21 research outputs found

    Hydrogeothermal resources in spa areas of Serbia: Main properties and possible improvement of use

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    Geological complexity of the territory of Serbia is a world curiosity: six main geo-tectonic regions and tens sub-regions are delineated in a small area of 88,000 km2. Geologic origin and regional structure of some areas has long been the subject of discussion. Notable magmatism and associated tectonic events in the Earth's crust provided for a fairly large hydrogeothermal resource potential, which is manifested in more than 250 warm (mainly mineral) springs and more than 100 hydrothermal wells. Thermal springs and wells together discharge some 5 m3/s. This potential is used in part for balneal therapy (waters differ in temperature and chemical composition) in the spa areas of Serbia. The amounts of thermal water unused therapeutically or the amounts of heat energy from unused geo-thermal water may be used in almost all spas for space heating/cooling and thus increase the efficiency of the thermal water energy utilization. This also will be cost-effective, reduce emission of noxious gases, and improve the environmental-health image of the resorts. The hydrogeothermal resources are described for 29 spas with 700 l/s total discharge capacity of water temperature between 25°C and 96ºC, or an overall heat energy of 78.40 MWt. Feasibility of additional energy utilization of thermal water in spas is generally considered

    Cave biofilms: Characterization of phototrophic cyanobacteria and algae and chemotrophic fungi from three caves in Serbia

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    Cyanobacteria, algae (Chlorophyta and Bacillariophyta), and fungi were identified from biofilm samples from three caves in western Serbia: Ribnička, Hadž i Prodanova, and Rćanska. Temperature, light intensity, and relative humidity varied from 16.9 8C to 24.9 8C, 61% to 87%, and 215 Lux to 4400 Lux, respectively. In general, the highest number of documented taxa belonged to Cyanobacteria, with chroococcalean taxa prevailing and Gloeocapsa species as the most diverse. A large percentage of observed fungi were Ascomycetes or Zygomycetes, while the only representative of Basidiomycetes was Rhizoctonia s. lat. However, a redundancy analysis revealed that different taxonomic groups were dominant at different localities: cyanobacteria and fungi in Ribnička and Hadž i Prodanova, and Chlorophyta and Bacillariophyta in Rćanska. The statistical analysis showed that relative humidity is an important physical parameter influencing the development of various microbial communities in different caves. Cyanobacteria were mostly found in places with lower relative humidity, while Chlorophyta and Bacillariophyta were found in places with higher humidity. The documented physical parameters did not have a significant impact on the distribution of fungi. Measured chlorophyll-a content was highest on horizontal surfaces, where the highest content of organic/inorganic matter were also recorded. The highest water content was observed in biofilm samples from which many cyanobacteria taxa were identified

    Mineral waters of Serbia and development of phototrophic microbial communities near points of emergence and on wellheads

