215 research outputs found
Impact of IT on management and humans in modern conditions
The introduction of IT changes the organizational structure and all the elements of management processes, particularly the way we manage organizations. The problem is the fact that information technology is not adequately implemented in all the parts of the business
process. Specifically, it is applied to the operatively executive, administrative, accounting jobs, archiving, retrieval and selection of data for planning and analysis, and its implementation is lagging behind in
leadership and management.
This paper aims to highlight the impact of IT on the management process, i.e. on people as the most valuable potential of each organization
Leaching of chromium from chromium contaminated soil: Speciation study and geochemical modeling
Distribution of chromium between soil and leachate was monitored. A natural process of percolating rainwater through the soil was simulated in the laboratory conditions and studied with column leaching extraction. Migration of chromium in the soil is conditioned by the level of chromium soil contamination, the soil organic matter content, and rainwater acidity. Chromium (III) and chromium(VI) were determined by spectrophotometric method with diphenilcarbazide in acidic media. Comparing the results of chromium speciation in leachate obtained by experimental model systems and geochemical modelling calculations using Visual MINTEQ model, a correlation was observed regarding the influence of the tested parameters. Leachate solutions showed that the concentration of Cr depended on the organic matter content. The influence of pH and soil organic matter content is in compliance after its definition through experimental and theoretical way. The computer model - Stockholm Humic Model used to evaluate the leaching results corresponded rather well with the measured values
The application of NMR and FTIR spectroscopic techniques results in the multivariate data analysis for propolis classification
У овом раду су приказане брзе и једноставне спектроскопске методе за
одређивање хемијског састава прополиса типа топола са подручја Србије, Босне и
Херцеговине и Бугарске коришћењем метаболомичког приступа. У циљу
корелисања разлика у хемијском саставу прополиса топола типа са надморском
висином са које су узорци прикупљени, коришћени су резултати NMR, IR и UV
спектроскопских техника у комбинацији са PCA и OPLS статистичким методама.
Ботаничко порекло прополиса је утврђено поређењем спектралних података
узорака прополиса са спектралним подацима фенолних смола пупољака
различитих врста топола које расту у близини локација са којих су узорци
прикупљени. За корелисање две матрице (табеле) спектралних података
коришћена је O2PLS метода. На основу примењених статистичких анализа (PCA,
OPLS i O2PLS), главне компоненте у узорцима прополиса прикупљеним у регији
умерено-континенталне климе на надморској висини изнад 500 m су ацетил
глицерил естри фенолних киселина са пупољака Populus tremula. Флавоноиди
фенолних смола пупољака врста P. nigra и P. x euramericana су најзаступљенији у
узорцима прополиса прикупљеним на надморској висини испод 400 m. Узорци
прикупљени на надморској висини између 400 и 500 m садрже све поменуте
секундарне метаболите топола у различитим односима.
Применом OPLS-DA методе на спектралне податке узорци прополиса типа
топола су класификовани у две класе назване Планински прополис типа топола и
Равничарски прополис типа топола.
Антимикробна активност прикупљених узорака је тестирана на Грам-
позитивним бактеријским сојевима Staphylococcus aureus (ATCC 6538),
клиничком изолату Bacillus cereus, Micrococcus flavus (ATCC 10240) и Listeria
monocytogenes (NCTC 7973), Грам-негативним бактеријама Pseudomonas
aeruginosa (ATCC 27853), Salmonella typhimurium (ATCC 13311), Escherichia coli
(ATCC 35210) и хуманом изолату Enterobacter cloacae и на гљиви Fusarium
oxysporum. Резултати антимикробних тестова показали су високу антимикробну
активност прополиса према свим испитиваним микроорганизмима.Here we have presented simple, fast and rapid spectroscopic methods for
determination of the chemical composition of Poplar type propolis from Serbia, Bosnia
and Herzegovina and Bulgaria, using metabolomics approach. The main objective was
to correlate variability in Poplar type propolis composition with the altitude of its
collection. This was carried out using NMR, IR, and UV spectroscopy followed by PCA
and OPLS methods. The botanical origin of the propolis was established by comparing
spectral data of propolis with those of various Populus species growing close to the
collection site. An O2PLS method was utilized to integrate two blocks of data.
