Zontar D.,Slovenian Radiation Protection Administration |
Zontar D.,Jozef Stefan Institute |
Kuhelj D.,University of Ljubljana |
Skrk D.,Slovenian Radiation Protection Administration |
Zdesar U.,Institute of Occupational Safety of Slovenia
Radiation Protection Dosimetry | Year: 2010
Interventional cardiac procedures not only lead to significant effective doses for the patient but also can potentially cause deterministic effects on the patient's skin. Information about the peak (maximal) skin doses (PSD) received by patients during percutaneous transluminal coronary angioplasty procedures were collected from three cardiac catheter rooms. Cumulative dose at the interventional reference point (CDIRP) was collected for 161 patients and for 16 patients PSD was determined using Gafchromic dosimetry films. The comparison showed that CDIRP readings give a useful but conservative estimation of patient peak skin dose as it can lead to a significant overestimation. The median and third quartile values of CDIRP were 0.64 and 0.92 Gy, respectively. The 2 Gy threshold for deterministic effects was exceeded in nine patients. A good correlation was found between CDIRP and kerma area product measurements while the correlation with fluorography time was very weak. © The Author 2010. Published by Oxford University Press.
Dezelak F.,Institute of Occupational Safety of Slovenia |
Cudina M.,University of Ljubljana
Proceedings of the Institution of Mechanical Engineers, Part C: Journal of Mechanical Engineering Science | Year: 2014
Impulse noise is one of the most hazardous and annoying types of noise, which is present in the working and community environment. A-weighted equivalent sound pressure level, describing most types of noise, appears not to be the appropriate descriptor, especially not for high-impulsive and high-energy impulsive noise. However, this descriptor is often used as a basis for impulse noise evaluation, when combined with appropriate adjustment terms. But despite of objective character of such evaluation, care should be taken regarding certain facts, especially the source of impulse noise, its environment and time of measurement. In this article, the relationships between all these influential parameters have been investigated in detail. Today, on the other hand, a sophisticated sound level meter offers the possibility of simultaneous measurement of many acoustical descriptors. By combining some of these descriptors with some analytical investigations, as shown in this article, more useful information concerning impulse noise can be obtained. In this article some of them are used for more detailed analysis of impulse correction, according to some international standards. © IMechE 2013.
Dezelak F.,Institute of Occupational Safety of Slovenia |
Curovic L.,Institute of Occupational Safety of Slovenia |
Cudina M.,University of Ljubljana
Applied Acoustics | Year: 2016
In some cases an impulsive noise source such as a gunshot can be a preferred alternative when investigating building acoustics, including sound insulation measurements, when compared to conventional steady state noise sources. A gun equipped with blank cartridges is an impulsive noise source that is lightweight and small enough to be easily transported. The differences in the noise characteristics between individual cartridges for the same gun are usually small, so the impulsive source can be replicated to a high degree. This paper is focused on the practical application of the sound exposure levels produced by a gunshot with a known sound energy level in the rooms under investigation. In this way, the equipment and methods required by the conventional method are simplified significantly. Furthermore, reverberation times need not be measured, since the equivalent absorption area can be directly obtained from the measured sound exposure levels. Using Green's theorem, the roles of the sound source and measuring microphone were exchanged, which simplified the determination of sound insulation as it was easier to change the position of the gun than the microphone. The results obtained using the impulsive noise source were in good agreement with those obtained using the conventional method. Above 100 Hz, their difference in any frequency band of interest was less than 1 dB. © 2015 Elsevier Ltd. All rights reserved.
