Problems of the design and construction of slab between floors

Ovaj članak daje kratak pregled izgradnje stropnih ploča počevši od ploče s drvenim gredama do današnjih armirano betonskih ploča (AB). Autori u ovom radu analiziraju neke nove logične poglede po pitanju izgradnje međukatnih ploča. Međukatne ploče analiziraju se ne samo u smislu nosivosti, već i u pogledu energetske učinkovitosti i sigurnosti tijekom seizmičke aktivnosti. Autori nude rješenje za izgradnju adaptabilnih velikih stambenih i poslovnih prostora uz mogućnost postizanja jeftinije i konkurentnije gradnje s istom dobiti (profit) u odnosu na skuplju klasičnu gradnju i visoku prodajnu cijenu. Ako se zahtijeva sposobnost da se postigne visoka nosivost s većim rasponima, manjom masom i većom otpornošću na potrese, lako se može doći do zaključka da roštiljno kasetne AB ploče imaju prednost nad drugim rješenjima za izgradnju međukatnih ploča. Pobuda zbog mogućih denivelacija oslonaca ili torzijske rotacije objekta je praktično moguća. To može dovesti do stanja osciliranja ploča zbog potresa, što je mnogo manje kod roštiljno kasetnih ploča u odnosu na pune armirano betonske ploče. StiroFert, širom svijeta patentirana i provjerena roštiljno kasetna AB ploča, ispunjava sve ove uvjete uz dodatni uvjet: energetska učinkovitost. StiroFert je posebno projektirana s konstrukcijski ugrađenim ekspandiranim polistirenom kao "zarobljenom oplatom" u fazi betoniranja i izgradnje. Ta ista "zarobljena oplata" je moćna izolacija na najpotrebnijem mjestu: na stropu, s učinkom usklađivanja temperature zraka između poda i stropa.This paper gives a brief overview of building floor slabs starting from slabs with wooden beams to the present reinforced concrete (panels AB). The authors in this paper analyze some new logical views on the issue of building floor slabs. Floor slabs are analyzed not only in terms of capacity, but also in terms of energy efficiency and safety during seismic activity. The authors offer a solution to build adaptive large residential and commercial area with the possibility of achieving cheaper and more competitive construction with the same gain (profit) in relation to the set of the classic construction and a high selling price. If you require the ability to achieve high capacity with longer spans, less weight and less prone to earthquakes, you can easily come to the conclusion that light grate cluster AB boards have an advantage over other solutions for building floor slabs. Excitation due to possible levelling of supports or torsion rotation of the object is practically possible. It can lead to a state of plate due to the earthquake, which is lower in the grate cluster plates compared to full-reinforced concrete slabs. StiroFert, the worldwide patented and tested light cluster grate AB panels, meet all of these requirements with an additional condition: energy efficiency. StiroFert have a specially designed and built structural expanded polystyrene as the "hull trapped" in the construction and concreting. This same "trapped payment" is a powerful insulation on the most needed place: on the ceiling, with the effect of harmonizing air temperature between the floor and the ceiling

Vegetable Production in the Republic of Serbia - Present State and Problems

The aim of the research in this paper is to consider the state and basic trends of vegetable production in the Republic of Serbia for the period from 2012. to 2020. Therefore, the paper indicates which necessary measures should be taken to increase the volume of vegetable crop production in our country and improve the production. In spite of all problems, and owing to significant but insufficiently used local resources (people) and favourable natural conditions (climate features, soil and water resources), vegetable production in the Republic of Serbia has a good opportunity for intensive development. This development has to be accompanied by the appropriate credit and monetary support, investment and incentives

Feasibility study of determing a risk assessment model for obstructive sleep apnea in children based on local findings and clinical indicators

