Influence of electromagnetic and nuclear radiation in medicine for therapy and diagnosis through processes, facts and statistical analysis

Contemporary medicine (biomedicine) cannot be imagined without diagnostics and therapeutic methods based on nuclear, laser, acoustical and other processes. The application of these methods is linked to common computer support, signal processing, measuring monitoring techniques, high degree of automatization, and image analyses. The paper analysed contemporary technical issues related to neonatology, ophthalmology, based on the influence of nuclear radiation and laser beams. Some statistical processing and presentations of results obtained in the IGA KCS Hospital, Belgrade, Serbia, in curing vision of prenatal type new-borns with a different degree of pathological state of retinopathy of prematurity are presented. The general conclusion is that, in spite of the good results, a multidisciplinary approach is needed for a deeper understanding of the role of lasers and laser techniques in medicine as well as possible couplings. Potential new applications of lasers important for the fields of neonatology and ophthalmology were also considered

Crack initiation and propagation resistance of hsla steel welded joint constituents

The welded joint is heterogeneous in its microstructure, mechanical and geometrical properties, thus the stress field is affected by different factors as well as by residual stress. Therefore, special procedures are needed for experimentally determining the fracture toughness in plane strain, K-Ic, and the impact toughness, usually associated with difficulties in interpreting the measured values. Notched specimens are tested by instrumented Charpy in order to determine impact energy and crack initiation and propagation energies. The pre-cracked specimens are tested by standard, using three-point bending specimens, as geometrically closest to Charpy specimens. In both cases, the notch and crack are located in all various regions of the welded joint of the high-strength low alloyed steel NIONIKRAL-70. Analysis of the results includes speculations on the ratio of energies for crack initiation and propagation vs. fracture toughness

Crack initiation and propagation resistance of hsla steel welded joint constituents

The welded joint is heterogeneous in its microstructure, mechanical and geometrical properties, thus the stress field is affected by different factors as well as by residual stress. Therefore, special procedures are needed for experimentally determining the fracture toughness in plane strain, K-Ic, and the impact toughness, usually associated with difficulties in interpreting the measured values. Notched specimens are tested by instrumented Charpy in order to determine impact energy and crack initiation and propagation energies. The pre-cracked specimens are tested by standard, using three-point bending specimens, as geometrically closest to Charpy specimens. In both cases, the notch and crack are located in all various regions of the welded joint of the high-strength low alloyed steel NIONIKRAL-70. Analysis of the results includes speculations on the ratio of energies for crack initiation and propagation vs. fracture toughness

Impact of co2 concentration on indoor air quality and correlation with relative humidity and indoor air temperature in school buildings in Serbia

Previous studies have shown that poorly ventilated classrooms can have negative impact on the health of children and school staff. In most cases, schools in Serbia are ventilated naturally. Considering their high occupancy, classroom air quality test determines the level of air pollution, after which it is possible to implement corrective measures. The research presented in this study, was conducted in four schools which are located in different areas and have different architecture designs. Measurements in these schools have been performed during the winter (heating season) and spring (non-heating season) and the following results were presented: indoor air temperature, relative humidity, and carbon dioxide concentration. These results show that the classroom average concentration of carbon dioxide often exceeds the value of 1500 ppm, during its full occupancy, which indicates inadequate ventilation. Measurement campaigns show that carbon dioxide concentration increased significantly from non-heating to heating season in three of the four schools. Analysis of measurements also determined high correlation between relative humidity and carbon dioxide concentration in all schools in winter season. This fact may constitute a solid basis for the fresh air supply strategy

Topological phase transition in a RNA model in the de Gennes regime

We study a simplified model of the RNA molecule proposed by G. Vernizzi, H. Orland and A. Zee in the regime of strong concentration of positive ions in solution. The model considers a flexible chain of equal bases that can pairwise interact with any other one along the chain, while preserving the property of saturation of the interactions. In the regime considered, we observe the emergence of a critical temperature T_c separating two phases that can be characterized by the topology of the predominant configurations: in the large temperature regime, the dominant configurations of the molecule have very large genera (of the order of the size of the molecule), corresponding to a complex topology, whereas in the opposite regime of low temperatures, the dominant configurations are simple and have the topology of a sphere. We determine that this topological phase transition is of first order and provide an analytic expression for T_c. The regime studied for this model exhibits analogies with that for the dense polymer systems studied by de GennesComment: 15 pages, 4 figure

Impact of co2 concentration on indoor air quality and correlation with relative humidity and indoor air temperature in school buildings in Serbia

