Download FASCICLE II, SUPPLEMENT, YEAR II (XXXI) 2008

THE ANNALS OF THE “DUNĂREA DE JOS” UNIVERSITY OF GALAŢI
MATHEMATICS, PHYSICS, CHEMISTRY, INFORMATICS
FASCICLE II, SUPPLEMENT, YEAR II (XXXI) 2008
Proceedings of the
Fourth National Conference on Applied Physics,
Galati, September 25-26, 2008
SUMMARY
OCCUPATIONAL DEAFNESS PROPHYLAXIS.................................................
L. Moraru, G. Ionescu
BIOLOGICALLY-EFFECTIVE DOSE SEMNIFICATIONS AND
CLINICAL APLICATIONS.....................................................................................
M.Dumitru, M.Praisler, L.Rebegea
EVALUATION AND CONTROL OF THE ENVIRONMENTAL NOISE.........
L.Moraru, A.Rauta
PERSPECTIVES ON TOMOGRAPHY.................................................................
M.C.Nicolae, L. Moraru
THE QUALITY OF THE SURFACE AND UNDERGROUND WATERS IN
THE SOUTH-EAST REGION.................................................................................
L. Marica, L. Moraru
ELECTROMAGNETIC FIELDS - RISK TO OUR HEALTH VERSUS
BENEFIT …………………………………………………………………………...
L.Moraru, L. Onose , D. Onose
OPERATIONAL PROGRAMME EDUCATION OF ROMANIA - A STUDY
CASE...........................................................................................................................
A.Onu, L. Moraru
INTERCONDITIONING OF HEAT AND MASS TRANSFER PROCESSES
WITHIN A VERTICAL FILM ABSORBER…………………………………….
Sava Porneala
STUDIES OF THE PERFORMANCE OF THE RESORPTION HEAT
PUMP..........................................................................................................................
Sava Porneala
STUDY
REGARDING
THE
NITRITES
AND
NITRATES
DETERMINATION, USING SPECTROPHOTOMETRY METHODS,
FOLLOWING THE DETERMINATION OF THE POLLUTION LEVEL
FROM BRATEŞ NURSERY ...................................................................................
D.Rusu, N.Patriche, M.Talpeş, M.Tenciu
SPECTRAL
AND
THERMODYNAMIC
PROPERTIES
OF
CHOLESTERYL MYRISTATE IN THE REGION OF PHASE
TRANSITION………………………………………………………………………
7
13
17
23
28
36
43
48
54
62
71
V. Danchuk, A. Kravchuk, G. Puchkovska, A. Yakubov
LUMINESCENT AND OPTICAL CHARACTERISTICS OF ZINC
SULFIDE THIN FILMS PRODUCED BY CLOSE-SPASED VACUUM
SUBLIMATION……………………………………………………………………
D. Kurbatov, A. Opanasyuk, S. Kshnyakina, V.Mеlnik, V.Nesprava
BIOLOGICAL EFFECTS AND PROTECTION AGAINST IONIZING
RADIATIONS………………………………………………………………………
M.Dumitru, M.Praisler , L. Paraschiv-Rebegea
ANTIOXIDANT PROPERTIES OF β-CAROTENE IN SOME FOOD
EMULSIONS.............................................................................................................
R. Creţu, Ş.Dima
COMPARATIVE
STUDY
OF
PHYSICAL,
CHEMICAL
AND
BIOLOGICAL METHODS FOR DETECTION OF
IRRADIATED
FOODSTUFFS……………………………………………………………………..
M.Cutrubinis, M.Virgolici, D.Negut, M.Alexandru, L.Trandafir, M. Manea,
M.Constantin
EXPERIMENTAL ASPECTS IN THE DETERMINATION OF ALLUVIAL
GOLD BY INSTRUMENTAL FAST NEUTRON ACTIVATION ANALYSIS
(FNAA).......................................................................................................................
A.Nat, A.Ene
TRANSFER COEFFICIENTS’ EVALUATIONS USING SYSTEM
SENSIBILITY ASSESSMENT................................................................................
G.Murariu, Gh. Puscasu, M. Dobrea, V. Vacarus
THE SOLVENT INFLUENCE OF SOME SUBSTITUTED PHENOLS
STRUCTURES……………………………………………………………………...
M. Dimitriu, E. Filip, D. O. Dorohoi, I. Humelnicu
UNIVERSAL INTERACTIONS IN BINARY SOLUTIONS,STUDIED BY
SPECTRAL MEANS……………………………………………………………….
L. V. Gheorghies, M. Dimitriu, E. Filip, D. O. Dorohoi
LIGHT-SURFACE INTERACTION IN THE STUDY OF THE
RESTAURED PAINTINGS………………………………………………………
N. Melniciuc-Puica, D. O. Dorohoi
SOME REMARKS ON THE HUMAN EYE ACCOMODATION PROCESS...
M. Miron, C. D. Nechifor, G. Gheorghies , D. O. Dorohoi
POLYMERIC FILMS UNDER UV AND GAMMA RADIATIONS...................
C. D. Nechifor, D. O. Dorohoi, C. Ciobanu
SELF-DUAL GAUGE THEORY WITH COSMOLOGICAL CONSTANT…..
D. H. Partenie, C. Popa
ELECTROSTATIC FIELD ACTION ON POLYMERIC ESTERS OF
ALKOXYBENZOIC ACID (PEABA) IN TETRACHLOROMETHANE
(TCM)………………………………………………………………………………..
A. Rogojanu, D.O. Dorohoi
ANALYSIS AND CONTROL OF METALLURGICAL MATERIALS
USING X-RAY FLUORESCENCE TECHNIQUE AND X-RAY
ATTENUATION........................................................................................................
Antoaneta Ene, Alina Boşneagă, Andreea Ene
EXPERIMENTAL METHODS TO DETERMINE THE LIGHT
POLARIZATION STATE........................................................................................
I.Dumitraşcu, L. Dumitraşcu, M. Antonia, D. O. Dorohoi
75
80
86
94
105
113
120
125
131
136
141
148
156
161
167
SOME EXPERIMENTS USED IN CHARACTERIZATION OF
ANISOTROPIC LAYERS BY A POLARIZING MICROSCOPE......................
L. Dumitraşcu, I. Dumitraşcu, N. Puica Melniciuc, D. O. Dorohoi
A MODERN WAY IN PHYSICS LABORATORY...............................................
A.Dănilă, E. Dănilă
A MODERN WAY IN SOLVING PHYSICS PROBLEMS..................................
A. Dănilă, E.Dănilă
CLASSICAL EXPERIMENTS IN MODERN PRESENTATION……………...
E.Dănilă, A.Dănilă
COMPUTER SIMULATIONS AND EXPERIMENTAL INVESTIGATIONS
ON THE UV-VIS ELECTRONIC SPECTRA OF THE DPPH RADICAL…....
E. Filip, I. Humelnicu, C. Ghirvu
BALANCE OF THE NATURAL RADIOACTIVITY IN IRON AND STEEL
MATERIALS BY LOW-LEVEL GAMMA SPECTROMETRY……………….
Mioara Tănase
A COMPARISON OF THE FOOD COLLOIDS COLOUR FORMATION BY
SOME COLOUR SPACES AND COMPUTERIZED IMAGE ANALYSIS.......
Romică Creţu
THE CHROMATOGRAPHIC PEAK AND THEIR QUANTITATIVE
PARAMETER VALUES...........................................................................................
