In the present study, a new sensitive and simple kinetic-spectrophotometric method for the determination of the insecticide dimethoate O,O-dimethyl-S-(N-methyl-carbomoylmethyl)-phosphoro-dithioate is ...developed. The method is based on the inhibition effect of dimethoate on the oxidation of malachite green (
MG
) by potassium periodate (KIO
4
) in the presence of Mn(II) ions. Inhibition kinetics of this catalytic reaction was investigated in the presence of dimethoate and the possibility of its analytical application was evaluated. The important variables that affected the reaction rate were investigated and the optimum conditions giving maximum sensitivity were established. Dimethoate was determined with linear calibration graph in the interval from 4.58 to 41.22 μg/mL. The optimized conditions yielded a theoretical detection limit of 1.24 μg/mL based on the 3
S
b
criterion. The RSDs of the method (
n
= 5) were 1.2–4.9% for the concentration interval of dimethoate from 4.58 to 41.22 μg/mL. The reaction was monitored spectrophotometrically by measuring the change in absorbance over time at 615 nm. The method was applied to the determination of dimethoate in waters and milk, and was compared with the spectrophotometric method. The quantitive method developed on the basis of inhibition kinetics is practical, fast and economical. For this reason, it is open for new application fields.
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DOBA, EMUNI, FIS, FZAB, GEOZS, GIS, IJS, IMTLJ, IZUM, KILJ, KISLJ, MFDPS, NLZOH, NUK, OILJ, PILJ, PNG, SAZU, SBCE, SBJE, SBMB, SIK, UILJ, UKNU, UL, UM, UPUK, VKSCE, ZAGLJ
The aim of this work was to develop a new kinetic spectrophoto-metric method for the determination of ibuprofen in pharmaceutical for-mulations. Ibuprofen was determined in an acidic ethanolic medium ...by monitoring the rate of appearance of 1-nitroso-2-naphthol, resulting from the displacement by ibuprofen of Co(III) from the tris(1-nitroso-2-naptholato)cobalt(III) complex. The optimum operating conditions regarding reagent concentrations and temperature were established. The tangent method was adopted for constructing the calibration curve, which was found to be linear over the concentration range 0.21–1.44 and 1.44–2.06 µg ml-1. The optimized conditions yielded a theoretical detection limit of 0.03 µg ml-1 based on the 3.3 S0 criterion. The interference effects of the usual excipients of powdery drugs, foreign ions and amino acids on the reaction rate were studied in order to assess the selectivity of the method. The developed procedure was successfully applied for the rapid determination of ibuprofen in commercial pharmaceutical formulations and human control serum. The unique features of this procedure are that the determination can be performed at room temperature and the analysis time is short. The newly developed method is simple, inexpensive and efficient for use in the analysis of a large number of samples.
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The reaction between doxycycline, hydrogen peroxide and Cu(II) was investigated spectrophotometrically in aqueous solutions. The absorption spectra show that the degradation of antibiotic drug occurs ...in weak alkaline aqueous solutions. The kinetics of the reaction was studied by applying the initial-rate method and the relative rate constants were calculated at different temperatures. The kinetic-spectrophotometric method for the determination of doxycycline based on the kinetics of pseudo-first order reaction at 20°C is proposed. The effects of several molecules and ions usually present in pharmaceutical formulations were studied in order to assess their interference. The calibration graph was applied to the determination of doxycycline in capsule dosage form. The relative standard deviation was no greater than 3.80%. The results were compared to those obtained by the official HPLC method.
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DOBA, EMUNI, FIS, FZAB, GEOZS, GIS, IJS, IMTLJ, IZUM, KILJ, KISLJ, MFDPS, NLZOH, NUK, OILJ, PILJ, PNG, SAZU, SBCE, SBJE, SBMB, SIK, UILJ, UKNU, UL, UM, UPUK, VKSCE, ZAGLJ
This paper presents a suitability analysis of silicon carbide diodes in buck converters with high input voltage and high voltage conversion ratio functional requirements. It provides a comparison of ...a conventional buck converter with silicon carbide diodes and ultrafast silicon diodes, illustrating the benefits of silicon carbide diode zero reverse-recovery losses. Experimental results are provided for a 768 W prototype.