Objective: To test a feasible and reliable model for diagnosing obstructive sleep apnea (OSA) in children, based on clinically relevant parameters, in comparison to a polysomnography. Methods: A total of 94 children with the suspected underlying OSA were included in the analyses. An association between clinical parameters (modified Mallampati score, tonsil size, adenoid size, age, gender, and body mass index) and apnea-hypopnea index (AHI) obtained following an overnight polysomnography was assessed, and significant variables were incorporated in the logistic regression model. Also, the sensitivity and specificity calculations of the model with the inclusion of ROC curve analysis were performed. Results: All three local clinical parameters were significantly associated with AHI (p<0.001). The most significant correlation with AHI was shown with the modified Mallampati score (r=0.723), following with tonsil size (r=0.673), and adenoid size (r=0.502). The sensitivity of the tested model was 84%, and specificity was 74%. Conclusion: This study derived a model based on the local clinical findings that significantly overlapped with the results of an overnight polysomnography, in diagnosing OSA in children

Karakterizacija različitih obalnih područja Jadrana u kasno proljeće

The objective of this study is to analyze the physical and chemical characteristics of three coastal zones of the Adriatic Sea during late spring, and to identify similarities and differences among the zones. The trophic status of the Southeastern Adriatic-Sea, dominated by the discharge from the Buna/Bojana river delta watersheds, is compared with two other Adriatic regions: the Northwestern Adriatic Sea and the Southwestern Adriatic Sea (Gulf of Manfredonia); the first is dominated by the Po River freshwater discharge and the second is one of the most productive areas of the Southwestern Adriatic. The areas are influenced by two main Adriatic surface currents: the Eastern Adriatic Current (EAC) that flows north-westward, and the Western Adriatic Current (WAC) that flows south-eastward. The measurements of temperature, salinity, fluorescence, oxygen, nutrients and chlorophyll a in the three areas were collected and compared. The areas showed similar physical and bio-chemical characteristics, despite the Northern Adriatic is impacted by the Po River runoff and the WAC carries out along the Western Adriatic water rich of nutrients from the northern Italian rivers. The area affected by the Po River discharge showed maximum chlorophyll and nitrogen concentrations within the river plume. Moreover, the Southwestern Adriatic Sea showed a load of nutrients and organic matter connected to substances coming from the northern Italian rivers (mainly the Po River). Similarly, in the Southeastern Adriatic-Sea, the Buna/Bojana River discharge contained relatively high values in the regional chlorophyll distribution. The three areas are directly or indirectly linked to river plume dynamics and the associated inorganic and organic inputs determine the trophic state of the areas. In particular, the Southeastern Adriatic Sea was a meso-eutrophic area; despite the most eastern side of the Adriatic was an oligotrophic basin.Cilj ovog istraživanja je analiza fizikalnih i kemijskih svojstava triju obalnih područja Jadrana u kasno proljeće i ustanovljenje sličnosti i razlika među zonama. Trofički status jugoistočnog Jadran- skog mora, pod utjecajem dotoka slatke vode iz sliva rijeke Bune / Bojane, je u ovom radu uspoređen s druge dvije jadranske regije: sjeverozapadnim Jadranom i jugozapadnim Jadranom (zaljev Man -fredonia) u prvom dominiraju pražnjenja rijeke Po, dok je drugi jedno od najproduktivnijih područja jugozapadnog Jadrana. Područja su pod utjecajem dviju glavnih površinskih struja Jadranskog mora: istočne jadranske struje (EAC) koja teče prema sjeverozapadu i zapadne jadranske struja (WAC) koja teče prema jugo-istoku. podaci o izmjerenoj temperaturu, slanosti, fluorescenciji, kisiku, hranjivim tvarima i klorofilu a su sakupljeni i uspoređeni za sva tri područja. Istraživana područja su pokazala slične fizičke i bio-kemijske karakteristike, unatoč činjenici da je sjeverni Jadran pod utjecajem dotoka rijeke Po, a zapadna jadranska struja (WAC) nosi duž zapadnog Jadrana vodu bogatu hranjivim tvarima iz talijanskih rijeka na sjeveru. Područje pogođeno dotokom rijeke Po pokazalo je maksimum koncentracije klorofila i dušika unutar rijeka. Štoviše, u jugozapadnom Jadranu količina hranjivih tvari i organske tvari je povezana s tvarima koje dolaze iz sjevernih talijanskih rijeka (uglavnom rijeke po). Slično tome, u jugoistočnom dijelu jadranskog mora, dotok rijeke Bune / Bojane sadržavao je relativno visoke vrijednosti klorofila na nivou regionalne distribucije. Tri područja su izravno ili neizravno povezana s dinamikom riječnih perjanica, te organskim i anorganskim riječnim unosom koji određuje trofičko stanje područja. Konkretno, jugoistočno Jadransko more je mezo-eutrofično područje; unatoč većoj istočnoj strani Jadrana koij je bio oligotrofan bazen