Gheorghe Zgherea, Cristina Stoian
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THE ANNALS OF THE “DUNĂREA DE JOS” UNIVERSITY OF GALATI
MATHEMATICS, PHYSICS, CHEMISTRY, INFORMATICS
FASCICLE II, SUPPLEMENT, YEAR II (XXXI) 2008, pp. 7-12
OCCUPATIONAL DEAFNESS PROPHYLAXIS
L. Moraru1, G. Ionescu 2
1
Physics Department, University of Galati, Romania.
2
General Hospital CF Galati, Romania
Abstract
The contribution presents a series of collective and individual prophylactic methods which are
still valid in high-noise level exposure work places. Even if there have been reached some
achievements with regard to some technical protection methods, highly costly for employers,
as regards the individual protection methods results are still poor because of the individuals’
attitude towards accepting or not hearing protectors. Yet, the results obtained imply low costs
as it is particularly common for the individual to be taken out from the noise environment.
Keywords: deafness, prophylactic methods, noise environment
THE ANNALS OF THE “DUNĂREA DE JOS” UNIVERSITY OF GALATI
MATHEMATICS, PHYSICS, CHEMISTRY, INFORMATICS
FASCICLE II, SUPPLEMENT, YEAR II (XXXI) 2008, pp. 13-16
BIOLOGICALLY-EFFECTIVE DOSE
SEMNIFICATIONS AND CLINICAL APLICATIONS
Mihaela Dumitru1, Mirela Praisler2, Laura Rebegea1
1
Emergency Clinical Hospital „St. Ap. Andrew”, Galati,
2
University „Dunarea de Jos”, Galati
Abstract
Major developments in radiotherapy fractionations have taken place during the past to
decades and these have grown out of developments in radiation biology. The relationships
between total dose and dose per fraction for late responding tissues, acutely responding tissues
and tumours, provide the basic information required to optimize radiotherapy according to the
dose per fraction and number of fractions.
Biollogically-effective dose (BED) represents the total dose that would be required in very
small dose fractions to produce a particular effect, as indicated by the linear-quadratic (LQ)
equation.
When multiple fractions per day are used, the repair (or more correctly, recovery) of damage
due to one radiation dose may not be complete before the next fraction is given, especially if
the half-time for repair is relatively long in relation to the time interval between fractions.
Incomplete repair will tend to reduce the isoeffective dose and corrections have to be made for
the consequent loss of tolerance.
Radiotherapy schedules using multiple fractions per day are associated with an increased
biological effect unless the interval between fractions is sufficiently long to allow full
recovery between fractions.
In clinical practice BED is used in case of: changes in fraction size during treatment, new
fraction size, constant throughout treatment.
A specific problem in clinical practice is the radiotherapeutic management of patients with a
new primary tumor or a loco-regional recurrence in an anatomical site that necessitates reirradiation of a previously irradiated tissue or organ. The most reasonable approach is to use
the LQ model to estimate BED values for organs and tissues at risk without any assumed
recovery and than to apply a clinically assessment of the re-irradiation tolerance.
In most of the cases we use BED calculation in cases of bone metastases, for re-irradiation
treatment, because of the tolerance at irradiation of spinal cord, knowing that over a total dose
by 40 Gy can occur radiation myelopathy.
Keywords: biologically-effective dose (BED), semnifications aplications, clinical aplications
THE ANNALS OF THE “DUNĂREA DE JOS” UNIVERSITY OF GALATI
MATHEMATICS, PHYSICS, CHEMISTRY, INFORMATICS
FASCICLE II, SUPPLEMENT, YEAR II (XXXI) 2008, pp. 17-22
EVALUATION AND CONTROL OF
THE ENVIRONMENTAL NOISE
Luminita Moraru1, Alina Rauta2
1
22
Physics Department, University of Galati, Romania.
Master Student, Physical-Chemical Methods of Analysis and Control,
Faculty of Sciences, University DUNAREA DE JOS of Galati
Abstract
This paper deals with the noise pollution study, the noxious effects action upon the population and
the measures that could be taken in order to prevent it. There is agreement that noise reduction at
source is the first choice for preventing noise pollution. Principles and measures for engineering
noise control, always placing control of noise at the source in the center of any preventive strategy.
For this very purpose, the European Parliament and Council have adopted the 2002/49/EC Directive
on June 29, 2002, whose main task is to create a common basis for the urban administering of the
environmental noise. The paper presents the experimental measurements of the noise level in the
Galati Municipality, inside an industrial enterprise. The measurement and analysis of noise are of
great importance for the amelioration of the quality of life.
Keywords: noise pollution, noxious effects
THE ANNALS OF THE “DUNĂREA DE JOS” UNIVERSITY OF GALATI
MATHEMATICS, PHYSICS, CHEMISTRY, INFORMATICS
FASCICLE II, SUPPLEMENT, YEAR II (XXXI) 2008, pp. 23-27
PERSPECTIVES ON TOMOGRAPHY
M.C.Nicolae1, L. Moraru2
Hospital “Buna Vestire” Galati, Romania
Physics Department, University of Galati, Romania.
1
2
Abstract
The paper presents a new and efficient computer aided method to investigate the interior of an
organ. The field of the numerical processing of images is a wide and dynamic one, using a lot of
computational techniques for data transmission, storing and processing. Current applications have
as objective automation and robotizing of industrial processes, robots path planning, form
recognition, obstacles detection, processing the television images but also, the complex field of
biomedical investigations. In the biomedical field, the automatic systems for images processing are
very important and imposing new techniques much more advanced and performing than before, in
order to aid a correct analysis and diagnosis. Through the medical techniques using computer
sciences could be noticed: scintigraphy, ecography, tomography, radiography, quantitative
microscopy, nuclear magnetic resonance. The computer tomography (CT) is very important for the
patients, it offering the possibility to get a good, precise and fast diagnosis.
Keywords: tomography
THE ANNALS OF THE “DUNĂREA DE JOS” UNIVERSITY OF GALATI
MATHEMATICS, PHYSICS, CHEMISTRY, INFORMATICS
FASCICLE II, SUPPLEMENT, YEAR II (XXXI) 2008, pp. 28-35
THE QUALITY OF THE SURFACE AND UNDERGROUND WATERS
IN THE SOUTH-EAST REGION
L. Marica1, L. Moraru2
1
2
Master Student, Physical-Chemical Methods of Analysis and Control, Faculty of Sciences,
University DUNAREA DE JOS of Galati,
Department of Physics, Faculty of Sciences, University DUNAREA DE
JOS of Galati,
Abstract
The notion of environment has a double meaning: a scientific and a political one. The issues related
to the environment are extremely complex, involving to an equal extent a future which belongs to
the next generations. Between an economy which exhausts the resources and the exaggerate
protection of the environment; it is imposed to follow a way, called by the Bruntland Committee,
sustainable development, development in a supportable rhythm for a long term. The sustainable
development means managing and preserving the basis of natural resources and orienting the
technological and institutional changes in such way to satisfy the human needs for the present and
future generations. Such development preserves the soil, the water, the vegetal and animal
resources, it doesn’t degrade the environment, and it is adequate from a technological point of view,
economically viable and acceptable from a social point of view.
Keywords: environment, quality of water
THE ANNALS OF THE “DUNĂREA DE JOS” UNIVERSITY OF GALATI
MATHEMATICS, PHYSICS, CHEMISTRY, INFORMATICS
FASCICLE II, SUPPLEMENT, YEAR II (XXXI) 2008, pp. 36-42
ELECTROMAGNETIC FIELDS - RISK TO OUR
HEALTH VERSUS BENEFIT
L. Moraru1, L. Onose2 , D. Onose3
1
Department of Physics, Faculty of Sciences, University DUNAREA DE
JOS of Galati
2
Grupul Şcolar Industrial Metalurgic Galaţi
3
Grupul Şcolar Industrial de Marină Galaţi
Abstract
Electromagnetic fields exposure for humans is a controversial, scientific, technical and public issue.