According to PCA, OPLS and O2PLS, the major compounds in propolis samples,
collected from temperate continental climate above 500 m, were phenolic glycerides
originating from Populus tremula buds. Flavonoids were predominant in propolis
samples collected below 400 m, originating from P. nigra and P. x euramericana buds.
Samples collected at 400 – 500 m were of mixed origin with variable amount of all
detected metabolites.
Using OPLS-DA method and spectral data, poplar propolis samples were
classified in two classes named Mountain populus type and Flatland populus type.
Antimicrobial activity of propolis samples was tested on Gram-positive bacteria
Staphylococcus aureus (ATCC 6538), clinical isolates of Bacillus cereus, Micrococcus
flavus (ATCC 10240) and Listeria monocytogenes (NCTC 7973), Gram-negative
bacteria Pseudomonas aeruginosa (ATCC 27853), Salmonella typhimurium (ATCC
13311), Escherichia coli (ATCC 35210), and human isolate of Enterobacter cloacae,
on fungus Fusarium oxysporum. The results of antimicrobial tests showed strong
antimicrobial activity of propolis against all tested microorganisms
Supplementary material for the article: Rašković, B.; Vatić, S.; Andelković, B.; Blagojević, V.; Polović, N. Optimizing Storage Conditions to Prevent Cold Denaturation of Trypsin for Sequencing and to Prolong Its Shelf Life. Biochemical Engineering Journal 2016, 105, 168–176. https://doi.org/10.1016/j.bej.2015.09.018
Supplementary material for: [https://doi.org/10.1016/j.bej.2015.09.018]Related to published version: [http://cherry.chem.bg.ac.rs/handle/123456789/2024
Uticaj agroekoloških uslova i hibridne kombinacije na klijavost semena kukuruza
Germination energy and seed germination of four maize combinations cultivated under different growing conditions were observed. Analysis of hybrid seed of four commercial combinations derived at the Maize Research Institute, Zemun Polje, grown in three locations, were done on the working sample of 4 x 100 seeds under laboratory conditions. The experimental data was processed for the mean and total variability (X and C.V.) for both seed traits and for each test variant. The total average values of germination energy and germination in the period of investigation amounted to 94.5% and 94.8%, respectively. The coefficient of variation for germination energy was 0.67%, while for germination it was 0.39%. In the five-year study, the hybrid combination ZP704 had the highest values of germination energy (95.9%) and total germination (96.3%).Test results indicate that coefficients of variations for both observed traits over years were low, which points out to homogeneity of the material. Significant effects of factors (hybrid and location) and their interaction on observed seed properties were established by the analysis of variance. Gained results indicate that all four hybrids had high level of expression of traits under changeable agroecological conditions, as well as, a great effect of factors (hybrid and location) on germination energy and seed germination.U ovim istraživanja proučavane su energija klijanja i klijavost semena kukuruza četiri genotipske kombinacije u različitim agroekološkim uslovima uspevanja. Analize hirbidnog semena četiri komercijalne kombinacije Instituta za kukuruz Zemun Polje, proizvedene na tri lokaliteta, urađene su u laboratorijskim uslovima na radnom uzorku 4 x 100 semena. Eksperimentalni podaci obrađeni su na srednju vrednost i ukupnu varijabilnost (X i C.V.) za obe osobine semena i svaku varijantu istraživanja. Ukupna prosečna vrednost energije klijanja u posmatranom periodu bila je 94.5%, a klijavost 94.8%. Koeficijent varijacije za energiju iznosio je 0.67%, a za klijavost 0.39%. Hibridna kombinacija ZP704 u petogodišnjim istraživanjima imala je najviši nivo energije klijanja (95.9%) i ukupne klijavosti (96.3%). Rezultati testova ukazuju da koeficijenti varijacije ispitivanih karakteristika kod obe osobine su mali i ukazuju na homogenost materijala. Dvofaktorijalnom analizom varijanse utvrđen je značajan uticaj faktora (hibrid i lokacija), kao i njihova interakcija na ispitivane osobine semena. Dobijeni rezultati pokazali su da sva četiri hibrida imaju visok nivo ispoljavanja ispitivanih osobina u promenljivim agroekološkim uslovima, kao i visok uticaj faktora ( hibrid i lokalitet) na energiju i klijavost semena
AUTOMATIC DETERMINATION OF FILTER COEFFICIENTS FOR LOCAL CONTRAST ENHANCEMENT