Prostorna raspodjela fizikalnih, kemijskih i bioloških oceanografskih karakteristika, fitoplanktona, hranjivih tvari i otopljene obojane organske materije (CDOM) u Bokokotorskom zaljevu na Jadranu

The temporal variations of temperature, salinity, fluorescence, dissolved oxygen concentration, Coloured Dissolved Organic Matter (CDOM) and of chemical (nutrients, chlorophyll a) and biological (phytoplankton composition) parameters in the Boka Kotorska Bay were observed during two periods. CDOM regulates the penetration of UV light into the sea and therefore plays an important role in many hydrological and biogeochemical processes in the sea surface layer including primary productivity. In the framework ADRICOSM-STAR it was possible to investigate the Boka Kotorska Bay during May and June 2008 in order to increase an understanding of optical and chemical characteristics and their evolution during these periods. In both periods station KO (located furthest from the open sea) presented different physical, chemical and biological characteristics with respect to the other stations inside the Boka Kotorska Bay. A positive correlation was found between CDOM and chlorophyll a (R = 0.7, P < 0.001, n = 15) and this implies that in this area, similarly to the open sea, the primary source of CDOM should be the biological production from phytoplankton. This is probably due to the fact that the rivers entering the Boka Kotorska Bay are not severely impacted by man.U Bokokotorskom zaljevu su mjerene vremenske promjene temperature, saliniteta, fluorescencije, koncentracije otopljenog kisika, obojene otopljene organske materije (CDOM) i kemijskih (hranjive soli, klorofila) i bioloških (sastav fitoplanktona) parametara tijekom dva razdoblja (svibanj i lipanj 2008. godine). CDOM određuje prodiranje UV svjetlosnih zraka u more i stoga igra vrlo važnu ulogu u mnogim hidrološkim i biogeokemijskim procesima u površinskom sloju mora koji uključuje primarnu produkciju. Unutar ADRICOSM-STAR projekta, bilo je moguće istražiti Bokokotorski zaljev tijekom svibnja i lipnja 2008. godine radi povećanja razumijevanja optičkih i kemijskih karakteristika i njihovog razvoja kroz ova razdoblja. Zbog dotoka krških rijeka i smanjenja razmjene s otvorenim morem, u oba razdoblja postaja KO (smještena najdalje od otvorenog mora) je pokazala različite fizikalne, kemijske i biolo{ke karakteristike u odnosu na postaje unutar Bokokotorskog zaljeva. Pronađena je pozitivna korelacija izme|u CDOM i klorofila a (R = 0.7, P < 0.001, n = 15) {to upućuje na to da bi u ovom području, slično otvorenom moru, primarni izvor CDOM trebao biti biološka produkcija od fitoplanktona. To je vjerojatno zbog toga što dotoci rijeka u Bokokotorskom zaljevu nisu ozbiljnije ugroženi ljudskim djelovanjem

Primjena bioloških markera u identifikaciji zagađivača naftnog tipa u recentnim sedimentima - aluvijalna formacija rijeke Dunav, Rafinerija nafte Pančevo