The widespread use of electromagnetic equipment and services means that in all residences and
workplaces, there are levels of fields that would be considered "normal." For population and
scientists, also, the controversy is over whether electromagnetic emissions from various sources
lead to cancer or other human diseases. Problems such as headache, fatigue, dizziness and memory
loss to miscarriage, leukaemia leucocythaemia and cancer may be considered effects of
electromagnetic fields exposure, but the evidence is inconclusive. Continued research comprising
epidemiological, biological and dosimetric endpoints should be carried out in order to discover the
actual risk. More studies are in progress in order to verify if electromagnetic fields exposure
represent a risk to our health or not. In this paper we present a review of recent studies on effects
after electromagnetic field exposure.
Keywords: electromagnetic exposure, health, risk
THE ANNALS OF THE “DUNĂREA DE JOS” UNIVERSITY OF GALATI
MATHEMATICS, PHYSICS, CHEMISTRY, INFORMATICS
FASCICLE II, SUPPLEMENT, YEAR II (XXXI) 2008, pp. 43-47
OPERATIONAL PROGRAMME
EDUCATION OF ROMANIA - A STUDY CASE
A. Onu1, L. Moraru2
1
Departament of tehnique, Industrial School Group Metallurgic Galati, Romania
2
Physics Department, University of Galati, Romania.
Abstract
Our operational curriculum programme Education has supported improvements of labour
force adaptability through exploitation of the quality and access to life-long learning. Specific
measures have been focused on the fully of awerness of a durable development and on the
importance of a continuos training for the institutions of life-long learning. The strategy of
UNECE is conceived to facilitate the promotion of EED in UNECE regions. All this measures
were taken for the benefit of the needs of the present generation whithout compromising the
capacities due to satisfy the next generations needs. We present this study on the education
situation in Romanian Republic due to the common bases of the former political and social
system and, also the same evolution in the actual European context.
Keywords: curriculum programme
THE ANNALS OF THE “DUNĂREA DE JOS” UNIVERSITY OF GALATI
MATHEMATICS, PHYSICS, CHEMISTRY, INFORMATICS
FASCICLE II, SUPPLEMENT, YEAR II (XXXI) 2008, pp. 48-53
INTERCONDITIONING OF HEAT AND MASS TRANSFER PROCESSES WITHIN
THE ANNALS OF THE “DUNĂREA DE JOS” UNIVERSITY OF GALAŢI – FASCICLE II
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A VERTICAL FILM ABSORBER
Sava Porneala
Mechanical Engineering Department, University of Galati, Romania.
Abstract
The phenomenon of absorption consists of the simultaneous developing processes of heat and
mass transfer undergone by a two-phase two-component mixture. Heat generating by chemical
interaction adds to the complexity of designing an absoerber when compared with usual,
single component, heat exchangers. Mathematical modeling of absorption processes reveals
thermal and species parameters whose variation along the absorber surface reflects the
interconnection between heat and mass transfer. In the present work, the operation of on
absorber is simulated numerically, considering: (1) temperature difference between solution
film and cooling agent, (2) solution-wall convection heat transfer coefficient, (3) local heat
and mass fluxes between vapor and solution, and (4) mass transfer coefficients, as varying
along the vertical surface of the apparatus. The ratio between heat and mass fluxes is
considered as a parameter. In the entrance region of the apparatus, termed adjustment region,
the heat and mass fluxes ratio varies sensibly due to the mutual influences of heat and mass
transfer processes. Beyond this region, the ratio between the transfer processes (heat and mass
fluxes) tends to became uniform and independent of the absorber operating parameters and of
the value of inlet thermodynamic properties of solution and vapor flows. It is concluded then
that beyond the adjustment region both, heat and mass transfer processes can be analyzed
within good approximation by considering the heat transfer process only.
Keywords: heat transfer, mass transfer, film absorber
THE ANNALS OF THE “DUNĂREA DE JOS” UNIVERSITY OF GALATI
MATHEMATICS, PHYSICS, CHEMISTRY, INFORMATICS
FASCICLE II, SUPPLEMENT, YEAR II (XXXI) 2008, pp. 54-61
STUDIES OF THE PERFORMANCE OF THE RESORPTION
HEAT PUMP
Sava Porneala
Mechanical Engineering Department, University of Galati, Romania.
Abstract
In a traditional heat pump absorption cycle the use of the ammonia-water solution is limited
by the high operating pressures. However, this working pair presents some advantages when
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THE ANNALS OF THE “DUNĂREA DE JOS” UNIVERSITY OF GALAŢI – FASCICLE II
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.
employed in a resorption heat pump cycle, which operates at reasonable pressures. The
technical advantage of the resorption heat pump is obtained due to the low boiling pressure
inside the vapor generator. This paper investigates the performance of the resorption cycle as a
function of parameter pF (the boiling pressure). For a normal heat pumping effect, the
maximum values for both the COP and the exergetic efficiency, correspond to boiling
pressures between 10 and 15 bar. The effect of the thermal potential of the heat sources on the
circulating factors, thermal consumption, COP and the exergetic efficiency is also
investigated.
Keywords: heat pump, resorption, COP
THE ANNALS OF THE “DUNĂREA DE JOS” UNIVERSITY OF GALATI
MATHEMATICS, PHYSICS, CHEMISTRY, INFORMATICS
FASCICLE II, SUPPLEMENT, YEAR II (XXXI) 2008, pp. 62-70
STUDY REGARDING THE NITRITES AND NITRATES DETERMINATION,
USING SPECTROPHOTOMETRY METHODS, FOLLOWING THE
DETERMINATION OF THE POLLUTION LEVEL FROM BRATEŞ NURSERY
D. Rusu, N.Patriche, M.Talpeş, M. Tenciu
Institute of Research and Development for Aquatic Ecology, Fishing and
Aquaculture Galaţi,54 Portului Street, 800211, Romania
Abstract
An important issue regarding surface water is maintaining its quality. Nowadays, one of the
research
directions within the field of hydrobiology, ecology and hydrochemistry is
represented by the dynamics and the migration processes of the chemical substances in surface
waters, which are extremely important for the theoretical basis of the aquatic ecosystems
functioning. The purpose of this paper is constituted by the evaluation of the chemical
processes dynamics, the study of the content of nitrites and nitrates by means of
spectrophotometer methods, in the ponds from Brateş Nursery, in order to establish the quality
of the aquatic environment.
The production capacity of the fish ponds is determined by their nutritive elements. The real
production possibilities depend however on the quantity of living or dead organic substance
formed in the water or brought into the pond and which directly or indirectly reaches the fish
through the trophic chain.
Consequently, the dynamics of the nutritive elements of the surface waters is interlinked with
the nitrites and nitrates concentration.
Keywords: nitrites, nitrates, spectrophotometry methods, pollution level
THE ANNALS OF THE “DUNĂREA DE JOS” UNIVERSITY OF GALATI
MATHEMATICS, PHYSICS, CHEMISTRY, INFORMATICS
FASCICLE II, SUPPLEMENT, YEAR II (XXXI) 2008, pp. 71-74
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THE ANNALS OF THE “DUNĂREA DE JOS” UNIVERSITY OF GALAŢI – FASCICLE II
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.