The aim of this work was to develop a new kinetic spectrophotometric method for the determination of ibuprofen in pharmaceutical formulations. Ibuprofen was determined in an acidic ethanolic medium ...by monitoring the rate of appearance of 1-nitroso-2-naphthol, resulting from the displacement by ibuprofen of Co(III) from the tris(1-nitroso-2-naptholato)cobalt(III) complex. The optimum operating conditions regarding reagent concentrations and temperature were established. The tangent method was adopted for constructing the calibration curve, which was found to be linear over the concentration range 0.21-1.44 and 1.44-2.06 ?g ml-1. The optimized conditions yielded a theoretical detection limit of 0.03 ?g ml-1 based on the 3.3 S0 criterion. The interference effects of the usual excipients of powdery drugs, foreign ions and amino acids on the reaction rate were studied in order to assess the selectivity of the method. The developed procedure was successfully applied for the rapid determination of ibuprofen in commercial pharmaceutical formulations and human control serum. The unique features of this procedure are that the determination can be performed at room temperature and the analysis time is short. The newly developed method is simple, inexpensive and efficient for use in the analysis of a large number of samples.
Cilj rada bio je razrada nove kineticke metode za odredjivanje ibuprofena u farmaceutskim preparatima i humanom kontrolnom serumu. Ibuprofen je odredjivan merenjem brzine pojavljivanja 1-nitrozo-2-naftola, koji nastaje usled njegovog istiskivanja iz tris(1-nitrozo-2-naftolato)kobalt(III) kompleksa. Odredjeni su optimalni uslovi. Primenjena je tangentna metoda i dobijena kalibraciona kriva koja je linearna u intervalu koncentracije ibuprofena od 0,21-1,44 i 1,44-2,06 ?g ml-1. Granica detekcije na osnovu 3,3 S0 kriterijuma je 0,03 ?g ml-1. Ispitan je uticaj punioca, jona i aminokiselina na brzinu reakcije. Razvijena metoda je primenjena za odredjivanje ibuprofena u farmaceutskim preparatima i humanom kontrolnom serumu. Prednost metode se ogleda u tome sto su odredjivanja vrsena na sobnoj temperaturi i u kratkom vremenskom intervalu. Nova metoda je jednostavna i omogucava brzo odredjivanje ibuprofena u pomenutim uzorcima.
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Photosynthetic efficiency of pedunculate oak seedlings under simulated water stress Popovic, Z., Institut za bioloska istrazivanja Sinisa Stankovic, Beograd (Serbia); Milanovic, S., Institut za sumarstvo, Beograd (Serbia); Miletic, Z., Institut za sumarstvo, Beograd (Serbia) ...
Glasnik Sumarskog fakulteta - Univerzitet u Beogradu (1987),
(2010), 2010-00-00, 2010-01-01, Volume:
2010, Issue:
101
Journal Article
Peer reviewed
Open access
Photosynthetic performance of seedlings of Quercus robur exposed to short-term water stress in the laboratory conditions was assessed through the method of induced fluorometry. The substrate for ...seedlings was clayey loam, with the dominant texture fraction made of silt, followed by clay and fine sand, with total porosity 68.2%. Seedlings were separated in two groups: control (C) (soil water regime in pots was maintained at the level of field water capacity) and treated (water-stressed, WS) (soil water regime was maintained in the range of wilting point and lentocapillary capacity). The photosynthetic efficiency was 0.642+/-0.25 and 0.522+/-0.024 (WS and C, respectively), which was mostly due to transplantation disturbances and sporadic leaf chlorosis. During the experiment Fv/Fm decreased in both groups (0.551+/-0.0100 and 0.427+/-0.018 in C and WS, respectively). Our results showed significant differences between stressed and control group, in regard to both observed parameters (Fv/Fm and T1/2). Photosynthetic efficiency of pedunculate oak seedlings was significantly affected by short-term water stress, but to a lesser extent than by sufficient watering.
