23 research outputs found
Diurnal variations in the activation level and some personality characteristics
Ispitivao se odnos između ekstraverzije-introverzije te navika svakodnevnog života (jutarnjost-večernjost) s jedne strane i dnevnih varijacija u stupnju aktivacije tokom dana s druge strane. Kao pokazatelji stupnja aktivacije upotrebljeni su frekvencija pulsa i oralna temperatura. Utvrđeno je da između dimenzije ekstraverzija-introverzija i svakodnevnih navika rada tokom dana (jutarnjost-večernjost) ne postoji značajna povezanost, ali da je svaka od tih dimenzija ponašanja pojedinačno povezana sa stupnjem aktivacije tokom dana. Najveće razlike u stupnju aktivacije tokom dana postižu se kad se kombinira sukladno djelovanje ispitivanih dimenzija ponašanja, jer su najveće razlike postignute između introvertiranih ispitanika koji su ujedno i jutarnji »radnici«, te ekstravertiranih ispitanika koji su ujedno i večernji »radnici«.The relationship between extroversion-introversion and every-day life habits (morningness-eveningness) on one hand, and diurnal variations in the activation level on the other hand were studied. Heart rate and oral temperature served as activation indicators. There was no significant correlation between the dimensions of extroversion-introversion and every-day working habits but each of these dimensions of behaviour was associated with the activation level during the day. The greatest differences in the activation level during the day were observed if congruent effects of the studied dimensions of behaviour were combined. This was the case with the subjects who were both introvert and »morning workers« and those who were both extrovert and »evening workers«
Preliminary approach to bio-based surface healing of structural repair cement mortars
Mitigating the maintenance and repair costs of structures and infrastructures is a major problem in all countries. The aim of this research work is to analyse the performance of surface healing technique for crack control of cement-based mortars for structural repair in maritime environments. Microbiologically induced calcite precipitation (MICP) with ureolytic bacteria Sporosarcina pasteuri DSM 33 was introduced for crack-healing. Only main cracks were filled with the bioagent (bacterial cells and nutrients) for cost-saving purpose. It is intended to analyse the effectiveness of this technique for structural application in areas exposed to cyclic moisture changes. Hygric properties and their relation to durability increase were analysed through moisture buffering tests, capillary, porosity, compressive strength, SEM and microscopy analysis before and after bio-agent application to evaluate the evolution of the precipitation. For the first time, moisture buffering value (MBV) was used to evaluate the performance of the self-healed mortar and time needed for bacterial precipitation. The treated material can be classified as good in terms of MBV, and there was a general increasing trend of moisture buffering behaviour in self-healed samples. SEM analysis showed distinctive differences between the treated and non-treated cracks. The results show that bio-agent had remarkable effect on compressive strength recovery (over 87% of original value) after 21 days of healing and positively affected the initial stage of capillary absorption
Influence of Long-Term Anti-Seizure Medications on Redox Parameters in Human Blood
Background: Epilepsy is a chronic brain disease affecting millions of people worldwide,
but little is known about the impact of anti-seizure medications on redox homeostasis. Methods:
This study aimed to compare the effects of the long-term use of oral anti-seizure medications in
monotherapy (lamotrigine, carbamazepine, and valproate) on antioxidant enzymes: superoxide dismutase,
catalase, glutathione peroxidase, glutathione reductase, haemoglobin, and methaemoglobin
content in erythrocytes, and concentrations of total proteins and thiols, nitrites, lipid peroxides and
total glutathione in the plasma of epilepsy patients and drug-naïve patients. Results: The results
showed that lamotrigine therapy led to lower superoxide dismutase activity (p < 0.005) and lower
concentrations of total thiols (p < 0.01) and lipid peroxides (p < 0.01) compared to controls. On the
other hand, therapy with carbamazepine increased nitrite levels (p < 0.01) but reduced superoxide
dismutase activity (p < 0.005). In the valproate group, only a decrease in catalase activity was observed
(p < 0.005). Canonical discriminant analysis showed that the composition of antioxidant enzymes in
erythrocytes was different for both the lamotrigine and carbamazepine groups, while the controls
were separated from all others. Conclusions: Monotherapy with anti-seizure medications discretely
alters redox homeostasis, followed by distinct relationships between antioxidant components
Comparison of Microbially Induced Healing Solutions for Crack Repairs of Cement-Based Infrastructure
Reinforced concrete crack repair and maintenance costs are around 84% to 125% higher than construction costs, which emphasises the need to increase the infrastructure service life. Prolongation of the designed service life of concrete structures can have significant economic and ecological benefits by minimising the maintenance actions and related increase of carbon and energy expenditure, making it more sustainable. Different mechanisms such as diffusion, permeation and capillary action are responsible for the transport of fluids inside the concrete, which can impact on the structure service life. This paper presents data on microbially induced repair and self-healing solutions for cementitious materials available in the contemporary literature and compares results of compressive strength test and capillary water absorption test, which are relevant to their sealing and mechanical characteristics. The results of the repair and self-healing solutions (relative to unassisted recovery processes) were “normalized.” Externally applied bacteria-based solutions can improve the compressive strength of cementitious materials from 13% to 27%. The internal solution based solely on bacterial suspension had 19% improvement efficacy. Results also show that “hybrid” solutions, based on both bio-based and non-bio-based components, whether externally or internally applied, have the potential for best repair results, synergistically combining their benefits