SPECTRAL AND THERMODYNAMIC PROPERTIES OF CHOLESTERYL
MYRISTATE IN THE REGION OF PHASE TRANSITION
V. Danchuk1, A. Kravchuk1, G. Puchkovska2, A. Yakubov3
1
National Transport University,1 Suvorova str., Kyiv, 01010, Ukraine
Institute of Physics NAS Ukraine,46 Nauki pr., Kyiv, 03680, Ukraine
3
Samarkand State University,14 University aven., 703004, Uzbekistan
2
Abstract
In the article we report on temperature dependence of Davydov
splitting value FTIR spectra study for the in-phase CH2 rocking
vibrations of methylene chains in crystalline cholesteryl
myristate (CholC14) for the temperature region from 100 K to
the crystal melting point.
A statistic-dynamic model in terms of stochastic equations is
used to explain the obtained results. We take into account the
damping of vibrational excitons on orientational defects due to
excitation of conformational, librational and position disorder
degrees of freedom. The explicit expression for the theoretical
dependence of Davydov splitting value on temperature was
considered. Good agreement between the experimental data and
the results of such dependence computer simulation is observed.
Keywords: FTIR, cholesteryl myristate, thermodynamic properties
THE ANNALS OF THE “DUNĂREA DE JOS” UNIVERSITY OF GALATI
MATHEMATICS, PHYSICS, CHEMISTRY, INFORMATICS
FASCICLE II, SUPPLEMENT, YEAR II (XXXI) 2008, pp. 75-79
LUMINESCENT AND OPTICAL CHARACTERISTICS OF ZINC SULFIDE THIN
FILMS PRODUCED BY CLOSE-SPASED VACUUM SUBLIMATION
D. Kurbatov 1, A. Opanasyuk 1, S. Kshnyakina 1,
V.Mеlnik2, V. Nesprava2
1
Sumy State University, Rimsky-Korsakov str. 2, UA-40007 Sumy, Ukraine,
e-mai: [email protected] ,e-mail: [email protected]
2
Іnstitute of Physics NAS of Ukraine, Nauky av. 46,UA-03028 Kyiv, Ukraine
e-mail:[email protected]
Abstract
The luminescent and optical characteristics of ZnS thin films produced by close-spaced
vacuum sublimation technique (CSVS) were investigated in this work. Luminescent and
optical investigations allowed determining the fluorescence centers of native defects and
uncontrolled impurities.
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THE ANNALS OF THE “DUNĂREA DE JOS” UNIVERSITY OF GALAŢI – FASCICLE II
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.
Keywords: thin film, ZnS, close-spaced vacuum sublimation technique, luminescent and
optical characteristics
THE ANNALS OF THE “DUNĂREA DE JOS” UNIVERSITY OF GALATI
MATHEMATICS, PHYSICS, CHEMISTRY, INFORMATICS
FASCICLE II, SUPPLEMENT, YEAR II (XXXI) 2008, pp. 80-85
BIOLOGICAL EFFECTS AND PROTECTION AGAINST IONIZING RADIATIONS
M.Dumitru1, M.Praisler2 , L.Paraschiv-Rebegea1
1
Emergency Clinical Hospital „St. Ap. Andrew”, Galati,
2
University „Dunarea de Jos”, Galati
Abstract
The aim of the paper is to highlight the biological effects of ionizing radiation and to illustrate
some of the methods of protection against them.
Ionizing radiation may act on the body in three ways: through direct action, through indirect
action and action at a distance. Following the direct action of radiation on the body are
affected macromolecules, nucleic acids. Indirect action is triggered by elements arising from
the radiochemical processes. The action occurs at a distance from local irradiation.
The intensity of the biological effects depend not only on the amount of radiation incidents,
but the radio-sensitivity of the body affected by the possibility exists to ensure the adaptation
and compensation functions disturbed, restoring tissue regeneration and even biological
organism.
All ionizing radiation, given in terms of quality, the same radiochemical reactions. In terms of
quantity, however, the yield depends on the reaction to radiation. Since water constitutes the
major component of living matter, the main effect of the primary radiation consists of
radiolysis of water molecule.
Genetic mutations are often fatal, but some are compatible with cell division. The most
serious in terms of its consequences, are mutations in the cells for breeding. There are two
kinds of genetic changes, which are two different degrees of altering the molecule of DNA:
genetic mutations and chromosomal aberrations. Ionizing radiation acting on DNA molecules
either directly, by breaking the molecular chains, or indirectly by chemical changes at
nucleotides causing rupture or simple double chains of DNA.
During life, the human body is subjected to the action of several nuclear radiation sources are:
natural radiation, radiation health, irradiation technique, various irradiation. Depending on the
mode of exposure, respectively assignment irradiation, are distinguished: professional
irradiation, irradiation population.
The most effective method of protection is given by reducing the maximum dose of radiation,
using the specific means to mitigate radiation (protection), depending on the type of radiation,
or by increasing the distance between the stationary source and body.
Keywords: biological effects, ionizing radiation
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THE ANNALS OF THE “DUNĂREA DE JOS” UNIVERSITY OF GALATI
MATHEMATICS, PHYSICS, CHEMISTRY, INFORMATICS
FASCICLE II, SUPPLEMENT, YEAR II (XXXI) 2008, pp. 86-93
ANTIOXIDANT PROPERTIES OF β-CAROTENE
IN SOME FOOD EMULSIONS
R. Creţu1, Ş. Dima1
1
University “Dunărea de Jos” of Galaţi, Faculty of Sciences, Chemistry Department,
Str. Domneasca 47, RO-800008, Galati, Romania. E-mail: [email protected]
Abstract
Lipid oxidation is a big problem in the case of the food emulsions because it leads to the
development of the rancidity. This is a major cause of food emulsions deterioration. The lipid
oxidation of food products has been summarized in some previously researches.
For this reason, we decided to investigate the influence of some physico-chemical parameters
on β-carotene antioxidant activity in some food products such as food coloured emulsions. At
the same time, the propylgalat (PG) and tartrazine (synthetic colorant) antioxidant activity in
food emulsions in presence of Tween 60 (surfactant) was studied. This study is focuses on the
antioxidant potential of β-carotene in oil-in-water or water-in-oil emulsions which have not
been widely investigated in the present conditions. The studies were achieved under forced
reaction conditions at 70 oC with air bubbling in the sample test tube on water bath. The
antioxidant effects of β-carotene on the peroxidation of food emulsions or on the system
models were by unsaturation index, peroxide index and TBA index assessed.
To assess more precisely the antioxidant effect of β-carotene the results were expressed by
comparison with the antioxidant activity of the propylgalat. The experimental results (for food
product and the model system food emulsions) show that at a concentration of 0.25% βcarotene significantly reduces the self oxidation process. Antioxidant properties in the case of
the β-carotene has a variation resembling that of the propylgalat, but less significant.
Keywords: β-carotene,
thiobarbituric acid index
antioxidant
potential,
nesaturation
index,
peroxide
index,
THE ANNALS OF THE “DUNĂREA DE JOS” UNIVERSITY OF GALATI
MATHEMATICS, PHYSICS, CHEMISTRY, INFORMATICS
FASCICLE II, SUPPLEMENT, YEAR II (XXXI) 2008, pp. 94-104
COMPARATIVE STUDY OF PHYSICAL, CHEMICAL AND BIOLOGICAL
METHODS FOR DETECTION OF IRRADIATED FOODSTUFFS
M.Cutrubinis1, M.Virgolici1, D.Negut1, M.Alexandru1, L.Trandafir1,
M. Manea1, M.Constantin1
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THE ANNALS OF THE “DUNĂREA DE JOS” UNIVERSITY OF GALAŢI – FASCICLE II
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.