This study proposes an algorithm whose main advantage is in enabling the automatic determination of non-linear homomorphic filter coefficients used for local contrast enhancement in digital image processing. The presented algorithm is tested in a real production environment. The obtained results are compared with relevant examples in literature, showing the advantages of the achieved results or a relatively high level of their correspondence with reference results. The proposed procedure can be used for various applications in mechatronics, robotics and automatized production systems
Arsenic removal from aqueous solutions by sorption onto zirconium- and titanium-modified sorbents
Arsenic reduction in drinking water can include treatment by adsorption, switching to alternative water sources, or blending with water that has a lower arsenic concentration. Commercial sorbents MTM, Greensand and BIRM (Clack Corporation) were modified with zirconium and titanium after activation. The modifications were performed with titanium tetrachloride and zirconium tetrachloride. The modified sorbents were dried at different temperatures. The sorption of arsenate and arsenite dissolved in drinking water (200μg L-1) onto the sorbents were tested using a batch procedure. After removal of the sorbent, the concentration of arsenic was determined by HG-AAS. Zirconium-modified BIRM showed the best performance for the removal of both arsenite and arsenate. Modification of the greensand did not affect arsenic sorption ability. Zirconium-modified BIRM diminished the concentration of total As to below 5 μg L-1
Crystal structures of mixed chloride-azide zinc (II) and chloride-isocyanate cadmium (II) complexes with the condensation product of 2-quinolinecarboxaldehyde and girard’s reagent
The mixed chloride-azide [ZnL(N3)1.65Cl0.35] (1) and chloride-isocyanate [CdL(NCO)1.64Cl0.36] (2)
complexes have been prepared in the reactions of (E)-N,N,N-trimethyl-2-oxo-2-(2-(quinolin-2-
ylmethylene)hydrazinyl)ethan-1-aminium chloride (HLCl) and the corresponding Zn2+ and Cd2+
salts by adding the NaN3 and NaOCN, respectively. The structures of complexes 1 and 2 were
determined by X-ray crystallography
Crystal structures of mixed chloride-azide zinc (II) and chloride-isocyanate cadmium (II) complexes with the condensation product of 2-quinolinecarboxaldehyde and girard’s reagent
The mixed chloride-azide [ZnL(N3)1.65Cl0.35] (1) and chloride-isocyanate [CdL(NCO)1.64Cl0.36] (2)
complexes have been prepared in the reactions of (E)-N,N,N-trimethyl-2-oxo-2-(2-(quinolin-2-
ylmethylene)hydrazinyl)ethan-1-aminium chloride (HLCl) and the corresponding Zn2+ and Cd2+
salts by adding the NaN3 and NaOCN, respectively. The structures of complexes 1 and 2 were
determined by X-ray crystallography
Genotype and soil type influence on morphological characteristics, Yield and oil content of oil-flax
The three-year trial investigated the individual and the mutual interaction among three genotypes of oil-flax (Olin, Zlatko, Ljupko) and subtype of soil (chernozem with signs of gleyzation and chernozem on sandy loess) and their influence on morpho-physiological traits, yield and oil-flax oil content. The tallest stems (70.3 cm) had the Olin variety in agro-ecological conditions of Southern Banat region. Number of capsules per plant and number of grains per capsule was dependent on agroecological conditions in the investigated year. The largest number of capsules (68) per plant had the Zlatko variety, while the highest average grains number in the capsules (8.2) was at the Olin variety. The obtained values of the studied varieties for these two variables were not statistically significant. On average, the highest oil-flax seed yield gave the Ruben variety (1416.3 kg ha-1), which was higher for about 9.45% compared to the Ljupko variety, and 9.65% compared to the Olin variety. The highest oil content was at the Ljupko variety (41.1%). This value was higher by 1.21 rel.% compared to the Zlatko variety (40.6%), and 0.07 rel.% compared to the Olin variety (40.8%). Three-year average grains yield (Starcevo locality) was 1430.6 kg ha-1. The yield increasing at chernozem with signs of gleyzation compared to plants grown on chernozem on sandy loess (Devojacki Bunar locality) was 17%. On the other hand, the oil content in general was higher in this type of soil than on chernozem with signs of gleyzation (41.0% vs. 40.7%)
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