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    Phototropic microorganisms in thermal mats had not attracted enough attention in Serbia in the past. The research presented in this paper is the first to address biofilms at selected occurrences of mineral water in Serbia (Bogatic, Metkovic and Belotic in the Macva District as well as Radaljska Banja, Lukovska Banja and Vranjska Banja) (in Serbian, banja denotes a spa town). The study period is from 2014 to 2016. The temperatures of the studied occurrences are in the 30-93.9 degrees C range and the chemical composition corresponds to the HCO3- -Na++ K+ and SO42-, HCO3--Na++ K+ types of mineral water. One of the objectives was to examine the condition of wellheads (incrustation, biofouling and corrosion), focusing on the presence of phototrophic microorganisms whose metabolites may lead to changes in mineral water quality, yield and chemistry. Analysis by light and scanning electron microscopy provides insight into the diversity of phototrophic microorganisms that populate biofilms near the points of emergence and on wellhead. The research reveals the presence of representatives of three groups of phototrophic microorganisms: Cyanobacteria, Chlorophyta and Bacillariophyta. Cyanobacteria were the most numerous, dominated by the order Oscillatoriales with ten recorded genera, of which Leptolynbgya and Phormidium feature the largest numbers of species. The order Chroococcales are the second most numerous, with seven recorded genera, of which Gloeocapsa and Synechocystisare the most noteworthy. The largest numbers of representative taxa were noted at Radaljska Banja and Vranjska Banja, where mineral waters originate from lithostratigraphic units of igneous origin, followed by mineral water occurrences in karst aquifers (Bogatic and Belotic) and an intergranular aquifer (Metkovic). The smallest number of identified phototrophic microorganisms is noted at Lukovska Banja, where the origin is associated with a fractured aquifer formed in sedimentary and metamorphic rocks, with occasional diabase interbeds. Although many representative taxa are found on only one of the studied localities, such as Synechococcus bigranulatus and Pseudanabaena thermalis, those of the genera Leptolyngbya, Phormidium and Cosmarium laeve, as well as genera of the phylum Bacillariophyta, occur at several sampling sites. Principal component analysis (PCA) was used to show the relationship between documented cyanobacterial and algal taxa and environmental parameters.Fototrofni mikroorganizmi v oblogah termalnih izvirov v Srbiji v preteklosti niso bili deležni posebne pozornosti. V članku predstavljena raziskava je prva, ki obravnava biofilme na izbranih mestih izvirov mineralnih vod v Srbiji (Bogatić, Metković in Belotić v Mačvi ter Radaljska Banja, Lukovska Banja in Vranjska Banja) (v srbskem jeziku je banja izraz za toplice). Preučevanje je potekalo med letoma 2014 in 2016. Temperature obravnavanih voda se gibljejo med 30 in 93,9 °C, glede na kemijsko sestavo pa jih uvrščamo v HCO3 − – Na++ K+ in SO4 2−, HCO3 − – Na++K+ tipe mineralne vode. Eden od ciljev raziskave je bil proučevati razmere na ustjih vrtin (inkrustacija, obrast in korozija) in se še posebej posvetiti navzočnosti fototrofnih mikroorganizmov, katerih metaboliti lahko spremenijo kakovost, izdatnost in kemizem mineralnih vod. Z analizo slik s svetlobnim in vrstičnim elektronskim mikroskopom lahko podrobneje spoznamo raznolikost fototrofnih organizmov, ki sestavljajo biofilme na mestih izvirov in na ustjih vrtin. Raziskava je pokazala obstoj predstavnikov treh skupin fototrofnih mikroorganizmov: cianobakterij ter predstavnikov debel Chlorophyta in Bacillariophyta. Cianobakterije so bile najbolj številčne, prevladovali so osebki reda Oscillatoriales z desetimi ugotovljenimi rodovi, od katerih je bilo največje število vrst iz rodov Leptolynbgya in Phormidium. Red Chroococcales je bil s sedmimi zabeleženimi rodovi drugi najbolj številčen, prevladovala sta Gloeocapsa in Synechocystis. Največreprezentativnih taksonov je bilo v Radaljski Banji in Vranjski Banji, kjer mineralne vode izvirajo iz litostratigrafskih enot vulkanskega izvora, sledijo mineralne vode iz kraškega (Bogatić in Belotić) in medzrnskega vodonosnika (Metković). Najmanjfototrofnih organizmov je bilo v vzorcu iz Lukovske Banje, kjer vode izvirajo iz razpoklinskih vodonosnikov v sedimentnih in metamorfnih kamninah z vmesnimi lečami diabaza. Čeprav soštevilne reprezentativne taksone našli le na eni od proučevanih lokacij, kot na primer Synechococcus bigranulatus in Pseudanabaena thermalis, se tisti iz rodu Leptolyngbya, Phormidium in Cosmarium laeve in predstavniki več rodov, ki pripadajo deblu Bacillariophyta, pojavljajo na več vzorčnih mestih. Za ugotavljanje odvisnosti med taksoni cianobakterij in alg ter okoljskimi parametri so uporabili analizo glavnih komponent

    Towards a Light-weight Bag-of-tasks Grid Architecture

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    The paper presents the application of SIP protocol in the context of bag-of-tasks grid architecture. The SIP protocol has been used in the realization of the execution management service. The main idea is the use of stateful SIP proxy as a request broker. The paper provides a description of the concept, and the prototype system that has been built, as well as the calculation of estimated performance level and its relation to maximum RTT of grid system. The main advantage of this light-weight grid architecture is the reuse of a mature infrastructure. A short overview of some approaches to the mathematical modeling of computer grids is included

    Cardboard nesting cavities may promote the development of Osmia cornuta

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    Mason bees (Osmia spp.) are receiving increasing attention as they are very effective pollinators of multiple crops. However, different bee‐associated kleptoparasites are known which can be detrimental to the development of the bees’ offspring. To date, clear evidence‐based guidelines to control these kleptoparasites are lacking for growers. This study investigates whether different types of artificial nesting materials—cardboard tubes and wooden grooved boards—influence the development of the European orchard bee (Osmia cornuta) as well as the infestation rate of kleptoparasitic mites in the bees’ nest. This preliminary study provides insight that cardboard tubes reduce the infestation rate of mites by 81.8% and as such promote successful development of the European orchard bee by 15.5%. Using cardboard tubes over wooden grooved boards should be advised to growers as an effective management strategy to avoid infestation of kleptoparasitic mites and to enhance successful bee development

    Tergal and Sternal Anomalies in Neobisium Chamberlin (Neobisiidae, Pseudoscorpiones, Arachnida)

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    Volume: 11Start Page: 243End Page: 25

    Strength testing of the relation between plate dentures and materials for making soft liners

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    Introduction. In clinical practice, the loss of adhesion between the denture base resin and reliner might cause the loss of material softness, water sorption, bacterial colonization and functional failure of the prosthesis. Aim. This study evaluated the effect of immersion on tensile bond strengths of four soft relining materials to a denture base acrylic resin. Material and methods. Four soft lining materials were bonded to heatpolymerized acrylic resin according to the manufacturers' directions. Forty specimens for bond strength test (10 for each liner type) were fabricated. Half of them (control group; n=5) were tested immediately after the fabrication. The other twenty specimens were stored in water at 37°C (test groups; n=5) for one week and then tested. Results. Bond strength of samples right after the fabrication is significantly higher in cases of the samples with silicone elastomer base reliner compared to the samples with soft acrylic base. Bond strength of soft reliners to a denture base resin increases after storing the samples in a water bath for one week at 37°C. Conslusion. Higher increment of tensile bond strength appeared for silicone elastomers in comparison with soft acrylic resins. There were no changes of failure mode except for GC Reline Soft application with the lowest tensile bond strength increment
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