”Horia Hulubei” National Institute for Nuclear Physics and Engineering, P.O.Box MG-6,
RO-077125 Bucharest-Magurele, Romania, E-mail: [email protected],
[email protected], [email protected], [email protected], [email protected],
[email protected], [email protected]
1
Abstract
The always larger offer on world market of irradiated foodstuffs has lead to the necessity for
existence of reliable tests which could ascertain that a food was irradiated or not. In this paper
there are presented the results of a comparative study between different physical, chemical and
biological methods for detection of irradiated foodstuffs. There were studied 8 detection
methods: electron spin resonance (ESR) on foods containing bone, cellulose or crystalline
sugar, 2 gas chromatography / mass spectrometry (GC/MS) methods on foods containing fat,
DNA comet assay on food containing cells, direct epifluorescence filter technique / aerobic
plate count (DEFT/APC) on foods with natural high bioburden, lymulus amoebocite lysate /
gram-negative bacteria (LAL/GNB) on foods containing meat. Between the results of the
study it could be mentioned first the fact that, because of the multitude of foodstuffs and their
characteristics, there is not any general valid detection method. Therefore, there exist a large
number of methods which have to be verified on every particular food product and also on
varieties of the same product. In addition, the detection can be made only at qualitative level
(irradiated/unirradiated), and not quantitative (irradiation dose). In conclusion, there were
proposed sets of detection methods which could be used together in order to achieve a better
detection of certain irradiated foodstuffs.
Keywords: biological method, electron spin resonance (ESR), gas chromatography, mass
spectrometry, direct epifluorescence filter technique
THE ANNALS OF THE “DUNĂREA DE JOS” UNIVERSITY OF GALATI
MATHEMATICS, PHYSICS, CHEMISTRY, INFORMATICS
FASCICLE II, SUPPLEMENT, YEAR II (XXXI) 2008, pp. 105-112
EXPERIMENTAL ASPECTS IN THE DETERMINATION OF ALLUVIAL GOLD BY
INSTRUMENTAL FAST NEUTRON ACTIVATION ANALYSIS (FNAA)
A. Nat, A. Ene
Department of Physics, Faculty of Sciences, “Dunarea de Jos” University of Galatz,
Galatz, Romania
Abstract
In this work we have studied the spectral interferences and matrix effects in alluvial gold
analysis by instrumental fast neutron activation analysis (FNAA), with the aid of a theoretical
field spectrum of gamma-rays emitted by the irradiated sample with 14 MeV neutrons,
considered as a point source, in the absence of any ambient interaction. In the case of the
chosen nuclear reactions n+Au, the optimum experimental conditions of gold determination,
using conventional NaI(Tl)- and Ge(Li)-based gamma-ray counting, were established using an
original computer program in order to assure a maximum peak-to-background ratio for gold,
in the circumstances of a variable background in the gamma-ray spectra. The samples of
10
THE ANNALS OF THE “DUNĂREA DE JOS” UNIVERSITY OF GALAŢI – FASCICLE II
█████████████████████████████████████████████████████████████████████████████████████████████████████████████████████████████████████████████████████████████████████████████████████████████████████████████████
.
auriferous sands from Rosia Montana, Somesul Mic, Gilau and Deva were irradiated with the
aid of the neutron generator facility from Activation Laboratory, Nuclear Unit at the Iron and
Steel Works of Galati. A study of the choosing of appropriate standards and reference
materials for neutron flux monitoring has also been carried out. We describe two rapid and
sensitive methods of gold determination at trace level, using short and long irradiation,
without chemical separation.
Keywords: spectral interferences, matrix, alluvial gold, fast neutron activation analysis
(FNAA)
THE ANNALS OF THE “DUNĂREA DE JOS” UNIVERSITY OF GALATI
MATHEMATICS, PHYSICS, CHEMISTRY, INFORMATICS
FASCICLE II, SUPPLEMENT, YEAR II (XXXI) 2008, pp. 113-119
TRANSFER COEFFICIENTS’ EVALUATIONS USING SYSTEM
SENSIBILITY ASSESSMENT
G.Murariu1, Gh. Puscasu2, M. Dobrea3, V. Vacarus3
1
2
Physics Department, University of Galati, Romania.
Computer Science Faculty, University of Galati, Romania.
3
Faculty of Veterinary Medicine ,Bucharest, Romania.
4
Faculty of Mechanics, University of Galati, Romania
Abstract
The cooling and freezing are very important features in industry. In the last period, a greater
focus is on the heat transfer coefficients’ evaluation. Considering a large set of experimental
data for natural cooling process, were estimated the heat balances during the time. In the first
step were considered different identification system methods in order to find out the
mathematical models. Basing on these representations is proposed a first order physics
representation, in order to succeed in explaining the obtained shapes. The computer interfaces
and the approaching software algorithm are presented too.
Keywords: heat transfer coefficients, evaluation
THE ANNALS OF THE “DUNĂREA DE JOS” UNIVERSITY OF GALATI
MATHEMATICS, PHYSICS, CHEMISTRY, INFORMATICS
FASCICLE II, SUPPLEMENT, YEAR II (XXXI) 2008, pp. 120-124
THE SOLVENT INFLUENCE OF SOME SUBSTITUTED PHENOLS STRUCTURES
M. Dimitriu1, E. Filip2, D. O. Dorohoi1, I. Humelnicu2
1
Faculty of Physics, "Al. I. Cuza" University of Iasi, 11 Carol I Blvd., 700506, Romania,
[email protected]
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THE ANNALS OF THE “DUNĂREA DE JOS” UNIVERSITY OF GALAŢI – FASCICLE II
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.
2
Faculty of Chemistry, "Al. I. Cuza" University of Iasi, 11 Carol I Blvd., 700506, Romania,
[email protected]
Abstract
Substituted phenols are very used compounds in pharmaceuticals, foods and beverages
industry. The study of a solute in different media can provide relevant information concerning
the influence of the medium on the electronic structure of the solute or on the nature and
strength of the specific intermolecular solvent-solute interaction. We investigated theoretically
the influence of some solvents to the ortho-methoxy-phenol (guaiacol) and 4-hydroxy-3methoxybenzaldehyde (vanillin). There have been estimated some physico-chemical
parameters such as: the boundary lengths, total energies, border energy levels and dipole
moments of the considered isolated molecules in their ground states. The same parameters
were estimated for solutions of the studied phenol derivatives in water, chloroform and
ethanol.
Keywords: substituted phenols, guaiacol, vanillin, solvent influence
THE ANNALS OF THE “DUNĂREA DE JOS” UNIVERSITY OF GALATI
MATHEMATICS, PHYSICS, CHEMISTRY, INFORMATICS
FASCICLE II, SUPPLEMENT, YEAR II (XXXI) 2008, pp. 125-130
UNIVERSAL INTERACTIONS IN BINARY SOLUTIONS,
STUDIED BY SPECTRAL MEANS
L. V. Gheorghies1, M. Dimitriu2, E. Filip3, D. O. Dorohoi2
“Dunărea de Jos” University, Faculty of Metallurgy
Faculty of Physics, Al.I. Cuza University, 11 Carol I Bdv., Iaşi, RO-700056,
[email protected]
3
“Al. I. Cuza” University, Faculty of Chemistry, Iaşi
1
2
Abstract
Universal interactions in binary solutions of some polar molecules are studied here by means
of the electronic absorption spectra. The spectral shifts measured in solvents with different
macroscopic parameters are correlated with dipole moments of the studied molecules on the
basis of the simple liquid theory. Two carbanion monosubstituted pyridazinium ylids are
considered as spectrally active molecules in this study. The dipole moments in the ground
states are estimated on the basis of the solvent influence on the intramolecular charge transfer
band of the studied pyridazinium ylids.
