33 research outputs found
Nuclear Track Detectors. Searches for Exotic Particles
We used Nuclear Track Detectors (NTD) CR39 and Makrofol for many purposes: i)
Exposures at the SPS and at lower energy accelerator heavy ion beams for
calibration purposes and for fragmentation studies. ii) Searches for GUT and
Intermediate Mass Magnetic Monopoles (IMM), nuclearites, Q-balls and
strangelets in the cosmic radiation. The MACRO experiment in the Gran Sasso
underground lab, with ~1000 m^2 of CR39 detectors (plus scintillators and
streamer tubes), established an upper limit for superheavy GUT poles at the
level of 1.4x10^-16 cm^-2 s^-1 sr^-1 for 4x10^-5 <beta<1. The SLIM experiment
at the high altitude Chacaltaya lab (5230 m a.s.l.), using 427 m^2 of CR39
detectors exposed for 4.22 y, gave an upper limit for IMMs of ~1.3x10^-15 cm^-2
s^-1 sr^-1. The experiments yielded interesting upper limits also on the fluxes
of the other mentioned exotic particles. iii) Environmental studies, radiation
monitoring, neutron dosimetry.Comment: Talk given at "New Trends In High-Energy Physics" (experiment,
phenomenology, theory) Yalta, Crimea, Ukraine, September 27-October 4, 200
Communicating Heritage through Intertwining Theory and Studio Based Course in Architectural Education
This paper has emerged from a belief in the importance of architectural history for modern architectural practice and the education of young architects today. It proposes an alternative teaching approach in which theory-based and studio-based methodology are interconnected and mutually challenged to communicate heritage in the most beneficial way. The approach attempts to avoid communicating basic descriptive facts, but is rather based on the interpretation of theoretical knowledge through individual designs, and provokes discussions questioning universal messages of architecture through individual spatial solutions. It was introduced at the Faculty of Architecture in Belgrade, through the elective course New Reading of Architecture for the third-year students, in the school year of 2014/15 and 2015/16. Results show that critical thinking through designing, as opposed to the usual factual approach, met a favourable response from student. Both in architectural history and in designing for protected historical sites, having been made more historically aware and place-sensitive, they were actively encouraged to conduct research, and to define and shape their own design approach accordingly. It can be noted that experiencing the theory of architecture through critical reading of well-known treatises and exploring it through a design lens made the history of architecture an equal partner in the construction of the present
Enhancing local identity through fostering research-based education in architecture
This paper emerged from the strong belief in the importance of research-based education for enhancing local identity in modern architectural practice and education of young architects today. It proposes an alternative teaching approach, introduced at the Faculty of Architecture, University of Belgrade, in the academic years 2014/15 and 2015/16. The main argument presented in the paper is: In order to strengthen the role of architectural history in education and in the profession, content-based teaching should be replaced with pedagogical experimentations, having an emphasis in converting from teaching to learning
Radon levels and resulting effective doses of residents in Gornja Stubla at Kosovo applying dosimetric lung models based on ICRP 65 and ICRP 66 methodology
The town Gornja Stubla, situated in the South-West part of Kosovo, is a community with high indoor radon
level due to its geochemical background. Radon activity concentration in indoor air has been measured by exposing
the 960 track-etch detectors for one year, in 172 rooms of 65 dwellings. Annual averages of concentration ranged from
35 Bq/m3 to 6010 Bq/m3. In a first attempt, the effective doses of residents have been calculated applying the ICRP 65
methodology, based on the average radon concentration for the dwelling and for concentrations in the rooms of a
dwelling in which they spend fractions of the entire time spent indoors. Both seasonal and annual doses have been
calculated. The annual values were in the range of 0.6−107 mSv/a with an average value of 8.6 mSv/a.
As nest step we considered that effective dose, being influenced by a number of different parameters and divided into
subject and aerosols related parameters, is connected with two crucial parameters, namely, the Dose Conversion
Factor (DCF) [mSv/WLM] for a particular person (accounting for real gender, age and physical activity level) and
indoor radon concentration and its short lived progeny at field area. Therefore, software based on ICRP Publication 66
was developed for determination of effective dose per unit inhaled activity of radon progeny, DCF. According to the
results of indoor radon measurements in the area of Gornja Stubla, the effective dose for its population was estimated
by using the dosimetric lung model. The results, obtained according to ICRP 66, were compared with results calculated
according to ICRP Publication 65
Ontogenetic profile of ecto-ATPase activity in rat hippocampal and caudate nucleus synaptic plasma membrane fractions
An ontogenetic study of ecto-ATPase activity and the content of enzyme proteins was assessed in the caudate nucleus and hippocampal synaptic plasma membranes isolated from rats at various ages (15, 30, 90, 180 and 365 days). The ontogenetic profile revealed that the enzyme activities in both brain areas were the highest on day 30 and 365, while the ecto-ATPase protein abundance was the highest on day 15 after birth. Possible explanation for obtained ontogenetic profile and the discrepancy between activity and abundance may reside in the fact that ecto-ATPase during development could exert additional roles other than those related to metabolism of ATP. It is likely that ecto-ATPase, regulating the concentration of ATP and adenosine in synaptic cleft, has important role in the processes of brain development and aging
Selective inhibition of brain Na,K-ATPase by drugs
The effect of drugs from the class of cardiac (methyldigoxin, verapamil, propranolol), antiepileptic ( carbamazepine), sedative (diazepam) and antihistaminic (promethazine) drugs on Na,K-ATPase activity of plasma membranes was studied in rat brain synaptosomes. Methyldigoxin in a concentration of 0.1 mmol/l inhibits enzyme activity by 80%. Verapamil, propranolol and promethazine in concentrations of 20, 20 and 2 mmol/l respectively, entirely inhibit the ATPase activity. Carbamazepine and diazepam in concentrations of 0.02-60 mmol/l have no effect on the activity of this enzyme. According to the drug concentrations that inhibit 50% of enzyme activity (IC50), the potency can be listed in the following order: methyldigoxin GT GT promethazine GT verapamil GT = propranolol. From the inhibition of commercially available purified Na, K-ATPase isolated from porcine cerebral cortex in the presence of chosen drugs, as well as from kinetic studies on synaptosomal plasma membranes, it may be concluded that the drugs inhibit enzyme activity, partly by acting directly on the enzyme proteins. Propranolol, verapamil and promethazine inhibitions acted in an uncompetitive manner. The results suggest that these three drugs may contribute to neurological dysfunctions and indicate the necessity to take into consideration the side effects of the investigated drugs during the treatment of various pathological conditions
Effective dose for real population exposed to indoor radon in former uranium mine area Kalna (Eastern Serbia)
This paper deals with calculated effective doses that members of real population received from radon gas and its short lived progeny during air inhalation in their dwellings at field site Kalna in Eastern Serbia. There are two crucial parameters in effective dose calculation: Dose Conversion Factor (DCF) for particular subjects (including real gender, age and physical activity level) and indoor concentration of
radon and its short lived progeny in field area. According to the results of indoor radon measurements in the area of former uranium mine, Kalna, the effective dose for this real population was estimated by using the dosimetric lung model, developed by authors according ICRP Publication 66 [1]. Authentic software was developed for determination of effective dose per unit inhaled activity of radon progeny, DCF expressed in unit [mSv/WLM]. The results, obtained according to ICRP66 dosimeter lung model [1], were compared with results calculated according to ICRP Publication 65 [2]. The dosimetric results were, also, compared and discussed with epidemiological approach data, according to UNSCEAR [3]