Previous studies have shown that poorly ventilated classrooms can have negative impact on the health of children and school staff. In most cases, schools in Serbia are ventilated naturally. Considering their high occupancy, classroom air quality test determines the level of air pollution, after which it is possible to implement corrective measures. The research presented in this study, was conducted in four schools which are located in different areas and have different architecture designs. Measurements in these schools have been performed during the winter (heating season) and spring (non-heating season) and the following results were presented: indoor air temperature, relative humidity, and carbon dioxide concentration. These results show that the classroom average concentration of carbon dioxide often exceeds the value of 1500 ppm, during its full occupancy, which indicates inadequate ventilation. Measurement campaigns show that carbon dioxide concentration increased significantly from non-heating to heating season in three of the four schools. Analysis of measurements also determined high correlation between relative humidity and carbon dioxide concentration in all schools in winter season. This fact may constitute a solid basis for the fresh air supply strategy

Green living roof implementation and influences of the soil layer on its properties

Affected by undeniable climatic change, the temperature of the urban areas rises continually, increasing rapidly the energy problem of cities and amplifying the pollution problems. The thermal stress is increased, thus both the indoor and the outdoor thermal comfort levels are decreased, enhancing the health problems. Green roof implementation in the building envelope is strategy that provides heat island amelioration, thermal comfort for occupants and reduces energy consumption of buildings. Green living roofs are a passive cooling technique, which can stop the incoming solar radiation from reaching the building structure below. In this paper, we assessed the importance of the green roofs in providing environmental and building energy benefits, and brief investigation on the different configuration of the soil layer in the green roof assembly influences to the temperature of the roof surface was presented. Investigation was conducted for first phase of the living roof growth. Four cells were designed in Solid Works software where the transient thermal study was performed in order to determine differences between the behavior of the conventional roof and three green roof types

Green living roof implementation and influences of the soil layer on its properties

Affected by undeniable climatic change, the temperature of the urban areas rises continually, increasing rapidly the energy problem of cities and amplifying the pollution problems. The thermal stress is increased, thus both the indoor and the outdoor thermal comfort levels are decreased, enhancing the health problems. Green roof implementation in the building envelope is strategy that provides heat island amelioration, thermal comfort for occupants and reduces energy consumption of buildings. Green living roofs are a passive cooling technique, which can stop the incoming solar radiation from reaching the building structure below. In this paper, we assessed the importance of the green roofs in providing environmental and building energy benefits, and brief investigation on the different configuration of the soil layer in the green roof assembly influences to the temperature of the roof surface was presented. Investigation was conducted for first phase of the living roof growth. Four cells were designed in Solid Works software where the transient thermal study was performed in order to determine differences between the behavior of the conventional roof and three green roof types

Numerical analysis of lean premixed combustor fueled by propane-hydrogen mixture

A numerical investigation of combustion of propane-hydrogen mixture in a swirl premixed micro gas turbine combustor is presented. The effects of hydrogen addition into propane on temperature distribution in the combustor, reaction rates of propane and hydrogen and NO, emissions for different equivalence ratios and swirl numbers are given. The propane-hydrogen mixture of 90/10% by volume was assumed. The numerical results and measurements of NO emissions for pure propane are compared. Excellent agreements are found for all equivalence ratios and swirl numbers, except for the highest swirl number (1.13). It is found that the addition of hydrogen into propane increases NO, emission. On the other hand, the increase of swirl number and the decrease of equivalence ratio decrease the NO, emissions

Comparative analyses of built environment exposures relevant to health of greenhouse gas emissions reduction strategies in Serbia

Paper presents comparative analysis of residential indoor air pollutant concentration change over future specified time horizon, implementing building physical and thermal retrofit measures, thus creating pollution mitigation scenarios for existing Belgrade and Nis housing stock followed by greenhouse gas emission reduction scenarios up to 2050. Regarding specified mitigation scenarios, the set of typical housing unit models has been generated which define existing housing stock of Belgrade and Nis. Extensive monitoring of physical and thermal parameters as well as detailed socio-technical survey of selected households was performed and used as an initial modeling input. Relationship between environment pollution and building performances was investigated, with respect to indoor-outdoor sources of pollution, thermal and physical properties of the stock samples and occupant's behavior. As a final output, indoor pollutant concentrations for each of the modelled cases was obtained and validated against the available data. This housing modelling framework has been created in order to develop an assessment of present and future exposure and health impact quantity regarding single/multiple scenario interventions introduced to the housing stock. This paper provides each strategy guidelines for taking measures towards achieving the healthier indoor environments