259 research outputs found

    Effective partitioning method for computing weighted Moore-Penrose inverse

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    We introduce a method and an algorithm for computing the weighted Moore-Penrose inverse of multiple-variable polynomial matrix and the related algorithm which is appropriated for sparse polynomial matrices. These methods and algorithms are generalizations of algorithms developed in [M.B. Tasic, P.S. Stanimirovic, M.D. Petkovic, Symbolic computation of weighted Moore-Penrose inverse using partitioning method, Appl. Math. Comput. 189 (2007) 615-640] to multiple-variable rational and polynomial matrices and improvements of these algorithms on sparse matrices. Also, these methods are generalizations of the partitioning method for computing the Moore-Penrose inverse of rational and polynomial matrices introduced in [P.S. Stanimirovic, M.B. Tasic, Partitioning method for rational and polynomial matrices, Appl. Math. Comput. 155 (2004) 137-163; M.D. Petkovic, P.S. Stanimirovic, Symbolic computation of the Moore-Penrose inverse using partitioning method, Internat. J. Comput. Math. 82 (2005) 355-367] to the case of weighted Moore-Penrose inverse. Algorithms are implemented in the symbolic computational package MATHEMATICA

    Research correlation vegetation index of corn with speed of movement sensor and elevation of field

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    This paper presents field scouting of corn in order to determine the content of nitrogen in the green parts of the plants. The aim was to measure the vegetative index using two optical sensors by OptRx AGL Technology. The sensors are positioned at a distance of 3.5 m, individually observing five rows of corn. The speed of movement of the tractor and also elevation of field are varied. The measured vegetative index of the plants is correlated, in first, with the speed of the sensor on the platform. The measured vegetative index of the plants is correlated after that with elevation also. Both of that case are shown that the Normalised Difference Red Edge (NDRE) as represent of vegetative index is not correlated with speed and elevation. This Results represented with Pearson Correlation Coefficient and Spearman's Correlation Coefficient are statistical signatifical. This conclusions are valid only for short rang of speed and elevation research. Average speed was 6,39 km/hr and rang of elevation was 1.6 m (106.8-108.4 m)

    Behavioral Public Choice and the Law

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    Behavioral public choice is the study of irrationality among political actors. In this context, irrationality means systematic bias, a deviation from rational expectations, or other departure from economistsā€™ conception of rationality. Behavioral public choice scholars extend the insights of behavioral economics to the political realm and show that irrational behavior is an important source of government failure. This Article makes an original contribution to the legal literature by systematically reviewing the findings of behavioral public choice and explaining their implications for the law and legal institutions. We discuss the various biases and heuristics that lead political actors to support and adopt bad laws and describe how irrationality influences specific areas of the law, including tax, antitrust, consumer protection, corporate, and employment law. We also discuss various proposals for minimizing the effects of irrationality on public policy. Our goal is to introduce this new field of research to legal scholars, most of whom have previously ignored it. Familiarity with behavioral public choice will help legal scholars better understand the types of policies that are likely to emerge from real-world political processes and will facilitate efforts to promote realistic policy reform

    Analysis of forensic samples of "Ecstasy" tablets seized in Novi Sad during the 2004 year

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    The paper presents results of the analysis of illicit synthetic drugs in the form of tablets distributed under the name "Ecstasy", seized by the police in the broader area of Novi Sad 2004. A huge number of tablets has been analyzed (n=121), of various colours and with impressed symbols from the total amount of 93 seizures, which totally amounted to 1458 tablets. Regarding the number of seizures ecstasy (3,4-methylendioxy-N-meth-yl-amphetamine - MDMA) is dominant among all, and according to the quantity of seized tablets it is amphetamine (AP), while other amphetamine-type drugs (methamphetamine MA 3,4-methylendioxiamphetamine - MDA, 3,4-methylendioxi-N-ethyl-amphetamine MDEA) have been found in rather small quantities and very rarely. Tablets mostly contain caffeine as an additive. In the analytical procedure, the samples of tablets were subjected to liquid-liquid extraction and afterwards analyzed on the GCD (GC-EI) Hewlett-Packard instrument. The method is fast reliable and reproducible for the analysis of amphetamine, methamphetamine MDA, MDMA, MDEA, as well as various additives in the samples of seized tablets

    Identification and molecular characterization of Chryseobacterium vrystaatense ST1 isolated from oligomineral water of southeast Serbia