Keywords: universal interactions, binary solution, electronic absorption spectra
THE ANNALS OF THE “DUNĂREA DE JOS” UNIVERSITY OF GALATI
MATHEMATICS, PHYSICS, CHEMISTRY, INFORMATICS
FASCICLE II, SUPPLEMENT, YEAR II (XXXI) 2008, pp. 131-135
12
THE ANNALS OF THE “DUNĂREA DE JOS” UNIVERSITY OF GALAŢI – FASCICLE II
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.
LIGHT-SURFACE INTERACTION IN THE STUDY OF THE RESTAURED
PAINTINGS
N. Melniciuc-Puica 1, D. O. Dorohoi2
1
Faculty of Orthodox Theology, “Al.I. Cuza” University, 9 Closca str., Iasi, Romania
2
Faculty of Physics, Al.I. Cuza University, 11 Carol I Bdv., Iaşi, RO-700056,
[email protected]
Abstract
This paper deals about a new method to restoration old paintings, based on light-surface
interaction. Diffuse reflectance spectra can offer information on the electronic absorption
spectra of the pigment samples, to be used to reduce the metamerism phenomenon. By mixing
modern blue pigments with titanium white it is possible to obtain pigments azurite imitative
retouching.
Keywords: restauration, light-surface interaction
THE ANNALS OF THE “DUNĂREA DE JOS” UNIVERSITY OF GALATI
MATHEMATICS, PHYSICS, CHEMISTRY, INFORMATICS
FASCICLE II, SUPPLEMENT, YEAR II (XXXI) 2008, pp. 136-140
SOME REMARKS ON THE HUMAN EYE ACCOMODATION PROCESS
M. Miron 1, C. D. Nechifor 2, G. Gheorghies 2, D. O. Dorohoi2
1
“Gr.T. Popa” University of Medicine and Pharmacy, Faculty of Medicine,Iaşi, Romania
2
Al.I. Cuza University, Faculty of Physics, 11 Carol I Bdv., Iaşi, RO-700056,
[email protected]
Abstract
Physical-chemical bases of the eye accommodation are discussed in this paper. The optical
equivalent eye is considered and the two types of phenomena concurring to the
accommodation phenomena are discussed using Geometrical Optics and some experimental
data which demonstrate the variation of the aqueous humours’ refractive index in the presence
of inorganic salts.
Keywords: eye accommodation, geometrical optics, aqueous humours’ refractive index
THE ANNALS OF THE “DUNĂREA DE JOS” UNIVERSITY OF GALATI
MATHEMATICS, PHYSICS, CHEMISTRY, INFORMATICS
FASCICLE II, SUPPLEMENT, YEAR II (XXXI) 2008, pp. 141-147
POLYMERIC FILMS UNDER UV AND GAMMA RADIATIONS
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THE ANNALS OF THE “DUNĂREA DE JOS” UNIVERSITY OF GALAŢI – FASCICLE II
█████████████████████████████████████████████████████████████████████████████████████████████████████████████████████████████████████████████████████████████████████████████████████████████████████████████████
.
C. D. Nechifor1, D. O. Dorohoi1, C. Ciobanu2
1
“Al.I.Cuza” University, Faculty of Physics, 11Carol I Bdv., RO-700506, Iasi,
[email protected]
2
“P.Poni” Institute of Macromolecular Chemistry, Grigore Ghica Vodă
Alley 41A, Iaşi, Romania
Abstract
Surface properties of polymer membranes, obtained from poly (hydroxy-urethane) (PHU) and
poly (vinyl alcohol) (PVA) treated with UV and Gamma radiation were analyzed in this work.
The aim of our study was to estimate the modification induced in physico-chemical properties
of polymer films by gamma and UV radiations. UV treatments in air decrease the contact
angles by increasing the surface energies of the polymer. Important modifications appear in
ATR spectra, especially in the range of stretching vibrations of carbonyl and amide II groups
at 1667 cm-1, 1636 cm-1 and 1540 cm-1; these indicate that surface configurations and bulk
chemical changes are induced through photo oxidation and photo degradation processes.
Gamma irradiation permit to obtain information about the degradation processes of the
polymeric films. Stabilization of polymeric film surfaces in UV treatment and also film
degradation in gamma irradiation were experimentally observed.
Keywords: polymeric films, UV, gamma radiation
THE ANNALS OF THE “DUNĂREA DE JOS” UNIVERSITY OF GALATI
MATHEMATICS, PHYSICS, CHEMISTRY, INFORMATICS
FASCICLE II, SUPPLEMENT, YEAR II (XXXI) 2008, pp. 148-155
SELF-DUAL GAUGE THEORY WITH COSMOLOGICAL CONSTANT
D. H. Partenie, C. Popa
Department of Physics Al. I. Cuza” University, Iaşi, 700050, Romania, E-mail:
[email protected], Email: [email protected]
Abstract
We search for a self-dual model in the four-dimensional space-time, considering that the
gauge group is the de-Sitter group. We chose spherical symmetric gauge potentials which
have three independent functions, each one depending only on the 3D radius r. Assuming null
components for the torsion tensor (Einstein model for gravitation), the components of the
gauge field tensor (with cosmological constant) and of its dual are calculated.
Keywords: self-dual model, gauge theory, cosmological constant
14
THE ANNALS OF THE “DUNĂREA DE JOS” UNIVERSITY OF GALAŢI – FASCICLE II
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.
THE ANNALS OF THE “DUNĂREA DE JOS” UNIVERSITY OF GALATI
MATHEMATICS, PHYSICS, CHEMISTRY, INFORMATICS
FASCICLE II, SUPPLEMENT, YEAR II (XXXI) 2008, pp. 156-160
ELECTROSTATIC FIELD ACTION ON POLYMERIC ESTERS OF
ALKOXYBENZOIC ACID (PEABA) IN TETRACHLOROMETHANE (TCM)
A. Rogojanu, D.O. Dorohoi
Al.I.Cuza University, Faculty of Physics, 11 Carol Bdv. RO -700506, Iaşi, Romania
Abstract
The polymeric esters of alkoxy benzoic acids (PEABA) in thermodynamically bad solvent,
such as tetra chloromethane (TCM) show a lyotropic liquid crystalline phase of the nematic
type, realized by side-chains parallel ordering. The degree of order in the side-chains increases
when an external electrostatic field is applied to the liquid crystalline layer. The birefringence
of PEABA in TCM can be modified in an electrostatic field in which the side-chains of the
polymer become aligned perpendicularly on the field direction. The liquid crystalline layer
between two electrically charged transparent walls becomes anisotropic with the director
perpendicular to the field direction. This kind of layer changes the polarization state of
radiation. One optical system consisting from one anisotropic layer (PEABA in TCM for
example) between two crossed polarizers induces changes in the spectral composition of
radiations. The wavenumber of the radiations which pass from this system depends on the
birefringence and thickness of the anisotropic layer. The values of the birefringence in the
absence and in the presence of the electrostatic field are determined in this paper
Keywords: electrostatic field, PEABA, TCM, anisotropic layer, birefringence
THE ANNALS OF THE “DUNĂREA DE JOS” UNIVERSITY OF GALATI
MATHEMATICS, PHYSICS, CHEMISTRY, INFORMATICS
FASCICLE II, SUPPLEMENT, YEAR II (XXXI) 2008, pp. 161-166
ANALYSIS AND CONTROL OF METALLURGICAL MATERIALS
USING X-RAY FLUORESCENCE TECHNIQUE AND
X-RAY ATTENUATION
Antoaneta Ene1, Alina Boşneagă2, Andreea Ene3
Department of Physics, Faculty of Sciences,“Dunarea de Jos” University of Galaţi,
[email protected]
2
“Physical-chemical Methods of analysis and control” Master Section,
Faculty of Sciences,“Dunarea de Jos” University of Galaţi, [email protected]
3
Technical University of Civil Engineering Bucharest, Civil Engineering – English Section,
124 Lacul Tei Bvd., Bucharest
1
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THE ANNALS OF THE “DUNĂREA DE JOS” UNIVERSITY OF GALAŢI – FASCICLE II
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.
