basal SOX3 gene expression in NT2/D1 cells. This is further confirmed by mutational analysis where mutation of CREB binding site results in reduction of SOX3 promoter activity. Our results point at CREB as a positive regulator of SOX3 gene transcription in NT2/D1 cells, while its contribution to RA induction of SOX3 promoter is not prominent. [BMB Reports 2014; 47(4): 197-202]

Adsorption of lipase from Candida rugosa on multi walled carbon nanotubes

Nevena Z. Prlainovic,Dejan I. Bezbradica,Zorica D. Knezevic-Jugovic,Sanja I. Stevanovic,Milka L. Avramov Ivic,Petar S. Uskokovic,Dusan Z. Mijin 한국공업화학회 2013 Journal of Industrial and Engineering Chemistry Vol.19 No.1

In this work lipase from Candida rugosa was adsorbed on unmodified surface of multi walled carbon nanotubes (raw-MWCNT). The effects of immobilization time, initial enzyme concentration and buffer ionic strength on enzyme loading and activity of immobilized preparations were tested. High loadings are attained. The immobilized enzyme obtained at lowest initial enzyme concentration and high ionic strength retained 85% of initial enzyme activity. It is assumed that immobilization on hydrophobic surface led to conformational changes that resulted in the adsorption of lipase in active conformation. Immobilized preparations were characterized, with FT-IR spectroscopy, AFM, and cyclic voltammetry.

Comparative Phenotypic Analysis of Anabaena sp. PCC 7120 Mutants of Porinlike Genes

( Hannah Schätzle ),( Eva-maria Brouwer ),( Elisa Liebhart ),( Mara Stevanovic ),( Enrico Schleiff ) 한국미생물생명공학회(구 한국산업미생물학회) 2021 Journal of microbiology and biotechnology Vol.31 No.5

Porins are essential for the viability of Gram-negative bacteria. They ensure the uptake of nutrients, can be involved in the maintenance of outer membrane integrity and define the antibiotic or drug resistance of organisms. The function and structure of porins in proteobacteria is well described, while their function in photoautotrophic cyanobacteria has not been systematically explored. We compared the domain architecture of nine putative porins in the filamentous cyanobacterium Anabaena sp. PCC 7120 and analyzed the seven candidates with predicted OprB-domain. Single recombinant mutants of the seven genes were created and their growth capacity under different conditions was analyzed. Most of the putative porins seem to be involved in the transport of salt and copper, as respective mutants were resistant to elevated concentrations of these substances. In turn, only the mutant of alr2231 was less sensitive to elevated zinc concentrations, while mutants of alr0834, alr4741 and all4499 were resistant to high manganese concentrations. Notably the mutant of alr4550 shows a high sensitivity against harmful compounds, which is indicative for a function related to the maintenance of outer membrane integrity. Moreover, the mutant of all5191 exhibited a phenotype which suggests either a higher nitrate demand or an inefficient nitrogen fixation. The dependency of porin membrane insertion on Omp85 proteins was tested exemplarily for Alr4550, and an enhanced aggregation of Alr4550 was observed in two omp85 mutants. The comparative analysis of porin mutants suggests that the proteins in parts perform distinct functions related to envelope integrity and solute uptake.