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Search Results: 1 - 10 of 192155 matches for " D?oni? Slobodan "
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Radiation-hygiene control of imported foodstuffs and cattle feed
Slavata Branislava,Vitorovi? Gordana,DoniSlobodan
Veterinarski Glasnik , 2002, DOI: 10.2298/vetgl0204237s
Abstract: The increasingly frequent use of nuclear energy in peacetime, experimental nuclear and thermo-nuclear explosions, as well as accidents in nuclear plants lead to an increased and unequal distribution of radioactive substances in the environment. Mankind is in this way threatened not only by environmental irradiation, but also by consuming contaminated food and water which contain radionuclides whose concentrations are above the level of natural radioactivity. From the aspect of the veterinary profession, the most important task is to organize the protection of domestic animals and their products from radioactive contamination. This work presents the results obtained by measurements of the activity level of 137Cs in products of animal origin and cattle feed, in samples obtained from border crossings in Yugoslavia and partly in Macedonia during the period from 1990 until 1999. Examined import samples were taken from cheese, prok, and corn and the activity level of 137Cs was within the permitted legal levels - less than 1 Bq/kg. However, powdered milk was found to contain an activity level of 137Cs from 1,22-7,27 Bq/kg, and saltwater fish from 1,10-3,30 Bq/kg, so that these products could not be released for sale under the Official Gazette of the FRY, Number 53/91.
On the integrated continuum radio spectrum of supernova remnant W44 (G34.7-0.4): new insights from Planck
D. Oni
Physics , 2015, DOI: 10.2298/SAJ150715004O
Abstract: In this paper, the integrated continuum radio spectrum of supernova remnant (SNR) W44 was analyzed up to 70 GHz, testing the different emission models that can be responsible for its particular shape. The observations by the Planck space telescope made possible to analyze the high frequency part of radio emission from SNRs. Although the quality of radio continuum spectrum (a high scatter of data points at same frequencies) prevents us to make definite conclusions, the possibility of spinning dust emission detection towards this remnant is emphasized. In addition, a concave-down feature, due to synchrotron losses, can not be definitely dismissed by the present knowledge of the integrated radio continuum spectrum of this SNR.
The Analysis of the Possible Thermal Emission at Radio Frequencies from an Evolved Supernova Remnant HB 3 (G132.7+1.3): Revisited
Oni, D.,Uro?evi?, D.
Serbian Astronomical Journal , 2008,
Abstract: It has recently been reported that some of the flux density values for an evolved supernova remnant (SNR) HB 3 (G132.7$+$1.3) are not accurate enough. In this work we therefore revised the analysis of the possible thermal emission at radio frequencies from this SNR using the recently published, corrected flux density values. A model including the sum of non-thermal (purely synchrotron) and thermal (bremsstrahlung) components is applied to fit the integrated radio spectrum of this SNR. The contribution of thermal component to the total volume emissivity at $1 mathrm{GHz}$ is estimated to be $approx37 \%$. The ambient density is also estimated to be $napprox 9 mathrm{cm}^{-3}$ for $mathrm{T}=10^{4} mathrm{K}$. Again we obtained a relatively significant presence of thermal emission at radio frequencies from the SNR, which can support interaction between SNR HB 3 and adjacent molecular cloud associated with the mbox{H,{sc ii}} region W3. Our model estimates for thermal component contribution to total volume emissivity at $1 mathrm{GHz}$ and ambient density are similar to those obtained earlier ($approx40 \%$, $approx10 mathrm{cm^{-3}}$). It is thus obvious that the corrected flux density values do not affect the basic conclusions.
On the continuum radio-spectrum of Cas A: possible evidence of the non-linear particle acceleration
D. Oni,D. Uro?evi?
Physics , 2015, DOI: 10.1088/0004-637X/805/2/119
Abstract: Integrated radio-spectrum of Cas A in continuum was analyzed with special emphasis on possible high frequency spectral curvature. We conclude that the most probable scenario is that Planck's new data reveal the imprint of non-linear particle acceleration in the case of this young Galactic supernova remnant (SNR).
Development and application of a machine vision system for measurement of surface roughness
D. A. Fadare,A. O. Oni
Journal of Engineering and Applied Sciences , 2009,
Abstract: Monitoring of surface roughness is an essential component in planning of machining processes as it affects the surface quality and dimensional accuracy of machined components. In this study, the development and application of a machine vision system suitable for on-line measurement of surface roughness of machined components using artificial neural network (ANN) is described. The system, which was based on digital image processing of the machined surface, consisted of a CCD camera, PC, Microsoft Windows Video Maker, frame grabber, Video to USB cable, digital image processing software (Photoshop, and MATLAB digital image processing toolbox), and two light sources. The images of the machined surface were captured; analyzed and optical roughness features were estimated using the 2-D fast Fourier transform (FFT) algorithm. A multilayer perceptron (MLP) neural network was used to model and predict the optical roughness values. Tool wear index and five features extracted from the surface images were used as input dataset in training and testing the ANN model. The results showed that the ANN predicted optical roughness values were found to be in close agreement with the calculated values (R2-value = 0.9529). Thus, indicating that the proposed machine vision system and ANN model are adequate for online monitoring and control of surface roughness in machining environment.