Abstract
In this paper a study of the capabilities of X-ray Fluorescence (XRF) technique for the
determination of major, minor and trace constituents of metallurgical materials has been done.
XRF analyses have been carried out at MITTAL Steel Galati, using a NITON portable X-ray
spectrometer and a THERMO wavelength-dispersive spectrometer. Using a radiometric
system (Radiometrie Limited RM215 gauge), the labs width can be determined on the basis of
the X-rays absorption law, knowing the labs composition, and so the absorption coefficient of
the material. The plate temperature is measured with a pyrometer in order to make the
corrections for the material dilatation and the width is displayed instantly for the cooled lab.
Keywords: XRF technique, X-ray attenuation , absorption coefficient
THE ANNALS OF THE “DUNĂREA DE JOS” UNIVERSITY OF GALATI
MATHEMATICS, PHYSICS, CHEMISTRY, INFORMATICS
FASCICLE II, SUPPLEMENT, YEAR II (XXXI) 2008, pp. 167-173
EXPERIMENTAL METHODS TO DETERMINE THE LIGHT POLARIZATION
STATE
I. Dumitraşcu, L. Dumitraşcu, M. Antonia, D. O. Dorohoi
„Al.I. Cuza”University, Faculty of Physics, 11 Carol I Bdv., Iaşi, RO-700056
Abstract
Demonstrative experiments for determining the light polarization state are described in this
paper. Three possibilities are considered: a) linearly polarized light; b) natural and/or
circularly polarized light; c) partially and/or elliptically polarized light. One experiment
illustrating the polarization by reflection at Brewster angle is described as it was organized for
the students teaching Optics, in order to assure a better understanding of the polarization
phenomenon.
Keywords: light polarization state
THE ANNALS OF THE “DUNĂREA DE JOS” UNIVERSITY OF GALATI
MATHEMATICS, PHYSICS, CHEMISTRY, INFORMATICS
FASCICLE II, SUPPLEMENT, YEAR II (XXXI) 2008, pp. 174-181
SOME EXPERIMENTS USED IN CHARACTERIZATION OF ANISOTROPIC
LAYERS BY A POLARIZING MICROSCOPE
L. Dumitraşcu1, I. Dumitraşcu1, N. Puica Melniciuc2, D. O. Dorohoi1
1
“AL. I. Cuza” University, Faculty of Physics, Iaşi
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THE ANNALS OF THE “DUNĂREA DE JOS” UNIVERSITY OF GALAŢI – FASCICLE II
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.
2
“AL. I. Cuza” University, Faculty of Theology, Iaşi
Abstract
The possibility to use a polarizing microscope in establishment of the crystal type, the cutting
mode of the anisotropic layers and also the relative orientation of optical axis/axes relative to
the cutting surface is proved in this paper. Some images of the isochromates obtained for
biaxial or uniaxial inorganic crystals with a Web camera attached to the polarizing microscope
offer information about the cutting mode and the relative orientation of the main axes relative
to the separation surface of crystal.
KEYWORDS: anisotropic layers, polarizing microscope
THE ANNALS OF THE “DUNĂREA DE JOS” UNIVERSITY OF GALATI
MATHEMATICS, PHYSICS, CHEMISTRY, INFORMATICS
FASCICLE II, SUPPLEMENT, YEAR II (XXXI) 2008, pp. 182-187
A MODERN WAY IN PHYSICS LABORATORY
A.Dănilă1, E.Dănilă2
1
Şcoala Gimnazială “Iulia Haşdeu”, nr. 40, Galaţi
2
Universitatea “Dunărea de Jos”, Galaţi
Abstract
For many students, the work in physics laboratory is unpleasant because they must use tables
and made some calculations and they lost the physical meaning of this activity. An alternative
using computer assisted practical activities is proposed. The way in which it is intended to
support learning is discussed.
A carefully designed computer simulation can maintain connections to real life but make the
student's perception of what is happening match those of experts. This is done by enhancing
certain features, hiding others, adjusting time scales, and so on, until the desired student
perception is achieved. Simulations also can provide visual representations that explicitly
show the models that experts use to understand phenomena that are not directly visible, such
as the motion of electrons. It is likely that both features are important in explaining the
observed benefits of simulations.
Keywords: computer simulation
THE ANNALS OF THE “DUNĂREA DE JOS” UNIVERSITY OF GALATI
MATHEMATICS, PHYSICS, CHEMISTRY, INFORMATICS
FASCICLE II, SUPPLEMENT, YEAR II (XXXI) 2008, pp. 187-191
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THE ANNALS OF THE “DUNĂREA DE JOS” UNIVERSITY OF GALAŢI – FASCICLE II
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.
A MODERN WAY IN SOLVING PHYSICS PROBLEMS
A.Dănilă1, E.Dănilă2
Şcoala Gimnazială “Iulia Haşdeu”, nr. 40, Galaţi
Universitatea “Dunărea de Jos”, Galaţi, , [email protected]
1
2
Abstract
For many students, solving physics problems raises difficulties that result from the difficulty
to imagine practical situations applications of physics laws. An alternative using applets, is
outlined in this paper, and the way in which it is intended to support learning is discussed.
Keywords: applets, physics problems
THE ANNALS OF THE “DUNĂREA DE JOS” UNIVERSITY OF GALATI
MATHEMATICS, PHYSICS, CHEMISTRY, INFORMATICS
FASCICLE II, SUPPLEMENT, YEAR II (XXXI) 2008, pp. 192-199
CLASSICAL EXPERIMENTS IN MODERN PRESENTATION
E.Dănilă 1, A.Dănilă 2
Physics Department, University of Galaţi
Şcoala Gimnazială “Iulia Haşdeu”, nr. 40, Galaţi
1
2
Abstract
The point is that exploratory software is not simple and its use is not simple. It is easily
misrepresented and its purpose easily abused by inadequate conceptualisation leading to crude
means of evaluation. Understanding and facing up to this complexity is the only way out of
the cycle of inertia; the only chance of realizing the potential of exploratory software. This is
the challenge we need to face.
Keywords: software, classical experiments
THE ANNALS OF THE “DUNĂREA DE JOS” UNIVERSITY OF GALATI
MATHEMATICS, PHYSICS, CHEMISTRY, INFORMATICS
FASCICLE II, SUPPLEMENT, YEAR II (XXXI) 2008, pp. 200-207
COMPUTER SIMULATIONS AND EXPERIMENTAL INVESTIGATIONS ON THE
UV-VIS ELECTRONIC SPECTRA OF THE DPPH RADICAL
E. Filip, I. Humelnicu, C. Ghirvu
Faculty of Chemistry, "Al. I. Cuza" University of Iasi, 11 Carol I Blvd., 700506, Romania,
[email protected]
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THE ANNALS OF THE “DUNĂREA DE JOS” UNIVERSITY OF GALAŢI – FASCICLE II
█████████████████████████████████████████████████████████████████████████████████████████████████████████████████████████████████████████████████████████████████████████████████████████████████████████████████
.