Bracic M.,University of Ljubljana |
Bracic M.,Institute of Occupational Safety of Slovenia |
Hadzic V.,University of Ljubljana |
Coh M.,University of Ljubljana |
Dervisevic E.,University of Ljubljana
Isokinetics and Exercise Science | Year: 2011
Background: Previous studies have investigated the role of hamstrings and quadriceps absolute and/or relative peak torque at high concentric velocities (240 and 300°/sec) and sprint performance but their findings were inconclusive. However, no study so far has investigated the relationship between time to peak torque (TPT) of hamstrings and quadriceps at high concentric velocity and sprint ability. This parameter may play and important role in sprinting, as it is one of the indicators of the explosive muscular strength that is crucial for sprinting performance. Method: Thirty six healthy physical education students without previous injury voluntarily participated in investigation. The measurements of the sprint times at 5, 10 and 20 meters were carried out using an infrared photocell. Quadriceps and hamstrings strength was tested concentrically at 240°/sec using Biodex System 3 dynamometer. Linear regression was used to evaluate the influence of hamstrings and quadriceps relative strength and TPT on sprint times at 5, 10 and 20 meters. Results. Hamstrings' TPT significantly predicted the sprint times at 5, 10 and 20 meters (p values were 0.001, 0.004 and 0.008, respectively). At 5, 10 and 20 meters the model was significant (F =7.12, p<0.01; F=5.31, p < 0.05; F=4.07, p < 0.05, respectively) while R square values were 0.31, 0.26, and 0.21, respectively. Subjects with hamstrings TPT below 200 ms had significantly shorter sprint times at all sprint distances in comparison with subjects whose hamstrings TPT was above 200 ms. Quadriceps' TPT was not correlated with sprint times. Conclusion: The ability of the hamstrings to produce torque quickly can significantly influence the sprint times at 20 m sprint. Most of this effect is seen in the initial acceleration phase (first 5 m) while later on (at 10 and 20 m) this influence slightly decreases but remains significant. It seems that not only the absolute amount of strength, but also the rate of strength development within the muscle can influence the sprint times. © 2011-IOS Press and the authors. All rights reserved.
Ravljen M.,University of Ljubljana |
Bilban M.,Institute of Occupational Safety of Slovenia |
Kajfez-Bogataj L.,University of Ljubljana |
Hovelja T.,University of Ljubljana |
Vavpotic D.,University of Ljubljana
International journal of environmental research and public health | Year: 2014
BACKGROUND: A nationwide study was conducted to explore the short term association between daily individual meteorological parameters and the incidence of acute coronary syndrome (ACS) treated with coronary emergency catheter interventions in the Republic of Slovenia, a south-central European country.METHOD: We linked meteorological data with daily ACS incidence for the entire population of Slovenia, for the population over 65 years of age and for the population under 65 years of age. Data were collected daily for a period of 4 years from 1 January 2008 to 31 December 2011. In line with existing studies, we used a main effect generalized linear model with a log-link-function and a Poisson distribution of ACS.RESULTS AND CONCLUSIONS: Three of the studied meteorological factors (daily average temperature, atmospheric pressure and relative humidity) all have relevant and significant influences on ACS incidences for the entire population. However, the ACS incidence for the population over 65 is only affected by daily average temperature, while the ACS incidence for the population under 65 is affected by daily average pressure and humidity. In terms of ambient temperature, the overall findings of our study are in line with the findings of the majority of contemporary European studies, which also note a negative correlation. The results regarding atmospheric pressure and humidity are less in line, due to considerable variations in results. Additionally, the number of available European studies on atmospheric pressure and humidity is relatively low. The fourth studied variable-season-does not influence ACS incidence in a statistically significant way.
PubMed | Institute of Occupational Safety of Slovenia and University of Ljubljana
Type: Journal Article | Journal: International journal of environmental research and public health | Year: 2014
A nationwide study was conducted to explore the short term association between daily individual meteorological parameters and the incidence of acute coronary syndrome (ACS) treated with coronary emergency catheter interventions in the Republic of Slovenia, a south-central European country.We linked meteorological data with daily ACS incidence for the entire population of Slovenia, for the population over 65 years of age and for the population under 65 years of age. Data were collected daily for a period of 4 years from 1 January 2008 to 31 December 2011. In line with existing studies, we used a main effect generalized linear model with a log-link-function and a Poisson distribution of ACS.Three of the studied meteorological factors (daily average temperature, atmospheric pressure and relative humidity) all have relevant and significant influences on ACS incidences for the entire population. However, the ACS incidence for the population over 65 is only affected by daily average temperature, while the ACS incidence for the population under 65 is affected by daily average pressure and humidity. In terms of ambient temperature, the overall findings of our study are in line with the findings of the majority of contemporary European studies, which also note a negative correlation. The results regarding atmospheric pressure and humidity are less in line, due to considerable variations in results. Additionally, the number of available European studies on atmospheric pressure and humidity is relatively low. The fourth studied variable-season-does not influence ACS incidence in a statistically significant way.