The purpose of this paper was to examine to which extent the abundance and distribution of certain biological markers may be used for the identification of oil-type pollutants in recent sediments and ground waters. The samples were taken from the area of the Oil Refinery Pančevo (alluvial formation of the Danube River). The organic matter of the investigated samples was isolated using an extraction method with chloroform. The group composition and usual biological markers were analyzed in the obtained extracts. n-Alkanes and acyclic isoprenoids, pristane and phytane were analyzed using gas chromatographie (GC) analysis of saturated hydrocarbons. Polycyclic alkanes of the sterane and terpane type were analyzed using gas chromatography-mass spectrometry (GC-MS), i.e. by analyzing the carbamide non-adduct of the total alkane fraction (Single Ion Monitoring SIM-technique). The obtained results indicate that n-alkanes can be used for the identification of oil-type pollutants (for example, if the oil-pollutant is biodegraded or present in very low concentrations), and steranes and triterpanes can be used as very reliable indicators of oil-type pollution in recent sediments and ground waters.Cilj ovog rada bio je da se utvrdi u kolikoj mjeri se obilnosti i raspodjele pojedinih bioloških markera mogu upotrijebiti za identifikaciju zagađivača naftnog tipa u recentnim sedimentima i podzemnim vodama. Ispitivani su uzorci sa lokaliteta Rafinerije nafte Pančevo (aluvijalna formacija rijeke Dunav). Organska supstanca ispitivanih uzoraka izolovana je ekstrakcijom pomoću hloroforma. U dobivenim ekstraktima određen je grupni sastav i analizirani su najpoznatiji biološki markeri. n-Alkani i aciklični izoprenoidni alkani, pristan i fitan, analizirani su gasnohromatografskom (GC) analizom frakcije zasićenih ugljovodonika, a policiklični alkani tipa sterana i triterpana primjenom gasnohromato-grafsko-masenospekrometrijske (GC-MS) analize karbamidnog neadukta ukupnih alkana (Single Ion Monitoring SIM, tehnika), Dobiveni rezultati pokazali su da u slučajevima kada se n-alkani ne mogu upotrijebiti u identifikaciji zagađivača naftnog tipa (na primjer, ukoliko je naftni zagađivač biodegradovan i/ili prisutan u veoma niskim koncentracijama), sterani i triterpani mogu poslužiti kao veoma pouzdani indikatori prisustva ovog zagađivača u recentnim sedimentima i podzemnim vodama

Effect of Adsorption Processing of Solvent Base Oils by Activated Bentonite

Solvent base oils of group API I contain larger quantities of aromatic compounds and sulfur, as compared to base oils of higher quality groups. Processing of base oils by commercial clays is performed in order to reduce the content of undesirable compounds, improving the color and oxidation stability. Commercial clays are based on aluminosilicates with a large specific surface area and developed porosity. Bentonite has good adsorption characteristics, which can be further improved by various methods of modification. In this paper, adsorption processing of solvent base oils is derived by acid-activated bentonite and commercial clay. The structural composition of starting oil and refined solvent oil (content of aromatics, paraffins, naphtenes and sulfur) is determined by following methods: IEC 590, UV, IP 346 and BAS ISO 20846. The results showed that processing of a solvent oil by activated bentonite leads to change of structural composition, similar to a change achived by processing with commercial clay

Supplementary data for article: Vilipić, J.; Novaković, I.; Stanojković, T.; Matić, I.; Šegan, D.; Kljajić, Z.; Sladić, D. Synthesis and Biological Activity of Amino Acid Derivatives of Avarone and Its Model Compound. Bioorganic and Medicinal Chemistry 2015, 23 (21), 6930–6942. https://doi.org/10.1016/j.bmc.2015.09.044

Supplementary material for: [https://doi.org/10.1016/j.bmc.2015.09.044]Related to published version: [http://cherry.chem.bg.ac.rs/handle/123456789/1997]Related to accepted version: [http://cherry.chem.bg.ac.rs/handle/123456789/3438