Abstract
The nature and strength of intermolecular interaction and the solvent structure may influence
the molecular structure of solvate in a mixture. This phenomenon is observed by modification
of the intensity and position of the electronic spectra. By using UV-VIS spectroscopy, we
investigated the spectral behaviour of the 2,2-diphenyl-1-picrylhydrazyl (DPPH) stable free
radical solvated in some solvents: n-hexane, n-heptane, dioxane, chloroform and ethanolchloroform mixtures with varied ethanol volumetric proportion. The spectra were recorded at
different time intervals from the preparation solution, because the stability and solubility of
this radical are different in these media. The theoretical investigations have followed the
determination of DPPH radical structure, characterized by minimum of energy and the spindensity calculations by using the high-level ab initio methods with the GAUSSIAN 98
program. The theoretical spectrum obtained by semi-empirical methods AM1 and PM3
included in Hyper-Chem software was compared with those recorded in non-polar solvents.
Keywords: intermolecular interaction, DPPH radical, UV-VIS spectroscopy
THE ANNALS OF THE “DUNĂREA DE JOS” UNIVERSITY OF GALATI
MATHEMATICS, PHYSICS, CHEMISTRY, INFORMATICS
FASCICLE II, SUPPLEMENT, YEAR II (XXXI) 2008, pp. 208-211
BALANCE OF THE NATURAL RADIOACTIVITY IN IRON AND STEEL
MATERIALS BY LOW-LEVEL GAMMA SPECTROMETRY
M. Tănase
National Commission for Nuclear Activities Control
14, Libertatii Blvd, Bucharest – 5, PO Box 42-4 Romania, [email protected]
Abstract
An integrated steel mill has all the functions for primary steel production:
• pretreatment of the ore in the ore preparation, sintering and, where applicable, pelletising,
• ironmaking (conversion of ore to pig iron in the blast furnace),
• steelmaking (conversion of pig iron to crude steel by top blowing or purging with oxygen
and
the addition of scrap),
• casting (solidification of the liquid steel. The crude steel is either continuously cast as blanks
or, after casting as slab ingots or blocks in permanent moulds, rolled in the hot rolling mill to
form sheets, billets or profiles),
• roughing rolling/billet rolling (reducing size of blocks)
• product rolling (finished shapes in the cold rolling mills and forges).
Modern cast iron smelting takes place in the cupola furnace, with increasing use of induction
furnaces.
All raw materials introduced in the metallurgical process are usually of background
radioactivity. The specific activities are in the order of 10 - 30 Bq/kg for iron ore and
limestone as well as 30 – 100 Bq/kg for coke.
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THE ANNALS OF THE “DUNĂREA DE JOS” UNIVERSITY OF GALAŢI – FASCICLE II
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.
Because of mixing within the technological process, residues of these processes may show
higher concentrations of radioactivity. However, enhanced radioactivity usually occur for at
least at some workplaces within the process.
High resolution low level gamma spectrometry was applied to perform a radioactivity balance
of iron and steel raw material (coal, coke, iron ore, pellets, manganese ore, limestone,
dolomite), auxiliary material (scorialite, TiO, bentonite), and some related final products (cast
iron, slag, blast-furnace flue dust) involved in the iron making process.The activity of
materials in various kinds of samples was controlled and the transfer of radioactivity during
the blast-furnace process was investigated. The investigations demonstrate an unequal transfer
of radioactivity during the blast-furnace process. A grown affinity of slag for most common
natural radioisotopes was found. Refractory materials used for the construction of the
metallurgical plants/facilities and the rolling units may contain minerals with enhanced
radioactivity (mainly corundum, zirconium sands) too. These materials accrue as residue if the
corresponding production line is refurbished or reconstructed or if the materials are exchanged
in regular intervals.
Keywords: iron, steel, radioactivity, gamma spectrometry
THE ANNALS OF THE “DUNĂREA DE JOS” UNIVERSITY OF GALATI
MATHEMATICS, PHYSICS, CHEMISTRY, INFORMATICS
FASCICLE II, SUPPLEMENT, YEAR II (XXXI) 2008, pp. 211-215
A COMPARISON OF THE FOOD COLLOIDS COLOUR FORMATION BY SOME
COLOUR SPACES AND COMPUTERIZED IMAGE ANALYSIS
Romică Creţu
University “Dunărea de Jos” of Galaţi, Faculty of Sciences, Chemistry Department,
Str. Domneasca 111, RO-800008, Galati, Romania, email: [email protected]
Abstract
Colour is one of the main organoleptic characteristics used to establish the quality and
acceptability of food products and food colloids. In this work, analysis of digital color images
of some food colloids were combined with parallel LC-MS based analysis of acrylamide in
order to develop a rapid tool for the estimation of acrylamide level during thermally treatment
of some food colloids. Acrylamide is produced when a wide variety of food colloid systems
are cooked (fry or bake our food).
In this way, the measurement of colour in a region of interest over a food colloid surface may
be of greater importance under certain circumstances. Images were segmented by software
programmed in Matlab that converts the colour RGB of the food image into L*a*b* units
(color space which is an international standard for colour measurements, adopted by the
Commission Internationale d'Eclairage - International Commission on Illumination (CIE) in
1976).
The initial pale soft yellow colour of some analysed cookie pudding type was first turned to
bright yellow (L* = 62.1; a* = -1.6; b* = 46.3 in the cases of the computer vision technique
and L* = 59.8; a* = -1.9; b* = 45.4 for portable colorimeter), then to brownish yellow and the
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THE ANNALS OF THE “DUNĂREA DE JOS” UNIVERSITY OF GALAŢI – FASCICLE II
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.
final browning in the surface became clearer and constant, reaching a dark brown at the end of
heating (L* = 44.2; a* = 18.2; b* = 22.4 in the cases of the computer vision technique and L*
= 43.8; a* = 16; b* = 21.7 for portable colorimeter).
The objective of this research was to implement an inexpensive computer vision method for
measuring the colour of a some heterogeneous food colloid surfaces in L * a * b * units from
RGB images and to comparate with CIE methods. From the viewpoint of acryl amide, surface
color is an important food attribute that can be used to predict the acryl amide level.
Keywords: colour, food colloids, RGB images
THE ANNALS OF THE “DUNĂREA DE JOS” UNIVERSITY OF GALATI
MATHEMATICS, PHYSICS, CHEMISTRY, INFORMATICS
FASCICLE II, SUPPLEMENT, YEAR II (XXXI) 2008, pp. 216-220
THE CHROMATOGRAPHIC PEAK
AND THEIR QUANTITATIVE PARAMETER VALUES
Gheorghe Zgherea, Cristina Stoian
Department of Chemistry, Faculty of Sciences, „Dunărea de Jos” University of Galaţi,
Romania
Abstract
The chromatographic separation of compounds mixtures is the result of moving them with
different rates between two immiscible phases, a stationary phase (identical particles
immobilized in the separation column) and a mobile phase (a fluid that move with constant
rate between the particles of stationary phase). Each compound is distributed in a successive
group of equal’s talers, generating a zone of concentration; the concentration zone has a stable
configuration and moves with constant rate. As follows, identically quantities of the same
compound, transported in identically conditions, will be represented by chromatographic
signals having identically values for retention times and for surfaces; this confirm that the
same quantities of unique compounds will be distributed in identically zone of concentration.
The stability of distribution process may be verified by statistically study of retention times
and area values of chromatographic signal.
In this paper are presented a statistically study on the retention times and area values for the
chromatographic signals of methanol. The analytically data was obtained for 52 volumes of
chromatographic separation, using a mechanism of repartition and the
thermoconductivity detector; the experimental data are normally distributed, confirming the
repeatability of chromatographic distribution.
Keywords: chromatography, peak, retention times, areas, statistically
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