Potencijalna upotreba izotopa važnih za okoliš u ispitivanju migracije onečišćujućih tvari
This article presents the use of natural abundance stable isotope (hydrogen, carbon, nitrogen, oxygen, chlorine) analysis data as a tool for providing important information about the origin of contaminants, the contribution of different sources to a multi-source plume, characterisation of their complex transport (rate and mechanisms) and for evaluating the success of contaminated site remediation. Isotopic signatures of contaminants are useful tracers of their sources, while isotopic fractionation can be used to quantitatively assess the progress of an environmental process such as biodegradation. This new isotopic approach is reliable and can offer more information than traditional techniques in pollutant migration studies, particularly after waste disposal. During biological degradation of any organic compound, molecules containing lighter isotopes are degraded, and the portion of heavier isotopes in the substrate is increased, identifying specific microbial roles in biogeochemical cycling. Since isotopic fractionation is proportional to degradation, depending on the type of contamination, a microbial degradation of 50 % to 99 % of the initial concentration can be quantified using isotope ratio measurements.Cilj ovog rada je da se prikaže korištenje podataka analize prirodne obilnosti stabilnih izotopa (vodika, ugljika, dušika, kisika i klora) kao alata za dobivanje važnih informacija o porijeklu onečišćujućih tvari, doprinosu različitih multikomponentnih onečišćivača, karakterizaciji njihova kompleksnog transporta (brzine i mehanizma) i praćenja uspjeha remedijacije onečišćenih mjesta. Izotopski sadržaji onečišćujućih tvari koriste se kao traseri za određivanje njihovih izvora, dok se izotopsko frakcioniranje može iskoristiti za kvantitativnu procjenu toka procesa kao što je biodegradacija. Takav nov izotopski pristup je pouzdan i nudi više informacija od tradicionalnih tehnika kontrole putovanja onečišćivala, napose nakon odlaganja opasnog otpada na zemljištu. Za vrijeme biodegradacije nekog organskog spoje molekule koje sadržavaju lake izotope lakše se degradiraju, a dio težih izotopa u supstratu se povećava, što upućuje na mikrobiološku ulogu u biokemijskom ciklusu. Kako je izotopsko frakcioniranje proporcionalno degradaciji zavisno od tipa onečišćenja, korištenjem podataka mjerenja izotopskih odnosa može se procijeniti mikrobiološka degradacija od 50 % do 99 % od početne koncentracije
An evaluation of residues at an oil refinery site following fires
Soil pollution at the oil refinery at Novi Sad following destruction of crude oil and its products in storage tanks during the Kosovo conflict was investigated. More than 100, 000 t of crude oil and its products were destroyed, and about 90% of these were burnt off, 10% leached and 130 t recovered. The acute injection of polycyclic aromatic hydrocarbons (PAHs) to the air of the town was widespread depending on the weather conditions and ranged from 1-431,000 ng/m(3). The presence of PAHs, polychlorinated biphenyls (PCBs), and elements in the surface zone and soil core samples taken from various sites were determined up to a depth of 100 cm. Concentrations of PAHs were in the range between 0.75 and 86.19 mug/g dry soil. The contaminated soil can be expected to act as a permanent pollution source, while the mobile constituents are likely to cause groundwater pollution
Mobility of heavy metals originating from bombing of industrial sites
Surface soil samples from the NIS Jugopetrol fuel storage sites has been studied. The aim of this work has been the detection of heavy and inorganic metals including As, Pb, Cd, Ni, Zn, Cr, and Cu in soils after bombing present due to outflow, burning or leaking of crude oil and oil products at five chosen locations: Belgrade-Cukarica, Smederevo, Ni, Bor and Prahovo. In order to get information of the future environmental and health risks, sampling was repeated after several months at the same locations. Certain locations present a threat on environment because of the possible transport of contaminants during higher water levels
Novel photocatalytic coating on façade paints: Functional properties and durability
The negative influence of the environmental pollutants on building materials
used for façades could be minimized by applying protective photocatalytic
coatings with selfcleaning properties. Novel inorganic-inorganic
nanocomposite photocatalytic coating based on TiO2/Zn-Al layered double
hydroxides (LDHs) was applied on commercial façade paint and the functional
properties (photocatalytic activity and surface properties) were studied
before and after durability tests towards the adhesion of the coating. The
results showed that the TiO2/ZnAl LDH based coating did not influence
esthetic appearance, surface roughness and microhardness of the façade
paints. The coating demonstrated a significant photocatalytic activity and
the photo-induced hydrophilicity, enabling the self-cleaning effect. The
study of the influence of temperature and relative humidity on
photocatalytic activity indicated that optimal weather conditions for the
application of coating precursors onto the façade paints are in the spring
and in autumn seasons. [Project of the Serbian Ministry of Education, Science and Technological Development, Grant no. III45008
Respiratory and cardiopulmonary nematode species of foxes and jackals in Serbia
As part of routine monitoring of foxes (Vulpes vulpes) and jackals (Canis aureus) on the territory of Vojvodina province (northern Serbia), an analysis of respiratory and cardiopulmonary parasitic nematodes was conducted. Both host species harbored Eucoleus aerophilus, E. boehmi and Crenosoma vulpis, whereas Angiostrongylus vasorum was found only in foxes. A high prevalence of infection (72.6 %) was noted for E. aerophilus in foxes. The remaining parasite species occurred less frequently in both host species. In all species where it could be quantified, a high degree of parasite aggregation within host individuals was noted. Single species infections were most common, whereas two and three species infections occurred less frequently in both host species. The distribution of abundance of E. aerophilus was affected by host sex, with abundances higher in male foxes. Sampling site and year influenced abundance variation in E. boehmi