Simulation of linear business processes Popovic, Branko; Miletic, Ljiljana
Journal of Engineering Management and Competitiveness (Online),
2017, Volume:
7, Issue:
2
Journal Article
Peer reviewed
Open access
Business processes are applied in business organizations, with interconnected and interactively working activities, which convert input into output elements. These are sets of linked and structured ...activities or tasks that create a specific process outcome. Characteristics of business processes are: definition, orderliness, user knowledge, identification of additional values for users, connection in the organizational structure and functionality of the activity. In a business activity, it is usual to differentiate business processes, production and service processes. Business Process Management focuses on workflow optimization and business process optimization, which usually includes any combination: modeling, simulation, automation, execution, verification and optimization of business activity flows to achieve the goals. Business processes in the new Six Sigma System apply process simulations, which enable rapid checking of the effectiveness and efficiency of the process, with certain levels of trust and risk. Simulation is the imitation of physical and abstract processes or systems, in the real world over time, with a developed model that represents the system itself, with the application of certain analytical and computer techniques. The best known is the computer simulation technique of linear business processes, which is quite detailed here so it can be routinely applied in practice of compressed air flow.
A new kinetically-based spectrophotometric method for the determination of micro quantities of neomycin is described in this paper. It is an adaptation of the modified Berthelot method which is a ...widely used colorimetric procedure for urea determination. The method was developed due to neomycin effect on 2,2′-dicarboxyindophenol formation. The experimental conditions for successful determination of neomycin were optimized. The relative standard deviation (
RSD
) for the neomycin concentration interval of 77–154 μg/mL, ranges from 0.7 to 1%. The method was directly applied to determining neomycin in ophthalmic drops. The obtained results in analyzed pharmaceutical samples were in accordance with disc-diffusion microbiological method results.
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DOBA, EMUNI, FIS, FZAB, GEOZS, GIS, IJS, IMTLJ, IZUM, KILJ, KISLJ, MFDPS, NLZOH, NUK, OILJ, PILJ, PNG, SAZU, SBCE, SBJE, SBMB, SIK, UILJ, UKNU, UL, UM, UPUK, VKSCE, ZAGLJ
The international ISO 9001:2015 standard for quality management system (QMS) is widely implemented in this country, especially in business organisations and in public administration. The Standard was ...created in 1987; it was revised and amended in 1994, 2000 and 2008, the latest amendments being of the largest scope. Compared to the previous ISO 9001:2008 standard, this standard does not require a complicated manual to be devised: instead of six, it needs no documented procedures now and only 18 prescribed reports are required in comparison with 21 in the previous version. The organisations that have already certified their standards to comply to the earlier ISO 2001:2008 standard have to adopt the new standard now, and no later than 2018. One of the greatest problems in this transition is designing the required databases necessary for the practical implementation of the new standard. The solution proposed by the authors is a general model with six priority databases: Documented information database; Measuring, control and testing equipment database; Qualified personnel database; Complaints on process output nonconformity database; Costs of process output nonconformity database and Plant and work equipment maintenance database. / Международный стандарт системы менеджемента качества ISO 9001: 2015 в Сербии имеет весьма широкое применение, особенно в коммерческих организациях и в государственном управлении. Стандарт был разработан в 1987 году а первые изменения были внесены