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    The isolation and molecular characterization of bacterial strains isolated from water sources in the Vlasina Mountain in southeast Serbia, confirmed the presence of a new species Chryseobacterium vrystaatense ST1. This Gram- negative species showed an extremely low level of biochemical reactivity in biochemical tests. The gene for 16S rRNA was amplified by PCR using universal primers and sequenced. Comparison of 16S rRNA gene sequence and phenotypic features indicated that the isolate ST belonged to Chryseobacterium vrystaatense. A BLAST search of sequenced 1088 nucleotides of the 16S rRNA gene with all sequences deposited in the NCBI collection showed the highest similarity (98%) with the strain Chryseobacterium vrystaatense sp. nov., designated as strain R-23533. The very high homology of these two strains allowed classification of our strain at the species level, but some differences indicate, and indirectly confirm, that the isolate ST is an authentic representative. On the basis of these results, we could conclude that Chryseobacterium vrystaatense ST was for first time isolated in Serbia, which is particularly important when one bears in mind that there are only three sequences of this species deposited in the NCBI collection

    Aqueous extraction of anions from coal and fly ash followed by ion-chromatographic determination

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    Three different techniques were applied for the aqueous extraction of anions from coal and fly ash: rotary mixer-and ultrasonic-assisted extraction with different duration time, and microwave-assisted extraction at different temperatures. Validation showed that the ion-chromatographic method was suitable for the analysis of anions in coal and fly ash extracts. The variations in the amounts of anions using different extraction times during rotary-assisted extraction were minimal for all investigated anions. The efficiency of ultrasound-assisted extraction of anions from coal depended on the sonication time and was highest at 30 min. The ultrasound-assisted extraction was less efficient for the extraction of anions from fly ash than rotary-assisted extraction. Increase of temperature in the microwave-assisted extraction had a positive effect on the amounts of all anions extracted from coal and sulphate from fly ash, while the amounts of fluoride and chloride in fly ash extracts decreased. The microwave-assisted extraction of coal at 150 degrees C was compared with standard ASTM methods, and results were in good agreement only for chloride. Changes in the pH value and conductivity during ultrasound-assisted extraction were measured in order to explain changes on the surface of coal particles in contact with water and different processes that occur under environmental conditions

    Remaining life assessment of a high pressure turbine casing in creep and low cycle service regime

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    Thick walled components such as high pressure (HP) steam turbine casings operating under high parameter conditions are subjected to a complex stress state. As a result of that stress state, some parts of HP turbine casing undergo to the creep fatigue caused by the combination of thermal fatigue resulted from repeated start/stop operation and the creep which occurs during long-term operation at high temperature and high-pressure. It is well known that domestic thermal power plants have been in use over 100000 h which means that significant cost is required not only for maintenance, but often for renewal of equipment. Based on comprehensive investigation, the results of residual life assessment of one high pressure steam turbine casing, which belongs to the older turbine generation, taking into account simultaneous action of thermal fatigue and creep, are presented in this paper. Also, the critical flaw crack size of HP turbine casing is determined because this parameter has a strong influence on casing integrity and residual life. The results of residual life assessment provide not only a basis for further maintenance, but also estimated time for reparation or renewal

    Comparison of sequential and single extraction in order to estimate the environmental impact of metals from fly ash

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    The aim of this paper is to simulate leaching of metals from fly ash in different environmental conditions using ultrasound and microwave-assisted extraction techniques. Single-agent extraction and sequential extraction procedures were used to determine the levels of different metals leaching. The concentration of metals (Al, Fe, Mn, Cd, Co, Cr, Ni, Pb, Cu, As and Be) in fly ash extracts were measured by inductively coupled plasma-atomic emission spectrometry. Single-agent extractions of metals were conducted at sonication times of 10, 20, 30, 40 and 50 min. Single-agent extraction with deionized water was also performed by exposing samples to microwave radiation at temperature of 50 degrees C. The sequential extraction was conducted according to the BCR procedure which was modified and applied to study the partitioning of metals in coal fly ash. The microwave-assisted sequential extraction was performed at different extraction temperatures: 50, 100 and 150 degrees C. The partitioning of metals between the individual fractions was investigated and discussed. The efficiency of the extraction process for each step was examined. In addition, the results of the microwave-assisted sequential extraction are compared to the results obtained by standard ASTM method. The mobility of most elements contained in the fly ash is markedly pH sensitive
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