PubMed | Institute of Occupational Safety of Slovenia, Slovenian Radiation Protection Administration and University of Ljubljana
Type: Journal Article | Journal: Radiology and oncology | Year: 2015
The aim of the study was to systematically evaluate population exposure from diagnostic and interventional radiological procedures in Slovenia.The study was conducted in scope of the Dose Datamed 2 project. A standard methodology based on 20 selected radiological procedures was adopted. Frequencies of the procedures were determined via questionnaires that were sent to all providers of radiological procedures while data about patient exposure per procedure were collected from existing databases. Collective effective dose to the population and effective dose per capita were estimated from the collected data (DLP for CT, MGD for mammography and DAP for other procedures) using dose conversion factors.The total collective effective dose to the population from radiological in 2011 was estimated to 1300 manSv and an effective dose per capita to 0.6 mSv of which approximately 2/3 are due to CT procedures.The first systematic study of population exposure to ionising radiation from radiological procedures in Slovenia was performed. The results show that the exposure in Slovenia is under the European average. It confirmed large contributions of computed tomography and interventional procedures, identifying them as the areas that deserve special attention when it comes to justification and optimisation.
Grgic I.,Slovenian National Institute of Chemistry |
Iskra I.,Ape Research |
Podkrajsek B.,Institute of Occupational Safety of Slovenia |
Gerjevic V.D.,Skocjan Caves Regional Park
Environmental Science and Pollution Research | Year: 2014
For the first time, continuous aerosol measurements were performed in the Škocjan Caves, one of the most important cave systems in the world, and listed by UNESCO as a natural and cultural world heritage site since 1986. Measurements of PM10 were performed during three different periods: (1) in December 2011, the average background concentration was found to be about 4 μg m-3; (2) in June 2012, a higher concentration was measured (8 μg m-3); and (3) from 8 to 20 August 2012, the highest concentration of 15.3 μg m-3 was measured. Based on the PM10 measurement results, and as compared to similar measurements outside the cave, it can be hypothesized that the increase in the cave's aerosol concentration during the summer was connected to both the higher number of visitors and the polluted atmospheric air entering the cave upon entering of the cave system. Additional measurement of nanoparticles with scanning mobility particle sizer spectrometer (size between 14.1 and 710.5 nm) confirmed these findings; during the summer period, a severe raise in the total aerosol concentration of 30-50 times was found when groups of visitors entered the cave. Our results on nanoparticles demonstrated that we were able to detect very small changes and variations in aerosol concentration inside the cave. To our knowledge, these are the first results on nanoaerosol measurements in a cave, and we believe that such measurements may lead to the implementation of better protection of delicate cave systems. © 2013 Springer-Verlag Berlin Heidelberg.
Jovanovic P.,Institute of Occupational Safety of Slovenia
Radioprotection | Year: 2011
Uranium mine Žirovski vrh in Slovenia was closed in the year 1993. In the past years a lot of work was done for restoration of the area around the mine. There are two tailing sites, Jazbec and Boršt, filled with material with high specific activity of 226Ra. Tailings are covered by different layers of clay and soil in depth of 2 m for reducing radon exhalation rate. Gras, growing on the surface of tailing sites has been used as fodder for domestic animals. We were interesting about the amount of the specific activity of natural radionuclides 238U, 226Ra or 210Pb, transferred from the covering soil on the tailing to the grass on the surface area. The transfer factors of naturally occurring radionuclides have not been studied to the same extent as their artificial counterparts, but some comprehensive investigations have been done by various institutions around the world. In case of 226Ra calculated values are two times or four times bigger than measured. For 210Pb measured values are up to hundred times bigger than calculated. The reason for that is radon in the air, decays to the 210Pb, deposited on the grass and not 210Pb coming from the soil. © 2011 EDP Sciences.
Dezelak F.,Institute of Occupational Safety of Slovenia
Noise Control Engineering Journal | Year: 2010
Industrial facilities often contain several simultaneously-operating noise sources that can cause the sound level in neighboring residential areas to exceed established limits, especially during nighttime hours. This paper describes an analytical procedure that may be used in conjunction with measurements of sound pressure levels near the individual sources and in a neighboring residential area to rank order the contribution of the various sources to the total sound level at a sensitive location in the community. The sources are assumed to be incoherent and not too close together.The procedure was applied to the sound from a coal-fired electricity-generating station that also provided steam heat for the community. A loudspeaker placed near a noise source produced an increment in near-field sound level along with the simultaneously-measured increment in total sound level in the neighboring residential area. Of 200 noise sources associated with the facility, 16 were shown to be the main contributors to the sound from the power station. Application of noise-control procedures reduced the sound level in the neighboring community by up to 15 dB. The uncertainty of the measurements was shown to be the least when the sound level changes were largest, and vice versa. © 2010 Institute of Noise Control Engineering.