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

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)

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

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

Ispitivanje adsorpcije fenola na makroporoznim polimernim adsorbensima

This work reports results on phenol adsorption from aqueous solution by porous copolymers based on glycidyl methacrylate: two samples of macroporous crosslinked poly(glycidyl methacrylate-co-ethylene glycol dimethacrylate), were synthetized by suspension copolymerisation with ethylene glycol dimethacrylate. In addition, the two copolymer samples were functionalized with ethylene diamine. The amounts of adsorbed phenol were presented in the form of adsorptions isotherms, which were interpreted using Langmuir, Freundlich and Sips' equations. The first was found to express high level of agreement with experimental data. Phenol adsorption indicate the homogeneous distribution of active sites present on the investigated polymers. It was found that adsorption of phenol on copolymers is fast and depends on the presence of amino groups and on the pore size. From the obtained results, it was possible to distinguish macroporous polymer as a material which possesses the capacity for adsorption of phenol comparable to that of activated carbon.Ovaj rad se bavi proučavanjem adsorpcije fenola iz vodenih rastvora na kopolimerima različitih poroznih karakteristika i polarnosti. Korišćeni adsorbensi se baziraju na glicidil metakrilatu: dva uzorka makroporoznog poli(glicidil metakrilat-co-etilen glikol dimethakrilat) su sintetisani suspenzionom kopolimerizacijom sa etilen glikol dimetakrilatom. Dodatno, dva kopolimera su funkcionalizovani sa etilen diaminom. Količina adsorbovanog fenola je predstavljena u vidu adsorpcionih izotermi, koje su interpretirane korišćenjem Langmuir-ove, Freundlich-ove i Sips-ove jednačine: prva od ovih daje visok nivo slaganja sa eksperimentalnim podacima. Adsorpcija fenola ukazuje na homogenu raspodelu aktivnih mesta prisutnih u ispitivanim polimernim sistemima. Rezultati dobijeni u ovom istraživanju pokazuju da adsorpcija fenola na ispitivanim kopolimerima zavisi od prisustva amino grupa i od veličine pora. Adsorpcija fenola iz vodenih rastvora je brza u slučaju svih korišćenih adsorbenasa. Na osnovu dobivenih rezultata, može se zaključiti da su makroporozni polimeri materijali čije je adsorpcioni kapacitet za fenol uporediv sa onim koji ima aktivni ugalj

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

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

Investigation of different extraction procedures for the determination of major and trace elements in coal by ICP-AES and ion chromatography

This paper presents the extraction of major and trace elements from a coal sample, in deionized water, by using three different extraction techniques. Rotary mixing and ultrasonic extraction were examined for different extraction times, while the microwave-assisted extraction was performed at different temperatures. Metal concentrations (Na, K, Ca, Mg, Al, Fe, Mn, Be, Cd, Co, Cr, Hg, As, Ni, Se, Sb and Pb) in solution were determined employing inductively coupled plasma atomic emission spectrometry; whereas the results obtained for Na, K, Ca and Mg were compared employing ion chromatography. Comparing the rotary-and ultrasonic-assisted extractions, it was shown that the former technique was more efficient for the determination of Fe, Na and Pb, whereas the latter one proved more efficient for the determination of Co and Cr ions. Microwave-assisted extraction was shown to be the most efficient method for all the tested elements in coal. In addition, sequential extraction of the elements was realized using microwave digestion. The results of the sequential extraction experiments indicated associations of investigated elements with a mineral phase and organic matrix. Sequential extraction provided information on possible leaching of As, Cd, Co, Cr, Ni, Pb, Fe and Mn under environmental conditions

ПОРЕЂЕЊЕ ELISA И HPLC МЕТОДЕ ЗА ДЕТЕКЦИЈУ МИКОТОКСИНА АНАЛИЗОМ РЕЗУЛТАТА PROFICIENCY ТЕСТОВА

Different analytical techniques for the detection of mycotoxins have been developed in order to control the levels of mycotoxins in food and feed. Conventional analytical methods for mycotoxin determination are involving techniques such as thinlayer chromatography (TLC), high-performance liquid chromatography (HPLC) and gas chromatography (GC). Also, rapid methods for mycotoxin analysis have become increasingly important. Enzyme-linked immuno-sorbent assay (ELISA) is one of the most common rapid methods for determination of these natural contaminants. The aim of this study was to provide a comparison between two different methods of analysis (HPLC and ELISA) for the detection of different mycotoxins using data that originate from commercial proficiency tests. Based on the statistical evaluation of the results for both methods, in three proficiency tests for various mycotoxins (aflatoxins, ochratoxin and zearalenone), it could be concluded that both techniques can equally be used, although ELISA is considered to be the screening one.У циљу контроле присуства микотоксина и нивоа контаминације хране и хране за животиње развијене су различите аналитичке технике за детекцију ових природних контаминената. Конвенционалне аналитичке методе за утврђивање микотоксина су танкослојна хроматографија (ТЛЦ), течна хроматографија високих перформанси (ХПЛЦ) и гасна хроматографија (ГЦ). Такође, брзе методе за микотоксиколошке анализе постају све важније, међу којима је ЕЛИСА (Enzyme linked immuno-sorbent assay) једна од најприменљивијих. Циљ овог рада био је да се две различите и најчешће коришћене лабораторијске методе за утврђивање различитих микотоксина (ХПЛЦ и ЕЛИСА) упореде анализом података који потичу из комерцијалних тестова оспособљености (proficiency тестова). На основу детаљне статистичке процене резултата добијених применом ових метода за квантификацију афлатоксина, охратоксина и зеараленона, у три комерцијална proficiency теста, може се закључити да обе технике могу равноправно да се користе с великом поузданошћу, иако се често наводи да је ЕЛИСА погодна само за почетну тријажу узорака