Development and application of a machine vision system for measurement of tool wear
A. O. Oni,D. A. Fadare
Journal of Engineering and Applied Sciences , 2009,
Abstract: Tool wear monitoring is of great concern in machining industry, as it affects the surface qualities, dimensional accuracy and production costs of the machined components. The orthodox methods of measuring tool wear are time consuming and limited in accuracy and application. In this study, machine vision system based on digital image processing was developed for measurement of tool wear. The basic components of the system are: a charge coupled device (CCD) camera, PC, Microsoft Windows Video Maker, frame grabber, Video to USB cable, digital image processing software (Photoshop and digital image processing toolbox for MATLAB), multi-directional insert fixture, and light source. Tool wear images were captured and ten different wear features: length, width, area, equivalent diameter, centroid, major axis length, minor axis length, solidity, eccentricity and orientation were extracted from the images. The pixels dimension of the system was found to be Px = 0.03306 and Py = 0.03333. The accuracy of the system compared to SANDVIK Coromant hand-held microscopic lens was found to have an absolute error less than 3.13%. The system has been applied in the analysis tool wear of uncoated cemented carbide inserts used for turning of NST 37.2 steel. A tool wear index (TWI) was proposed as a potential indicator for tool wear monitoring. A graphical user interface (GUI) was designed for easy application of system.
Microwaves in organic chemistry and organic chemical
Mijin Du?an ?.,Petrovi? Slobodan D.
Hemijska Industrija , 2005, DOI: 10.2298/hemind0510224m
Abstract: The usual way of applying heat to a chemical reaction is the use of a Bunsen burner, an oil or some other type of bath, or an electric heater. In inorganic chemistry, microwave technology has been used since the late 1970s while it has been implemented in organic chemistry since the mid-1980s. Microwave heating has been used in the food industry for almost fifty years. The shorter reaction times and expanded reaction range that is offered by microwave technology are suited to the increased demands in industry. For example, there is a requirement in the pharmaceutical industry for a higher number of a novel chemical entities to be produced, which requires chemists to employ a number of resources to reduce time for the production of compounds. Also, microwaves are used in the food industry, as well as in the pyrolysis of waste materials, sample preparation, the solvent extraction of natural products and the hydrolysis of proteins and peptides.
Existence and Stability of Equilibrium Points in the Robe’s Restricted Three-Body Problem with Variable Masses  [PDF]
Jagadish Singh, Oni Leke
International Journal of Astronomy and Astrophysics (IJAA) , 2013, DOI: 10.4236/ijaa.2013.32013
Abstract:

The positions and linear stability of the equilibrium points of the Robe’s circular restricted three-body problem, are generalized to include the effect of mass variations of the primaries in accordance with the unified Meshcherskii law, when the motion of the primaries is determined by the Gylden-Meshcherskii problem. The autonomized dynamical system with constant coefficients here is possible, only when the shell is empty or when the densities of the medium and the infinitesimal body are equal. We found that the center of the shell is an equilibrium point. Further, when k1; k being the constant of a particular integral of the Gylden-Meshcherskii problem; a pair of equilibrium point, lying in the \"\"-plane with each forming triangles with the center of the shell and the second primary exist. Several of the points exist depending on k; hence every point inside the shell is an equilibrium point. The linear stability of the equilibrium points is examined and it is seen that the point at the center of the shell of the autonomized system is conditionally stable; while that of the non-autonomized system is unstable. The triangular equilibrium points on the \"\"-plane of both systems are unstable.

Fermented Milk Products from Different Milk Types  [PDF]
Olusola Ladokun, Sarah Oni
Food and Nutrition Sciences (FNS) , 2014, DOI: 10.4236/fns.2014.513133
Abstract: Yogurt was produced from milk obtained from cow milk, goat milk, soymilk and coconut milk by fermentation using starter cultures of Lactobacillus bulgaricus and Lactobacillus acidophilus.The results obtained showed that the initial pH of the fresh milk samples were slightly acidic: cow milk (6.3), goat milk (6.2), soymilk (6.4) and coconut milk (6.0). The pH results of the various fermented milk at 0 hour of production were goat milk (5.24), cow milk (5.85), soymilk (5.73) and coconut milk (5.98), but at 72 hours, all the milk samples tended to be more acidic due to the fermentation and had lower pH values. All the fresh milk samples had the high moisture content which ranged from 63.34% - 76.90%. Fat content ranged between 9.76% - 15.02%. Crude protein ranged from 7.17% - 32.17% with goat milk having the highest protein level of (32.17%). Ash content had the range of 0.52% - 0.96%. Goat milk had the highest ash content value and coconut milk had the least value. Specific gravities of soymilk, goat milk, cow milk and coconut milk were 1.018, 1.030, 1.016 and 1.01 g/ml respectively. Taste, color, mouth feel and odor were acceptable at 0 hours of production but their value depreciated with storage at room temperature. This study was able to establish the close nutritional gap between cow milk, goat milk, soya and coconut milk yoghurt preparations. The nutritional values obtained from the proximate analysis of the milk samples were comparable. This clearly points to the fact that either of the food can substitute for each other based on the values established from this study.
Energy analysis for production of powered and pelletised organic fertilizer in Nigeria
D. A. Fadare,O. A. Bamiro,A. O. Oni
Journal of Engineering and Applied Sciences , 2009,
Abstract: Energy study was conducted in an organic fertilizer plant in Ibadan, Nigeria, to determine the energy requirement for production of both powdered and pelletised organic fertilizer. The energy consumption patterns of the unit operations were evaluated for production of 9,000 kg of the finished products. The analysis revealed that eight and nine defined unit operations were required production of powder and pellets, respectively. The electrical and manual energy required for the production of powder were 94.45 and 5.55% of the total energy, respectively, with corresponding 93.9 and 5.07% for the production of pellets. The respective average energy intensities were estimated to be 0.20 and 0.35 MJ/kg for powder and pellets. The most energy intensive operation was identified as the pulverizing unit with energy intensity of 0.09 MJ/kg, accounting for respective proportions of 33.4 and 27.0% of the total energy for production of powder and pellets. Optimization of the pulverizing process is suggested to make the system energy efficient.
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