в 1994 году, а затем в 2000-ом и 2008--ом годах, объем изменений с каждым разом увеличивался, упрощая документооборот при его внедрении Так, например, по сравнению с предыдущим стандартом ISO 9001: 2008, последний стандарт не требует сложных Регламентов, вместо шести, теперь вовсе не требуется проведение документированной процедуры и вместо 21-го теперь достаточно подготовить 18 предписанных отчетов. Организации, которые уже сертифицированы на соответствие с предыдущим стандартом ISO 9001: 2008 должны перейти к новому стандарту до сентября 2018-го года. Одной из основных проблем в этом переходе является создание необходимых баз данных, которые необходимы для практического применения нового стандарта. Авторы статьи в качестве решения этой проблемы, предлагают общую модель, состоящую из шести приоритетных баз данных: База данных по документообороту; База данных по измерительному, контрольному и испытательному оборудованию; База данных по персоналу; База данных по претензиям на дефекты; База данных по затратам на дефекты; и База данных по эксплуатации и техническому обслуживанию рабочего оборудования. / Međunarodni standard za Sistem upravljanja kvalitetom ISO 9001:2015 ima u nas veoma široku primenu, naročito u privrednim organizacijama i javnoj upravi. Standard je nastao 1987, a revidiran je 1994, 2000. i 2008. godine, svaki put uz sve veće izmene, a poslednji put i uz najveće promene. U odnosu na prethodni standard ISO 9001:2008, ovaj standard ne zahteva izradu komplikovanog priručnika, umesto šest sada nije potreban nijedan dokumentovani postupak, a umesto 21 sada je dovoljno 18 propisanih izveštaja. Organizacije koje su već certifikovale svoje sisteme prema ranijem standardu ISO 9001:2008 sada moraju da pređu na novi standard, najkasnije do septembra 2018. godine. Jedan od većih problema u ovom prelasku predstavlja izrada potrebnih baza podataka koje su neophodne za praktičnu primenu novog standarda. Kao rešenje ovog problema autori predlažu generalni model sa šest prioritetnih baza podataka: baza za dokumentovane informacije; baza za mernu, kontrolnu i ispitnu opremu; baza za stručne kadrove; baza za reklamacije neispravnosti rezultata procesa; baza za troškove neispravnosti rezultata procesa i baza za održavanje pogonske i radne opreme.
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A rapid, relatively sensitive and simple kinetic-spectrophotometric method for determining sodium salicylate content has been developed and validated. This method was based on the Fenton reaction ...that involved mixing of ferrous ions, hydrogen peroxide and sodium salicylate in acetic buffer medium. Ferrous ions, oxidized by hydrogen peroxide, formed with salicylate anion purple complex whose degradation started immediately. This effect was monitored by the decrease of absorbance at 525 nm. The experimental results showed that the most favorable conditions for complex degradation are: pH = 3.9,
= 4.7 × 10
−5
M, and
= 1/150. The activation energy (
E
a
) calculated from the slope (
= 2.84 × 10
3
) was 54.3 ± 0.6 kJ/mol. The absorbance increased linearly with the increment of sodium salicylate concentration (
r
= 0.9983). The system obeyed Beer’s law in a range of 0.93–9.3 μg/mL of sodium salicylate concentration. The calculated values for the detection limit, according to two formulas, available in the literature, were found to be 0.67 and 0.48 μg/mL. The variables affecting the rate of the proposed reaction were investigated. The relative standard deviations for five-replicate determinations of 0.93, 3.31, and 9.30 μg/mL of sodium salicylate were calculated to be 6.80, 2.95, and 1.71%, respectively. The proposed method has been successfully applied to determining sodium salicylate in human serum and wine and validated by HPLC (high-pressure liquid chromatography) reference method.
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DOBA, EMUNI, FIS, FZAB, GEOZS, GIS, IJS, IMTLJ, IZUM, KILJ, KISLJ, MFDPS, NLZOH, NUK, OILJ, PILJ, PNG, SAZU, SBCE, SBJE, SBMB, SIK, UILJ, UKNU, UL, UM, UPUK, VKSCE, ZAGLJ
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