Synthesis, structure and thermogravimetric analysis of α,ω-telechelic polydimethylsiloxanes of low molecular weight

A series of α,ω-telechelic polydimethylsiloxanes (PDMS), with predetermined molecular weights of about 2500 g mol-1, was synthesized by siloxane equilibration reaction. Syntheses were performed using octamethylcyclotetrasiloxane (D4) and various disiloxanes: hexamethyldisiloxane (HMDS), 1,1,3,3-tetramethyldisiloxane (TMDS), 1,3-divinyltetramethyldisiloxane (DVTMDS), 1,3-bis(3-carboxypropyl)tetramethyldisiloxane (DCPTMDS) and 1,3-bis(3-aminopropyl)tetramethyldisiloxane (DAPTMDS). The role of the disiloxane was to introduce terminal functional groups at the end of the polymer chains and to control the molecular weight of the polymers. Polymers with trimethyl, hydrido, vinyl, carboxypropyl and aminopropyl end-groups were obtained in this way. The structure of the α,ω-telechelic PDMSs was confirmed by NMR and IR spectroscopy. The molecular weights of the polymers were determined by 1H-NMR, gel permeation chromatography (GPC) and dilute solution viscometry. Thermogravimetric analysis (TGA) under nitrogen and air showed that the type of the terminal groups significantly influenced the thermal and thermo-oxidative stability, as well as the degradation mechanism of the α,ω-telechelic PDMSs. [Project of the Serbian Ministry of Education, Science and Technological Development, Grant no. 172062

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

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°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. [Projekat Ministarstva nauke Republike Srbije, br. 172030, br. 176006 i br. III43009

Influence of oil sources in the nutrition of laying hens on production results

Исхрана кока носиља има значајну улогу за њихово здравствено и кондиционно стање, као и за производне резултате. Задовољавајући производни резултати могу да се остваре употребом нутријената који осигуравају енергетске потребе, потребе у протеинима (аминокисе- лине), витаминима и минералима. Основна сировина у исхрани кока носиља је најчешће кукуруз (преко 50%), сојина и сунцокретова сачма, сточна креда, сточни квасац и премикс (витамини, аминокиселине, макро и микроелементи). Циљ овог рада био је да се испита утицај сојиног уља (1,5% К0 група) и замене сојиног уља и дела кукуруза ланеним уљем (К1 1,5%, К2 3% и К3 4,5%) на производне резултате кока носиља хибрида Isa Brown (просечна маса на почетку и крају огледа, просечан прираст, потрошња хране, просечан дневни број и проценат снешених јаја и просечна маса јаја). Оглед је трајао 70 дана (од 155. до 220. дана старости). Просечна маса кока носиља на почетку огледа била је уједначена, а на крају огледа била је већа код К3 групе у односу на остале испитиване групе. Просечан при- раст био је од 88,50 г (К0) до 114 г (К3 група). Утрошак хране био је 120,15 г код К0 групе и 115,38 г код К2 групе. Просечан дневни број снешених јаја био је од 37,27 (К0 група) до 38,83 (К2 група),а изражено у процентима био је од 93,11% (К0 група) до 97,19 (К2 група). Између просечног дневног броја снешених јаја и просечног броја јаја изражених у процентима утврђене су статистички значајне разлике (р<0,01) између поређених група. Просечна маса јаја била је од 58,13 г (К1 група) до 60,34 (К3 група). Утврђене су статистички значајне разлике (р<0,01) између поређених просечних маса јаја кока носиља поређених група. Добијени резултати указују на чињеницу да избор уља у исхрани кока носиља утиче на производне резултате.The diet of laying hens plays a significant role in their health and fitness, as well as in their production results. Satisfactory production results can be achieved by using nutrients that provide energy needs, protein needs (amino acids), vitamins and minerals. The basic raw materials in the diet of laying hens are most often corn (over 50%), soybean and sunflower meal, fodder chalk, fodder yeast and premix (vitamins, amino acids, macro and microelements). The aim of this study was to examine the impact of soybean oil (1.5% K0 groups) and the replacement of soybean oil and corn with flaxseed oil (K1 1.5%, K2 3% and K3 4.5%) on the production results of laying hens hybrid Isa Brown (average weight at the beginning and end of the experiment, average growth, food consumption, average daily number and percentage of eggs laid and average egg weight). The experiment lasted 70 days (from 155 to 220 days of age). The average weight of laying hens at the beginning of the experiment was uniform, and at the end of the experiment it was higher in the K3 group compared to the other examined groups. The average increase was from 88.50 g (K0) to 114 g (K3 group). Food consumption was 120.15 g in the K0 group and 115.38 g in the K2 group. The average daily number of laid eggs ranged from 37.27 (K0 group) to 38.83 (K2 group), and expressed as a percentage ranged from 93.11% (K0 group) to 97.19 (K2 group). Significant differences (p<0.01) between the compared groups were found between the average daily number of laid eggs and the average number of eggs expressed as a percentage. The average egg weight was from 58.13 g (K1 group) to 60.34 (K3 group). Significant differences (p<0.01) were found between the compared average weights of laying hen eggs of the compared groups. The obtained results indicate the fact that the choice of oil in the diet of laying hens affects the production results.Zbornik radova i kratkih sadržaj